The effect of surgical treatments for trapeziometacarpal osteoarthritis on wrist biomechanics: a cadaver study

Abstract

Purpose: Studies have shown the effects of surgical treatments for trapeziometacarpal osteoarthritis on thumb biomechanics; however, the biomechanical effects on the wrist have not been reported. This study aimed to quantifyalterations in wrist muscle forces following trapeziectomy with or withoutligament reconstruction and replacement. Methods: A validated physiological wrist simulator replicatedcyclic wrist motions in cadaveric specimens by applying tensile loads to six muscles. Muscle forces required to move the intact wrist were compared to those required after performing trapeziectomy, suture suspension arthroplasty, prosthetic replacement and ligament reconstruction with tendon interposition (LRTI). Results: Trapeziectomy requiredhigher abductor pollicis longusforcesinflexion, and higher flex or carpi radialis forces coupled with lower extensor carpi ulnaris forces in radial deviation. Of the three surgical reconstructions tested post-trapeziectomy, wrist muscle forces following LRTI were closest to those observed in the intact case, throughout the range of all simulated motions. Conclusions: This study shows that wrist biomechanics weresignificantly altered following trapeziectomy, and of the reconstructions tested, LRTI most closely resembled the intact biomechanics in this cadaveric model.