Case Reports

THE CASE

A 24-year-old woman came to our clinic because she had pain in her right foot. Over the previous 4 weeks, she’d noticed increasing pain in the ball of her foot while walking and climbing stairs, particularly in the push-off portion of her gait. She described it as a nagging, localized pain that she rated as a 2 or 3 out of 10. It was an annoyance, but not unbearable. She felt no pain when standing in place or in a non-weight-bearing position.

She denied any trauma to the foot or change in activity, and had been exercising her usual amount (running 2-5 miles per week). Her medical and social histories were unremarkable, and her family history was negative for relevant conditions.

An examination of the right foot revealed no evidence of pes planus, pes cavus, hallux valgus, hammertoes, or other structural abnormalities of the foot or toes. She had no calluses, nor any erythema or edema of the foot or toes. Direct palpation of the medial sesamoid reproduced the patient’s symptoms. Passive dorsiflexion and plantar flexion of the first hallux elicited pain only at the extreme ends of range of motion. Active dorsiflexion and plantar flexion of the right first hallux showed 5 out of 5 strength. A mid-foot squeeze test was negative, and the remainder of the exam was normal.

THE DIAGNOSIS

Pain on palpation of the sesamoids prompted us to gather a more detailed history. The patient had never been a dancer or a long-distance or competitive runner. However, upon delving into possible causes of the pain, she admitted that she was a frequent “knuckle cracker,” and cracked many joints regularly, including the right first metatarsophalangeal joint (MTPJ). She explained that she cracked this joint by hyper-plantarflexing her big toe against the ground, and had been doing this multiple times a day for many years. In the past 4 weeks, she had noticed significant pain in the right first MTPJ while cracking the joint, but she was having difficulty breaking the longstanding habit.

The patient’s description of right foot pain associated with the push-off portion of her gait, and the fact that the pain was exacerbated by the extremes of dorsiflexion and plantar flexion of the great toe, was consistent with MTPJ pain. This, paired with our ability to reproduce the pain by direct palpation of the medial sesamoid, prompted us to make a clinical diagnosis of sesamoiditis. To our knowledge, this is the first case report of sesamoiditis caused by knuckle cracking.

DISCUSSION

Sesamoiditis—chronic pain and inflammation of the hallucal sesamoids—is an overuse or misuse injury that’s typically seen in runners and dancers.¹ The hallucal sesamoids are 2 small bones located underneath the head of the first metatarsal and encased within the flexor hallucus brevis tendon that disperses weight from the head of the first metatarsal during the push-off portion of gait.² Runners and dancers place significant, repetitive axial loading on the sesamoids, which often leads to injury.¹ Although our patient initially seemed to have no typical risk factors for developing sesamoiditis, she later revealed that she regularly cracked the MTPJ, which we believe led to her injury.

Interestingly, despite the common assumption that long-term “cracking” of joints can lead to adverse effects such as osteoarthritis, research has not supported this assumption.^3,4 A retrospective case-control study of patients with and without hand osteoarthritis found no association between knuckle cracking and osteoarthritis, and the prevalence of osteoarthritis was not higher in patients who cracked their knuckles more frequently and for more years.⁴

To our knowledge, this is the first case report of sesamoiditis caused by knuckle cracking.

Nonetheless, there have been reports of acute injuries associated with knuckle cracking, consistent with forcing a joint past its normal range of motion, as is typically done in knuckle cracking.⁵ In forcefully plantarflexing her great toe against a surface until a “crack” was elicited, our patient may have injured the sesamoid by forcing it along the head of the first metatarsal. Conversely, her injury may have been caused by the repetitive displacement of the sesamoid past its usual location, resulting in chronic irritation.

Differential diagnosis includes fracture and stress injury

The differential diagnosis for subacute to chronic pain localized to the sesamoids includes repetitive stress injury (sesamoiditis or capsular strain), fracture or stress fracture, osteoarthritis, osteonecrosis, and gout.^1,2 Given our patient’s age and lack of erythema and edema, osteoarthritis and gout were unlikely.

To treat the injury, eliminate the behavior that caused it

Imaging studies may not be necessary in cases of suspected sesamoiditis because such studies are often negative for sesamoiditis and stress fractures of the sesamoids, and because they typically would not affect how the injury is initially treated.^1,2,6 In cases in which radiographic confirmation of sesamoiditis is necessary to rule out more serious pathology, 99mTc-methylene diphosphonate (99mTc-MDP) bone scan and magnetic resonance imaging (MRI) are far more sensitive than plain films.¹ While a 99mTc-MDP bone scan will show increased uptake at the sesamoids, it has been replaced by MRI, which will show bone marrow edema of the sesamoids and can rule out fracture or osteoarthritis.¹

Sesamoiditis is typically managed with a combination of ice, analgesics, activity modification, and/or orthoses.² Of course, the key to successfully treating sesamoiditis (and all musculoskeletal injuries) is to not only make the diagnosis, but to find the underlying cause in order to prevent continued—or worsening—pain.

Our patient agreed to close follow-up rather than imaging. We established that the only inciting event was the cracking of her MTPJ, and that she should try to eliminate this action before trying other interventions. Our patient stopped cracking her MTPJ and her pain completely resolved in 2 weeks. She remains symptom-free.

THE TAKEAWAY

Ask about knuckle cracking when taking the history of a patient who presents with sesamoiditis, which is characterized by chronic pain and inflammation of the hallucal sesamoids.

THE CASE

A 24-year-old woman came to our clinic because she had pain in her right foot. Over the previous 4 weeks, she’d noticed increasing pain in the ball of her foot while walking and climbing stairs, particularly in the push-off portion of her gait. She described it as a nagging, localized pain that she rated as a 2 or 3 out of 10. It was an annoyance, but not unbearable. She felt no pain when standing in place or in a non-weight-bearing position.

She denied any trauma to the foot or change in activity, and had been exercising her usual amount (running 2-5 miles per week). Her medical and social histories were unremarkable, and her family history was negative for relevant conditions.

An examination of the right foot revealed no evidence of pes planus, pes cavus, hallux valgus, hammertoes, or other structural abnormalities of the foot or toes. She had no calluses, nor any erythema or edema of the foot or toes. Direct palpation of the medial sesamoid reproduced the patient’s symptoms. Passive dorsiflexion and plantar flexion of the first hallux elicited pain only at the extreme ends of range of motion. Active dorsiflexion and plantar flexion of the right first hallux showed 5 out of 5 strength. A mid-foot squeeze test was negative, and the remainder of the exam was normal.

THE DIAGNOSIS

Pain on palpation of the sesamoids prompted us to gather a more detailed history. The patient had never been a dancer or a long-distance or competitive runner. However, upon delving into possible causes of the pain, she admitted that she was a frequent “knuckle cracker,” and cracked many joints regularly, including the right first metatarsophalangeal joint (MTPJ). She explained that she cracked this joint by hyper-plantarflexing her big toe against the ground, and had been doing this multiple times a day for many years. In the past 4 weeks, she had noticed significant pain in the right first MTPJ while cracking the joint, but she was having difficulty breaking the longstanding habit.

The patient’s description of right foot pain associated with the push-off portion of her gait, and the fact that the pain was exacerbated by the extremes of dorsiflexion and plantar flexion of the great toe, was consistent with MTPJ pain. This, paired with our ability to reproduce the pain by direct palpation of the medial sesamoid, prompted us to make a clinical diagnosis of sesamoiditis. To our knowledge, this is the first case report of sesamoiditis caused by knuckle cracking.

DISCUSSION

Sesamoiditis—chronic pain and inflammation of the hallucal sesamoids—is an overuse or misuse injury that’s typically seen in runners and dancers.¹ The hallucal sesamoids are 2 small bones located underneath the head of the first metatarsal and encased within the flexor hallucus brevis tendon that disperses weight from the head of the first metatarsal during the push-off portion of gait.² Runners and dancers place significant, repetitive axial loading on the sesamoids, which often leads to injury.¹ Although our patient initially seemed to have no typical risk factors for developing sesamoiditis, she later revealed that she regularly cracked the MTPJ, which we believe led to her injury.

Interestingly, despite the common assumption that long-term “cracking” of joints can lead to adverse effects such as osteoarthritis, research has not supported this assumption.^3,4 A retrospective case-control study of patients with and without hand osteoarthritis found no association between knuckle cracking and osteoarthritis, and the prevalence of osteoarthritis was not higher in patients who cracked their knuckles more frequently and for more years.⁴

To our knowledge, this is the first case report of sesamoiditis caused by knuckle cracking.

Nonetheless, there have been reports of acute injuries associated with knuckle cracking, consistent with forcing a joint past its normal range of motion, as is typically done in knuckle cracking.⁵ In forcefully plantarflexing her great toe against a surface until a “crack” was elicited, our patient may have injured the sesamoid by forcing it along the head of the first metatarsal. Conversely, her injury may have been caused by the repetitive displacement of the sesamoid past its usual location, resulting in chronic irritation.

Differential diagnosis includes fracture and stress injury

The differential diagnosis for subacute to chronic pain localized to the sesamoids includes repetitive stress injury (sesamoiditis or capsular strain), fracture or stress fracture, osteoarthritis, osteonecrosis, and gout.^1,2 Given our patient’s age and lack of erythema and edema, osteoarthritis and gout were unlikely.

To treat the injury, eliminate the behavior that caused it

Imaging studies may not be necessary in cases of suspected sesamoiditis because such studies are often negative for sesamoiditis and stress fractures of the sesamoids, and because they typically would not affect how the injury is initially treated.^1,2,6 In cases in which radiographic confirmation of sesamoiditis is necessary to rule out more serious pathology, 99mTc-methylene diphosphonate (99mTc-MDP) bone scan and magnetic resonance imaging (MRI) are far more sensitive than plain films.¹ While a 99mTc-MDP bone scan will show increased uptake at the sesamoids, it has been replaced by MRI, which will show bone marrow edema of the sesamoids and can rule out fracture or osteoarthritis.¹

Sesamoiditis is typically managed with a combination of ice, analgesics, activity modification, and/or orthoses.² Of course, the key to successfully treating sesamoiditis (and all musculoskeletal injuries) is to not only make the diagnosis, but to find the underlying cause in order to prevent continued—or worsening—pain.

Our patient agreed to close follow-up rather than imaging. We established that the only inciting event was the cracking of her MTPJ, and that she should try to eliminate this action before trying other interventions. Our patient stopped cracking her MTPJ and her pain completely resolved in 2 weeks. She remains symptom-free.

THE TAKEAWAY

Ask about knuckle cracking when taking the history of a patient who presents with sesamoiditis, which is characterized by chronic pain and inflammation of the hallucal sesamoids.

THE CASE

A 24-year-old woman came to our clinic because she had pain in her right foot. Over the previous 4 weeks, she’d noticed increasing pain in the ball of her foot while walking and climbing stairs, particularly in the push-off portion of her gait. She described it as a nagging, localized pain that she rated as a 2 or 3 out of 10. It was an annoyance, but not unbearable. She felt no pain when standing in place or in a non-weight-bearing position.

She denied any trauma to the foot or change in activity, and had been exercising her usual amount (running 2-5 miles per week). Her medical and social histories were unremarkable, and her family history was negative for relevant conditions.

An examination of the right foot revealed no evidence of pes planus, pes cavus, hallux valgus, hammertoes, or other structural abnormalities of the foot or toes. She had no calluses, nor any erythema or edema of the foot or toes. Direct palpation of the medial sesamoid reproduced the patient’s symptoms. Passive dorsiflexion and plantar flexion of the first hallux elicited pain only at the extreme ends of range of motion. Active dorsiflexion and plantar flexion of the right first hallux showed 5 out of 5 strength. A mid-foot squeeze test was negative, and the remainder of the exam was normal.

THE DIAGNOSIS

Pain on palpation of the sesamoids prompted us to gather a more detailed history. The patient had never been a dancer or a long-distance or competitive runner. However, upon delving into possible causes of the pain, she admitted that she was a frequent “knuckle cracker,” and cracked many joints regularly, including the right first metatarsophalangeal joint (MTPJ). She explained that she cracked this joint by hyper-plantarflexing her big toe against the ground, and had been doing this multiple times a day for many years. In the past 4 weeks, she had noticed significant pain in the right first MTPJ while cracking the joint, but she was having difficulty breaking the longstanding habit.

