Arthrodesis Versus Arthroplasty in Thumb Carpometacarpal Osteoarthritis: Impact on Maximal Voluntary Force, Endurance, and Accuracy of Pinch

To investigate differences in pinch strength recovery among patients with first carpometacarpal joint osteoarthritis treated with either arthrodesis or suspension arthroplasty. Thirty-seven subjects who underwent arthrodesis or suspension arthroplasty for carpometacarpal osteoarthritis were included. Force exerted during maximal voluntary contraction (MVC) in a pinch task was measured. Maximal voluntary contraction was recorded using a haptic device equipped with a load cell from which an analog signal was acquired and digitized for visual feedback. Dynamic force was assessed by a task consisting of 10 repetitions, with a target of 70% of MVC. Endurance was assessed by the length of sustained pinch task at 30% of MVC. Task performance was quantified by mean distance and offset error from the target force as error indices, and standard deviation of force was used as index of force steadiness. The arthrodesis group obtained considerably higher MVC values than the arthroplasty group. No notable differences were found for pinch endurance. The standard deviation for dynamic force was lower for arthroplasty, indicating greater force steadiness. Arthrodesis is associated with greater pinch strength. Arthroplasty is associated with better pinch precision. Therapeutic IV.