Editorial Commentary: It Is Not the Size, But the Location of Hill-Sachs Lesion That Matters

Reverse Hill-Sachs and Hill-Sachs Lesion Repair with Fresh Talus Osteochondral Allograft: A Series of 3 Patients

CASE

Hill-Sachs lesions and reverse Hill-Sachs lesions (HSLs) are common in patients with shoulder instability, and addressing these lesions effectively is crucial for patient outcomes. Our study investigates a novel technique using talus osteochondral allografts (TOA) for the treatment of these lesions. The TOA offers several advantages, including congruency to the humeral head, dense bone structure, and a reduced risk of contamination compared with other allografts.

CONCLUSION

We present 3 patients with large engaging Hill-Sachs lesions or reverse HSLs, who were treated using a TOA, highlighting its feasibility and positive clinical outcomes.

Arthroscopic Humeral Head Hill-Sachs Grafting With Talus Allograft

The presence of a Hill-Sachs lesion is a known risk factor for recurrent shoulder instability. Many procedures have been described for the treatment of off-track Hill-Sachs lesions; however, each of these techniques is fraught with potential disadvantages and complications. In this Technical Note and accompanying video, we describe our technique for arthroscopic treatment of a Hill-Sachs lesion with talus osteochondral allograft. This technique recreates native humeral head anatomy with a highly congruent graft without altering the biomechanics of the glenohumeral joint.

Outcomes following arthroscopic treatment of off-track Hill-Sachs lesions using fresh osteochondral allograft plugs: a case series

BACKGROUND AND HYPOTHESIS

Osteochondral allograft (OCA) transplantation is a well-described technique for the treatment of large, engaging Hill-Sachs lesions (HSLs). Traditionally, OCAs are size-matched to the defect, which can be expensive and time-consuming, and the majority of described techniques require an open approach. Recently, an all-arthroscopic approach to Hill-Sachs OCA transplantation using premade plugs was described, eliminating the need for size-matching and graft harvest. The purpose of this study was to evaluate postoperative outcomes of patients who have undergone arthroscopic treatment of HSLs using premade OCA plugs. We hypothesized that these patients would have improved pain and function without recurrent instability.

METHODS

A retrospective chart review was performed using operative reports for a single surgeon with search terms Hill-Sachs and allograft. Patients were excluded if an open approach was used or if graft harvest was performed. Postoperative imaging was reviewed to assess for graft incorporation and reconstitution of the HSL. Recurrent instability and reoperation were recorded. Patients completed surveys including the American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form (ASES) score and the Western Ontario Shoulder Instability Index (WOSI).

RESULTS

Five patients were identified through chart review and met inclusion criteria. All patients underwent concurrent labral repair and 2 patients underwent a concurrent open Latarjet procedure. Postoperative radiographs showed reconstitution of the HSLs in all patients. There were no complications in the postoperative period with no recurrent instability or reoperations in any patient. The average ASES score was 87% (higher score indicating better outcome) with standard deviation 9.7, and the average WOSI score was 27% (lower score indicating better outcome) with standard deviation 8.3.

CONCLUSION

Favorable outcomes can be expected after arthroscopic treatment of Hill-Sachs lesions using premade OCA plugs. Further research is needed to assess larger patient cohorts and compare outcomes to size-matched approaches.

Longer peripheral-track lesions are associated with instability after arthroscopic Bankart repair

BACKGROUND

The glenoid track concept has enabled the categorization of Hill-Sachs lesions (HSLs) into on-track lesions and off-track lesions. Furthermore, among the on-track lesions, further categorization has been established based on the distance from the medial edge of the Hill-Sachs lesion to the medial edge of the glenoid track, into peripheral-track lesions and central-track lesions. Recent studies on peripheral-track lesions and central-track lesions within the glenoid track have shown inconsistencies in failure rates, which deserves further investigation.

METHODS

A retrospective cohort comparison of patients who underwent arthroscopic Bankart repair between 2015 and 2020 was performed. 102 patients with peripheral-track HSLs were included. The patients were divided into 2 groups based on the results of the postoperative apprehension test: the apprehension positive group (n = 30), and the apprehension negative group (n = 72). Using preoperative computed tomography (CT) and an image reconstruction program, 3-dimensional (3D) images were segmented to calculate the length, width, depth, and distance of the HSLs. A multivariate logistic regression was used to determine the risk factors of recurrence, for which odds ratio (OR) and 95% confidence interval (CI) were provided.