The patient’s description of right foot pain associated with the push-off portion of her gait, and the fact that the pain was exacerbated by the extremes of dorsiflexion and plantar flexion of the great toe, was consistent with MTPJ pain. This, paired with our ability to reproduce the pain by direct palpation of the medial sesamoid, prompted us to make a clinical diagnosis of sesamoiditis. To our knowledge, this is the first case report of sesamoiditis caused by knuckle cracking.

DISCUSSION

Sesamoiditis—chronic pain and inflammation of the hallucal sesamoids—is an overuse or misuse injury that’s typically seen in runners and dancers.¹ The hallucal sesamoids are 2 small bones located underneath the head of the first metatarsal and encased within the flexor hallucus brevis tendon that disperses weight from the head of the first metatarsal during the push-off portion of gait.² Runners and dancers place significant, repetitive axial loading on the sesamoids, which often leads to injury.¹ Although our patient initially seemed to have no typical risk factors for developing sesamoiditis, she later revealed that she regularly cracked the MTPJ, which we believe led to her injury.

Interestingly, despite the common assumption that long-term “cracking” of joints can lead to adverse effects such as osteoarthritis, research has not supported this assumption.^3,4 A retrospective case-control study of patients with and without hand osteoarthritis found no association between knuckle cracking and osteoarthritis, and the prevalence of osteoarthritis was not higher in patients who cracked their knuckles more frequently and for more years.⁴

To our knowledge, this is the first case report of sesamoiditis caused by knuckle cracking.

Nonetheless, there have been reports of acute injuries associated with knuckle cracking, consistent with forcing a joint past its normal range of motion, as is typically done in knuckle cracking.⁵ In forcefully plantarflexing her great toe against a surface until a “crack” was elicited, our patient may have injured the sesamoid by forcing it along the head of the first metatarsal. Conversely, her injury may have been caused by the repetitive displacement of the sesamoid past its usual location, resulting in chronic irritation.

Differential diagnosis includes fracture and stress injury

The differential diagnosis for subacute to chronic pain localized to the sesamoids includes repetitive stress injury (sesamoiditis or capsular strain), fracture or stress fracture, osteoarthritis, osteonecrosis, and gout.^1,2 Given our patient’s age and lack of erythema and edema, osteoarthritis and gout were unlikely.

To treat the injury, eliminate the behavior that caused it

Imaging studies may not be necessary in cases of suspected sesamoiditis because such studies are often negative for sesamoiditis and stress fractures of the sesamoids, and because they typically would not affect how the injury is initially treated.^1,2,6 In cases in which radiographic confirmation of sesamoiditis is necessary to rule out more serious pathology, 99mTc-methylene diphosphonate (99mTc-MDP) bone scan and magnetic resonance imaging (MRI) are far more sensitive than plain films.¹ While a 99mTc-MDP bone scan will show increased uptake at the sesamoids, it has been replaced by MRI, which will show bone marrow edema of the sesamoids and can rule out fracture or osteoarthritis.¹

Sesamoiditis is typically managed with a combination of ice, analgesics, activity modification, and/or orthoses.² Of course, the key to successfully treating sesamoiditis (and all musculoskeletal injuries) is to not only make the diagnosis, but to find the underlying cause in order to prevent continued—or worsening—pain.

Our patient agreed to close follow-up rather than imaging. We established that the only inciting event was the cracking of her MTPJ, and that she should try to eliminate this action before trying other interventions. Our patient stopped cracking her MTPJ and her pain completely resolved in 2 weeks. She remains symptom-free.

THE TAKEAWAY

Ask about knuckle cracking when taking the history of a patient who presents with sesamoiditis, which is characterized by chronic pain and inflammation of the hallucal sesamoids.

Flexor tendons are considered the strongest component of the musculotendinous unit; they generally do not rupture unless weakened by an underlying pathologic condition.¹ According to traditional teaching, when the musculotendinous unit is subjected to excessive forces, failure invariably occurs at the tendon insertion, at the musculotendinous junction, within the muscle substance, or at its origin from the bone before the tendon itself ruptures.¹

Midsubstance tears in nonrheumatoid patients are less frequent and are typically attributable to an underlying cause.² Possible pathologic conditions include, but are not limited to, osteoarthritis of the pisotriquetral joint,³ nonunion fracture of the hook of the hamate,⁴ lunate dislocation,⁵ accessory carpal bone,⁶ gouty infiltration of the flexor tendon,⁷ and tumor.⁸ In 1960, Boyes and colleagues⁹ presented a series of 80 flexor tendon ruptures in 78 patients over a 13-year period. Only 3 cases had no identifiable cause. The authors recommended using the term spontaneous for those ruptures that occur within the tendon substance without underlying or associated pathologic changes.

We describe a patient with spontaneous rupture of the flexor digitorum profundus (FDP) tendon at zone III, satisfying Boyes’ definition of the term spontaneous. The patient provided written informed consent for print and electronic publication of this case report.

Case Report

A 65-year-old, right-handed manual worker was assessed in our hand clinic 3 days after he felt a cramp in his left palm while lifting a heavy object. Shortly thereafter, he noted he could not flex his ring finger distal interphalangeal (DIP) joint. He could not recall any previous injury to his finger. No predisposing pathologic conditions or bone abnormalities were identified. Clinically, there was no tenderness, swelling, or ecchymosis evident. He had full passive range of motion (ROM) of his ring finger, and proximal interphalangeal (PIP) joint active ROM was 0/110º; however, he had no activity of the FDP of the ring finger. Preoperative radiographs were normal. The hook of the hamate was clinically and radiographically normal.

A preoperative diagnosis of FDP avulsion from the distal phalanx was made, and the operation was carried out 16 days after injury. Surgical exploration started in zone II and extended proximally into the distal palmar crease, but no stump was found in either location. Therefore, exploration was carried out to the midpalmar region, revealing the tendon rupture in zone III, in the region of the origin of the ring finger lumbrical muscle (Figure 1). The flexor digitorum superficialis tendon was intact. Macroscopically, both tendon and carpal tunnel appeared normal, with no evidence of tendon attrition; thus, the tendon was not sent for histologic examination. The ends of the ruptured FDP tendon to the ring finger were at the level of the superficial palmar arch, with the distal end appearing as though it had been cut sharply with a knife. Because of the short period of time from injury to exploration, delayed primary tendon repair was possible, along with side-to-side tenodesis to the intact ring finger flexor superficialis tendon in the palm (Figure 2). Two days after surgery, the patient started a controlled mobilization program using the Duran method.¹⁰

At final follow-up of 18 months, total active motion was 126°, which corresponds to a good outcome, according to the Strickland and Glogovac criteria.¹¹ Grip strength was 50 kg, which was 84% of grip strength on the uninjured side. The patient was back to recreational activity but had not returned to work.

Discussion

Most flexor tendon ruptures result from avulsion of the FDP tendon at its distal phalanx insertion, commonly known as Jersey finger. However, true midsubstance spontaneous ruptures are infrequent. Reports of spontaneous tendon ruptures of all types, including those of the hand, have increased in incidence in most countries.¹² Bois and colleagues,¹³ who have reviewed the literature over a 50-year period, found a total of 50 spontaneous ruptures of “normal” flexor tendon in 43 cases. The authors point to unique historical and physical examinaton findings that help differentiate spontaneous tendon ruptures from the more common FDP avulsions. Such findings include the sensation of a pop or snap, or a sudden sharp pain or cramp within the palmar region. In contrast, most avulsion ruptures cause discomfort within the region of the digit. In type I avulsion injuries of the FDP tendon, the proximal tendon stump usually retracts proximal to the digital tendon sheath, causing a tender mass in the palm.¹⁴ Flexor digitorum profundus tendon avulsions, however, are not typically associated with a snap or pop in the palm. When spontaneous ruptures of the hand occur, they typically involve the profundus tendon of the small finger, in the area of the lumbrical origin.¹³

In equivocal cases when the site of rupture is uncertain, ultrasound and magnetic resonance imaging may assist in making the diagnosis and provide important preoperative information for surgical decision-making and planning; this information may decrease postoperative morbidity by minimizing surgical dissection.

The etiology of spontaneous ruptures is incompletely understood. For any rupture of the ulnar flexor tendons, the hook of the hamate should be examined to rule out a previous fracture as a cause of tendon attrition.¹⁵ Tendon vascularization may be a cause for tendon rupture in the hand. When the blood supply of the lumbrical muscles was examined in 100 upper extremities from human cadavers using vascular injection studies,¹⁶ it was discovered that each lumbrical muscle received its arterial supply from 4 sources: the superficial palmar arch, the common palmar digital artery, the deep palmar arch, and the dorsal digital artery. There were no anastomoses between the networks supplying the lumbrical muscles and the FDP tendons within the palm, suggesting a possible watershed zone between the FDP tendon and lumbrical muscle origin. The patient described in this case had the tendon rupture in the area of potential hypovascularity at the lumbrical origin.

Important factors in the decision-making process for surgical treatment include the length of time between rupture and treatment, the site of rupture, and the condition of the ruptured tendon ends. Patients who present in the first 3 weeks of injury can be treated by primary tendon repair, provided that the ruptured tendon ends are not significantly frayed or attenuated. For patients presenting more than 3 weeks after injury, interposition tendon grafts or tendon transfers are suitable options for ruptures in zone III. Distal interphalangeal joint arthrodesis is another alternative in specific cases where reconstruction is not possible. In this case, direct end-to-end repair was possible, as well as tenodesis to the intact ring finger superficialis in order to prevent stretching of the repair.

Localizing the level of the tendon rupture clinically is difficult. When the site of the profundus tendon rupture is uncertain, and there is no tenderness in zone I or the PIP joint, the first incision should be made at the metacarpophalangeal joint level. This first incision will indicate if the rupture occurred in zone III. If the tendon is intact at that location, then the next incision should be at the level of the PIP joint.

Conclusion

We report a patient treated for spontaneous rupture of the flexor tendon in zone III. He was treated in the acute setting with direct tendon repair. It is important to consider spontaneous rupture of the tendon in patients presenting with a snap/pop and the sudden inability to flex a finger. A tendon rupture can be diagnosed as spontaneous in the absence of an underlying pathologic condition such as rheumatoid arthritis, gout, or occult carpal fractures. In the acute setting, these may be repaired primarily; however, if presenting after a few weeks, alternative surgical options, including interposition tendon grafts, tendon transfer, and DIP joint arthrodesis, should be considered.

Flexor tendons are considered the strongest component of the musculotendinous unit; they generally do not rupture unless weakened by an underlying pathologic condition.¹ According to traditional teaching, when the musculotendinous unit is subjected to excessive forces, failure invariably occurs at the tendon insertion, at the musculotendinous junction, within the muscle substance, or at its origin from the bone before the tendon itself ruptures.¹

Midsubstance tears in nonrheumatoid patients are less frequent and are typically attributable to an underlying cause.² Possible pathologic conditions include, but are not limited to, osteoarthritis of the pisotriquetral joint,³ nonunion fracture of the hook of the hamate,⁴ lunate dislocation,⁵ accessory carpal bone,⁶ gouty infiltration of the flexor tendon,⁷ and tumor.⁸ In 1960, Boyes and colleagues⁹ presented a series of 80 flexor tendon ruptures in 78 patients over a 13-year period. Only 3 cases had no identifiable cause. The authors recommended using the term spontaneous for those ruptures that occur within the tendon substance without underlying or associated pathologic changes.

We describe a patient with spontaneous rupture of the flexor digitorum profundus (FDP) tendon at zone III, satisfying Boyes’ definition of the term spontaneous. The patient provided written informed consent for print and electronic publication of this case report.

Case Report

A 65-year-old, right-handed manual worker was assessed in our hand clinic 3 days after he felt a cramp in his left palm while lifting a heavy object. Shortly thereafter, he noted he could not flex his ring finger distal interphalangeal (DIP) joint. He could not recall any previous injury to his finger. No predisposing pathologic conditions or bone abnormalities were identified. Clinically, there was no tenderness, swelling, or ecchymosis evident. He had full passive range of motion (ROM) of his ring finger, and proximal interphalangeal (PIP) joint active ROM was 0/110º; however, he had no activity of the FDP of the ring finger. Preoperative radiographs were normal. The hook of the hamate was clinically and radiographically normal.

