Objective functional outcomes and patient satisfaction after silicone metacarpophalangeal arthroplasty for rheumatoid arthritis

Abstract

Purpose: Patient satisfaction is an essential measure of quality of care for rheumatoid arthritis. Prior research demonstrates that patient satisfaction improves after silicone metacarpophalangeal arthroplasty (SMPA) despite minimal change in hand function. The purpose of this study was to identify the level of objective functional recovery that yields satisfaction after SMPA. We hypothesized that measurable gains in objective hand function after SMPA will discriminate between satisfied and dissatisfied patients.

Methods: In this prospective, multicenter, cohort study, we observed 46 patients with rheumatoid arthritis and metacarpophalangeal (MCP) joint subluxation for 2 years after reconstructive surgery. We derived satisfaction scores from the Michigan Hand Outcomes Questionnaire, ranging from 0 (least satisfied) to 100 (most satisfied), and dichotomized them using the Cohen large effect size. We measured hand function at baseline and follow-up including strength (grip strength and pinch strength), finger position (extensor lag and ulnar drift), and MCP arc of motion. We constructed receiver operating characteristic curves to identify optimal cutoffs in hand function that correspond with satisfaction.

Results: At 2 years of follow-up, patients who achieved an extension lag of 30° or less were considered satisfied, which represented a 52% improvement (preoperative lag = 63°). Similarly, patients who gained improvement in ulnar drift from an average of preoperatively 62° to 9° postoperatively were satisfied. Finally, patients who achieved an improvement in MCP arc of motion from an average of 21° to 31° postoperatively were satisfied. No improvements in grip or pinch strength corresponded with postoperative patient satisfaction.

Conclusions: Patients were satisfied with only modest gains in grip and pinch strength after silicone metacarpophalangeal arthroplasty. However, maintaining finger position, without recurrence of ulnar drift or extensor lag, and MCP arc of motion corresponded with patient satisfaction in the postoperative period.

Type of study/level of evidence: Therapeutic II.