Modeling Distraction Force in First Carpometacarpal Joint

First carpometacarpal osteoarthritis is a chronic non-inflammatory disease of the proximal joint, which is diagnosed with degenerative changes in the articular cartilage and pain. Reducing the joint pain requires a condition for its reformation. A possible treatment method is unloading joint through creating distraction force between the two sides of the constituent bone. The purpose of this research is thus to distract the two sides of the joint, and then measure the amount of and changes in intra-articular force on cadaver. In doing so, several experiments are conducted by using the designed distractor device on the cadaver, and a variety of its functions are examined and analyzed. The results of carpometacarpal joint force analysis on its motion degrees of freedom showed that an increase in the distraction force on bone results in an increase in the installed sensor force, and, ultimately, a decrease in joint force. Quantitative assessment shows that this forces for every person is unique.