Hyperextension injuries of the MP joint of the thumb

Locking of the Metacarpophalangeal Joint of the Thumb Caused by Entrapment of the Radial Sesamoid Bone

Locking of metacarpophalangeal (MCP) joints of the thumb may be a consequence of dorsal subluxation from hyperextension injury. The joint is locked in mild hyperextension and cannot flex actively or passively. We report four patients with locked MCP joint of the thumb due to radial sesamoid entrapment after hyperextension or forced flexion injury. All patients had a prominent radial condyle of the metacarpal bone. Three patients had a deformity of the longitudinal groove on which the sesamoid was overlaid. The radial sesamoid was entrapped proximal to the radial condyle which could result in limited extension and hinged flexion of the joint. Excision of the radial sesamoid could release the locked joint. The radial sesamoid should be assessed if the motion of the thumb MCP joint is limited after flexion or extension injury.

Level of Evidence: Level V (Therapeutic)

Thumb metacarpophalangeal joint palmar plate chronic avulsion in children: diagnosis and treatment

INTRODUCTION

Thumb metacarpophalangeal joint instability can have a considerable functional impairment. Acute injuries are usually overlooked in children due to the high pain threshold and the presence of ligamentous laxity. Chronicity of the injury results in failure of conservative treatment. Literature is poor in defining such injuries. The purpose of our study is to determine the clinical and radiological tools for the diagnosis of metacarpophalangeal joint instability and we propose a simple surgical technique for their management.

METHODS

From 2015 till 2019, we present a case series of four patients with chronic post-traumatic thumb metacarpophalangeal joint instability. Patients were assessed for palmar plate avulsion clinically and radiologically using plain X-ray and sonography. Surgical repair through a palmar approach with direct repair of the palmar plate was done in all patients. Patient demographics, complications, and clinical outcomes were recorded.

RESULTS

Mean follow-up was 22.5 months. At the latest follow-up the metacarpophalangeal joint was stable in all patients. They were all pain free except one patient suffered from temporary pain at the dorsum of the metacarpal due to prominence of the suture anchor, which disappeared at 1-year follow-up. They had improvement in pinch strength. Full range of motion was obtained and all the patients have returned to full activity without limitations.

CONCLUSION

Chronic post-traumatic thumb metacarpophalangeal joint instability results in functional impairment. Clinical suspicion and sonographic assessment can verify the diagnosis. Surgical repair with transosseous sutures or anchors yields satisfactory results in the paediatric age group with the preservation of normal range of motion.

Fracture of the ulnar sesamoid bone of the thumb with a concurrent ulnar collateral ligament tear: A case report

While the ulnar sesamoid bone of the thumb and the ulnar collateral ligament (UCL) are in close anatomic proximity, concurrent injury to these structures has not been reported. We report a case of such an injury in a 53-year-old male after an altercation. He was treated with surgical repair of the UCL, postoperative immobilization, and a graduated rehabilitation program consisting of range of motion and strengthening exercises. After review of the literature, we recommend that clinicians consider not just a volar plate injury, but also a UCL injury, in patients presenting with radiographic evidence of a sesamoid fracture. Clinicians should have a low threshold for advanced imaging in these patients to confirm any suspected ligamentous injury.

Fracture of the Sesamoid Bone of the Thumb: A Case Report and Review of the Literature

CASE

Fracture of a sesamoid bone of the thumb is rare. We report a case of such a fracture after hyperextension of the thumb in a 26-year-old woman. After a volar plate injury was excluded, she was treated nonoperatively with 5 weeks of immobilization followed by physical therapy.

CONCLUSION

After reviewing the current literature describing sesamoid fractures of the thumb, we recommend that fracture of the sesamoid of the metacarpophalangeal (MCP) joint should be regarded as an avulsion fracture. The role of surgical intervention should be limited to patients with a painful nonunion.

Vertical locking of the metacarpophalangeal joint of the little finger: A case report

Locking of the metacarpophalangeal (MCP) joint is commonly caused by hyperextension of the thumb or moderate flexion of the index or middle finger. We report a rare case of vertical locking of the MCP joint of the little finger in a 16-year old female after blunt trauma to the little finger. The MCP joint was locked when positioned at approximately 90-degree-flexion and could not extend actively or passively. A manual reduction was easily achieved and no immobilization was applied. Vertical locking of the MCP joint can be easily reduced, and immobilization is unnecessary after reduction. Correct diagnosis prior to reduction and differentiation from other types of locking are essential to prevent overtreatment.

Locking of the Metacarpophalangeal Joint of the Thumb Caused by a Fracture Fragment of the Radial Condyle of the Metacarpal Head after Dorsal Dislocation

We report a case of a locked thumb metacarpophalangeal joint secondary to metacarpal head fracture. As fractures of the radial condyle are not readily seen in routine X-rays, other imaging modalities, including CT, should be considered if the patient complains of limited extension after hyperextension injury of the thumb.

Pathoanatomy and treatment modifications of metacarpophalangeal joint locking of the thumb

Ten patients with metacarpophalangeal joint locking of the thumb were studied. Three of them underwent surgical release. During surgery, it was found that the radial sesamoid was seated in a cartilage defect on the volar aspect of the metacarpal head. It appeared that the defect was created by the proximal edge of sesamoid. When the abductor pollicis brevis and flexor pollicis brevis muscles were partially detached from their insertion at the base of the proximal phalanx, the locking could be successfully released. We hypothesize the mechanism of the metacarpophalangeal joint locking of the thumb in our cases was a hyperextension injury that displaced the radial sesamoid distally and radially. In turn, the sesamoid's pointed proximal edge wore a groove in the cartilage on the metacarpal head, and under abductor pollicis brevis and flexor pollicis brevis tension, the radial sesamoid was locked into the cartilage defect; thereby causing locking of the joint.