A preoperative diagnosis of FDP avulsion from the distal phalanx was made, and the operation was carried out 16 days after injury. Surgical exploration started in zone II and extended proximally into the distal palmar crease, but no stump was found in either location. Therefore, exploration was carried out to the midpalmar region, revealing the tendon rupture in zone III, in the region of the origin of the ring finger lumbrical muscle (Figure 1). The flexor digitorum superficialis tendon was intact. Macroscopically, both tendon and carpal tunnel appeared normal, with no evidence of tendon attrition; thus, the tendon was not sent for histologic examination. The ends of the ruptured FDP tendon to the ring finger were at the level of the superficial palmar arch, with the distal end appearing as though it had been cut sharply with a knife. Because of the short period of time from injury to exploration, delayed primary tendon repair was possible, along with side-to-side tenodesis to the intact ring finger flexor superficialis tendon in the palm (Figure 2). Two days after surgery, the patient started a controlled mobilization program using the Duran method.¹⁰

At final follow-up of 18 months, total active motion was 126°, which corresponds to a good outcome, according to the Strickland and Glogovac criteria.¹¹ Grip strength was 50 kg, which was 84% of grip strength on the uninjured side. The patient was back to recreational activity but had not returned to work.

Discussion

Most flexor tendon ruptures result from avulsion of the FDP tendon at its distal phalanx insertion, commonly known as Jersey finger. However, true midsubstance spontaneous ruptures are infrequent. Reports of spontaneous tendon ruptures of all types, including those of the hand, have increased in incidence in most countries.¹² Bois and colleagues,¹³ who have reviewed the literature over a 50-year period, found a total of 50 spontaneous ruptures of “normal” flexor tendon in 43 cases. The authors point to unique historical and physical examinaton findings that help differentiate spontaneous tendon ruptures from the more common FDP avulsions. Such findings include the sensation of a pop or snap, or a sudden sharp pain or cramp within the palmar region. In contrast, most avulsion ruptures cause discomfort within the region of the digit. In type I avulsion injuries of the FDP tendon, the proximal tendon stump usually retracts proximal to the digital tendon sheath, causing a tender mass in the palm.¹⁴ Flexor digitorum profundus tendon avulsions, however, are not typically associated with a snap or pop in the palm. When spontaneous ruptures of the hand occur, they typically involve the profundus tendon of the small finger, in the area of the lumbrical origin.¹³

In equivocal cases when the site of rupture is uncertain, ultrasound and magnetic resonance imaging may assist in making the diagnosis and provide important preoperative information for surgical decision-making and planning; this information may decrease postoperative morbidity by minimizing surgical dissection.

The etiology of spontaneous ruptures is incompletely understood. For any rupture of the ulnar flexor tendons, the hook of the hamate should be examined to rule out a previous fracture as a cause of tendon attrition.¹⁵ Tendon vascularization may be a cause for tendon rupture in the hand. When the blood supply of the lumbrical muscles was examined in 100 upper extremities from human cadavers using vascular injection studies,¹⁶ it was discovered that each lumbrical muscle received its arterial supply from 4 sources: the superficial palmar arch, the common palmar digital artery, the deep palmar arch, and the dorsal digital artery. There were no anastomoses between the networks supplying the lumbrical muscles and the FDP tendons within the palm, suggesting a possible watershed zone between the FDP tendon and lumbrical muscle origin. The patient described in this case had the tendon rupture in the area of potential hypovascularity at the lumbrical origin.

Important factors in the decision-making process for surgical treatment include the length of time between rupture and treatment, the site of rupture, and the condition of the ruptured tendon ends. Patients who present in the first 3 weeks of injury can be treated by primary tendon repair, provided that the ruptured tendon ends are not significantly frayed or attenuated. For patients presenting more than 3 weeks after injury, interposition tendon grafts or tendon transfers are suitable options for ruptures in zone III. Distal interphalangeal joint arthrodesis is another alternative in specific cases where reconstruction is not possible. In this case, direct end-to-end repair was possible, as well as tenodesis to the intact ring finger superficialis in order to prevent stretching of the repair.

Localizing the level of the tendon rupture clinically is difficult. When the site of the profundus tendon rupture is uncertain, and there is no tenderness in zone I or the PIP joint, the first incision should be made at the metacarpophalangeal joint level. This first incision will indicate if the rupture occurred in zone III. If the tendon is intact at that location, then the next incision should be at the level of the PIP joint.

Conclusion

We report a patient treated for spontaneous rupture of the flexor tendon in zone III. He was treated in the acute setting with direct tendon repair. It is important to consider spontaneous rupture of the tendon in patients presenting with a snap/pop and the sudden inability to flex a finger. A tendon rupture can be diagnosed as spontaneous in the absence of an underlying pathologic condition such as rheumatoid arthritis, gout, or occult carpal fractures. In the acute setting, these may be repaired primarily; however, if presenting after a few weeks, alternative surgical options, including interposition tendon grafts, tendon transfer, and DIP joint arthrodesis, should be considered.

Flexor tendons are considered the strongest component of the musculotendinous unit; they generally do not rupture unless weakened by an underlying pathologic condition.¹ According to traditional teaching, when the musculotendinous unit is subjected to excessive forces, failure invariably occurs at the tendon insertion, at the musculotendinous junction, within the muscle substance, or at its origin from the bone before the tendon itself ruptures.¹

Midsubstance tears in nonrheumatoid patients are less frequent and are typically attributable to an underlying cause.² Possible pathologic conditions include, but are not limited to, osteoarthritis of the pisotriquetral joint,³ nonunion fracture of the hook of the hamate,⁴ lunate dislocation,⁵ accessory carpal bone,⁶ gouty infiltration of the flexor tendon,⁷ and tumor.⁸ In 1960, Boyes and colleagues⁹ presented a series of 80 flexor tendon ruptures in 78 patients over a 13-year period. Only 3 cases had no identifiable cause. The authors recommended using the term spontaneous for those ruptures that occur within the tendon substance without underlying or associated pathologic changes.

We describe a patient with spontaneous rupture of the flexor digitorum profundus (FDP) tendon at zone III, satisfying Boyes’ definition of the term spontaneous. The patient provided written informed consent for print and electronic publication of this case report.

Case Report

A 65-year-old, right-handed manual worker was assessed in our hand clinic 3 days after he felt a cramp in his left palm while lifting a heavy object. Shortly thereafter, he noted he could not flex his ring finger distal interphalangeal (DIP) joint. He could not recall any previous injury to his finger. No predisposing pathologic conditions or bone abnormalities were identified. Clinically, there was no tenderness, swelling, or ecchymosis evident. He had full passive range of motion (ROM) of his ring finger, and proximal interphalangeal (PIP) joint active ROM was 0/110º; however, he had no activity of the FDP of the ring finger. Preoperative radiographs were normal. The hook of the hamate was clinically and radiographically normal.

A preoperative diagnosis of FDP avulsion from the distal phalanx was made, and the operation was carried out 16 days after injury. Surgical exploration started in zone II and extended proximally into the distal palmar crease, but no stump was found in either location. Therefore, exploration was carried out to the midpalmar region, revealing the tendon rupture in zone III, in the region of the origin of the ring finger lumbrical muscle (Figure 1). The flexor digitorum superficialis tendon was intact. Macroscopically, both tendon and carpal tunnel appeared normal, with no evidence of tendon attrition; thus, the tendon was not sent for histologic examination. The ends of the ruptured FDP tendon to the ring finger were at the level of the superficial palmar arch, with the distal end appearing as though it had been cut sharply with a knife. Because of the short period of time from injury to exploration, delayed primary tendon repair was possible, along with side-to-side tenodesis to the intact ring finger flexor superficialis tendon in the palm (Figure 2). Two days after surgery, the patient started a controlled mobilization program using the Duran method.¹⁰

At final follow-up of 18 months, total active motion was 126°, which corresponds to a good outcome, according to the Strickland and Glogovac criteria.¹¹ Grip strength was 50 kg, which was 84% of grip strength on the uninjured side. The patient was back to recreational activity but had not returned to work.

Discussion

Most flexor tendon ruptures result from avulsion of the FDP tendon at its distal phalanx insertion, commonly known as Jersey finger. However, true midsubstance spontaneous ruptures are infrequent. Reports of spontaneous tendon ruptures of all types, including those of the hand, have increased in incidence in most countries.¹² Bois and colleagues,¹³ who have reviewed the literature over a 50-year period, found a total of 50 spontaneous ruptures of “normal” flexor tendon in 43 cases. The authors point to unique historical and physical examinaton findings that help differentiate spontaneous tendon ruptures from the more common FDP avulsions. Such findings include the sensation of a pop or snap, or a sudden sharp pain or cramp within the palmar region. In contrast, most avulsion ruptures cause discomfort within the region of the digit. In type I avulsion injuries of the FDP tendon, the proximal tendon stump usually retracts proximal to the digital tendon sheath, causing a tender mass in the palm.¹⁴ Flexor digitorum profundus tendon avulsions, however, are not typically associated with a snap or pop in the palm. When spontaneous ruptures of the hand occur, they typically involve the profundus tendon of the small finger, in the area of the lumbrical origin.¹³

In equivocal cases when the site of rupture is uncertain, ultrasound and magnetic resonance imaging may assist in making the diagnosis and provide important preoperative information for surgical decision-making and planning; this information may decrease postoperative morbidity by minimizing surgical dissection.

The etiology of spontaneous ruptures is incompletely understood. For any rupture of the ulnar flexor tendons, the hook of the hamate should be examined to rule out a previous fracture as a cause of tendon attrition.¹⁵ Tendon vascularization may be a cause for tendon rupture in the hand. When the blood supply of the lumbrical muscles was examined in 100 upper extremities from human cadavers using vascular injection studies,¹⁶ it was discovered that each lumbrical muscle received its arterial supply from 4 sources: the superficial palmar arch, the common palmar digital artery, the deep palmar arch, and the dorsal digital artery. There were no anastomoses between the networks supplying the lumbrical muscles and the FDP tendons within the palm, suggesting a possible watershed zone between the FDP tendon and lumbrical muscle origin. The patient described in this case had the tendon rupture in the area of potential hypovascularity at the lumbrical origin.

Important factors in the decision-making process for surgical treatment include the length of time between rupture and treatment, the site of rupture, and the condition of the ruptured tendon ends. Patients who present in the first 3 weeks of injury can be treated by primary tendon repair, provided that the ruptured tendon ends are not significantly frayed or attenuated. For patients presenting more than 3 weeks after injury, interposition tendon grafts or tendon transfers are suitable options for ruptures in zone III. Distal interphalangeal joint arthrodesis is another alternative in specific cases where reconstruction is not possible. In this case, direct end-to-end repair was possible, as well as tenodesis to the intact ring finger superficialis in order to prevent stretching of the repair.

Localizing the level of the tendon rupture clinically is difficult. When the site of the profundus tendon rupture is uncertain, and there is no tenderness in zone I or the PIP joint, the first incision should be made at the metacarpophalangeal joint level. This first incision will indicate if the rupture occurred in zone III. If the tendon is intact at that location, then the next incision should be at the level of the PIP joint.

Conclusion

We report a patient treated for spontaneous rupture of the flexor tendon in zone III. He was treated in the acute setting with direct tendon repair. It is important to consider spontaneous rupture of the tendon in patients presenting with a snap/pop and the sudden inability to flex a finger. A tendon rupture can be diagnosed as spontaneous in the absence of an underlying pathologic condition such as rheumatoid arthritis, gout, or occult carpal fractures. In the acute setting, these may be repaired primarily; however, if presenting after a few weeks, alternative surgical options, including interposition tendon grafts, tendon transfer, and DIP joint arthrodesis, should be considered.

Hair pigmentation is a complex phenomenon that involves many hormones, neurotransmitters, cytokines, growth factors, eicosanoids, cyclic nucleotides, nutrients, and a physicochemical milieu.¹ Repigmentation of gray hair has been associated with herpes zoster infection,² use of systemic corticosteroids,³ thyroid hormone therapy,⁴ or treatment with interferon and ribavirin.⁵ We report a case of repigmentation of gray hairs in lesions of annular elastolytic giant cell granuloma (AEGCG) on the scalp of a 67-year-old man.

Case Report

A 67-year-old man presented to the dermatology department for evaluation of pruritic lesions on the face and scalp of 1 year’s duration. The patient reported that hairs in the involved areas of the scalp had turned from gray to a dark color since the appearance of the lesions. The patient had a history of hypertension and type 2 diabetes mellitus. His current medications included irbesartan, atorvastatin, metformin, acetylsalicylic acid, omeprazole, and repaglinide.

Physical examination revealed plaques on the scalp and cheeks that were 2 to 10 mm in diameter. Some of the plaques had an atrophic center and a desquamative peripheral border. The patient had androgenetic alopecia. The remaining hair was dark in the areas affected by the inflammatory plaques while it remained white-gray in the uninvolved areas (Figure 1).

