Symptomatic multifocal osteonecrosis - A multicenter study

Osteonecrosis of the femoral head frequently occurs in a young population ( mean age, approximately 35 years) and may lead to disabling arthritis requi ring hip arthroplasty surgery. This disease is compounded when it has concu rrent involvement of other joints. Multifocal osteonecrosis is defined as d isease involving three or more anatomic sites. The purpose of this study wa s to review the demographic, clinical, radiographic staging patterns, and t reatment options in patients with multifocal osteonecrosis to facilitate ea rlier diagnosis and optimize treatment. Twenty-one centers participated by submitting completed data forms on patients under their care after review o f their databases. One hundred one patients were identified. Patient demogr aphics, associated diseases, corticosteroids and other medications used, pr esenting joints, and symptomatology were evaluated. Radiographs and magneti c resonance imaging scans or both were used to diagnose and stage osteonecr otic lesions. Ninety-two of the 101 (91%) patients had a history of cortico steroid therapy. Twelve patients (of 14 tested) were found to have a coagul ation disorder. All 101 patients had femoral head involvement. Osteonecrosi s also was seen in the knee (96%), shoulder (80%), ankle (44%), and seven o ther sites. Overall, 631 joints were involved (6.2 lesions per patient). Bi laterality was common: hips, 98%; knees, 86%; and shoulders, 83%. Most lesi ons (69%) were in a precollapse stage at the time the patients presented fo r treatment. In eleven patients, the knee was the sole presenting symptomat ic joint, and the shoulder and ankle were the sole presenting symptomatic j oints in five and four patients, respectively. An improved understanding of the epidemiology, pathogenesis, and etiology of multifocal osteonecrosis w ill facilitate the diagnosis and treatment of this disease. In patients wit h osteonecrosis of the hip, all symptomatic joints should be evaluated with radiographs. In patients with osteonecrosis presumably not involving the f emoral head, the patient's femoral heads should be evaluated radiographical ly, regardless of whether the hips are symptomatic.