CASE 154
BY: Dr. Nizar Al-Nakshabandi MD, FRCPC
HISTORY: 20-year-old male sustained high energy injury to the shoulder.
What are your findings?
What is the differential diagnosis?
What are the causes?
FINDINGS:
AP radiograph [A] demonstrates a humeral head lying anterior and medial to the glenoid fossa. Close-up view [B] AP radiograph also shows the humeral head inferior to the glenoid fossa.
Trans-scapular view [C] confirms the anterior dislocation of the humeral head lying anterior, medial and inferior to the glenoid fossa closest to the chest wall. Depression of the humeral head superiorly and posteriorly is highly suggestive of a Hill-Sachs lesion.
DIAGNOSIS:
Anterior shoulder dislocation with Hill-Sachs lesion of the humeral head.
PEARLS AND DISCUSSION:
Mechanism: Dislocation usually results from forceful abduction with external rotation and extension. Some people are predisposed to it by a shallow dysplastic glenoid: predisposing them to recurrent dislocations. They are usually treated with closed reduction.
A Hill-Sachs lesion is a compression fracture of the posterolateral superior humeral surface. Previous shoulder dislocation predisposes people to recurrent anterior shoulder dislocation if present. They can be associated with Bankart lesion [fracture of the anterior inferior aspect of the glenoid] in up to 11% of the cases. They can be seen on plain radiographs or CT if the Bankart lesion is an osseous one. However, this requires an MR arthrogram if it is a cartilaginous Bankart lesion.
The bony lesion in Hill-Sachs does not require treatment. However, if there is a labral Bankart lesion. it requires surgical repair.
The bony defect will be treated by bony grafting or placement of a soft tissue within the defect.
FURTHER READING:
1. Hill, Harold A.; Sachs, Maurice D. The Grooved Defect of the Humeral Head Radiology. 35 (6): 690. doi:10.1148/35.6.690
2. Manaster BJ, Disler DG, May DA et-al. Musculoskeletal imaging, the requisites. Mosby Inc. (2002) ISBN:0323011896
3. Simon RR, Sherman SC, Koenigsknecht SJ. Emergency orthopedics, the extremities. McGraw-Hill Professional. (2007) ISBN:0071448314.
