Volar Tilt as a Predictor in Dorsal Proximal Interphalangeal Joint Fracture-Dislocations.

Abstract

Background: Restoring the volar lip of the middle phalanx is key to regaining concentric joint gliding after dorsal proximal interphalangeal (PIP) joint fracture-dislocations, but no reliable radiographic assessment currently exists. This study introduces volar tilt as a new radiographic measure. Methods: We evaluated 27 dorsal PIP fracture-dislocations in 25 patients, analysing clinical outcomes, osteoarthritis (OA) and volar tilt on lateral radiographs at injury, after extension block pinning and at 16-year follow-up. Results: Initial volar tilt averaged 22°, improving to 12° after extension block pinning and 9° at follow-up, while adjacent uninjured fingers averaged -2°. Increased residual volar tilt was associated with pain and volar tilt ≥10° revealed significantly poorer Patient-Rated Wrist/Hand Evaluation scores and increased radiographic OA. Conclusions: Volar tilt reflects subluxation in both acute and chronic dorsal PIP joint fracture-dislocations and predicts better long-term outcomes and less radiological OA when properly restored. Level of Evidence: Level IV (Therapeutic).