LAUSR

Understanding the biomechanics of plicating the shoulder capsule is central to the treatment of patients with recurrent glenohumeral joint instability. Specifically, capsular plication effects both translational laxity and joint rotation. By determining the impact of sequential sectioning of the glenohumeral ligaments in cadavers on glenohumeral joint translation, O’Brien and colleagues [11] determined that the anterior band of the inferior glenohumeral ligament complex is the primary restraint to anterior translation with the arm in abduction, and they also characterized the function of the other bands of the glenohumeral ligament and the rotator interval in other shoulder positions. Their discoveries are essential to surgeons when treating patients with shoulder instability. In a cadaveric model, Bigliani and colleagues [3] demonstrated that the creation of a Bankart lesion alone could not cause a glenohumeral dislocation; a capsular injury/redundancy should be present as well. As such, simply repairing a torn glenoid labrum is not adequate for the surgical treatment of recurrent instability; a related capsular plication or shift must also be present. In the late 1990s and early 2000s, surgeons generally preferred to perform open stabilization procedures only on the side of the clinical instability pattern. During this time, we performed an anterior capsular shift [1] for patients with anterior instability without a Bankart lesion [10]. And for patients with a torn anterior-inferior labrum, we generally preferred to perform an isolated anterior Bankart repair [4]. But the advent and popularity of arthroscopic stabilization procedures changed our thinking. Although early results were poor, the development of the suture anchor and better delivery cannulas were major steps forward in tensioning the joint capsule and labrum [2]. Even with these new approaches, the risk of persistent or recurrent instability remained high, and many surgeons indicated that they preferred open stabilizations for their contact athletes, and arthroscopic procedures for their more sedentary patients [6]. The development of the “circle concept”, which states that a patient cannot have an injury on one side of the joint without a concomitant injury to the opposite side, eased these disparities. Considered a major advancement, this approach prompted surgeons to investigate capsular laxity and redundancy on the opposite side of the joint from the primary instability pattern as well. The “Kim lesion” [7], tearing of the posterior band of the inferior glenohumeral ligament complex in the setting of anterior instability, is a potential risk factor for recurrent instability when only one side of the joints is plicated or repaired surgically. Some surgeons now add rotator interval closure or even anterior This CORR Insights is a commentary on the article “What Are the Effects of Capsular Plication on Translational Laxity of the Glenohumeral Joint? A Study in Cadaveric Shoulders” by Mayer and colleagues available at: DOI: 10.1007/s11999. 0000000000000277. The author certifies that neither he, nor any members of his immediate family, have any commercial associations (such as consultancies, stock ownership, equity interest, patent/ licensing arrangements, etc.) that might pose a conflict of interest in connection with the submitted article. The opinions expressed are those of the writers, and do not reflect the opinion or policy of CORR or The Association of Bone and Joint Surgeons. This CORR Insights comment refers to the article available at DOI: 10.1007/s11999. 0000000000000277. Thomas J. Gill MD (✉), Massachusetts General Hospital, Department of Orthopaedic Surgery, Sports Medicine, 175 Cambridge Street, 4th Floor, Boston, MA, 02114 USA, Email: [email protected]