SESAMOIDECTOMY AND VOLAR PLATE REPAIR USING SUTURE ANCHOR FOR HYPEREXTENSION INJURY OF THE METACARPOPHALANGEAL JOINT OF THE THUMB

A retrospective study for the combination of suture anchor and selective sesamoidectomy for treating volar instability of the metacarpophalangeal joint (MCPJ) of the thumb. Eleven patients with hyperextension of the MCPJ of the thumb underwent volar plate repair using a volar or voloradial approach. All the patients were reviewed radiologically and clinically using both objective and subjective criteria. The patients presented with sesamoid fractures (n = 2), sesamoid subluxation (n = 1), isolated volar plate laxity (n = 4), isolated sesamoid fracture (n = 4), and metacarpal condyle fracture (n = 2). The inner intersesamoid distance was 4.6 mm and the outer intersesamoid distance was 14.2 mm. The Disabilities of the Arm Shoulder and Hand and Michigan Hand Outcomes Questionnaire scores showed improvement. Volar plate repair using a suture anchor and selective sesamoidectomy is effective with regard to pain relief and stabilisation of volar instability of the thumb.

Volar A1 pulley sparing technique for fixation of avulsion fractures of the base of the proximal phalanx

For open reduction and internal fixation of the displaced avulsion fractures of the base of the proximal phalanx of the fingers, the volar A1 pulley approach was introduced instead of the dorsal approach. Although this procedure is quite useful, the A1 pulley and volar plate need to be divided. As a less invasive alternative, the authors developed the volar A1 pulley sparing technique and treated six patients with the median follow-up period of 14 months. All fractures healed without displacement, and all patients regained full range of motion without any evidence of instability. The volar A1 pulley sparing technique is minimally invasive and provides good visualization of the fracture site without damage to the metacarpophalangeal joint and flexor tendon structure.

Locking of the metacarpophalangeal joint of the thumb with the radial collateral ligament rupture after stress radiography

Stress test is a commonly used diagnostic examination to evaluate the radial collateral ligament (RCL) tear of the thumb metacarpophalangeal (MCP) joint to indicate the surgical intervention. We experienced a locked MCP joint after stress test in a patient with the RCL and volar plate injury.

A split-EPB tendon sling for chronic post-traumatic palmar instability of the thumb metacarpophalangeal joint

Kessler's extensor pollicis brevis (EPB) palmar tendon sling is a simple and reliable reconstruction for symptomatic palmar instability of the thumb metacarpophalangeal (MP) joint. However, we encountered subluxation of the extensor pollicis longus tendon and extension lag at the MP joint when the entire tendon was used. We modified the technique, splitting the tendon to preserve its function as an MP joint extensor. Six thumb MP joints with anteroposterior instability secondary to hyperextension injury were reconstructed using the split-EPB technique. At an average of 22 months postoperatively, all patients had stable and pain-free MP joints. Pinch strength improved an average of 5.6 kg. MP joint flexion was decreased an average of 17.5 degrees and two patients had flexion contractures of 5 degrees and 20 degrees, respectively. Extensor pollicis longus subluxation and MP extension lag did not occur, and there were no recurrences.

Metacarpophalangeal joint dislocation of the thumb in children

There are few reports describing dislocation of the metacarpophalangeal joint of the thumb in children. This study describes the clinical features and outcome of 37 such dislocations and correlates the radiological pattern with the type of dislocation. The mean age at injury was 7.3 years (3 to 13). A total of 33 children underwent closed reduction (11 under general anaesthesia). Four needed open reduction in two of which there was soft-tissue interposition. All cases obtained a good result. There was no infection, recurrent dislocation or significant stiffness. So-called 'simple complete' dislocations that present with the classic radiological finding of the joint at 90 degrees dorsal angulation may be 'complex complete' injuries and require open reduction.

Prolonged use of electronic games--a word of caution

Post-traumatic hyperextension deformity of the thumb due to rupture of volar plate is a rare but clinically important phenomenon. These injuries are usually related to ball sports like basketball and handball. However, we describe an unusual association in an elderly patient with chronic use of an electronic game, which merits a high index of suspicion for early diagnosis and treatment to prevent long-term complications.

Volar A1 pulley approach for fixation of avulsion fractures of the base of the proximal phalanx

Avulsion fractures of the base of the proximal phalanx associated with collateral ligament instability, excluding the thumb, are relatively rare. While the indications for surgical intervention vary, dorsal approaches have been advocated despite the volar location of the fracture fragment and orientation of the collateral ligaments. Ten patients with 11 avulsion fractures at the base of the proximal phalanx associated with collateral ligament instability were treated with open reduction and internal fixation using a volar A1 pulley approach. Anatomic restoration of the articular surface and collateral ligament stability were obtained in all patients. All fractures healed between 5 and 9 weeks (average, 6 weeks). After an average 19.4-month follow-up period all patients had full range of motion of the metacarpophalangeal joint, collateral ligament stability, and grip strength of at least 90% of the uninjured hand. No perioperative complications occurred. The average DASH score at last follow-up examination was 1.8 (range, 0-6). All patients were satisfied with the outcome of surgery. The volar A1 pulley approach is a direct and effective approach for reduction and fixation of avulsion fractures of the base of the proximal phalanx associated with collateral ligament instability.