Avulsion of the lesser tuberosity
General considerations
Anatomic total shoulder
In the case of an anatomic total shoulder arthroplasty, a fracture or avulsion of the lesser tuberosity is of high importance because it is the point of attachment of the subscapularis which provides anterior stability to the shoulder.
Reverse total shoulder
In the case of a reverse total shoulder arthroplasty, a fracture or avulsion of the lesser tuberosity has less significance, but anterior stability may still be compromised.
Etiology
Failure of the repair of a lesser tuberosity osteotomy due to excessive or forceful external rotation before healing has occurred.
Clinical signs
- Pain at the front of the shoulder
- Weakness of internal rotation
- Positive belly press sign
- Shoulder instability including dislocation
Imaging
Plain x-rays, particularly the scapular Y view, can demonstrate the fracture, especially in displaced cases. CT is recommended in suspected fractures and to evaluate displacement.
