Locked Metacarpophalangeal Joint of the Little Finger in Extension Position due to the Incarceration of a Chronic Fracture Fragment: A Case Report.

We managed a case of locked metacarpophalangeal joint of the little finger in the extension position. Incarceration of a chronic osteochondral fracture fragment led to this unique condition. The fracture fragment partially adhered to the volar plate and ulnar collateral ligament on the joint side, which is supposed to have resulted in manually irreducible locking of the joint. We performed open reduction and achieved release of the locked joint by excising the fracture fragment.