Figure 1. Repigmentation of gray hair in the areas affected by plaques on the scalp.

A biopsy of one of the lesions was performed. Histopathology revealed a granulomatous dermatitis involving mostly the upper and mid dermis (Figure 2). Granulomas were epithelioid with many giant cells, some of which contained many nuclei. A ringed array of nuclei was noted in some histiocytes. Elastic fibers were absent in the central zone of the granulomas, a finding that was better evidenced on orcein staining (Figure 3). On the contrary, the peripheral zone of the granulomas showed an increased amount of thick elastotic material. Elastophagocytosis was observed, but no asteroid bodies, Schaumann bodies, or mucin deposits were noted. Histochemistry for microorganisms with Ziehl-Neelsen and periodic acid–Schiff staining was negative. Other findings included a mild infiltrate of melanophages in the papillary dermis as well as a mild superficial dermal inflammatory infiltrate that was rich in plasma cells. Immunostaining for Treponema pallidum was negative. The lymphocytic infiltrate was CD4⁺predominant. A prominent dermal elastosis also was noted. Hair follicles within the plaques were small in size, penetrating just the dermis. Immunostaining for HMB-45, melan-A, and S-100 demonstrated preserved melanocytes in the hair bulbs (Figure 4). CD68 immunostaining made the infiltrate of macrophages stand out. Based on the results of the histopathologic evaluation, a diagnosis of AEGCG was made.

Figure 2. Biopsy showed granulomatous dermatitis in which many giant cells were seen. The latter contained several nuclei, sometimes in a ringed array (H&E, original magnification ×20).

Figure 3. Orcein stain demonstrated a decrease in elastic fibers in the center of the granulomas as well as an increase of elastic fibers in the periphery. Elastophagocytosis was easily observed (original magnification ×40).

Figure 4. Immunohistochemical staining for HMB-45 showed preservation of melanocytes in the hair bulbs (original magnification ×20).

Comment

Annular elastolytic giant cell granuloma is a controversial entity that was first described by O’Brien⁶ in 1975 as actinic granuloma. Hanke et al⁷ proposed the term annular elastolytic giant cell granuloma to encompass lesions previously called actinic granuloma, atypical necrobiosis lipoidica, and Miescher granuloma. Some researchers have claimed that AEGCG is an independent entity, therefore separate and distinguishable from granuloma annulare. Histopathologic clues to distinguish AEGCG from granuloma annulare have been noted in the literature.^7-9 Other investigators believe AEGCG is a type of granuloma annulare that appears on exposed skin.¹⁰ There are several variants of the classic clinical presentation of AEGCG, such as cases including presentation in unexposed areas of the skin,¹¹ a papular variant,¹² a rapidly regressive variant,¹³ a reticular variant,¹⁴ a variant of early childhood,¹⁵ a generalized variant,¹⁶ presentation in a necklace distribution,¹⁷ presentation as alopecia,¹⁸ a sarcoid variant,¹⁹ or presentation as reticulate erythema.²⁰ However, no variant has been associated with hair repigmentation.

Melanin units from the proximal hair bulb are responsible for pigmentation in adult hair follicles and are integrated by the hair matrix, melanocytes, keratinocytes, and fibroblasts.²¹ Hair bulb melanocytes are larger and more dendritic than epidermal melanocytes (Figure 5). The hair only pigments during the anagen phase; therefore, its pigmentation is cyclic, as opposed to epidermal pigmentation, which is ongoing. Hair pigmentation is the result of a complex interaction between the epithelium, the mesenchyme, and the neuroectoderm. This complex pigmentation results from the interaction between follicular melanocytes, keratinocytes, and the fibroblasts from the hair papilla.²² Hair pigmentation involves many hormones, neurotransmitters, cytokines, growth factors, eicosanoids, cyclic nucleotides, nutrients, and a physicochemical milieu^1,23-25 (Table), and it is regulated by autocrines, paracrines, or intracrines.²¹ Therefore, it is likely that many environmental factors may affect hair pigmentation, which may explain why repigmentation of the hair has been seen in the setting of herpes zoster infection,² use of systemic corticosteroids in the treatment of bullous pemphigoid,³ thyroid hormone therapy,⁴ treatment with interferon and ribavirin,⁵ porphyria cutanea tarda,²⁶ or lentigo maligna.²⁷ In our patient, AEGCG might have induced some changes in the dermal environment that were responsible for the repigmentation of the patient’s gray hair. It is speculated that solar radiation and other factors can transform the antigenicity of elastic fibers and induce an immune response in AEGCG.^12,15 The lymphocytic infiltrate in these lesions is predominantly CD4⁺, as seen in our patient, which is consistent with an autoimmune hypothesis.¹⁵ Nevertheless, it most likely is too simplistic to attribute the repigmentation to the influence of just these cells.

Figure 5. A hair bulb of a normal follicle showing the morphology of melanocytes, which are dendritic and large (H&E,original magnification ×100).

Hair pigmentation is a complex phenomenon that involves many hormones, neurotransmitters, cytokines, growth factors, eicosanoids, cyclic nucleotides, nutrients, and a physicochemical milieu.¹ Repigmentation of gray hair has been associated with herpes zoster infection,² use of systemic corticosteroids,³ thyroid hormone therapy,⁴ or treatment with interferon and ribavirin.⁵ We report a case of repigmentation of gray hairs in lesions of annular elastolytic giant cell granuloma (AEGCG) on the scalp of a 67-year-old man.

Case Report

A 67-year-old man presented to the dermatology department for evaluation of pruritic lesions on the face and scalp of 1 year’s duration. The patient reported that hairs in the involved areas of the scalp had turned from gray to a dark color since the appearance of the lesions. The patient had a history of hypertension and type 2 diabetes mellitus. His current medications included irbesartan, atorvastatin, metformin, acetylsalicylic acid, omeprazole, and repaglinide.

Physical examination revealed plaques on the scalp and cheeks that were 2 to 10 mm in diameter. Some of the plaques had an atrophic center and a desquamative peripheral border. The patient had androgenetic alopecia. The remaining hair was dark in the areas affected by the inflammatory plaques while it remained white-gray in the uninvolved areas (Figure 1).

Figure 1. Repigmentation of gray hair in the areas affected by plaques on the scalp.

A biopsy of one of the lesions was performed. Histopathology revealed a granulomatous dermatitis involving mostly the upper and mid dermis (Figure 2). Granulomas were epithelioid with many giant cells, some of which contained many nuclei. A ringed array of nuclei was noted in some histiocytes. Elastic fibers were absent in the central zone of the granulomas, a finding that was better evidenced on orcein staining (Figure 3). On the contrary, the peripheral zone of the granulomas showed an increased amount of thick elastotic material. Elastophagocytosis was observed, but no asteroid bodies, Schaumann bodies, or mucin deposits were noted. Histochemistry for microorganisms with Ziehl-Neelsen and periodic acid–Schiff staining was negative. Other findings included a mild infiltrate of melanophages in the papillary dermis as well as a mild superficial dermal inflammatory infiltrate that was rich in plasma cells. Immunostaining for Treponema pallidum was negative. The lymphocytic infiltrate was CD4⁺predominant. A prominent dermal elastosis also was noted. Hair follicles within the plaques were small in size, penetrating just the dermis. Immunostaining for HMB-45, melan-A, and S-100 demonstrated preserved melanocytes in the hair bulbs (Figure 4). CD68 immunostaining made the infiltrate of macrophages stand out. Based on the results of the histopathologic evaluation, a diagnosis of AEGCG was made.

Figure 2. Biopsy showed granulomatous dermatitis in which many giant cells were seen. The latter contained several nuclei, sometimes in a ringed array (H&E, original magnification ×20).

Figure 3. Orcein stain demonstrated a decrease in elastic fibers in the center of the granulomas as well as an increase of elastic fibers in the periphery. Elastophagocytosis was easily observed (original magnification ×40).

Figure 4. Immunohistochemical staining for HMB-45 showed preservation of melanocytes in the hair bulbs (original magnification ×20).

Comment

Annular elastolytic giant cell granuloma is a controversial entity that was first described by O’Brien⁶ in 1975 as actinic granuloma. Hanke et al⁷ proposed the term annular elastolytic giant cell granuloma to encompass lesions previously called actinic granuloma, atypical necrobiosis lipoidica, and Miescher granuloma. Some researchers have claimed that AEGCG is an independent entity, therefore separate and distinguishable from granuloma annulare. Histopathologic clues to distinguish AEGCG from granuloma annulare have been noted in the literature.^7-9 Other investigators believe AEGCG is a type of granuloma annulare that appears on exposed skin.¹⁰ There are several variants of the classic clinical presentation of AEGCG, such as cases including presentation in unexposed areas of the skin,¹¹ a papular variant,¹² a rapidly regressive variant,¹³ a reticular variant,¹⁴ a variant of early childhood,¹⁵ a generalized variant,¹⁶ presentation in a necklace distribution,¹⁷ presentation as alopecia,¹⁸ a sarcoid variant,¹⁹ or presentation as reticulate erythema.²⁰ However, no variant has been associated with hair repigmentation.

Melanin units from the proximal hair bulb are responsible for pigmentation in adult hair follicles and are integrated by the hair matrix, melanocytes, keratinocytes, and fibroblasts.²¹ Hair bulb melanocytes are larger and more dendritic than epidermal melanocytes (Figure 5). The hair only pigments during the anagen phase; therefore, its pigmentation is cyclic, as opposed to epidermal pigmentation, which is ongoing. Hair pigmentation is the result of a complex interaction between the epithelium, the mesenchyme, and the neuroectoderm. This complex pigmentation results from the interaction between follicular melanocytes, keratinocytes, and the fibroblasts from the hair papilla.²² Hair pigmentation involves many hormones, neurotransmitters, cytokines, growth factors, eicosanoids, cyclic nucleotides, nutrients, and a physicochemical milieu^1,23-25 (Table), and it is regulated by autocrines, paracrines, or intracrines.²¹ Therefore, it is likely that many environmental factors may affect hair pigmentation, which may explain why repigmentation of the hair has been seen in the setting of herpes zoster infection,² use of systemic corticosteroids in the treatment of bullous pemphigoid,³ thyroid hormone therapy,⁴ treatment with interferon and ribavirin,⁵ porphyria cutanea tarda,²⁶ or lentigo maligna.²⁷ In our patient, AEGCG might have induced some changes in the dermal environment that were responsible for the repigmentation of the patient’s gray hair. It is speculated that solar radiation and other factors can transform the antigenicity of elastic fibers and induce an immune response in AEGCG.^12,15 The lymphocytic infiltrate in these lesions is predominantly CD4⁺, as seen in our patient, which is consistent with an autoimmune hypothesis.¹⁵ Nevertheless, it most likely is too simplistic to attribute the repigmentation to the influence of just these cells.

Figure 5. A hair bulb of a normal follicle showing the morphology of melanocytes, which are dendritic and large (H&E,original magnification ×100).

Hair pigmentation is a complex phenomenon that involves many hormones, neurotransmitters, cytokines, growth factors, eicosanoids, cyclic nucleotides, nutrients, and a physicochemical milieu.¹ Repigmentation of gray hair has been associated with herpes zoster infection,² use of systemic corticosteroids,³ thyroid hormone therapy,⁴ or treatment with interferon and ribavirin.⁵ We report a case of repigmentation of gray hairs in lesions of annular elastolytic giant cell granuloma (AEGCG) on the scalp of a 67-year-old man.

Case Report

A 67-year-old man presented to the dermatology department for evaluation of pruritic lesions on the face and scalp of 1 year’s duration. The patient reported that hairs in the involved areas of the scalp had turned from gray to a dark color since the appearance of the lesions. The patient had a history of hypertension and type 2 diabetes mellitus. His current medications included irbesartan, atorvastatin, metformin, acetylsalicylic acid, omeprazole, and repaglinide.

Physical examination revealed plaques on the scalp and cheeks that were 2 to 10 mm in diameter. Some of the plaques had an atrophic center and a desquamative peripheral border. The patient had androgenetic alopecia. The remaining hair was dark in the areas affected by the inflammatory plaques while it remained white-gray in the uninvolved areas (Figure 1).

Figure 1. Repigmentation of gray hair in the areas affected by plaques on the scalp.

