Effect of Partial and Complete Trapezoid Excision on Radiographic and Functional Results After Abductor Pollicis Longus Suspensionplasty

Abstract

We hypothesized that adding complete or partial trapezoid excision is associated with greater radiographic carpal collapse and worse functional outcomes compared with a simple trapeziectomy and abductor pollicis longus suspensionplasty. A total of 69 patients had abductor pollicis longus suspensionplasty (79 hands), 87% of whom were female, mean age 64 years. Scaphotrapezium-trapezoid arthritis noted at surgery was treated with an additional proximal trapezoid excision (PT) in 21 (27%) or complete trapezoid resection (CT) in 22 hands (28%). No trapezoid was excised in 36 hands. The primary outcome was final radiolunate (RL) extension of 15° or greater on lateral radiographs. Logistic regression (for change in RL angle) and linear regression (for continuous variables) with robust variance estimate to account for within-subject correlation (generalized estimating equation method) were used to investigate whether the trapezoid excision groups had an effect on the outcomes of interest. Models were adjusted for age and sex. Median follow-up was 92 months. Complete trapezoid resection had the most increase in RL angle, but PT had a higher incidence (29% vs 26%) of final RL angle of 15° or greater compared with CT. When stratified into groups with a final RL greater than or less than 15°, the former group had worse total function (Patient-Rated Wrist Evaluation) and Quick-Disabilities of the Arm, Shoulder, and Hand scores. Symptomatic index metacarpal migration was seen in 4 CT and 2 PT wrists (18% and 10%, respectively) and was considered to indicate failure. Compared with no trapezoid excised, both PT and CT had a greater incidence of lunate extension of 15° or greater, consistent with radiographic nondissociative-dorsal intercalated carpal instability, which was associated with inferior functional scores. Symptomatic proximal collapse of the index metacarpal was seen in both CT and PT. Further studies should evaluate whether routine excision of the proximal trapezoid is necessary for scaphotrapezoid arthritis, because any disruption of the scaphotrapezoid ligament complex appears to increase risk for developing carpal instability nondissociative-dorsal intercalated carpal instability over time and may be associated with inferior functional results. Complete trapezoid excision is not recommended. Therapeutic IV.