Scaphotrapezoid arthritis: prevalence in thumbs undergoing trapezium excision arthroplasty and efficacy of proximal trapezoid excision.

Between June 1995 and May 1998, 37 patients underwent trapezium excision arthroplasty. Preoperative radiographic assessment for scaphotrapezoid arthritis was performed. At the time of surgery intraoperative inspection of the scaphotrapezoid joint allowed calculation of the true prevalence of arthritis as well as sensitivity and specificity of the radiographic diagnosis. The true prevalence of scaphotrapezoid arthritis was 62%. The sensitivity of the radiographic diagnosis was 44% and the specificity was 86%. Comparison of surgical results in 23 patients who underwent both trapezium excision arthroplasty and proximal trapezoid excision, with 14 patients who underwent the former procedure, only showed that there was no morbidity associated with the latter. Because of the potential that scaphotrapezoid arthritis may cause residual symptoms following trapezium excision arthroplasty, and in light of the low sensitivity of radiographs, routine intraoperative assessment of the joint is recommended so that proximal trapezoid excision can be performed if degenerative change is present.