Summary

The purpose of this study is to determine the prevalence of on-track and off-track Hill-Sachs lesions(HSL) amongst male and female patients with shoulder instability.

Abstract

OBJECTIVES
The purpose of this study is to determine the prevalence of on-track and off-track Hill-Sachs lesions(HSL) amongst male and female patients with shoulder instability. We hypothesize that females will have more on-track lesions in comparison to males.

Methods

The present study was conducted utilizing a retrospective analysis of a clinical series of consecutive patients who underwent a shoulder MRI during a workup for anterior glenohumeral instability between January 2021 and January 2024. The Research Patient Data Registry(RPDR) Mass General Brigham(MGB) database was searched using CPT codes and ICD-9/10. Patients between 13 and 35 years old with anterior shoulder instability met the inclusion criteria for this study. Each patient’s medical record was reviewed to retrieve clinical and demographic data. Furthermore, the MRI was read independently by research team members to determine the glenoid track(GT), Hill-Sachs interval(HSI), and distance-to-dislocation(DTD). Any discrepant reading was evaluated by an orthopedic surgeon to determine a final score. Descriptive statistics were utilized to encapsulate patient and clinical characteristics.

Results

Forty-two patients who met inclusion criteria were included in the data analysis. The study cohort was stratified by sex and statistics were generated. 14(33.4%) patients in the cohort were female with the average age of dislocation 22.72(SD 11.46) years and the average body mass index(BMI) 28.01kg/m2(SD 6.36). 6(42.8%) patients sustained injury to their dominant side in the female cohort, 4(28.6%) patients sustained injury to their non-dominant side and in 4(28.6%) patients this statistic could not be generated. 7(50%) patients in the female cohort endured a sport related mechanism of injury while 7(50%) patients suffered injury during activities of daily life. 9(64%) patients had recurrent instability, and 2(14%) patients experienced hyperlaxity. 4(28.6%) patients experienced instability related to subluxation while 10(71.4%) patients endured a dislocation. 10(71.4%) patients in the female cohort had a on-track Hill-Sachs lesion(HSL) while 4(28.6%) patients had an off-track HSL.

28(66.6%) patients in the study were male with the average age of dislocation 22.05(SD 11.47) years and the average BMI 27.95kg/m2(SD 6.48). 8(28.6%) patients sustained injury to their dominant side in the male cohort, 12(42.8%) patients sustained injury to their non-dominant side and in 8(28.6%) patients this statistic could not be generated. 18(64.3%) patients in the male cohort endured a sport related mechanism of injury while 10(35.7%) patients suffered injury during activities of daily life. 14(50%) patients had recurrent instability, and 6(21.4%) patients experienced hyperlaxity. 3(10.7%) patients experienced subluxation, 23(82.2%) patients endured a dislocation, and in 2(7.1%) patients this statistic could not be generated. 18(64.3%) patients in the male cohort had an on-track HSL while 10(35.7%) patients had an off-track HSL.

Conclusion

This study’s cohort of patients with anterior shoulder instability was predominantly male, with the average age of dislocation below 25 years, and mean BMI below 30. Importantly, when stratified by sex, patients in the female cohort generated a higher percentage of on-track lesions than those in the male cohort.

LEVEL OF EVIDENCE
Level III, Retrospective Clinical Study