Vertical locking of the metacarpophalangeal joint in young adults

Locking of the metacarpophalangeal joint: A comprehensive review of the literature

Locked metacarpophalangeal joint is an uncommon phenomenon with many possible etiologies. Diagnosis can be difficult because of the many more common pathologies (trigger finger, sagittal band lesion, etc.) that can lead to a clinical picture that may resemble the locked metacarpophalangeal joint. Once the differential diagnoses have been eliminated, the etiology of this blockage must be determined and the surgical procedure must be oriented. The origin of the problem is often difficult to determine, especially since standard imaging tests are often not very informative. Several clinical forms are possible, with blockages in extension or flexion, but which will have a disabling functional impact on the overall function of the hand. Currently, there is no gold standard for the management of this condition. In this study, we performed a review of the literature in order to better understand the different possible etiologies but also to analyze the different diagnostic and therapeutic management. LEVEL OF EVIDENCE: IV.

Type I locking of the metacarpophalangeal joint: A case report

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The locked metacarpophalangeal joint is rare.

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We present an unusual case with impingement to the sesamoid.

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Differential diagnosis and management are discussed.

Introduction

Type I locking of the metacarpophalangeal joint (MCPJ) is rare and is characterized by loss of extension at the MCPJ with full flexion of all joints of the digit. The condition is usually seen in the index and middle fingers when the normal osseous prominence or degenerative osteophytes of the radial condyle of the metacarpal head catches the accessory collateral ligaments of the MCPJ.

Presentation of case

We report on a case of Type I locking of the MCPJ affecting the index finger. The case was unusual because it might have been related to repeated stress while opening caps of specimen bottles in the laboratory. Furthermore, the impingement of the radial condyle of the metacarpal was to the sesamoid bone, and not to the collateral ligaments of the MCPJ. Finally, management was done by excision of the sesamoid bone rather than trimming of the prominence of the radial condyle of the metacarpals head.

Discussion

Locking of the metacarpophalangeal joint (MCPJ) should be viewed as two different entities: The “locked MCPJ with further flexion possible” (Type I locking) and the “locked MCPJ with further flexion not possible” (Type II locking). Once the type of MCPJ locking is diagnosed clinically, radiological testing (X-rays, CT scan, MRI) may be done to direct further management to the cause of locking.

Conclusion

We present an unusual case of Type I locking of the MCPJ affecting the index finger.

Ligament preserving technique for a locked metacarpophalangeal joint of the index finger

BACKGROUND

Locking of metacarpophalangeal joint (MPJ) of the index finger occurs when volar radial osteophytes of the metacarpal head catch the accessory collateral ligament. We devised a ligament-preserving approach to quickly restore the MPJ motion while protecting the radial collateral ligament.

METHODS

We retrospectively reviewed the results of nine patients treated for a locked MPJ of the index finger. In three patients, closed reduction was successful. In six cases, volar radial osteophytes were excised from the metacarpal head using a ligament-preserving technique through a longitudinal incision on the radial side. We analyzed osteophyte shape and height as demonstrated by X-ray and computed tomography (CT). Function was evaluated by examining the range of motion, recurrence, Disabilities of the Arm, Shoulder and Hand (DASH) score, and MPJ stability based on the key pinch strength. One male and eight female patients were followed for an average of 33 months (range, 12 to 65 months); the average age of patients was 41 years (range, 34 to 47 years). The average duration of locking of the MPJ was 23 days (range, 1 to 53 days).

RESULTS

The sharp type of osteophytes was identified in six patients and the blunt type of osteophytes was indentified in three patients. The average height of radial osteophytes on the index finger metacarpal was 4.6 ± 0.4 mm in the axial CT image. At the final follow-up, the average extension limitation decreased from 26° (range, 10° to 45°) to 0°, and further flexion increased from 83° (range, 80° to 90°) to 86°. There was no recurrent locking after surgery. The DASH score improved from 24.3 to 7.2. Key pinch strength improved from 67.3% to 90.4%.

CONCLUSIONS

We obtained satisfactory outcomes in irreducible locking of the MPJ of the index finger by excising volar radial osteophytes of the metacarpal head using a ligament-preserving approach.