The outcome of silicone metacarpophalangeal (MCP) joint implant arthroplasty in the osteoarthritic patient population has not been well established. Typically patients with idiopathic osteoarthritis have no history of underlying systemic disease and may respond well to treatment with MCP joint implant arthroplasty. This study examined the efficacy of silicone MCP joint implant arthroplasty for patients with idiopathic osteoarthritis for whom nonsurgical treatment had failed.
Of 14 patients (15 arthroplasties) who had silicone MCP joint implant arthroplasty for idiopathic osteoarthritis 12 (13 arthroplasties) returned for follow-up evaluation at an average of 40 months after surgery. There were 9 index finger and 4 middle finger arthroplasties. The average age at the time of surgery was 62 years. Patients completed a subjective questionnaire and were examined by a certified therapist. Range of motion and strength were recorded and the Jebsen-Taylor examination was administered to assess function. Range of motion values at final follow-up evaluation were compared with preoperative and early postoperative values. Radiographs were taken at final follow-up evaluation and compared with preoperative and early postoperative films to assess joint position, wear, and radioulnar alignment.
At final follow-up evaluation excellent (9 patients) and good (3 patients) overall improvement were reported. Nine patients (10 implants) reported greater than 75% functional improvement. A notable increase was seen in MCP joint flexion. Grip and lateral pinch strengths were below age-matched normative data. Of the 11 patients (12 implants) who came in for follow-up evaluation 7 performed all tasks of the Jebsen-Taylor examination within the allotted time. At final follow-up evaluation all silicone implants were located and showed no signs of subluxation. Radiographic radioulnar alignment was maintained. One implant was revised at 35 months secondary to fracture.
Silicone implant arthroplasty is a motion-sparing procedure that provides good pain relief and maintenance of function at intermediate follow-up evaluation in patients with idiopathic osteoarthritis of the MCP joint.