In vivo Comparison of Changes in Glenohumeral Translation after Arthroscopic Capsulolabral Reconstructions

Abstract

Background The objective of this study was to quantify anteroposterior glenohumeral translation of patients undergoing arthroscopic capsulolabral repairs using cutaneous electromagnetic position sensors. Hypothesis Anteroposterior translation will be restored after arthroscopic capsulolabral repairs to values similar to the contralateral or uninjured shoulder. Study Design Cohort study; Level of evidence, 2. Methods With use of an electromagnetic tracking system, preoperative anteroposterior translation was measured in the injured and uninvolved shoulders of 32 patients with a diagnosis of glenohumeral labral tears. Testing was done with patients placed in the supine position with the arm suspended in 90° of abduction and neutral rotation. The American Shoulder and Elbow Society index and range of motion were also measured. Patients with capsulolabral injuries requiring arthroscopic repair were reexamined at 3 and 6 months postoperatively. Results In patients with anteroinferior/posteroinferior capsulolabral repairs, glenohumeral translation at 3 and 6 months postoperative ( P < .0001) was significantly decreased compared with preoperative values ( P = .0007) and the uninvolved side (preoperative, P = .04; postoperative, P = .002). In patients with superior capsulolabral (superior labral anterior-posterior) repairs, the mean glenohumeral translation at 3 and 6 months postoperative was decreased significantly compared with the preoperative value; however, no significant differences were found between the uninvolved side (preoperative, P = .5) and the operative shoulder (postoperative, P = .2). By 6-month follow-up, no significant difference existed in external rotation when compared with preoperative values for either repair group. Conclusion Arthroscopic superior capsulolabral reconstructions successfully restored anteroposterior translation. However, arthroscopic capsulolabral techniques for treating recurrent anterior or posterior instability resulted in decreased anteroposterior translation compared to the uninvolved side while restoring external rotation.