Rotatory subluxation of the proximal interphalangeal joint: an easily missed diagnosis.

We present a case of volar rotatory subluxation of index finger proximal interphalangeal joint (PIPJ) following a skiing accident. The injury was initially perceived to be a central slip rupture and treatment was directed as such. After the initial delay in the diagnosis, the patient underwent surgery during which his radial collateral ligament was found to be avulsed from the proximal origin, the radial lateral band palmarly subluxed and was interposed in the joint space. This structure was also adhered to the uninjured volar plate.PIPJ volar rotatory subluxation could be readily missed in the acute setting. Without surgery, the functional outcome could be mediocre and to the patient's detriment.