Early outcome of spherical ceramic trapezial-metacarpal arthroplasty.

Purpose: A retrospective review of 50 ceramic, spherical implants for the treatment of trapezial-metacarpal osteoarthritis in 49 patients assessed clinical and radiographic outcome.

Methods: Thirty-five patients returned for a clinical examination and completed an outcome survey at a mean follow-up of 3 years. A radiographic review was available for all 50 implants with a mean follow-up of 3 years. Average patient age at surgery was 59 years (35 women and 15 men). Twenty-five patients were retired and 24 were regularly employed preoperatively.

Results: Overall satisfaction was between "very satisfied" and "satisfied" for 32 patients, and none were dissatisfied. Twenty-nine patients rated both frequency and severity of pain as "less than before surgery" or "much less than before surgery." Average rating for thumb and hand strength was the "same as before surgery." Thumb pinch strength averaged 40 N (91% that of the opposite thumb). Postoperative thumb opposition was Kapandji stage 8 or better in 34 of 50 thumbs and stage 6 or better in patients who had an interphalangeal joint or metacarpophalangeal joint fusion. All 24 employed patients returned to work, but 2 required substantial modifications of pinch and grasp movements. Implant subsidence occurred in 47 of 50 thumbs, ranging from 1 to 13 mm. Trapezium fractures occurred in 15 thumbs. Eleven additional thumbs showed erosions and cystic changes within the trapezium or metacarpal. There was no evidence of arthritis developing in surrounding joints. In addition to adverse radiographic changes, there were 10 complications in 10 patients, including implant subluxation in 7 patients.

Conclusions: Although most patients were satisfied with their function and pain relief, adverse radiographic findings were nearly universal. Implant subsidence, especially into the trapezium, was often severe, with some resulting in a trapezium fracture. Based on the radiographic outcome at this medium-term follow-up, we no longer use this implant.

Type Of Study/level Of Evidence: Therapeutic IV.