Use of Mini TightRope® for Delayed Presentation of a Fifth Carpometacarpal Joint Dislocation

Introduction: Isolated dislocations of the fifth carpometacarpal joint (CMCJ) are uncommon injuries of the hand that is often missed but can be diagnosed correctly with a high index of suspicion and adequate imaging. Treatment for chronic cases is usually open reduction with temporary fixation using Kirschner wires, but for this case, we used Mini TightRope® as well to allow for early finger exercise. The case presented here is unique because of a delayed dislocation of a CMCJ detected 9 weeks from initial injury which was treated with a novel form of fixation with Mini TightRope®. Case Report: A 70-year-old, right-hand dominant, male farmer injured his left hand when he slipped and fell on a concrete surface, landing on the ulnar side of his left hand. He was immediately seen in the clinic, just with a swollen left hand but no obvious deformity and with apparently normal PA and oblique radiographs of the hand. Nine weeks later, he came back due to persistent ulnar-sided hand pain; repeat radiographs and a CT scan of the left hand showed ulno-palmar dislocation of the fifth CMCJ. He then underwent trial closed reduction of the 5th CMCJ dislocation but failed. Open reduction, temporary K-wire fixation, and fixation using Mini TightRope® through the 4th and 5th metacarpals were done. A full range of motion of the hand was allowed immediately post-operative. Reduction was maintained and no complications were noted on subsequent follow-up visits. Conclusion: This paper presents a brief literature review on 5th CMCJ dislocation, discussing the anatomic considerations contributing to joint stability, helpful radiographic parameters for diagnosis, and enumeration of treatment options. Keywords: Fifth carpometacarpal joint, dislocation, reduction, mini tightrope, internal fixation