Assessing sex differences in joint kinematics and ligament recruitment in CMC-1 OA patients: a preliminary study

Abstract

First carpometacarpal osteoarthritis (CMC-1 OA) is the most common form of OA in the hand, disproportionately affecting more women than men. The risk factors predisposing women to CMC-1 OA remain poorly understood. Fourdimensional CT (4DCT) imaging coupled with four-dimensional ultrasound (4DUS) imaging was utilized in this study to assess sex differences in joint kinematics and laxity. A male to female ratio of 1:2 CMC-1 OA patients were recruited for this preliminary study. 4DCT and 4DUS images were collected while patients performed primary thumb motions without loading on the joint. Kinematic models of the CMC-1 joint were developed to assess differences in joint kinematics between men and women. Ligament recruitment patterns at the thumb joint were assessed using our 4DUS system. The developed biomechanical models presented joint motion accurately throughout all performed motions. Current work is focused on evaluating the biomechanical risk factors that predispose women to CMC-1 OA. Anticipated results include assessing sex differences in CMC-1 joint bone morphology, the degree of joint centroid translation, joint space narrowing, as well as changes in joint congruency throughout each motion. In addition, changes in length of the dorsoradial ligament throughout thumb motion will be measured from the 4D ultrasound images collected. To the best of our knowledge, this is the first study utilizing 4DCT and 4DUS in tandem to assess thumb joint kinematics and ligament recruitment patterns. This work is a step forward in understanding the biomechanical factors and ligament recruitment patterns that result in women’s increased predisposition to the development of CMC-1 OA.