A biopsy of one of the lesions was performed. Histopathology revealed a granulomatous dermatitis involving mostly the upper and mid dermis (Figure 2). Granulomas were epithelioid with many giant cells, some of which contained many nuclei. A ringed array of nuclei was noted in some histiocytes. Elastic fibers were absent in the central zone of the granulomas, a finding that was better evidenced on orcein staining (Figure 3). On the contrary, the peripheral zone of the granulomas showed an increased amount of thick elastotic material. Elastophagocytosis was observed, but no asteroid bodies, Schaumann bodies, or mucin deposits were noted. Histochemistry for microorganisms with Ziehl-Neelsen and periodic acid–Schiff staining was negative. Other findings included a mild infiltrate of melanophages in the papillary dermis as well as a mild superficial dermal inflammatory infiltrate that was rich in plasma cells. Immunostaining for Treponema pallidum was negative. The lymphocytic infiltrate was CD4⁺predominant. A prominent dermal elastosis also was noted. Hair follicles within the plaques were small in size, penetrating just the dermis. Immunostaining for HMB-45, melan-A, and S-100 demonstrated preserved melanocytes in the hair bulbs (Figure 4). CD68 immunostaining made the infiltrate of macrophages stand out. Based on the results of the histopathologic evaluation, a diagnosis of AEGCG was made.

Figure 2. Biopsy showed granulomatous dermatitis in which many giant cells were seen. The latter contained several nuclei, sometimes in a ringed array (H&E, original magnification ×20).

Figure 3. Orcein stain demonstrated a decrease in elastic fibers in the center of the granulomas as well as an increase of elastic fibers in the periphery. Elastophagocytosis was easily observed (original magnification ×40).

Figure 4. Immunohistochemical staining for HMB-45 showed preservation of melanocytes in the hair bulbs (original magnification ×20).

Comment

Annular elastolytic giant cell granuloma is a controversial entity that was first described by O’Brien⁶ in 1975 as actinic granuloma. Hanke et al⁷ proposed the term annular elastolytic giant cell granuloma to encompass lesions previously called actinic granuloma, atypical necrobiosis lipoidica, and Miescher granuloma. Some researchers have claimed that AEGCG is an independent entity, therefore separate and distinguishable from granuloma annulare. Histopathologic clues to distinguish AEGCG from granuloma annulare have been noted in the literature.^7-9 Other investigators believe AEGCG is a type of granuloma annulare that appears on exposed skin.¹⁰ There are several variants of the classic clinical presentation of AEGCG, such as cases including presentation in unexposed areas of the skin,¹¹ a papular variant,¹² a rapidly regressive variant,¹³ a reticular variant,¹⁴ a variant of early childhood,¹⁵ a generalized variant,¹⁶ presentation in a necklace distribution,¹⁷ presentation as alopecia,¹⁸ a sarcoid variant,¹⁹ or presentation as reticulate erythema.²⁰ However, no variant has been associated with hair repigmentation.

Melanin units from the proximal hair bulb are responsible for pigmentation in adult hair follicles and are integrated by the hair matrix, melanocytes, keratinocytes, and fibroblasts.²¹ Hair bulb melanocytes are larger and more dendritic than epidermal melanocytes (Figure 5). The hair only pigments during the anagen phase; therefore, its pigmentation is cyclic, as opposed to epidermal pigmentation, which is ongoing. Hair pigmentation is the result of a complex interaction between the epithelium, the mesenchyme, and the neuroectoderm. This complex pigmentation results from the interaction between follicular melanocytes, keratinocytes, and the fibroblasts from the hair papilla.²² Hair pigmentation involves many hormones, neurotransmitters, cytokines, growth factors, eicosanoids, cyclic nucleotides, nutrients, and a physicochemical milieu^1,23-25 (Table), and it is regulated by autocrines, paracrines, or intracrines.²¹ Therefore, it is likely that many environmental factors may affect hair pigmentation, which may explain why repigmentation of the hair has been seen in the setting of herpes zoster infection,² use of systemic corticosteroids in the treatment of bullous pemphigoid,³ thyroid hormone therapy,⁴ treatment with interferon and ribavirin,⁵ porphyria cutanea tarda,²⁶ or lentigo maligna.²⁷ In our patient, AEGCG might have induced some changes in the dermal environment that were responsible for the repigmentation of the patient’s gray hair. It is speculated that solar radiation and other factors can transform the antigenicity of elastic fibers and induce an immune response in AEGCG.^12,15 The lymphocytic infiltrate in these lesions is predominantly CD4⁺, as seen in our patient, which is consistent with an autoimmune hypothesis.¹⁵ Nevertheless, it most likely is too simplistic to attribute the repigmentation to the influence of just these cells.

Figure 5. A hair bulb of a normal follicle showing the morphology of melanocytes, which are dendritic and large (H&E,original magnification ×100).

Extensor tendon rupture in chronic Madelung deformity, as a result of tendon attrition on the dislocated distal ulna, occurs infrequently. However, it is often seen in patients with rheumatoid arthritis. This issue has been reported in only a few English-language case reports. Here we report a case of multiple tendon ruptures in a previously undiagnosed Madelung deformity. The patient provided written informed consent for print and electronic publication of this case report.

Case Report

A 56-year-old active woman presented with 50 days’ inability to extend the fourth and fifth fingers of her dominant right hand. The loss of finger extension progressed, over several weeks, to involve the third finger as well. The first 2 tendon ruptures had been triggered by lifting a light grocery bag, when she noticed a sharp sudden pain and “pop.” The third rupture occurred spontaneously with a snapping sound the night before surgery.

 The patient had observed some prominence on the ulnar side of her right wrist since childhood but had never experienced any pain or functional disability. There was neither history of trauma, inflammatory disease, diabetes mellitus, or infection, nor positive family history of similar wrist deformity.

The physical examination showed a dorsally subluxated distal radioulnar joint, prominent ulnar styloid, and mild ulnar and volar deviation of the wrist along with limitation of wrist dorsiflexion. Complete loss of active extension of the 3 ulnar fingers was demonstrated, while neurovascular status and all other hand evaluations were normal. The wrist radiographs confirmed the typical findings of Madelung deformity (Figure 1).

Repair of the ruptured tendons and resection of the prominent distal ulna (Darrach procedure) was planned. (Given the patient’s age and evidence of degenerative changes in the radiocarpal joint, correction of the Madelung deformity did not seem necessary). At time of surgery, the recently ruptured third finger extensor tendon was easily found and approximated, and end-to-end repair was performed. The fourth and fifth fingers, however, had to be fished out more proximally from dense granulation tissue. After the distal ulna was resected for a distance of 1.5 cm, meticulous repair of the ulnar collateral ligament and the capsule and periosteum over the end of the ulna was performed. Then, for grafting of the ruptured tendons, the extensor indicis proprius tendon was isolated and transected at the second metacarpophalangeal joint level. A piece of this tendon was used as interpositional graft for the fourth extensor tendon, and the main tendon unit was transferred to the fifth finger extensor. The extensor digiti quinti tendon, which was about to rupture, was further reinforced by suturing it side to side to the muscle and tendon of the extensor indicis proprius (Figure 2).

Postoperatively, the wrist was kept in extension in a cast for 3 weeks while the fingers were free for active movement. A removable wrist splint was used for an additional month. At 3-month follow-up, the patient had regained full and strong finger extension and wrist motion.

At 3-year follow-up, the patient was pain-free, and had full extension of all fingers, full forearm rotation, and near-normal motion (better than her preoperative motion). The grip power on the operated right hand was 215 N, and pinch power was 93 N. (The values for the left side were 254 N and 83 N, respectively, using the Jamar hydraulic hand dynamometer [Patterson Medical].) The patient has had no additional tendon rupture (Figure 3).

Discussion

Madelung deformity was first described by Madelung in 1878 and several cases have reported this deformity. However, extensor tendon rupture caused by Madelung deformity is very rare, reported in few cases.¹

Extensor tendon rupture caused by chronic Madelung deformity has been reported few times in the English literature. Goodwin¹ apparently published the first report of such an occurrence in 1979. Ducloyer and colleagues² from France reported 6 cases of extensor tendon rupture as a result of inferior distal radioulnar joint deformity of Madelung. Jebson and colleagues³ reported bilateral spontaneous extensor tendon ruptures in Madelung deformity in 1992.

The mechanism of tendon rupture seems to be mechanical, resulting from continuous rubbing and erosion of tendons over the deformed ulnar head, which has a rough irregular surface⁴ and leads to fraying of the tendons and eventual rupture and retraction of the severed tendon ends. This rupture usually progresses stepwise from more medial to the lateral tendons.² Older patients are, therefore, subject to chronic repetitive attritional trauma leading to tendon rupture.

Tendons may rupture as a result of a variety of conditions, such as chronic synovitis in rheumatoid arthritis, systemic lupus erythematosus, mixed connective tissue disease, or crystal deposition in gout.^5-8 Some other metabolic or endocrine conditions that involve tendon ruptures include diabetes mellitus, chronic renal failure, and hyperparathyroidism. Steroid injection into the tendons also has a detrimental effect on tendon integrity and may cause tendon tear.⁹ Mechanical factors, such as erosion on bony prominences, are well-known etiologies for tendon rupture, as commonly seen in rheumatoid arthritis, and have been reported in Kienböck disease,¹⁰ thumb carpometacarpal arthritis,¹¹ Colles fracture, scaphoid fracture nonunion,¹² and Madelung deformity.

Conclusion

Our case reflects the usual middle-aged female presentation of such a tendon rupture. The tendon ruptures were spontaneous in the reported order of ulnar to radial, beginning with the little and ring fingers, and progressed radially. The patient had isolated Madelung deformity with no other sign of dyschondrosteosis¹³ or dwarfism, conditions commonly mentioned in association with Madelung deformity. This case report should raise awareness about possible tendon rupture in any chronic case of Madelung deformity.

Extensor tendon rupture in chronic Madelung deformity, as a result of tendon attrition on the dislocated distal ulna, occurs infrequently. However, it is often seen in patients with rheumatoid arthritis. This issue has been reported in only a few English-language case reports. Here we report a case of multiple tendon ruptures in a previously undiagnosed Madelung deformity. The patient provided written informed consent for print and electronic publication of this case report.

Case Report

A 56-year-old active woman presented with 50 days’ inability to extend the fourth and fifth fingers of her dominant right hand. The loss of finger extension progressed, over several weeks, to involve the third finger as well. The first 2 tendon ruptures had been triggered by lifting a light grocery bag, when she noticed a sharp sudden pain and “pop.” The third rupture occurred spontaneously with a snapping sound the night before surgery.

 The patient had observed some prominence on the ulnar side of her right wrist since childhood but had never experienced any pain or functional disability. There was neither history of trauma, inflammatory disease, diabetes mellitus, or infection, nor positive family history of similar wrist deformity.

The physical examination showed a dorsally subluxated distal radioulnar joint, prominent ulnar styloid, and mild ulnar and volar deviation of the wrist along with limitation of wrist dorsiflexion. Complete loss of active extension of the 3 ulnar fingers was demonstrated, while neurovascular status and all other hand evaluations were normal. The wrist radiographs confirmed the typical findings of Madelung deformity (Figure 1).

Repair of the ruptured tendons and resection of the prominent distal ulna (Darrach procedure) was planned. (Given the patient’s age and evidence of degenerative changes in the radiocarpal joint, correction of the Madelung deformity did not seem necessary). At time of surgery, the recently ruptured third finger extensor tendon was easily found and approximated, and end-to-end repair was performed. The fourth and fifth fingers, however, had to be fished out more proximally from dense granulation tissue. After the distal ulna was resected for a distance of 1.5 cm, meticulous repair of the ulnar collateral ligament and the capsule and periosteum over the end of the ulna was performed. Then, for grafting of the ruptured tendons, the extensor indicis proprius tendon was isolated and transected at the second metacarpophalangeal joint level. A piece of this tendon was used as interpositional graft for the fourth extensor tendon, and the main tendon unit was transferred to the fifth finger extensor. The extensor digiti quinti tendon, which was about to rupture, was further reinforced by suturing it side to side to the muscle and tendon of the extensor indicis proprius (Figure 2).

Postoperatively, the wrist was kept in extension in a cast for 3 weeks while the fingers were free for active movement. A removable wrist splint was used for an additional month. At 3-month follow-up, the patient had regained full and strong finger extension and wrist motion.

At 3-year follow-up, the patient was pain-free, and had full extension of all fingers, full forearm rotation, and near-normal motion (better than her preoperative motion). The grip power on the operated right hand was 215 N, and pinch power was 93 N. (The values for the left side were 254 N and 83 N, respectively, using the Jamar hydraulic hand dynamometer [Patterson Medical].) The patient has had no additional tendon rupture (Figure 3).

