(Kiosk 2) Multifocal Osteonecrosis: A Case Report

Case Diagnosis: Multifocal osteonecrosis at the hip and shoulder.

Case Description or Program Description: 59-year-old male with a history of hip avascular necrosis treated with total hip replacement and intermittent corticosteroid use presents to the clinic with one year of bilateral shoulder pain and no inciting injury. He is a former personal trainer and exercises regularly. He has right anterior shoulder pain worse with abduction and adduction. It has become so severe that he can no longer perform lateral dumbbell raises with 10 pounds, which is typically a very light weight for him. The pain in his left shoulder is deep and worse at night. An x-ray of both shoulders showed sclerotic lesion of the left humeral head. The right humerus demonstrated bony sclerosis but no obvious lesions. Originally thought to have right AC arthritis. Given the severity of the pain, an MRI of bilateral shoulders was ordered.

Setting: Outpatient clinic.

Assessment/Results: MRI of bilateral shoulders revealed osteonecrosis of the superior aspect of the left humeral head without cartilage breach or subchondral collapse, “rim rent” tear of the supraspinatus tendon anterior leading edge, infraspinatus tendinosis, and mild osteoarthritis at the acromioclavicular joint with mild joint widening. Slight osteoarthritis in the glenohumeral joint without effusion.

Discussion (relevance): The most commonly reported risk factor for multifocal osteonecrosis is corticosteroid use. It is considered a rare clinical condition, reported in approximately 3% of osteonecrosis patients. However, it is difficult to diagnose, as many patients experience no symptoms. Thus, the exact incidence of multifocal osteonecrosis among patients with various risk factors remains unclear and case reports have been limited.

Conclusions: It is important to maintain a high clinical suspicion for multifocal osteonecrosis, especially in patients with a history of corticosteroid use.