Effect of Tendon Strip (FCR vs APL) on Outcome of CMC Thumb Joint Arthroplasty With Pyrocarbon Disk Interposition.

BACKGROUND: Pyrocarbon disk interposition for carpometacarpal (CMC) thumb joint osteoarthritis can be performed with a flexor carpi radialis (FCR) or abductor pollicis longus (APL) tendon strip. With the FCR technique, a ligament reconstruction is performed in addition to disk fixation, whereas with the APL technique the disk is simply secured in place. Our aim is to compare long-term postoperative outcomes between both techniques. METHODS: In this observational study, we included 106 patients in 2 centers operated on between 2006 and 2011. We assigned patients to the FCR group or the APL group based on the respective tendon strip used. As a primary outcome, we analyzed postoperative key pinch. In addition, we analyzed postoperative tip pinch and tripod pinch, grip strength, range of motion, thumb height maintenance, and patient-reported outcome measures (PROMs). RESULTS: The analysis showed clinically important stronger key pinch for the APL group (β = 1.28 kg). Tip pinch and grip strength showed higher outcome for the FCR group (β = 1.22 kg and 5.14 kg, respectively). Palmar abduction was in favor of the FCR group and opposition in favor of the APL group, but these were interpreted as not clinically relevant. Radiological thumb height maintenance and PROMs showed no clinical difference. CONCLUSIONS: Pyrocarbon disk interposition arthroplasty for CMC thumb joint osteoarthritis can be secured with an APL or FCR tendon strip. At long-term follow-up, use of an APL tendon strip results in significantly higher key pinch and better opposition. Tip pinch, grip strength, and palmar abduction were better after use of the FCR tendon strip. The choice of the tendon strip can be based on outcomes considered most important for the individual patient

Medium to Long-Term Follow-Up After Pyrocarbon Disc Interposition Arthroplasty for Treatment of CMC Thumb Joint Arthritis

PURPOSE: Pyrocarbon disc interposition arthroplasty has been designed for the surgical treatment of Eaton-Glickel grade II/III carpometacarpal thumb joint arthritis. This study presents the results of this technique with a minimum 5-year follow up. METHODS: We assessed 4 questionnaires for patient-reported outcome measurements in a cross-sectional study: the Patient-Rated Wrist and Hand Evaluation, Disabilities of Arm, Shoulder, and Hand questionnaire, Michigan Hand Questionnaire, and questions about satisfaction at the 5-year follow up. We evaluated grip and pinch strength, range of motion, and the radiological position of the disc. Finally, a Kaplan-Meier survival analysis was performed. RESULTS: A total of 164 thumbs (in 137 patients) were available for follow-up varying from 5 to 12 years. Median Patient-Rated Wrist and Hand Evaluation, Disabilities of Arm, Shoulder, and Hand, and Michigan Hand Questionnaire scores were 17, 18, and 76, respectively. The satisfaction score was 9 (Likert scale of 1-10). Grip and pinch strength reached nearly 100% compared with the contralateral hand. Range of motion resulted in a Kapandji score of 10. Thumb height showed a marginal loss and the Kaplan-Meier survival curve showed a survival rate of 91%. CONCLUSIONS: Our study suggests that pyrocarbon disc interposition arthroplasty is a reliable and feasible treatment for carpometacarpal thumb joint arthritis at medium-term follow-up. It was associated with a high level of patient satisfaction; it maintained thumb height and the implant survived in 91% of patients. Strength and range of motion were comparable to the contralateral hand after a minimum follow-up of 5 years. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV