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.