Arthroscopic posterior capsuloplasty for chronic shoulder instability using Lasso-Loop sutures and the Bump effect: Retrospective study of 19 patients

Posterior shoulder instability is an uncommon but challenging condition, representing less than 5% of all shoulder instability cases. Arthroscopic capsuloplasty has progressively replaced open repair; however, the optimal soft-tissue construct to restore posterior capsulolabral anatomy remains debated. The purpose of this study was to report the clinical outcomes of arthroscopic posterior capsulolabral reconstruction using Lasso-Loop sutures combined with a capsulolabral “Bump effect” for chronic posterior shoulder instability. We hypothesized that recreating a reinforced posterior capsulolabral thickening would enhance posterior constraint and stabilize the shoulder. This single-center retrospective study included 19 patients (mean age 26 ± 8 years; 68% male) treated between 2010 and 2020 for chronic symptomatic posterior shoulder instability without bone loss or glenoid retroversion >10°. The standardized arthroscopic technique used Lasso-Loop sutures with 2.9-mm biocomposite anchors (Biopusclock®) to achieve an anatomic capsulolabral reduction and create a stabilizing capsulolabral thickening (“bump effect”). Functional evaluation included the Constant-Murley, Walch-Duplay, and Rowe scores, shoulder range of motion, the posterior jerk test, and the return-to-sport level (competitive vs recreational). All functional outcomes improved significantly. The Constant–Murley score increased significantly from 55 ± 10 preoperatively to 87 ± 8 postoperatively (mean gain +32; 95% CI 27–36; p < 0.001). Similarly, the Walch–Duplay score improved from 41 ± 9 to 93 ± 7 (gain +52; 95% CI 46–58; p < 0.001), and the Rowe score increased from 39 ± 8 to 92 ± 6 (gain +53; 95% CI 48–57; p < 0.001). Clinical stability was restored in most cases, with the posterior jerk test becoming negative in 18 of 19 shoulders (95%). Shoulder range of motion was largely preserved, with postoperative external rotation reaching 85% of the contralateral side. A total of 14 patients (74%) returned to sports, including 8 patients (42%) who resumed their previous competitive level. One recurrence of posterior subluxation occurred in a hyperlax patient (Beighton ≥ 4). No intraoperative complications were observed. Arthroscopic posterior capsuloplasty using a Lasso-Loop Bump reconstruction appears to restore the posterior capsulolabral anatomy effectively and provide satisfactory functional recovery in chronic posterior shoulder instability without bone loss or excessive retroversion. IV, Retrospective case series.