Joint Survival Analysis and Clinical Outcome of Total Joint Arthroplasties With the ARPE Implant in the Treatment of Trapeziometacarpal Osteoarthritis With a Minimal Follow-Up of 5 Years

Purpose: The ARPE joint arthroplasty was introduced in 1991 for the treatment of symptomatic trapeziometacarpal (TMC) osteoarthritis. The primary outcome of this prospective study is to report the medium- to long-term joint survival of this prosthesis. Our secondary outcomes are the clinical and functional results.

Methods: A prospective, consecutive case series study was done at our hand unit. Patients included in the study had at least 5 years follow-up after a total joint arthroplasty for osteoarthritis of the TMC joint using the ARPE implant. The Kaplan-Meier method was used to estimate implant survival over time. Clinical and radiological assessment was recorded prospectively: before surgery and at 1 year and 5 years or more after surgery. We compared the means of the Kapandji index (assessing the thumb range of motion and opposition), the grip strength, and the pinch strength before surgery and at the latest follow-up.

Results: We included all 166 prostheses in the survival analysis with a mean follow-up of 80 months. Five prostheses (3%) required revision surgery and 1 implant (0.6%) failed. Therefore, Kaplan-Meier survival probability was 96% with a mean follow-up of 80 months (95% confidence interval, 91-98). A total of 120 arthroplasties from 115 patients were included in the clinical analysis. At 5 years' follow-up, the median Disabilities of the Arm, Shoulder, and Hand (DASH) score was 4.6 (range, 0-86.6). There was a significant improvement of the mean opposition and grip strength of the affected thumb at final follow-up in comparison with the preoperative values. There was also a significant improvement in the mean pinch strength at 1 year and 5 years after surgery compared with preoperative measurements.

Conclusions: In our series, the ARPE prosthesis of the thumb TMC joint has proven to be a reliable and effective implant. Mean motion and strength increased whereas pain decreased after surgery and these results remained constant within the follow-up period.

Type of study/level of evidence: Therapeutic IV.