ACUTE TRAUMATIC DISLOCATION OF THE TRAPEZ IO-METACARPAL JOINT - REVIEW OF 8 CASES

Purpose of the study Eight cases of acute traumatic dislocation of the trapezio-metacarpal joint treated by percutaneous pinning without lig amentoplasty are reported in order to evaluate this method. Material E ight patients, two women aged 32 to 38 and six men aged 17 to 43, were treated for acute traumatic dislocation of the trapezio-metacarpal jo int between 1986 and 1943. The injury happened in a road traffic accid ent in five cases, during a fight in one case, and in a fall in two ca ses, The mechanism of injury could be determined only twice as a longi tudinal force applied on the first metacarpal bone with the trapeziome tacarpal joint in flexion. The dominent hand was injured in five cases . The metacarpal base was always dislocated dorsally. Closed reduction was always easy but remained unstable. On the initial radiographs, on e patient had a small fragment avulsed from the volar aspect of the me tacarpal base, another had a small osteochondral fragment avulsed from the joint surfaces and two patients presented asymptomatic degenerati ve changes with osteophytes. Methods All patients were treated on the day of injury by reduction and stabilization by one (in four cases) or two (in tour cases) percutaneous Kirchner wires followed by a scaphoi d-type cast for six weeks. In only one case an arthrotomy was performe d to remove a small osteochondral fragment lodged in the joint, and sh owed a disruption of the dorsal ligament. All patients were followed-u p until the tenth postoperative week, and five of them were reviewed f or this study between eight and seventy-eight months (mean 27,5 months ) after injury, Enquiries were made about return to work, pain, stabil ity, and range of motion, key-pinch and grasp compared with the uninju red side. The joint was examined radiographically with particular atte ntion to the presence of subluxation and degenerative changes. Results One patient with a dislocation of the five carpometacarpal joints had reflex algodystrophy; she was not seen for review. Five patients had a completely satisfactory early result at ten week's follow-up examina tion that maintained at late review for this study. There were no symp toms, no subluxations on the radiographs, and the patients had returne d to work between ten to sixteen weeks (mean 11 weeks) post injury. Th e two patients with degenerative changes on the initial radiographs ha d early unsatisfactory results with early dorsal subluxation, loss of strength of 30 per cent, but no limitation of joint motion and pain in one case. Discussion Acute traumatic dislocation of the trapezio-meta carpal joint is an uncommon injury; it may be associated with a small fragment of bone avulsed from the volar aspect of the metacarpal base or from the articular surfaces. Pequignot and cell. in 1988, and Fonte s in 1992 recommended opened reduction and ligamentous reconstruction in acute injuries. Our experience indicates that closed reduction foll owed by stabilization by percutaneous pinning gives satisfactory resul ts. An arthrotomy may be necessary when an osteochondral fragment avul sed causes incoercibility. Conclusion Closed reduction followed by sta bilization by percutaneous pinning gives good results in the treatment of acute traumatic dislocation of the trapezio-metacarpal joint. it f inds its limits with patients with degenerative changes on the initial radiographs, and in this case ligamentous reconstruction, arthrodesis or arthroplasty might be advocated.