Histologic Evaluation of the Glenohumeral Joint Capsule After the Laser-Assisted Capsular Shift Procedure for Glenohumeral Instability

Abstract

Glenohumeral joint capsule obtained from 42 patients who had undergone an arthroscopic laser-assisted capsular shift procedure was evaluated histologically. A total of 53 samples from the anterior inferior glenohumeral ligament of the joint capsule were collected before and at various times after the procedure (range, 0 to 38 months). Despite glenohumeral instability, joint capsule of the patients before the procedure showed no significant histologic lesions. Laser treatment significantly altered the histologic properties of the tissue as evidenced by hyalinization of collagen and necrotic cells (time 0). Tissues sampled during the short-term period (3 to 6 months) after the procedure demonstrated fibrous connective tissue with reactive cells and vasculature. Collagen and cell morphology returned to normal in the middle- to long-term period (7 to 38 months) after the procedure, while the number of fibroblasts remained elevated. Joint capsule collected from the shoulders of six patients who experienced stiffness after the procedure showed persistent synovial, cellular, and vascular reaction even after 1 year postoperatively, the cause of which is unclear. This study re-