Development of a Patient-Specific Computer Model of Glenohumeral Capsular Plication and Shoulder Instability

Shoulder dislocations occur when the humeral head translates over the edge of the glenoid socket of the scapula, permanently stretching the capsular ligaments. This injury of the capsular tissue results in pathological joint laxity which is a major contributor to recurrent dislocations and is a key feature of shoulder instability. The ideal surgical parameters to correct this pathology have yet to be established due to a lack of understanding of how shoulder kinematics and capsular mechanics are affected by different surgical procedures. To address this knowledge gap, we developed patient-specific computer models of the shoulder which include anatomically accurate models of the capsule. The purpose of this study was to simulate capsular plication of the glenohumeral ligaments and to evaluate the effect different degrees of plication had on glenohumeral joint laxity and rotation.