Discussion

Madelung deformity was first described by Madelung in 1878 and several cases have reported this deformity. However, extensor tendon rupture caused by Madelung deformity is very rare, reported in few cases.¹

Extensor tendon rupture caused by chronic Madelung deformity has been reported few times in the English literature. Goodwin¹ apparently published the first report of such an occurrence in 1979. Ducloyer and colleagues² from France reported 6 cases of extensor tendon rupture as a result of inferior distal radioulnar joint deformity of Madelung. Jebson and colleagues³ reported bilateral spontaneous extensor tendon ruptures in Madelung deformity in 1992.

The mechanism of tendon rupture seems to be mechanical, resulting from continuous rubbing and erosion of tendons over the deformed ulnar head, which has a rough irregular surface⁴ and leads to fraying of the tendons and eventual rupture and retraction of the severed tendon ends. This rupture usually progresses stepwise from more medial to the lateral tendons.² Older patients are, therefore, subject to chronic repetitive attritional trauma leading to tendon rupture.

Tendons may rupture as a result of a variety of conditions, such as chronic synovitis in rheumatoid arthritis, systemic lupus erythematosus, mixed connective tissue disease, or crystal deposition in gout.^5-8 Some other metabolic or endocrine conditions that involve tendon ruptures include diabetes mellitus, chronic renal failure, and hyperparathyroidism. Steroid injection into the tendons also has a detrimental effect on tendon integrity and may cause tendon tear.⁹ Mechanical factors, such as erosion on bony prominences, are well-known etiologies for tendon rupture, as commonly seen in rheumatoid arthritis, and have been reported in Kienböck disease,¹⁰ thumb carpometacarpal arthritis,¹¹ Colles fracture, scaphoid fracture nonunion,¹² and Madelung deformity.

Conclusion

Our case reflects the usual middle-aged female presentation of such a tendon rupture. The tendon ruptures were spontaneous in the reported order of ulnar to radial, beginning with the little and ring fingers, and progressed radially. The patient had isolated Madelung deformity with no other sign of dyschondrosteosis¹³ or dwarfism, conditions commonly mentioned in association with Madelung deformity. This case report should raise awareness about possible tendon rupture in any chronic case of Madelung deformity.

Extensor tendon rupture in chronic Madelung deformity, as a result of tendon attrition on the dislocated distal ulna, occurs infrequently. However, it is often seen in patients with rheumatoid arthritis. This issue has been reported in only a few English-language case reports. Here we report a case of multiple tendon ruptures in a previously undiagnosed Madelung deformity. The patient provided written informed consent for print and electronic publication of this case report.

Case Report

A 56-year-old active woman presented with 50 days’ inability to extend the fourth and fifth fingers of her dominant right hand. The loss of finger extension progressed, over several weeks, to involve the third finger as well. The first 2 tendon ruptures had been triggered by lifting a light grocery bag, when she noticed a sharp sudden pain and “pop.” The third rupture occurred spontaneously with a snapping sound the night before surgery.

 The patient had observed some prominence on the ulnar side of her right wrist since childhood but had never experienced any pain or functional disability. There was neither history of trauma, inflammatory disease, diabetes mellitus, or infection, nor positive family history of similar wrist deformity.

The physical examination showed a dorsally subluxated distal radioulnar joint, prominent ulnar styloid, and mild ulnar and volar deviation of the wrist along with limitation of wrist dorsiflexion. Complete loss of active extension of the 3 ulnar fingers was demonstrated, while neurovascular status and all other hand evaluations were normal. The wrist radiographs confirmed the typical findings of Madelung deformity (Figure 1).

Repair of the ruptured tendons and resection of the prominent distal ulna (Darrach procedure) was planned. (Given the patient’s age and evidence of degenerative changes in the radiocarpal joint, correction of the Madelung deformity did not seem necessary). At time of surgery, the recently ruptured third finger extensor tendon was easily found and approximated, and end-to-end repair was performed. The fourth and fifth fingers, however, had to be fished out more proximally from dense granulation tissue. After the distal ulna was resected for a distance of 1.5 cm, meticulous repair of the ulnar collateral ligament and the capsule and periosteum over the end of the ulna was performed. Then, for grafting of the ruptured tendons, the extensor indicis proprius tendon was isolated and transected at the second metacarpophalangeal joint level. A piece of this tendon was used as interpositional graft for the fourth extensor tendon, and the main tendon unit was transferred to the fifth finger extensor. The extensor digiti quinti tendon, which was about to rupture, was further reinforced by suturing it side to side to the muscle and tendon of the extensor indicis proprius (Figure 2).

Postoperatively, the wrist was kept in extension in a cast for 3 weeks while the fingers were free for active movement. A removable wrist splint was used for an additional month. At 3-month follow-up, the patient had regained full and strong finger extension and wrist motion.

At 3-year follow-up, the patient was pain-free, and had full extension of all fingers, full forearm rotation, and near-normal motion (better than her preoperative motion). The grip power on the operated right hand was 215 N, and pinch power was 93 N. (The values for the left side were 254 N and 83 N, respectively, using the Jamar hydraulic hand dynamometer [Patterson Medical].) The patient has had no additional tendon rupture (Figure 3).

Discussion

Madelung deformity was first described by Madelung in 1878 and several cases have reported this deformity. However, extensor tendon rupture caused by Madelung deformity is very rare, reported in few cases.¹

Extensor tendon rupture caused by chronic Madelung deformity has been reported few times in the English literature. Goodwin¹ apparently published the first report of such an occurrence in 1979. Ducloyer and colleagues² from France reported 6 cases of extensor tendon rupture as a result of inferior distal radioulnar joint deformity of Madelung. Jebson and colleagues³ reported bilateral spontaneous extensor tendon ruptures in Madelung deformity in 1992.

The mechanism of tendon rupture seems to be mechanical, resulting from continuous rubbing and erosion of tendons over the deformed ulnar head, which has a rough irregular surface⁴ and leads to fraying of the tendons and eventual rupture and retraction of the severed tendon ends. This rupture usually progresses stepwise from more medial to the lateral tendons.² Older patients are, therefore, subject to chronic repetitive attritional trauma leading to tendon rupture.

Tendons may rupture as a result of a variety of conditions, such as chronic synovitis in rheumatoid arthritis, systemic lupus erythematosus, mixed connective tissue disease, or crystal deposition in gout.^5-8 Some other metabolic or endocrine conditions that involve tendon ruptures include diabetes mellitus, chronic renal failure, and hyperparathyroidism. Steroid injection into the tendons also has a detrimental effect on tendon integrity and may cause tendon tear.⁹ Mechanical factors, such as erosion on bony prominences, are well-known etiologies for tendon rupture, as commonly seen in rheumatoid arthritis, and have been reported in Kienböck disease,¹⁰ thumb carpometacarpal arthritis,¹¹ Colles fracture, scaphoid fracture nonunion,¹² and Madelung deformity.

Conclusion

Our case reflects the usual middle-aged female presentation of such a tendon rupture. The tendon ruptures were spontaneous in the reported order of ulnar to radial, beginning with the little and ring fingers, and progressed radially. The patient had isolated Madelung deformity with no other sign of dyschondrosteosis¹³ or dwarfism, conditions commonly mentioned in association with Madelung deformity. This case report should raise awareness about possible tendon rupture in any chronic case of Madelung deformity.

A few days after an incidental cat bite, a patient presented to the emergency department for treatment of poison sumac exposure. He was discharged with oral methylprednisolone for the dermatitis and returned 1 week later with symptoms, examination findings, and laboratory results consistent with sepsis and bilateral upper extremity necrotizing soft-tissue infections. After administering multiple irrigation and débridement procedures, hyperbaric oxygen treatments, and an antibiotic regimen, the patient’s status greatly improved. However, the patient returned 1 month later with a new sternoclavicular joint prominence that was associated with painful crepitus. Additionally, he noted that his wrists were gradually becoming more swollen and painful. Imaging studies showed a lytic destruction of the sternoclavicular joint and erosive changes throughout the carpus and radiocarpal joint bilaterally, consistent with osteomyelitis. The patient was treated with ertapenem for 6 weeks, and his polyarthropathy resolved. The patient provided written informed consent for print and electronic publication of this case report.

Case Report

A 73-year-old, right-hand–dominant man with no notable medical history presented to the emergency department for treatment of poison sumac exposure, incidentally, a few days after being bitten by a cat on the bilateral distal upper extremities. He was prescribed a course of oral methylprednisolone for dermatitis. A week later, the patient returned to the emergency department with altered mental status, fevers, diaphoresis, lethargy, and polyarthralgia. At the time of presentation, the patient’s vital signs were labile, and he was found to have extensive bilateral upper extremity erythema, blistering, petechiae, purpuric lesions, and exquisite pain with passive range of motion of his fingers and wrists. His leukocyte count was 25.1 × 10⁹/L, and he had elevated C-reactive protein level and erythrocyte sedimentation rate of 150 mg/L and 120 mm/h, respectively. He was admitted for management of sepsis and presumed bilateral upper extremity necrotizing soft-tissue infection.

Broad-spectrum intravenous (IV) antibiotics (vancomycin, piperacillin, tazobactam) were initiated after blood cultures were obtained, and the patient was taken emergently to the operating theatre for irrigation and débridement of his hands and wrists bilaterally. Arthrotomy of the wrist and débridement of the distal extensor compartment and its tenosynovium were performed on the right forearm, in addition to a decompressive fasciotomy of the left forearm. Postoperatively, the patient’s mental status improved and his vital signs gradually normalized. He received multiple hyperbaric oxygen treatments and underwent several additional operative débridement procedures with eventual closure of his wounds. At initial presentation, the differential diagnosis for the severe soft-tissue infection included necrotizing fasciitis or myositis caused by any of a variety of bacterial pathogens. Most notably, it was important to elicit the history of a cat bite to include and consider Pasteurella multocida as a potential pathogen. Initial cultures supported the diagnosis of acute P multocida necrotizing skin and soft-tissue infection, in addition to septic arthritis. The patient’s blood and intraoperative wound cultures grew P multocida. The antibiotic treatment was tailored initially to ampicillin and sulbactam and then to a final regimen of orally administered ciprofloxacin (750 mg twice a day), once susceptibility testing was performed on the cultures. On hospital day 10, the patient was discharged home, receiving a 6-week course of ciprofloxacin to complete the 8-week course of treatment.

At follow-up, approximately 1 month after discharge, the patient noted that he had developed a new right sternoclavicular joint prominence that was associated with painful crepitus. He also noted that his wrists were gradually becoming more swollen and painful bilaterally. Computed tomography scans of the chest were obtained to evaluate the sternoclavicular joint (Figure 1). Repeat radiographs of the wrists were also obtained (Figure 2). Imaging showed lytic destruction of the sternoclavicular joint and erosive changes throughout the carpus and radiocarpal joint, consistent with osteomyelitis. The C-reactive protein level and erythrocyte sedimentation rate at this time were 34 mg/L and 124 mm/h, respectively.

The patient returned to the operating room for débridement and biopsy of the right sternoclavicular joint and left wrist. This patient’s delayed presentation was characterized by a subacute worsening of isolated musculoskeletal complaints. The differential diagnosis then included infection with the same bacterial pathogen versus reactive or inflammatory arthritis. Several intraoperative cultures failed to grow any bacteria, including P multocida, although P multocida was the presumptive cause of the erosive polyarthropathy, considering that symptoms eventually resolved with a repeated course of IV-administered ertapenem for 6 weeks. The patient experienced complete resolution of his joint pain and swelling. He was able to resume his activities of daily living and had no further recurrence of symptoms at follow-up 3 months later.

Discussion

Cat bites often are the source of Pasteurella species infections because the bacteria are carried by more than 90% of cats.¹ These types of infections can cause septic arthritis, osteomyelitis, and deep subcutaneous and myofascial infections because of the sharp and narrow morphology of cat teeth. The infections can progress to necrotizing fasciitis and myositis if not recognized early, as was the case with our patient. Prophylactic antibiotic administration for animal bites is controversial and is not a universal practice.^1,2Pasteurella bacteremia is an atypical progression that occurs more often in patients with pneumonia, septic arthritis, or meningitis. Cases of Pasteurella sepsis, necrotizing fasciitis, and septic arthritis have been reported.^3-7 However, associated progressive septic arthritis and osteomyelitis, despite initial clinical improvement, have not been reported. Severe infection (ie, sepsis and septic shock) can occur in infants, pregnant women, and other immunocompromised patients.⁷ Immune suppression of our patient with steroid medication for poison sumac dermatitis likely contributed to the progression and systemic spread of an initially benign cat bite. Before prescribing steroids, it is imperative to ask about exposures and encourage patients to seek prompt medical attention with worsening or new symptoms. Healthy individuals rarely develop bacteremia; however, in these cases, mortality remains high at approximately 25%.^4,6

The clinical course of this case emphasizes the need for vigilance and thoroughness in obtaining histories from patients presenting with seemingly benign complaints, especially in vulnerable populations, such as infants, pregnant women, and immunocompromised adults. In this case, the progression of symptoms might have been avoided if the patient’s dermatitis had been treated conservatively or with topical rather than systemic steroids.

