Total wrist fusions alter scapular kinematics during functional task performance

Total wrist fusion is a surgical procedure used to manage pain in late-stage arthritis, though it results in a complete loss of wrist mobility. This loss can lead to compensatory movement patterns in other upper limb joints, which may increase the risk of secondary musculoskeletal disorders. This study investigated scapular kinematics in wrist fusion patients compared to healthy controls. Eighteen participants (nine wrist fusion patients, nine age- and sex-matched controls) were recruited. Scapular motion was tracked using motion capture during seven functional tasks. Bilateral scapular kinematics (upward rotation, internal rotation and anterior tilt) were analyzed at 30° increments of humeral elevation. Kinematic outcomes were assessed using linear mixed models with group and side (fusion or non-fusion) as independent factors. Participants with wrist fusion demonstrated greater scapular internal rotation, upward rotation, and anterior tilt for both arms as compared with the control group. Upward rotation was greater on the fusion side than the non-fusion side in the surgery group. These findings suggest that scapular kinematics are altered to compensate for wrist immobility during daily living and functional tasks. Understanding these compensatory patterns is important to guide post-surgical rehabilitation strategies and help prevent secondary upper limb injuries.