ISAKOS Congress 2021

2021 ISAKOS Biennial Congress Paper

 

Characterization Of Hill-Sachs Lesions Based On Location, Orientation, And Volume: A 3-Dimensional Modeling Study Of 100 Anterior Shoulder Instability Patients

Justin W. Arner, MD, Vail, CO UNITED STATES
Petar Golijanin, MD, MBA, Boston, MA UNITED STATES
Liam A. Peebles, BA, Vail, CO UNITED STATES
Brenton Douglass , BS, Vail, CO UNITED STATES
Matthew T. Provencher, MD, Vail, CO UNITED STATES

The Steadman Clinic, Vail, CO, UNITED STATES

FDA Status Not Applicable

Summary

As it has been established that more medialized lesions have poorer clinical outcomes, this study highlights other HS parameters which are strongly associated with these more difficult lesions and therefore should be considered during evaluation.

Abstract

Purpose

To qualitatively and quantitatively describe advanced imaging characteristics of Hill-Sachs lesions (HSL) in a cohort of anterior shoulder instability patients using 3-dimensional (3-D) modeling software and 2) assess the impact of various HSL parameters on the HSL location and orientation in a patient cohort with anterior shoulder instability.

Methods

A cohort of 100 recurrent anterior instability patients with evidence of HSL with a mean age of 27.2 years (range = 18 to 43 years) were evaluated. 3-D models of unilateral proximal humeri were reconstructed from CT scans and the volume, surface area (SA), width, and depth of identified HSLs were quantified along with their location (medial, superior, and inferior extent). Multiple angular orientation measures of HSLs were recorded, including Hill-Sachs rim [HSLr] and Hill-Sachs center [HSLc] angles in order to classify the level and location of potential engagement. Mann-Whitney test was run to assess the relationship between measured parameters

Results

Larger HSL had greater HH SA loss (p=0.001), HSL width (p=0.001), were more medial (p=0.015), and more inferior (p=0.001). Additionally, more medial lesions had greater HSLr angles (p=0.001). The mean depth and width of identified HSLs were 3.3 mm (range = 1.2 – 7.1 mm) and 16.0 mm (range = 6.2 – 30.4 mm), respectively. The mean volume of the HSL was 449.2 mm3 (range = 62.0 – 1365.6 mm3). The medial border of the HSL extended to 17.2 ± 4.4 (range = 9.3 - 28.3 mm) off the most medial edge of the HH cartilage margin (medialization). The mean HSLr and HSLc were 29.3 ± 10.5° and 30.1 ± 11.2°, respectively.

Conclusion

This is the first large study to analyze various HS parameters and their associations amongst each other by utilizing high quality 3-D modeling. There was a statistically significant association between more medialized HSL lesions and HSL volume, width, angles, humeral head SA loss and distance from the most superior point of the HH. More medialized lesions tended to have larger volume, width, SA loss and angles while being located more inferior. As it has been established that more medialized lesions have poorer clinical outcomes, this study highlights other HS parameters which are strongly associated with these more difficult lesions and therefore should be considered during evaluation.

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