Understanding the Hill-Sachs Lesion in Its Role in Patients with Recurrent Anterior Shoulder Instability

Abstract

The most recent literature covering the Hill-Sachs lesion has focused on the relatively new and unexplored topic of the importance of concomitant injuries while treating a humeral head defect. The glenoid track concept has been clinically validated as a method to predict engagement. 3D-CT has become the "gold standard" for Hill-Sachs imaging; however, it has been noted that 3D-MRI produces results that are not significantly different from CT. Also, it has been found that when the arm is in a position of abduction during the primary injury, there is a higher risk of engagement and subsequent dislocation. Recent studies have demonstrated successful results stemming from purely arthroscopic procedures in treating Hill-Sachs lesions. Anterior shoulder instability, specifically the Hill-Sachs lesion, is an area of orthopedic study that is highly active and constantly producing new studies in an attempt of gaining the best outcomes for patients. The past few years have yielded many excellent discoveries, but there is still much more work to be done in order to fully understand the role of the Hill-Sachs lesion in anterior shoulder instability.

Accuracy and Reliability of Imaging Modalities for the Diagnosis and Quantification of Hill-Sachs Lesions: A Systematic Review

“…However, they determined that CT has the highest accuracy in measuring bone loss and that radiography is a valid screening tool with good clinical predictive power. 10 The current standards are in agreement with the conclusions made by Saliken et al 6,7,12 Therefore, the purpose of this systematic review was to determine the reliability and accuracy of different imaging modalities in assessing Hill-Sachs lesions within the setting of anterior shoulder instability. We hypothesized that CT-based imaging modalities (2-dimensional [2D] CT, 3D CT, and CTA) would show the highest levels of accuracy and reliability in identifying and quantifying Hill-Sachs lesions across the current literature.…”

“…1 In fact, the literature from the past 20 years has shown that Hill-Sachs lesions can be found in 67% to 93% of anterior shoulder dislocations, and some studies have even measured an incidence of 100% in patients with anterior shoulder instability. [2][3][4][5][6] Given this prevalence, the recent literature has focused on diagnosing these lesions with different imaging modalities. For example, plain radiographs in the lateral, axillary, and anteroposterior (AP) views have been found to be a useful screening tool for diagnosing Hill-Sachs lesions but may lack accuracy when compared with other imaging modalities.…”

“…Humeral bone loss not only is an associated injury with anterior shoulder dislocation but also can serve as a pathologic cause of recurrent anterior shoulder instability. 6,7 Therefore, physicians rely on the aforementioned imaging modalities as a more precise preoperative way to quantify the dimension and volume of humeral bone loss. Furthermore, these modalities provide insight by allowing the presence of associated glenoid bone loss to be evaluated and, thus, the lesion to be characterized as on or off track.…”

“…The literature confirms 3D CT as the gold standard to reliably detect lesions with humeral bone loss, accurately measure dimensions, and quantify the amount of bone loss. 1,[6][7][8][9][10] However, plain radiographs are more widely used because of their relatively low cost and their value as a screening tool. Furthermore, this modality has proved useful for clinical predictions of future instability.…”

Microfracture in Linear, Isolated, Narrow, Engaging Hill-Sachs Lesion

“…In general, a small (<20%) osseous defect can be treated with nonsurgical management if it is a first-time dislocation. 11 However, it is essential to address the Hill-Sachs defect in the setting of an engaging lesion because multiple studies have shown increased recurrence rates of shoulder instability after arthroscopic repair when the Hill-Sachs lesion is not addressed at the time of surgery. 11 Shibayama and Iwaso 12 found that an engaging Hill-Sachs lesion is highly susceptible to recurrence if treated with a typical arthroscopic capsuloligamentous repair with no attention to the osseous defect.…”