A few days after an incidental cat bite, a patient presented to the emergency department for treatment of poison sumac exposure. He was discharged with oral methylprednisolone for the dermatitis and returned 1 week later with symptoms, examination findings, and laboratory results consistent with sepsis and bilateral upper extremity necrotizing soft-tissue infections. After administering multiple irrigation and débridement procedures, hyperbaric oxygen treatments, and an antibiotic regimen, the patient’s status greatly improved. However, the patient returned 1 month later with a new sternoclavicular joint prominence that was associated with painful crepitus. Additionally, he noted that his wrists were gradually becoming more swollen and painful. Imaging studies showed a lytic destruction of the sternoclavicular joint and erosive changes throughout the carpus and radiocarpal joint bilaterally, consistent with osteomyelitis. The patient was treated with ertapenem for 6 weeks, and his polyarthropathy resolved. The patient provided written informed consent for print and electronic publication of this case report.

Case Report

A 73-year-old, right-hand–dominant man with no notable medical history presented to the emergency department for treatment of poison sumac exposure, incidentally, a few days after being bitten by a cat on the bilateral distal upper extremities. He was prescribed a course of oral methylprednisolone for dermatitis. A week later, the patient returned to the emergency department with altered mental status, fevers, diaphoresis, lethargy, and polyarthralgia. At the time of presentation, the patient’s vital signs were labile, and he was found to have extensive bilateral upper extremity erythema, blistering, petechiae, purpuric lesions, and exquisite pain with passive range of motion of his fingers and wrists. His leukocyte count was 25.1 × 10⁹/L, and he had elevated C-reactive protein level and erythrocyte sedimentation rate of 150 mg/L and 120 mm/h, respectively. He was admitted for management of sepsis and presumed bilateral upper extremity necrotizing soft-tissue infection.

Broad-spectrum intravenous (IV) antibiotics (vancomycin, piperacillin, tazobactam) were initiated after blood cultures were obtained, and the patient was taken emergently to the operating theatre for irrigation and débridement of his hands and wrists bilaterally. Arthrotomy of the wrist and débridement of the distal extensor compartment and its tenosynovium were performed on the right forearm, in addition to a decompressive fasciotomy of the left forearm. Postoperatively, the patient’s mental status improved and his vital signs gradually normalized. He received multiple hyperbaric oxygen treatments and underwent several additional operative débridement procedures with eventual closure of his wounds. At initial presentation, the differential diagnosis for the severe soft-tissue infection included necrotizing fasciitis or myositis caused by any of a variety of bacterial pathogens. Most notably, it was important to elicit the history of a cat bite to include and consider Pasteurella multocida as a potential pathogen. Initial cultures supported the diagnosis of acute P multocida necrotizing skin and soft-tissue infection, in addition to septic arthritis. The patient’s blood and intraoperative wound cultures grew P multocida. The antibiotic treatment was tailored initially to ampicillin and sulbactam and then to a final regimen of orally administered ciprofloxacin (750 mg twice a day), once susceptibility testing was performed on the cultures. On hospital day 10, the patient was discharged home, receiving a 6-week course of ciprofloxacin to complete the 8-week course of treatment.

At follow-up, approximately 1 month after discharge, the patient noted that he had developed a new right sternoclavicular joint prominence that was associated with painful crepitus. He also noted that his wrists were gradually becoming more swollen and painful bilaterally. Computed tomography scans of the chest were obtained to evaluate the sternoclavicular joint (Figure 1). Repeat radiographs of the wrists were also obtained (Figure 2). Imaging showed lytic destruction of the sternoclavicular joint and erosive changes throughout the carpus and radiocarpal joint, consistent with osteomyelitis. The C-reactive protein level and erythrocyte sedimentation rate at this time were 34 mg/L and 124 mm/h, respectively.

The patient returned to the operating room for débridement and biopsy of the right sternoclavicular joint and left wrist. This patient’s delayed presentation was characterized by a subacute worsening of isolated musculoskeletal complaints. The differential diagnosis then included infection with the same bacterial pathogen versus reactive or inflammatory arthritis. Several intraoperative cultures failed to grow any bacteria, including P multocida, although P multocida was the presumptive cause of the erosive polyarthropathy, considering that symptoms eventually resolved with a repeated course of IV-administered ertapenem for 6 weeks. The patient experienced complete resolution of his joint pain and swelling. He was able to resume his activities of daily living and had no further recurrence of symptoms at follow-up 3 months later.

Discussion

Cat bites often are the source of Pasteurella species infections because the bacteria are carried by more than 90% of cats.¹ These types of infections can cause septic arthritis, osteomyelitis, and deep subcutaneous and myofascial infections because of the sharp and narrow morphology of cat teeth. The infections can progress to necrotizing fasciitis and myositis if not recognized early, as was the case with our patient. Prophylactic antibiotic administration for animal bites is controversial and is not a universal practice.^1,2Pasteurella bacteremia is an atypical progression that occurs more often in patients with pneumonia, septic arthritis, or meningitis. Cases of Pasteurella sepsis, necrotizing fasciitis, and septic arthritis have been reported.^3-7 However, associated progressive septic arthritis and osteomyelitis, despite initial clinical improvement, have not been reported. Severe infection (ie, sepsis and septic shock) can occur in infants, pregnant women, and other immunocompromised patients.⁷ Immune suppression of our patient with steroid medication for poison sumac dermatitis likely contributed to the progression and systemic spread of an initially benign cat bite. Before prescribing steroids, it is imperative to ask about exposures and encourage patients to seek prompt medical attention with worsening or new symptoms. Healthy individuals rarely develop bacteremia; however, in these cases, mortality remains high at approximately 25%.^4,6

The clinical course of this case emphasizes the need for vigilance and thoroughness in obtaining histories from patients presenting with seemingly benign complaints, especially in vulnerable populations, such as infants, pregnant women, and immunocompromised adults. In this case, the progression of symptoms might have been avoided if the patient’s dermatitis had been treated conservatively or with topical rather than systemic steroids.

A few days after an incidental cat bite, a patient presented to the emergency department for treatment of poison sumac exposure. He was discharged with oral methylprednisolone for the dermatitis and returned 1 week later with symptoms, examination findings, and laboratory results consistent with sepsis and bilateral upper extremity necrotizing soft-tissue infections. After administering multiple irrigation and débridement procedures, hyperbaric oxygen treatments, and an antibiotic regimen, the patient’s status greatly improved. However, the patient returned 1 month later with a new sternoclavicular joint prominence that was associated with painful crepitus. Additionally, he noted that his wrists were gradually becoming more swollen and painful. Imaging studies showed a lytic destruction of the sternoclavicular joint and erosive changes throughout the carpus and radiocarpal joint bilaterally, consistent with osteomyelitis. The patient was treated with ertapenem for 6 weeks, and his polyarthropathy resolved. The patient provided written informed consent for print and electronic publication of this case report.

Case Report

A 73-year-old, right-hand–dominant man with no notable medical history presented to the emergency department for treatment of poison sumac exposure, incidentally, a few days after being bitten by a cat on the bilateral distal upper extremities. He was prescribed a course of oral methylprednisolone for dermatitis. A week later, the patient returned to the emergency department with altered mental status, fevers, diaphoresis, lethargy, and polyarthralgia. At the time of presentation, the patient’s vital signs were labile, and he was found to have extensive bilateral upper extremity erythema, blistering, petechiae, purpuric lesions, and exquisite pain with passive range of motion of his fingers and wrists. His leukocyte count was 25.1 × 10⁹/L, and he had elevated C-reactive protein level and erythrocyte sedimentation rate of 150 mg/L and 120 mm/h, respectively. He was admitted for management of sepsis and presumed bilateral upper extremity necrotizing soft-tissue infection.

Broad-spectrum intravenous (IV) antibiotics (vancomycin, piperacillin, tazobactam) were initiated after blood cultures were obtained, and the patient was taken emergently to the operating theatre for irrigation and débridement of his hands and wrists bilaterally. Arthrotomy of the wrist and débridement of the distal extensor compartment and its tenosynovium were performed on the right forearm, in addition to a decompressive fasciotomy of the left forearm. Postoperatively, the patient’s mental status improved and his vital signs gradually normalized. He received multiple hyperbaric oxygen treatments and underwent several additional operative débridement procedures with eventual closure of his wounds. At initial presentation, the differential diagnosis for the severe soft-tissue infection included necrotizing fasciitis or myositis caused by any of a variety of bacterial pathogens. Most notably, it was important to elicit the history of a cat bite to include and consider Pasteurella multocida as a potential pathogen. Initial cultures supported the diagnosis of acute P multocida necrotizing skin and soft-tissue infection, in addition to septic arthritis. The patient’s blood and intraoperative wound cultures grew P multocida. The antibiotic treatment was tailored initially to ampicillin and sulbactam and then to a final regimen of orally administered ciprofloxacin (750 mg twice a day), once susceptibility testing was performed on the cultures. On hospital day 10, the patient was discharged home, receiving a 6-week course of ciprofloxacin to complete the 8-week course of treatment.

At follow-up, approximately 1 month after discharge, the patient noted that he had developed a new right sternoclavicular joint prominence that was associated with painful crepitus. He also noted that his wrists were gradually becoming more swollen and painful bilaterally. Computed tomography scans of the chest were obtained to evaluate the sternoclavicular joint (Figure 1). Repeat radiographs of the wrists were also obtained (Figure 2). Imaging showed lytic destruction of the sternoclavicular joint and erosive changes throughout the carpus and radiocarpal joint, consistent with osteomyelitis. The C-reactive protein level and erythrocyte sedimentation rate at this time were 34 mg/L and 124 mm/h, respectively.

The patient returned to the operating room for débridement and biopsy of the right sternoclavicular joint and left wrist. This patient’s delayed presentation was characterized by a subacute worsening of isolated musculoskeletal complaints. The differential diagnosis then included infection with the same bacterial pathogen versus reactive or inflammatory arthritis. Several intraoperative cultures failed to grow any bacteria, including P multocida, although P multocida was the presumptive cause of the erosive polyarthropathy, considering that symptoms eventually resolved with a repeated course of IV-administered ertapenem for 6 weeks. The patient experienced complete resolution of his joint pain and swelling. He was able to resume his activities of daily living and had no further recurrence of symptoms at follow-up 3 months later.

Discussion

Cat bites often are the source of Pasteurella species infections because the bacteria are carried by more than 90% of cats.¹ These types of infections can cause septic arthritis, osteomyelitis, and deep subcutaneous and myofascial infections because of the sharp and narrow morphology of cat teeth. The infections can progress to necrotizing fasciitis and myositis if not recognized early, as was the case with our patient. Prophylactic antibiotic administration for animal bites is controversial and is not a universal practice.^1,2Pasteurella bacteremia is an atypical progression that occurs more often in patients with pneumonia, septic arthritis, or meningitis. Cases of Pasteurella sepsis, necrotizing fasciitis, and septic arthritis have been reported.^3-7 However, associated progressive septic arthritis and osteomyelitis, despite initial clinical improvement, have not been reported. Severe infection (ie, sepsis and septic shock) can occur in infants, pregnant women, and other immunocompromised patients.⁷ Immune suppression of our patient with steroid medication for poison sumac dermatitis likely contributed to the progression and systemic spread of an initially benign cat bite. Before prescribing steroids, it is imperative to ask about exposures and encourage patients to seek prompt medical attention with worsening or new symptoms. Healthy individuals rarely develop bacteremia; however, in these cases, mortality remains high at approximately 25%.^4,6

The clinical course of this case emphasizes the need for vigilance and thoroughness in obtaining histories from patients presenting with seemingly benign complaints, especially in vulnerable populations, such as infants, pregnant women, and immunocompromised adults. In this case, the progression of symptoms might have been avoided if the patient’s dermatitis had been treated conservatively or with topical rather than systemic steroids.

