Abstract
Objectives:
More recently, the glenoid track has been described as a continuum rather than a binary “on-track/off-track” concept. “Distance to dislocation” (DTD), which defines how far an on-track lesion is from being off-track, has proven to be a strong predictor for recurrent dislocation following arthroscopic Bankart repair. Risk of recurrent instability following a Latarjet as it relates to DTD, however, is unknown. The purpose of this study was to determine if DTD is a predictor of recurrent dislocation and return-to-sport/work (RTS). We hypothesized higher DTD values would correlate with lower failure rates and higher rates of RTS.
Methods:
We retrospectively identified 106 consecutive patients who underwent a Latarjet between 2012 and 2022. Glenoid bone loss, Hills-Sachs Interval (HSI), glenoid track (GT), and DTD (DTD = GT – HSI) were determined from preoperative MRIs. On-track shoulders corresponded with positive DTD values, while off-track shoulders revealed negative DTD values. Relatedly, the more positive or negative the DTD value, the more on-track or off-track the shoulder. Univariate and multivariate cox regression analyses were utilized to evaluate the association between recurrent dislocation, patient demographics, and DTD. Using parametric survival analysis, we evaluated the association between RTS, demographics, and DTD.
Results:
Seventeen patients (16%) experienced recurrent dislocations. Our cohort was 70% male with an average follow-up of 1.5 years. Patient age (p=0.035), revision status (p=0.033), and DTD (p=0.005) were significant predictors of reoperation on univariate analysis. After adjusting for confounders, only DTD (p=0.043) remained a significant predictor of recurrent instability, Figure 1. Regarding RTS, patient age (p=0.14), sex (p=0.029), and DTD (p<0.0005) were predictive of RTS on univariate analysis. After adjusting for covariates, we observed an interaction between patient age and DTD (p=0.036). More specifically, older patients have a more prolonged RTS at lower DTD values compared to younger patients, Figure 2.
Conclusions:
Regardless of on-track vs off-track status, DTD is a useful variable in the work-up of patients undergoing Latarjet reconstruction. Lower DTD values are predictive of higher rates of recurrent instability and lower rates of RTS, especially in older patients.
