Bilateral Locking of the Metacarpophalangeal Joint: A Case Report and Systematic Literature Review

Background The purposes of this article were to present an exemplary case of bilateral locked metacarpophalangeal (MCP) joint of the second metacarpal and to review the literature for a more comprehensive understanding of this condition. Methods For the literature review, PubMed and Google Scholar research were performed using the term "metacarpophalangeal joint (MCP joint) locking or locked metacarpophalangeal joint (MCP Joint)" with a set of inclusion and exclusion criteria. Results We recently treated a patient with bilateral locked MCP, which presented to our office on 2 separate occasions in the space of 3 years. The left hand was affected in 2015 and the right hand in 2018. After clinical and imaging investigations, the patient was operated on. The patient had a locking of the accessory collateral ligament behind a radial sided prominence of the second metacarpal head. After surgery, the patient regained full function of her index finger. On the basis of our literature review, we found 47 cases described in the literature, plus our case, the index finger (22), and the long finger (11) were most commonly involved. Conclusion Left untreated, the locked MCP joint may lead to a flexion contracture and disabilities in performing daily life activities. The diagnosis is mainly clinical. The radiographs can show degenerative changes or a particular shape of the metacarpal head/neck as a first clue to the possible cause. Gentle closed reduction can be attempted, but surgery is most often required. The surgical approach depends on the presumed localization of the pathology.