Functional capacity before and after simulated thumb carpometacarpal joint fusion.

Lateral pinch strength, grooved pegboard test time, and 22 activities of daily living (ADLs) were assessed in 10 asymptomatic patients initially without and then with splinting of the thumb carpometacarpal (CMC) joint (simulating thumb CMC fusion). Before immobilization, all patients rated a perfect total score of 88 on the 22 ADLs. After immobilization, mean total score dropped to 78.3, with particular difficulty noted in manipulating money, cutting meat, turning a doorknob, using a can opener, using scissors, and writing. Lateral pinch strength decreased from 22.4 lb without immobilization to 20.8 lb after splinting. Mean grooved pegboard test time increased from 53.1 to 58.3 seconds with immobilization. Thumb CMC fusion is not without particular functional defects. Patients' understanding of these difficulties allows for informed decisions regarding whether surgical treatment for thumb CMC arthritis is desired.