Clinical Classification of Hill-Sachs Lesions: A Systematic Review of Radiographic Measurement Techniques

Background A Hill-Sachs lesion (HSL) is a significant risk factor for recurrent shoulder instability and an indication for surgery. Currently, several available methods exist to measure these lesions on imaging, combined into a multitude of classification and grading systems. There is no consensus on a universal classification system for HSLs leading to extensive heterogeneity in how surgeons classify lesions and identify surgical necessity. The purpose of this review is to provide a comprehensive overview of established HSL classification measures that may guide future HSL classification systems. Methods A comprehensive search of PubMed, Embase, CINAHL, and Scopus was conducted up to June 20, 2025, following PRISMA guidelines. Inclusion criteria consisted of peer-reviewed human studies using imaging to evaluate HSL. Exclusion criteria were reverse HSLs, reviews, case reports, cadaveric, and biomechanical studies. Risk of bias was assessed via the MINORS criteria. Results This study identified 39 studies pertaining to HSL classification or grading. Depth (21 studies), width (20), glenoid track/Hill-Sachs interval (18), volume (9), and location/medialization (9) were the five most commonly used measurements in classification. Wide variability exists in how each of these measurements should be made, and differing levels of agreement on their usefulness in different contexts. Of included measurements, the pooled conclusions on lesion depth, width, and location on severity were most consistent. Conclusions This study highlights the most common methods and measurements used to classify HSLs in the current literature. Width, depth, and glenoid track calculations were by far the most prevalent measurements, often being incorporated into larger classification criteria. By breaking down the published classification systems into individual measurements, this review aims to help guide future standardized HSL classification criteria.