Humeral Head Reconstruction With Osteochondral Allograft: Bone Plug Optimization for Hill-Sachs Lesions Using CT-Based Computer Modeling Analysis

Phob Ganokroj; Justin Hollenbeck; Annalise M Peebles; Justin R Brown; Jared A Hanson; Ryan J Whalen; Petar Golijanin; Capt Matthew T Provencher

doi:10.1177/23259671231193768

Humeral Head Reconstruction With Osteochondral Allograft: Bone Plug Optimization for Hill-Sachs Lesions Using CT-Based Computer Modeling Analysis

Orthop J Sports Med. 2023 Sep 6;11(9):23259671231193768. doi: 10.1177/23259671231193768. eCollection 2023 Sep.

Authors

Phob Ganokroj^{1

2}, Justin Hollenbeck¹, Annalise M Peebles¹, Justin R Brown¹, Jared A Hanson¹, Ryan J Whalen¹, Petar Golijanin³, Capt Matthew T Provencher^{1

4}

Affiliations

¹ Steadman Philippon Research Institute, Vail, Colorado, USA.
² Faculty of Medicine, Siriraj Hospital, Mahidol University, Bangkok, Thailand.
³ The University of Texas at Austin Dell Medical School, Austin, Texas, USA.
⁴ The Steadman Clinic, Vail, Colorado, USA.

Abstract

Background: Engaging Hill-Sachs lesions (HSLs) pose a significant risk for failure of surgical repair of recurrent anterior shoulder instability. Reconstruction with fresh osteochondral allograft (OCA) has been proposed as a treatment for large HSLs.

Purpose: To determine the optimal characteristics of talus OCA bone plugs in a computer-simulated HSL model.

Study design: Descriptive laboratory study; Level of evidence, 6.

Methods: Included were 132 patients with recurrent anterior instability with visible HSLs; patients who had multidirectional instability or previous shoulder surgery were excluded. Three-dimensional computed tomography models were constructed, and a custom computer optimization algorithm was generated to maximize bone plug surface area at the most superior apex (superiorization) and minimize its position relative to the most medial margin of the HSL defect (medialization). The optimal number, diameter, medialization, and superiorization of the bone plug(s) were reported. Percentages of restored glenoid track width and conversion from off- to on-track HSLs after bone plug optimization were calculated.

Results: A total of 86 patients were included in the final analysis. Off-track lesions made up 19.7% of HSLs and, of these, the mean bone plug size was 9.9 ± 1.4 mm, with 2.2 mm ± 1.7 mm of medialization and 3.3 mm ± 2.9 mm of superiorization. The optimization identified 21% of HSLs requiring 1 bone plug, 65% requiring 2 plugs, and 14% requiring 3 plugs, with a mean overall coverage of 60%. The mean width of the restored HSLs was 68%, and all off-track HSLs (n = 17) were restored to on-track. A Jenks natural-breaks analysis calculated 3 ideal bone plug diameters of 8 mm (small), 10.4 mm (medium), and 12 mm (large) in order to convert this group of HSLs to on-track.

Conclusion: Using a custom computer algorithm, we have demonstrated the optimal talus OCA bone plug diameters for reconstructing HSLs to successfully restore the HSL track and, on average, 60% of the HSL surface area and 68% of the HSL width.

Clinical relevance: Reconstructing HSLs with talus OCA is a promising treatment option with excellent fit and restoration of HSLs. This study will help guide surgeons to optimize OCA bone plugs from the humeral head, femoral head, and talus for varying sizes of HSLs.

Keywords: Hill-Sachs lesions; bone plugs and computer modeling analysis; humeral head reconstruction; off-track HSL; osteochondral allograft; shoulder instability.