The Female Thumb Carpometacarpal Joint: Motion and Force Changes Due to Arthritis and Surgical Intervention.

Thumb carpometacarpal (CMC) osteoarthritis (OA) has been one of the most common locations of hand OA. CMC OA disproportionately occurs in females over males. In severe cases, surgical intervention may be needed. However, to determine the effects of surgical treatment, normative, pre-, and postsurgery function must be understood. The goals of this work were to compare the thumb motion and force abilities of older healthy (OH) females without CMC OA to those of females with CMC OA and who received ligament reconstruction with tendon interposition (LRTI) surgery at time points presurgery, 3- and 6-months postsurgery. On average, CMC OA participants 3- and 6-months postsurgery showed 35.6% and 32.9% less overall metacarpal motion compared to presurgery, 31.9% and 29.1% less than OH, and exhibited altered motion. Metacarpal flexion/extension and abduction/adduction ranges were 51.9 deg and 43.4 deg for OH, 52.9 deg and 40.3 deg presurgery, 39.9 deg and 33.5 deg at 3-months, and 42.6 deg and 32.7 deg at 6-months postsurgery. On average, participants had increased force generation at 6-months postsurgery compared to presurgery, and 20% of participants returned to the level of OH females. These data sets highlight changes in thumb metacarpal movement and thumb force generation due to disease and surgical intervention. This work has the ability to support both surgeons and patients through improved outcome assessments as well as additional data to inform the decision process on intervention.