The thumb carpometacarpal joint (CMC), located at the base of the thumb, is one of the most likely joints to develop osteoarthritis (OA) and its symptoms of pain and inability to use the thumb. If treatments like physical therapy cannot alleviate symptoms, surgery may be the next option. Although some results of these CMC surgical procedures have been identified and reported, patient motion abilities have not been fully explored and displayed. The goals of this work were to 1) develop a new and robust system to measure these motion abilities, 2) determine how age and biological sex impact motion abilities in a group of healthy individuals, and 3) determine the impacts of the thumb surgery in a group of individuals who have CMC OA and examining them before, 3-months after, and 6-months after surgery. There were 52 (26 males, 26 females) healthy participants, and 18 (3 males, 15 females) surgical participants that were examined. Patient thumbs was evaluated using motion capture sensors to gather three-dimensional motion data, and two-dimensional motion maps were created for the joints at the base and middle of the thumb (CMC joint maps shown below). Analysis of the data suggested that the older healthy individuals had more wear in their CMC joints than the younger individuals, even though they did not have symptoms of CMC OA. Also, healthy females had 31% more motion at the middle joint of the thumb than healthy males, potentially increasing the risk of OA in females due to the different forces applied to the CMC joint. For the individuals that had surgery, their pain significantly decreased by 72% at 6-month post-surgery, but their motion abilities were less than before their surgery by 20-28%, and less than healthy participants by 24-40%. These new techniques have the potential to identify changes in motion that could lead towards CMC OA, including those at multiple thumb joints, while reducing the progression of OA and the need for surgery. In the clinic, these results could enable a more personalized patient rehabilitation process that is specific to their needs.
CMC joint maps
