Would non-anatomical fixation of coracoid bone block (Latarjet procedure) reproduce normal scapular kinematics? In vivo three-dimensional dynamic comparison with contralateral healthy shoulders

Abstract

This study explores the Latarjet procedure to address shoulder instability, yet its impact on shoulder kinematics remains insufficiently studied. This controlled laboratory study aimed to analyze shoulder kinematics during active motions following the Latarjet procedure, hypothesizing that the nonanatomical transfer of the coracoid process would disrupt normal kinematics. Ten patients (age range, 20-52 years) undergoing the modified Latarjet procedure from June 2016 to November 2021 were included. Computed tomography and fluoroscopy generated 3-dimensional models of both shoulder joints, and a 3-dimensional–2-dimensional model-image registration technique assessed shoulder kinematics. Scapular rotation parameters were compared during humeral abduction, and anteroposterior (AP) translation during active humeral external rotation. The Latarjet side exhibited significantly increased scapular upward rotation at higher humeral elevations (130°, 140°, and 150°) compared to the nonsurgical side (P = 0.027). Posterior tilt, external rotation, and scapulohumeral rhythm showed no significant differences. AP translation at maximal humeral rotation revealed no significant disparity between Latarjet and nonsurgical sides (P = 0.28). Notably, on the Latarjet side, AP translation increased until 40° of humeral rotation (4.27 ± 4.64 mm) but decreased from 50°. These findings suggest that the Latarjet procedure induces notable alterations in scapular upward rotation during maximal humeral elevation. However, most of the parameters (posterior tilt, external rotation, and scapulohumeral rhythm) showed no significant differences. While the observed posterior movement of the humeral head beyond 50° of rotation may represent an intended effect, the long-term implications, particularly the potential for osteoarthritis, warrant careful consideration. This study contributes to the understanding of the Latarjet procedure's impact on shoulder kinematics and underscores the importance of evaluating both short-term benefits and potential complications in the clinical application of this surgical intervention.