Functional Outcomes of Thumb Trapeziometacarpal Arthrodesis With a Locked Plate Versus Ligament Reconstruction and Tendon Interposition

Purpose To compare standardized functional and patient-reported early outcomes following trapeziometacarpal arthrodesis (TMA) using a locking cage plate construct with trapezial excision, ligament reconstruction, and tendon interposition (LRTI). Methods This prospective cohort enrolled 50 consecutive patients with trapeziometacarpal osteoarthritis undergoing TMA or LRTI. Demographic data, objective measurements, Sollerman function testing, and patient-reported outcomes were collected before surgery and at various time intervals up to 12 months after surgery. The study was powered to detect a minimally clinically important difference on the Michigan Hand Questionnaire between groups at 12 months. To account for selection bias, we performed between-group statistical analysis of the magnitude of change from preoperative to postoperative data. All complications were recorded. Results There were no significant differences in the amount of change in grip or pinch strength, patient-reported outcomes, or functional hand testing between TMA and LRTI. The TMA group had significantly increased thumb tip opposition distance. The TMA group was complicated by a 26% overall nonunion rate of which 8% were symptomatic. The LRTI group (Wagner incision) had a significantly increased incidence of superficial branch of the radial nerve paresthesia. The incidence of complications was similar between operative groups, but revision surgery was more common after TMA. Conclusions Compared with LRTI, TMA failed to demonstrate superior improvement in strength, standardized functional performance, or patient-reported function and is associated with an increased likelihood of revision surgery in the first 12 months. Trapeziometacarpal arthrodesis with a locking plate and screw construct does not ensure union, although most radiographic nonunions were asymptomatic. Wagner incisions are associated with a significantly increased incidence of superficial branch of the radial nerve paresthesia compared with dorsal trapeziometacarpal exposure. Type of study/level of evidence Therapeutic II.