Figure. Anteroposterior radiograph of the left shoulder.
A 78-year-old woman presents to the office with left shoulder pain that has persisted for 6 months. Two years ago, the patient sustained a proximal humerus fracture on the left side, which she reports healed without incident. The patient does not recall any new injury that may have caused the shoulder pain, but her symptoms have gradually increased over the past 6 months. Anteroposterior radiograph of the left shoulder (Figure) shows advanced avascular necrosis of the proximal humerus. The glenoid cavity appears to be intact without signs of arthritic changes.
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The anterior and posterior humeral circumflex arteries provide most of the blood supply to the humeral head. Fractures of the proximal humerus can disrupt these vessels, which, over time, causes avascular necrosis (AVN) of the humeral head. A displaced proximal humerus fracture may heal and remain asymptomatic for a period of time before AVN starts to develop.1
Symptoms associated with AVN include increasing pain and decreasing range of motion in the shoulder. Early radiographic findings may be normal or show signs of humeral head sclerosis and osteopenia. As AVN progresses, the subchondral bone of the humeral head begins to break down and collapse; later in the disease, the glenoid cartilage may degenerate. The average length of time from proximal humerus fracture to the development of symptomatic AVN is usually around 2 years.1
The risk of AVN may be greater after operative fixation with a proximal humerus plate compared with nonoperative treatment.2 Conservative treatment of proximal humerus AVN includes rest, nonsteroidal anti-inflammatory drugs, and intra-articular steroid injections. Patients will often respond well with conservative treatment and may be asymptomatic.1,2
If conservative treatments fail, surgical fixation generally involves a hemiarthroplasty in which the humeral surface is replaced, or a total shoulder replacement, which replaces both the humeral and glenoid surfaces. A hemiarthroplasty is generally chosen when the articular surface of the glenoid is intact; a total shoulder replacement is preferred when the glenoid shows signs of degeneration.1,2
Dagan Cloutier, MPAS, PA-C, practices in a multispecialty orthopedic group in the southern New Hampshire region and is editor in chief of the Journal of Orthopedics for Physician Assistants.
1. Large TM, Adams MR, Loeffler BJ, Gardner MJ. Posttraumatic avascular necrosis after proximal femur, proximal humerus, talar neck, and scaphoid fractures. J Am Acad Orthop Surg. 2019;27(21):794-805.
2. Xu J, Zhang C, Wang T. Avascular necrosis in proximal humeral fractures in patients treated with operative fixation: a meta-analysis. J Orthop Surg Res. 2014;9:31.