Glenoid Bone Loss Directly Affects Hill-Sachs Morphology: An Advanced 3-Dimensional Analysis

Area of Science:

• Orthopedic surgery
• Biomechanics
• Radiology

Background:

• The glenoid track concept aids in predicting recurrent glenohumeral instability.
• Humeral head bony architecture's relation to glenoid erosion in bipolar bone loss remains unclear.

Purpose of the Study:

• Analyze the interplay between glenoid bone loss (GBL) and Hill-Sachs lesions (HSLs) in anterior instability.
• Assess relationships between GBL and HSL characteristics using 3D imaging.

Main Methods:

• Reconstructed 3D models of humeral head and glenoid from CT scans of 100 patients with anterior instability and GBL.
• Quantified GBL and HSL dimensions, categorizing GBL severity (low, moderate, high, extensive).
• Utilized ANOVA to compare GBL severity with HSL morphology.

Main Results:

• Greater glenoid bone loss (GBL) was associated with wider and shallower Hill-Sachs lesions (HSLs).
• Low-grade GBL (5%-10%) showed significantly narrower and deeper HSLs compared to other groups.
• Significant differences in GBL and HSL parameters were observed across GBL severity groups.

Conclusions:

• HSLs exhibit distinct morphological characteristics based on GBL severity.
• GBL directly influences HSL morphology, with smaller defects yielding narrower, deeper HSLs and larger defects resulting in wider, shallower HSLs.