Presentation
Fourth finger deformity.
Patient Data
Dorsal dislocation of the ring finger proximal interphalangeal joint. No fracture identified.
Finger splint. Persistent dorsal dislocation of the fourth finger proximal interphalangeal joint.
Dorsal dislocation of the proximal interphalangeal joint with mild marrow edema signal and low T1 signal at the middle phalangeal base. Generalized soft tissue swelling and edema of the fourth finger. Edema of the radial and ulnar collateral ligaments. The volar plate is avulsed from the middle phalanx volar lip and is retracted to the volar aspect of the proximal phalangeal neck. Extensor tendon, in particular the central slip, is intact. Flexor tendon is intact with no "buttonhole-ing" of the proximal phalangeal head.
Case Discussion
No clear structural abnormality preventing reduction was identified on the pre-operative MRI. The patient proceeded to open reduction with the volar plate avulsion confirmed, complete radial collateral ligament tear, 30% osteochondral fracture of the middle phalangeal base. Intra-operatively, it was unclear why the joint could not be reduced and reduction was transient. The patient underwent volar plate and collateral ligament repairs with a K-wire used to hold the reduction.