Comparison of Ligament Reconstruction Tendon Interposition and Trapeziometacarpal Interposition Arthroplasty for Basal Joint Arthritis

Abstract

This study compared patients with basal joint arthritis who underwent either ligament reconstruction tendon interposition (LRTI) or trapeziometacarpal interposition arthroplasty (TMIA). Twenty-two consecutive LRTI and 22 TMIA procedures were compared. Arthritis was graded using the staging system of Eaton. In the LRTI group, 1 patient (4.5%) had stage II, 3 patients (13.6%) had stage III, and 14 patients (15 LRTI procedures; 68.1%) had stage IV disease; 3 patients had previous silicone implants (13.6%). In the TMIA group, 3 patients (13.6%) had stage II and 19 patients (86.4%) had stage III disease. Mean age was 62.5 years in LRTI patients and 54.7 years in TMIA patients (P=.005). Mean follow-up was 48 months for both groups. Thumb shortening was determined using preoperative lateral and follow-up pinch lateral radiographs. Functional outcomes and patient satisfaction were analyzed. Pinch strength averaged 8.1 lb for LRTI and 12.6 lbs for TMIA patients; this difference was significant (P<.002). Patients in both groups had high overall satisfaction rates, with scores averaging 8.5 for LRTI patients and 9.2 for TMIA patients. Thumb metacarpal proximal migration was 20.5% in the LRTI group, and 6.5% in the TMIA group; this difference was significant (P=.0006). There was no statistically significant linear correlation between proximal migration and pinch strength (R=0.32, P=.13). Five TMIA patients required revision to LRTI. Patients in both groups reported high satisfaction. Pinch strength was greater in TMIA patients, and proximal migration of the thumb metacarpal was greater in LRTI patients. There was no correlation between proximal metacarpal migration and pinch strength. Increased pinch strength with TMIA may not be sufficiently advantageous to outweigh the risk for revision surgery.