Hill Sachs lesion (HSL)

Hill-Sachs lesion and Bankart lesion (1):

• common sequelae to recurrent anterior dislocation of the shoulder joint
• Hill-Sachs lesion
  • is a compression fracture of the posterolateral humeral head due to its compression against the anteroinferior part of the glenoid when the humerus is anteriorly dislocated
  • the anatomical apposition gives a characteristic position of the lesion; the comparable injury caused by posterior dislocation is a reverse Hill-Sachs lesion
• Bankart lesion
  • commonly seen in patients with an anterior shoulder dislocation
  • defined as a detachment of the anetroinferior labrum associated with a glenoid rim fracture
  • may occur as an isolated injury to the labrum, or it can extend to the bony glenoid margin, where it is called a "bony Bankart"
• in most cases, both findings are associated together
• first anatomic description of the traumatic notch on the humeral head was made in 1855 by Malgaigne
  • in 1940 two radiologists, Harold Arthur Hill and Maurice David Sachs, published a paper, in which they made the radiographic description of lesion, naming it Hill–Sachs lesion (HSL)
  • later on the glenoid rim lesions were reported (2)
  • HSL is often linked with recurrent anterior shoulder instability
    • demonstrated in 67–93% of anterior dislocations and can reach an incidence rate of 100% in patients with recurrent anterior shoulder instability (3)
    • typically occurs with an anteroinferior glenohumeral dislocation event
    • young age and hyperlaxity of the ligaments surrounding the glenohumeral joint lead to a predisposition for recurrence of dislocation
    • most common method of determining the HSL is the Calandra classification, which uses arthroscopy to measure the depth of the lesion
      
      

• quantifying bone loss is of utmost importance to decide the best treatment for recurrent anterior glenohumeral instability patients (3)
  • this is the determinant factor influencing the choice of the surgical technique: soft tissue procedure or bone block procedure
  • has been extensively reported in the literature that the limit of glenoid bone loss above which an arthroscopic Bankart repair may fail is >= 25% of the glenoid width
    • this percentage is equivalent to >= 20% of the surface area created by a bestfit circle on the inferior surface of the glenoid
• 3DCT 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 (4)

Reference:

• Radiopaedia. Hill-Sachs lesion with bony Bankart lesion

(accessed 10/6/2020)

• Charousset C, Beauthier V, Bellaïche L, et al. Can we improve radiological analysis of osseous lesions in chronic anterior shoulder instability? Orthop Traumatol Surg Res 2010;96:S88–S93.
• Maio M et al. How to measure a Hill–Sachs lesion: a systematic review. EFORT Open Rev 2019;4:151-157.
• Fox JK et al. Understanding the Hill-Sachs Lesion in Its Role in Patients with Recurrent Anterior Shoulder Instability. Curr Rev Musculoskelet Med (2017) 10:469–479
• Shibayama K, Iwaso H. Hill-Sachs lesion classification under arthroscopic findings. J Shoulder Elb Surg. 2017;26(5):888–94