To Remplissage or Not to Remplissage Part 1: Prognostic Factors Influencing Recurrent Shoulder Instability in High-Risk Individuals with On-Track Shoulders Undergoing Primary Arthroscopic Anterior Stabilization

Abstract

Objectives: Recent studies have shown that a subset of on-track Hill-Sachs lesions (HSL), defined as near-track lesions, may have a high risk of failure after primary arthroscopic Bankart repair (ABR) alone. The aim of this study was to evaluate rates of recurrent shoulder instability among patients with on-track HSL who underwent primary ABR with and without remplissage in the setting of numerous risk factors highlighted in recent literature. We hypothesized that primary ABR with remplissage (ABR+R) would lower postoperative rates of recurrent shoulder instability, particularly for “high-risk” patients defined as “near-track” lesions, hyperlaxity, younger age, contact athletes, and >1 preoperative instability episodes. Methods: Prospectively collected data was retrospectively reviewed for consecutive patients aged 14-40 years who underwent either ABR or ABR+R between 2013 and 2021 for anterior glenohumeral instability. Glenoid bone loss, Hills-Sachs Interval (HSI), glenoid track (GT), and distance-to-dislocation (DTD) values (DTD = GT-HSI) were determined via preoperative magnetic resonance imaging. Additionally, “near-track” lesions are a subset of on-track lesions with a DTD from 0 – 10mm. Capsuloligamentous laxity (i.e., hyperlaxity) was defined as external rotation greater than 85 degrees and/or grade 2+ posterior and inferior load-and-shift on examination under anesthesia. Recurrent shoulder instability was defined as recurrent dislocation and/or subjective subluxation postoperatively. Patients were excluded if the indexed surgery was a revision procedure, < 2-year follow-up, or glenoid bone loss (GBL) >20%. Univariate and multivariate Cox regression analysis was used to determine predictors of recurrent shoulder instability and reoperation. Results: One-hundred-and-fifty-five patients were included for analysis (ABR: 116 | ABR+R: 39) with an average age of 21.6 ± 6.2 years and an average follow-up of 5.1 ± 2.0 years (range: 2.0 – 8.7 yrs). Overall, 30 patients (19%) experienced recurrent shoulder instability postoperatively (4.3 per 100 person-years), and 20 (13%) underwent secondary surgery (2.9 per 100 person-years) for revision stabilization. Among the 116 patients who underwent primary ABR only, 27 (23.3%) experienced recurrent shoulder instability, compared with only three of the 39 ABR+R patients (7.7%). Risk factors assessed included: age, gender, sport, number of preoperative instability episodes, shoulder laxity, GBL, and DTD. Multivariate analysis demonstrated that younger age (p=0.003), increased shoulder laxity (p=0.010), 2+ episodes of preoperative instability episodes (p=0.009), and a lower DTD (p=0.046) were independent risk factors for recurrent shoulder instability postoperatively. However, contact athlete status was not identified as a significant predictor of recurrent shoulder instability. According to multivariate results, patients who underwent primary ABR only were roughly 9-times more likely to experience recurrent shoulder instability (HR: 8.7, p=0.002) and 7-times more likely to undergo reoperation (HR:6.8, p=0.019) than those who underwent primary ABR+R. When considering patients with three or more risk factors (i.e., “near-track” lesions, hyperlaxity, age < 25, or 2+ preoperative instability episodes), 9 of 12 ABR patients (75%) and 2 of 16 ABR+R (13%) experienced recurrent shoulder instability (p = 0.001), Table 1. Survival rates for ABR only versus ABR+R for patients with three or more risk factors are plotted in Figure 1 using Kaplan-Meier survival plots. Conclusions: Arthroscopic primary Bankart repair with remplissage may be an effective approach for decreasing the likelihood of recurrent shoulder instability and the need for secondary surgery among patients with on-track HSL. This surgical approach is especially beneficial for patients with lower DTD, increased shoulder laxity, younger age, or 2+ preoperative instability episodes in a dose-dependent manner. Those with higher risks of recurrence may benefit significantly more with the addition of a remplissage than those with fewer risk factors.