A promising thumb Basal joint hemiarthroplasty for treatment of trapeziometacarpal osteoarthritis.

BACKGROUND

Trapeziometacarpal joint osteoarthritis is a painful, disabling condition that primarily affects women who are postmenopausal. Arthroplasty has been performed to treat this condition; however, subluxation has been a problem with all previous implants. We report the results of hemiarthroplasty using a prosthesis designed to address the problems associated with previous implants.

QUESTIONS/PURPOSES: We wished to (1) determine if this prosthesis results in pain relief and functional improvement and preserves the appearance of the thumb, (2) assess the prosthetic reconstruction during followup, (3) assess complications that occur with the use of this prosthesis, and (4) determine the survivorship of this prosthesis.

METHODS

We performed 159 basal joint hemiarthroplasties (138 patients) to treat osteoarthritis of the trapeziometacarpal joint. The mean age of the patients was 63 years, 78% were women, and all had Eaton-Littler Stage II or III changes. Only the damaged articular surfaces of the metacarpal and trapezium were excised; no tendon grafts or transfers were performed. Seven patients (seven thumbs) were lost to followup and seven (nine thumbs) died, leaving 124 patients (143 thumbs) for review. Clinical and radiographic assessments were made preoperatively, 12 weeks postoperatively, and annually thereafter. Minimum followup was 35 months (mean, 72.1 months; range, 35-120 months).

RESULTS

At latest followup, pain relief occurred in 135 thumbs, function improved in 138 thumbs, 139 thumbs were excellent or good in overall assessment, and 142 thumbs had good or excellent cosmetic appearance. The mean tip pinch improved from 4.9 kg preoperatively to 6.44 kg postoperatively. Mean postoperative Buck-Gramcko score was 49 (excellent); overall Kaplan-Meier analysis with revision as the end point showed 94% implant survivorship at a mean followup of 72.1 months.

CONCLUSIONS

Our results are superior to those of other implants and support continued use of this implant. Studies with longer followup are required to confirm these results.

LEVEL OF EVIDENCE

Level IV, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.