A 29 year old soccer player presents to your ER with a shoulder deformity after falling backwards onto an outstretched arm. He has dislocated the same shoulder three times previously. What two specific lesions should you look for on the xray? Why do they matter?
Answer: Bankart and Hill-Sachs lesions.
Bankart lesions are deformations sustained to the glenoid labrum during forceful impaction of the humeral head during dislocation. These may involve soft tissue alone (occurs in 90% of anterior dislocations), or may be a true fracture/avulsion (occurs in 5% of anterior dislocations, referred to as a “bony” Bankart, seen below).
Hill-Sachs lesions are cortical indentations or flattening sustained to the humeral head during dislocation (see below). They occur in about 1/3 of anterior dislocations.
Both of these lesions can predispose the patient to recurrent dislocations and they should be referred to orthopedics for possible surgical repair. Lesions >20% of the respective cortical surface are of particular concern and should be seen by ortho urgently.
Sources:
- Milano G, Grasso A, Russo A, Magarelli N, Santagada DA, Deriu L, Baudi P, Bonomo L, Fabbriciani C. Analysis of risk factors for glenoid bone defect in anterior shoulder instability. Am J Sports Med. 2011 Sep;39(9):1870-6. Epub 2011 Jun 27.
- Bushnell BD, Creighton RA, Herring MM. Bony instability of the shoulder. Arthroscopy. 2008 Sep;24(9):1061-73. Epub 2008 Jun 30.
- Cleeman E, Flatow EL. Shoulder dislocations in the young patient. Orthop Clin North Am. 2000 Apr;31(2):217-29.
