Dynamic Anterior Stabilization for Anterior Shoulder Instability: A Meta-Analysis and Systematic Review of Clinical and Biomechanical Studies

Background Dynamic anterior shoulder stabilization (DAS) combined with Bankart repair (BR) has emerged as a promising technique for managing anterior shoulder instability (ASI) in cases of subcritical anterior glenoid bone loss (GBL). This study aims to systematically evaluate the biomechanical outcomes, clinical outcomes, and complication rates of DAS combined with BR for ASI. Methods A comprehensive search of PubMed, Embase, and Scopus was conducted through August 2024 to identify biomechanical and clinical studies assessing DAS in ASI. Exclusion criteria included reviews, surgical techniques, case reports, and abstracts. The study adhered to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Biomechanical outcomes of interest included glenohumeral anterior translation, joint stability under various loading conditions, and load-to-dislocation. Clinical outcomes evaluated included patient-reported shoulder scores, range of motion (ROM), and complication rates. A meta-analysis was performed using a random-effects model, with using weighted mean differences (WMD) for continuous variables to compare pre-to-post treatment effects. Results Five biomechanical studies (60 cadaveric shoulders, glenoid bone loss (GBL) 10%-20%) demonstrated that DAS significantly improved anterior glenohumeral stability and load-to-dislocation compared to isolated BR, particularly in models with <20% GBL and on-track Hill-Sachs lesions (HSL). DAS using the long head of the biceps tendon (LHBT) provided superior stability under higher loads compared to the conjoint tendon (CJT) in one study but was less effective than the Latarjet procedure in 20% GBL and remplissage in off-track HSL. Clinical outcomes from three studies (100 shoulders, mean age ranged from 23.4 to 21, GBL 8.2%-10.5%) revealed significant pre-to-post intervention improvements in Rowe scores (mean difference [WMD] = 58.7; p < 0.001) and forward elevation (WMD = 4.8; p = 0.02), with no significant changes in external or internal rotation range of motion. Return-to-sport rates were high (90% at any level, 71% at the same level), with 8% experiencing recurrent instability and 2% requiring reoperation. No significant differences were observed between DAS techniques using LHBT or CJT. Conclusion Based on limited evidence from biomechanical studies and clinical case series, DAS combined with BR offered significant biomechanical improvements, substantial patient-reported outcome improvements, better forward elevation, high return-to-sport rates, and a low complication profile for ASI with subcritical GBL. However, caution is advised when considering DAS in cases with off-track HSL and GBL of approximately 20%, as it was found that DAS offers less stability biomechanically when compared to Remplissage and Latarjet and increased reoperations in such scenarios.