International Journal of Orthopaedic Trauma 1994;4: 80 Complete volar dislocation of the proximal interphalangeat joint of the nftle finger F O HASSAN Summary A complete volar dislocation of the proximal inter- phalangeal (PIP) joint of a little finger occurred in a 52- year-old man and was successfully treated by closed reduction and a dynamic PIP extension splint. Case report A 52-year-old male stumbled while descending stairs and fell down on his left hand. Examination revealed flexion of the PlPjoint and extension of the distal interphalangeal joint of the left little finger, with no radial or ulnar deviation of the finger. There was no active movement of the finger, nor neurovascular deficit; an X-ray showed complete dislocation of the PIP joint (Figure 1). Reduction was performed under entonox by traction and extension. The collateral ligaments were stable after reduction, but the joint was unstable in flexion of the finger. A dynamic PIP extension splint with metacarpophalangeal joint support was applied for six weeks, then a night splint for four weeks. Regular follow-up for 14 months showed full range of movement of the finger, no ligamentous laxity, nor any residual deformity. Discussion Volar dislocation of the PlPjoint is a very rare injury compared to the dorsal dislocation. Only L2 cases of this type have been described in the literature,r-s and all were irreducible due to soft tissue interposition or osteochondral fragment. All of the reported cases necessitated open reduction. The mechanism of the injury in our case was hyperflexion force to the middle phalanx, although Spinner and Choi found that a varus or valgus force was necessary to cause the injury.s Figure L Complete volar dislocation of the PIP joint of the little finger. There was no mention in the literature about the reducible volar dislocation of the PIP, apart from the higher incidence of the rupture of the extensor mechanism which needed to be repaired, but this case showed that conservative treatment may have a role. References 1. Johnson FG, Greene MH. Another cause of irreducible dislocation of the PIPJ of a finger. J Bone Joint Surg (Am) 1966; 482 542-4. 2. Inoue G, Maeda N. Irreducible palmar dislocation of the PIP joint of the finger. Report 3 cases. J Hand Surg 1990; 15A: 301-4, 3. Murakami Y. Ireducible volar dislocation of the PIP joint of the finger. Hand 1974; 6: 87-90. 4. Martin AP, Michael W. Irreducible volar dislocation of the PIPJ of a finger caused by interposition of an intact central slip. J Bone Joint Surg (Am) 1978; 60: 133-4. 5. Spinner M, Choi BY. Anterior dislocation of the PIPJ. J Bone Joint Surg (Am) 1970; 52: 1329-36. Department of Orthopaedic Surgery, University of Jordan, Amman, Jordan Mr FO Hassan FRCS (Ene) Correspondence to: Mr FO Hassan FRCS (Eng), Orthopaedic Registrar, Robert Jones and Agnes Hunt Orthopaedic Hospital, Oswestry, Shropshire SYl0 7AG, UK. 80