Case 8 - Avulsion fracture of the greater tuberosity

Summary

Imaging description

Radiographs may show the non-displaced or displaced fractures with cortical step-off in the greater tuberosity (Figure 8.1).

Importance

The greater tuberosity is the attachment site of the supraspinatus, infraspinatus, and teres minor tendons. Isolated fractures of the greater tuberosity are uncommon. It is difficult to distinguish between isolated humeral avulsion fractures of the greater tuberosity and rotator cuff tears at clinical examination. However, the distinction is crucial because treatment of the two injuries is different. Non-displaced fractures of the greater tuberosity are particularly common in association with fractures of the surgical neck of the humerus and anterior shoulder dislocation.

Typical clinical scenario

Patients present with a history of falling on an outstretched hand with the elbow extended and often with anterior dislocation.

Differential diagnosis

Occasionally, a grooved defect, Hill–Sachs lesion, in the humeral head may be confused with a fracture of the greater tuberosity.

Teaching point

At radiography, the avulsion fracture of the greater tuberosity may not be readily apparent and may be seen only on delayed images. MR imaging is often requested in cases of suspected rotator cuff tear in which marrow edema is incidentally seen surrounding the greater tuberosity and denoting the margins of the occult avulsion fracture.