Outcome of uncemented trapeziometacarpal prosthesis for treatment of thumb carpometacarpal joint arthritis.

BACKGROUND: Osteoarthritis of the trapeziometacarpal joint of thumb occurs frequently and can be very disabling. Numerous surgical techniques including trapeziectomy with or without tendon interposition arthrodesis and partial or total joint arthroplasty with cemented and noncemented prosthesis have been described for the treatment of trapeziometacarpal joint osteoarthritis. Initial problems of osteolysis and implant loosening have been substantially reduced with improvement in implant design. The aim of this study is to demonstrate that trapeziometacarpal osteoarthritis of the thumb can be effectively treated with uncemented total joint replacement prosthesis.

MATERIALS AND METHODS: We retrospectively collected data for 16 trapeziometacarpal joint replacements in 14 patients. One patient was excluded as they required revision with trapeziectomy and ligament reconstruction following fracture of Trapezium. The trapeziometacarpal joint prosthesis was used in all cases and all operations were carried out by one surgeon. Clinical outcome was determined by a pre and postoperative patient rated wrist evaluation (PRWE) and Michigan Hand Questionnaire Score. Range of motion, grip, tip pinch and key pinch strength were measured and compared with the unoperated hand. Radiological assessment was carried out by plain radiographs for preoperative staging of arthritis and postoperative radiographs at latest followup for evaluation of osteolysis and implant loosening. Average followup period was 26 months.

RESULTS: There was an improvement in hand function and pain level based on PRWE and Mischigan Hand outcome Questionnaire Score. One patient had intraoperative fracture of Trapezium and subsequent radiographs at 14 months followup showed loosening of the trapezial component due to nonunion of the fracture and complete disintegration of the trapezium. There were no cases of dislocation or implant loosening for the remaining 15 CMC joints at the latest followup.

CONCLUSION: The use of uncemented prosthesis in treatment of Questionnaire Score. Range of motion joint osteoarthritis gives excellent short term results in improving hand function in terms of strength and stability and achieving pain relief.