Acromial stress fracture after anatomic shoulder arthroplasty: a case report

An acromial stress fracture is an uncommon complication after reverse shoulder arthroplasty (RSA). The cause has been associated with the altered biomechanics of the shoulder after surgery. Theoretically since the shoulder center of rotation is being distalized and medialized after an RSA, there is increased tension on the deltoid muscle origin, which in turn increases strain and causes a stress reaction / fracture of the acromion. Although an acromial stress fracture is a well-known complication after reverse shoulder arthroplasty, to our knowledge, it has never been reported as a complication after anatomic shoulder arthroplasty. We present the first reported case of an acromial stress fracture after anatomic shoulder arthroplasty.