Patient-Reported Outcomes 1 Year After Proximal Interphalangeal Joint Arthroplasty for Osteoarthritis

Abstract

Purpose: Implant survival, range of motion, and complications of proximal interphalangeal joint arthroplasty have been reported often, but patient-reported outcomes are less frequently described. This study evaluated patients' experiences during the first year after proximal interphalangeal joint arthroplasty, measured with the Michigan Hand Outcomes Questionnaire (MHQ). The primary focus was the reduction of patient-reported pain after proximal interphalangeal joint implant placement and the percentage of patients who considered this reduction clinically relevant, indicated by the minimal clinically important difference (MCID).

Methods: Data were collected prospectively; 98 patients completed the MHQ before and at 3 and 12 months after surgery. Our primary outcome was the change in the pain score. An increase of 24 points or more was considered a clinically important difference. Secondary outcomes included changes in MHQ total and subscale scores and MCIDs, range of motion (ROM), patient satisfaction with the outcome of the surgery, and complications.

Results: The pain score improved significantly, from 42 (95% confidence interval, 38-46) at baseline to 65 (95% confidence interval, 60-69) at 12 months after surgery. The MCID was reached by 50% (n = 49) of patients. The ROM did not improve, reoperations occurred in 13% (n = 13) of patients, and swan neck deformities only occurred among surface replacement implants.

Conclusions: Although most patients undergoing arthroplasty for osteoarthritis experienced significantly less pain after surgery, the pain reduction was considered clinically relevant in only 50% (n = 49) of patients. Patients with high MHQ pain scores before surgery are at risk for postoperative pain reduction that will not be clinically relevant. Likewise, the other subscales of the MHQ improved after surgery, but reached a clinically relevant improvement in only 46% (n = 45) to 63% (n = 62) of patients. This knowledge can be used during preoperative consultation to improve shared decision making.

Type of study/level of evidence: Prognostic IV.

Keywords: Arthroplasty; MHQ; PIP; PROM; osteoarthritis.