THE CASE

A 21-year-old male college student sought care at our urology clinic for a 2-year history of progressive abdominal distention and loss of appetite due to abdominal pressure. On physical examination, his abdomen was distended and tense, but without any tenderness on palpation or any costovertebral angle tenderness. He had no abdominal or flank pain, and wasn’t in acute distress. His blood pressure was normal.

Initial lab test results were significant for elevated creatinine at 2.7 mg/dL (normal: 0.7-1.3 mg/dL) and blood urea nitrogen (BUN) at 31.1 mg/dL (normal: 6-20 mg/dL). Results of a complete blood count (CBC) were within normal ranges, including a white blood cell (WBC) count of 7900, hemoglobin level of 15.1 g/dL, and platelet count of 217,000/mcL. A urinalysis showed only a mild increase in the WBC count.

THE DIAGNOSIS

We performed a computed tomography (CT) scan of the patient’s abdomen, which revealed bilateral hydronephrosis secondary to ureteropelvic junction obstruction (UPJO). The patient’s right kidney was mildly to moderately enlarged, but the left kidney was massive (FIGURE 1A). The hydronephrotic left kidney had extended itself across the midline (FIGURE 1B), pushed the ipsilateral diaphragm upward, and displaced the bladder downward.

The patient underwent right-sided ureteral stent placement for temporary drainage and a complete left-sided nephrectomy. During the surgery, the left kidney was first aspirated, and more than 11,000 cc of clear urine was drained. (Aspiration reduced the kidney size, allowing the surgeon to make a smaller incision.) The removed kidney contained an additional 1200 cc of cloudy residual fluid (FIGURE 2). UPJO was confirmed by the pathological examination of the excised organ.

DISCUSSION

UPJO is the most common etiology for congenital hydronephrosis.¹ Because it can cause little to no pain, hydronephrosis secondary to UPJO can be asymptomatic and may not present until later in life. Frequently, an abdominal mass is the initial clinical presentation.

When the hydronephrotic fluid exceeds 1000 cc, the condition is referred to as giant hydronephrosis.² Although several cases of giant hydronephrosis secondary to UPJO have been reported in the medical literature,^3-5 the volume of the hydronephrotic fluid in these cases rarely exceeded 10,000 cc. We believe our patient may be the most severe case of hydronephrosis secondary to bilateral UPJO, with 12,200 cc of fluid. His condition reached this late stage only because his right kidney retained adequate function.

Diagnosis of hydronephrosis is straightforward with an abdominal ultrasound and/or CT scan. Widespread use of abdominal ultrasound as a screening tool has significantly increased the diagnosis of asymptomatic hydronephrosis, and many cases are secondary to UPJO.⁶ The true incidence of UPJO is unknown, but it is more prevalent in males than in females, and in 10% to 40% of cases, the condition is bilateral.⁷ Congenital UPJO typically results from intrinsic pathology of the ureter. The diseased segment is often fibrotic, strictured, and aperistaltic.⁸

Treatment choice depends on whether renal function can be preserved

Treatment of hydronephrosis is straightforward; when there is little or no salvageable renal function (<10%), a simple nephrectomy is indicated, as was the case for our patient. Nephrectomy can be accomplished by either an open or laparoscopic approach.

When there is salvageable renal function, treatment options include pyeloplasty and pyelotomy. Traditionally, open dismembered pyeloplasty has been the gold standard. However, with advances in endoscopic and laparoscopic techniques, there has been a shift toward minimally invasive procedures. Laparoscopic pyeloplasty—with or without robotic assistance—and endoscopic pyelotomy—with either a percutaneous or retrograde approach—are now typically performed. Ureteral stenting should only be used as a temporary measure.

Our patient. Four weeks after the nephrectomy, our patient underwent a right side pyeloplasty, which was successful. He had an uneventful recovery from both procedures. His renal function stabilized and other than routine follow-up, he required no additional treatment.

THE TAKEAWAY

Most cases of hydronephrosis in young people are due to congenital abnormalities, and UPJO is the leading cause. However, the condition can be asymptomatic and may not present until later in life. Whenever a patient presents with an asymptomatic abdominal mass, hydronephrosis should be part of the differential diagnosis. Treatment options include nephrectomy when there is no salvageable kidney function or pyeloplasty and pyelotomy when some kidney function can be preserved.

THE CASE

A 21-year-old male college student sought care at our urology clinic for a 2-year history of progressive abdominal distention and loss of appetite due to abdominal pressure. On physical examination, his abdomen was distended and tense, but without any tenderness on palpation or any costovertebral angle tenderness. He had no abdominal or flank pain, and wasn’t in acute distress. His blood pressure was normal.

Initial lab test results were significant for elevated creatinine at 2.7 mg/dL (normal: 0.7-1.3 mg/dL) and blood urea nitrogen (BUN) at 31.1 mg/dL (normal: 6-20 mg/dL). Results of a complete blood count (CBC) were within normal ranges, including a white blood cell (WBC) count of 7900, hemoglobin level of 15.1 g/dL, and platelet count of 217,000/mcL. A urinalysis showed only a mild increase in the WBC count.

THE DIAGNOSIS

We performed a computed tomography (CT) scan of the patient’s abdomen, which revealed bilateral hydronephrosis secondary to ureteropelvic junction obstruction (UPJO). The patient’s right kidney was mildly to moderately enlarged, but the left kidney was massive (FIGURE 1A). The hydronephrotic left kidney had extended itself across the midline (FIGURE 1B), pushed the ipsilateral diaphragm upward, and displaced the bladder downward.

The patient underwent right-sided ureteral stent placement for temporary drainage and a complete left-sided nephrectomy. During the surgery, the left kidney was first aspirated, and more than 11,000 cc of clear urine was drained. (Aspiration reduced the kidney size, allowing the surgeon to make a smaller incision.) The removed kidney contained an additional 1200 cc of cloudy residual fluid (FIGURE 2). UPJO was confirmed by the pathological examination of the excised organ.

DISCUSSION

UPJO is the most common etiology for congenital hydronephrosis.¹ Because it can cause little to no pain, hydronephrosis secondary to UPJO can be asymptomatic and may not present until later in life. Frequently, an abdominal mass is the initial clinical presentation.

When the hydronephrotic fluid exceeds 1000 cc, the condition is referred to as giant hydronephrosis.² Although several cases of giant hydronephrosis secondary to UPJO have been reported in the medical literature,^3-5 the volume of the hydronephrotic fluid in these cases rarely exceeded 10,000 cc. We believe our patient may be the most severe case of hydronephrosis secondary to bilateral UPJO, with 12,200 cc of fluid. His condition reached this late stage only because his right kidney retained adequate function.

Diagnosis of hydronephrosis is straightforward with an abdominal ultrasound and/or CT scan. Widespread use of abdominal ultrasound as a screening tool has significantly increased the diagnosis of asymptomatic hydronephrosis, and many cases are secondary to UPJO.⁶ The true incidence of UPJO is unknown, but it is more prevalent in males than in females, and in 10% to 40% of cases, the condition is bilateral.⁷ Congenital UPJO typically results from intrinsic pathology of the ureter. The diseased segment is often fibrotic, strictured, and aperistaltic.⁸

Treatment choice depends on whether renal function can be preserved

Treatment of hydronephrosis is straightforward; when there is little or no salvageable renal function (<10%), a simple nephrectomy is indicated, as was the case for our patient. Nephrectomy can be accomplished by either an open or laparoscopic approach.

When there is salvageable renal function, treatment options include pyeloplasty and pyelotomy. Traditionally, open dismembered pyeloplasty has been the gold standard. However, with advances in endoscopic and laparoscopic techniques, there has been a shift toward minimally invasive procedures. Laparoscopic pyeloplasty—with or without robotic assistance—and endoscopic pyelotomy—with either a percutaneous or retrograde approach—are now typically performed. Ureteral stenting should only be used as a temporary measure.

Our patient. Four weeks after the nephrectomy, our patient underwent a right side pyeloplasty, which was successful. He had an uneventful recovery from both procedures. His renal function stabilized and other than routine follow-up, he required no additional treatment.

THE TAKEAWAY

Most cases of hydronephrosis in young people are due to congenital abnormalities, and UPJO is the leading cause. However, the condition can be asymptomatic and may not present until later in life. Whenever a patient presents with an asymptomatic abdominal mass, hydronephrosis should be part of the differential diagnosis. Treatment options include nephrectomy when there is no salvageable kidney function or pyeloplasty and pyelotomy when some kidney function can be preserved.

THE CASE

A 21-year-old male college student sought care at our urology clinic for a 2-year history of progressive abdominal distention and loss of appetite due to abdominal pressure. On physical examination, his abdomen was distended and tense, but without any tenderness on palpation or any costovertebral angle tenderness. He had no abdominal or flank pain, and wasn’t in acute distress. His blood pressure was normal.

Initial lab test results were significant for elevated creatinine at 2.7 mg/dL (normal: 0.7-1.3 mg/dL) and blood urea nitrogen (BUN) at 31.1 mg/dL (normal: 6-20 mg/dL). Results of a complete blood count (CBC) were within normal ranges, including a white blood cell (WBC) count of 7900, hemoglobin level of 15.1 g/dL, and platelet count of 217,000/mcL. A urinalysis showed only a mild increase in the WBC count.

THE DIAGNOSIS

We performed a computed tomography (CT) scan of the patient’s abdomen, which revealed bilateral hydronephrosis secondary to ureteropelvic junction obstruction (UPJO). The patient’s right kidney was mildly to moderately enlarged, but the left kidney was massive (FIGURE 1A). The hydronephrotic left kidney had extended itself across the midline (FIGURE 1B), pushed the ipsilateral diaphragm upward, and displaced the bladder downward.

The patient underwent right-sided ureteral stent placement for temporary drainage and a complete left-sided nephrectomy. During the surgery, the left kidney was first aspirated, and more than 11,000 cc of clear urine was drained. (Aspiration reduced the kidney size, allowing the surgeon to make a smaller incision.) The removed kidney contained an additional 1200 cc of cloudy residual fluid (FIGURE 2). UPJO was confirmed by the pathological examination of the excised organ.

DISCUSSION

UPJO is the most common etiology for congenital hydronephrosis.¹ Because it can cause little to no pain, hydronephrosis secondary to UPJO can be asymptomatic and may not present until later in life. Frequently, an abdominal mass is the initial clinical presentation.

When the hydronephrotic fluid exceeds 1000 cc, the condition is referred to as giant hydronephrosis.² Although several cases of giant hydronephrosis secondary to UPJO have been reported in the medical literature,^3-5 the volume of the hydronephrotic fluid in these cases rarely exceeded 10,000 cc. We believe our patient may be the most severe case of hydronephrosis secondary to bilateral UPJO, with 12,200 cc of fluid. His condition reached this late stage only because his right kidney retained adequate function.

Diagnosis of hydronephrosis is straightforward with an abdominal ultrasound and/or CT scan. Widespread use of abdominal ultrasound as a screening tool has significantly increased the diagnosis of asymptomatic hydronephrosis, and many cases are secondary to UPJO.⁶ The true incidence of UPJO is unknown, but it is more prevalent in males than in females, and in 10% to 40% of cases, the condition is bilateral.⁷ Congenital UPJO typically results from intrinsic pathology of the ureter. The diseased segment is often fibrotic, strictured, and aperistaltic.⁸

Treatment choice depends on whether renal function can be preserved

Treatment of hydronephrosis is straightforward; when there is little or no salvageable renal function (<10%), a simple nephrectomy is indicated, as was the case for our patient. Nephrectomy can be accomplished by either an open or laparoscopic approach.

When there is salvageable renal function, treatment options include pyeloplasty and pyelotomy. Traditionally, open dismembered pyeloplasty has been the gold standard. However, with advances in endoscopic and laparoscopic techniques, there has been a shift toward minimally invasive procedures. Laparoscopic pyeloplasty—with or without robotic assistance—and endoscopic pyelotomy—with either a percutaneous or retrograde approach—are now typically performed. Ureteral stenting should only be used as a temporary measure.

Our patient. Four weeks after the nephrectomy, our patient underwent a right side pyeloplasty, which was successful. He had an uneventful recovery from both procedures. His renal function stabilized and other than routine follow-up, he required no additional treatment.

THE TAKEAWAY

Most cases of hydronephrosis in young people are due to congenital abnormalities, and UPJO is the leading cause. However, the condition can be asymptomatic and may not present until later in life. Whenever a patient presents with an asymptomatic abdominal mass, hydronephrosis should be part of the differential diagnosis. Treatment options include nephrectomy when there is no salvageable kidney function or pyeloplasty and pyelotomy when some kidney function can be preserved.