RESULTS

A multivariate logistic regression analysis revealed that the length of the peripheral-track HSLs was a significant independent predictor of failure in this study. (OR 1.380; 95% CI 1.170-1.627; P < .001). The receiver operating characteristics curve (ROC) demonstrated a predictive power (area under the curve = 0.841) and a threshold value of 14.2 mm.

CONCLUSION

Length was the only risk factor for the recurrent instability of peripheral-track HSLs after ABR. In the context of surgical decision-making, utilizing the glenoid track concept, medical practitioners may need to evaluate instability by considering the length as a continuous factor, while differentiating between peripheral-track and central-track classifications.

All-Arthroscopic Treatment of Off-Track Hill-Sachs Lesions Using Fresh Osteochondral Allograft Plugs: "Rocks in a Stream"

Osteochondral allograft transplantation is a well-described technique for the treatment of large, engaging Hill-Sachs lesions. Traditionally, osteochondral allografts are size-matched to the defect, which can be expensive and time-consuming, and the majority of described techniques require an open approach. This Technical Note describes an all-arthroscopic approach to Hill-Sachs osteochondral allograft transplantation using premade osteochondral allograft plugs, eliminating the need for size-matching and graft harvest. This approach works not by anatomically filling the defect, but rather by bridging the defect to prevent it from engaging the glenoid.

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

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.

Glenoid Track Assessment at Imaging in Anterior Shoulder Instability: Rationale and Step-by-Step Guide

Anterior shoulder dislocation is the most common form of joint instability in humans, usually resulting in soft-tissue injury to the glenohumeral capsuloligamentous and labral structures. Bipolar bone lesions in the form of fractures of the anterior glenoid rim and posterolateral humeral head are often associated with anterior shoulder dislocation and can be a cause or result of recurrent dislocations. Glenoid track assessment is an evolving concept that incorporates the pathomechanics of anterior shoulder instability into its management. Currently widely endorsed by orthopedic surgeons, this concept has ramifications for prognostication, treatment planning, and outcome assessment of anterior shoulder dislocation. The glenoid track is the contact zone between the humeral head and glenoid during shoulder motion from the neutral position to abduction and external rotation. Two key determinants of on-track or off-track status of a Hill-Sachs lesion (HSL) are the glenoid track width (GTW) and Hill-Sachs interval (HSI). If the GTW is less than the HSI, an HSL is off track. If the GTW is greater than the HSI, an HSL is on track. The authors focus on the rationale behind the glenoid track concept and explain stepwise assessment of the glenoid track at CT or MRI. Off-track to on-track conversion is a primary goal in stabilizing the shoulder with anterior instability. The key role that imaging plays in glenoid track assessment warrants radiologists' recognition of this concept along with its challenges and pitfalls and the production of relevant and actionable radiology reports for orthopedic surgeons-to the ultimate benefit of patients. ©RSNA, 2023 Online supplemental material is available for this article. Quiz questions for this article are available through the Online Learning Center.

Arthroscopic Hill-Sachs Filling Technique Using an Absorbable Interference Screw

We present an arthroscopic technique used to treat traumatic shoulder instability in the patient with a Hill-Sachs lesion, especially an off-track lesion. The incidence of this bony defect is approximately 40% to 90% of all anterior shoulder instability cases-and up to 100% in patients with recurrent anterior instability. Incorrect management of this humeral bone defect can lead to treatment failure, and it is essential to define characteristics such as the lesion's location, depth, width, and orientation. Many arthroscopic and open procedures have been described for the surgical management of the Hill-Sachs lesion. Using arthroscopy for the surgical treatment of shoulder instability offers numerous advantages. We describe an arthroscopic technique that consists of filling the Hill-Sachs lesion with absorbable interference screws made out of an advanced biocomposite material. After repair of the Hill-Sachs lesion, the Bankart lesion is repaired. As these screws are resorbed by bone tissue over several months, the bony anatomy is restored.