Abstract
Introduction
Multifocal osteonecrosis (ON) was defined by Mont et al. as a disease involving three or more anatomic sites. Few papers have been published on the Chinese experience. The purpose of this study was to characterize the experience with multifocal ON in order to make an earlier diagnosis for more patients with this disorder.
Methods
From 2003 to 2008, thirty nine patients with multifocal ON were identified in our clinical practice. Among them, thirty seven patients were post-SARS rehabilitating patients and two patients were found in clinic. All patients had a history of high dose corticosteroid therapy. The diagnosis was done by magnetic resonance imaging (MRI) and radiographs. All patients were treated by drug or other joint-salvaging procedure. Three patients had bilateral total hip arthroplasties.
Results
Osteonecerotic foci involved three joints (hip, knee, and shoulder) in fifteen patients, three joints (hip, knee, and ankle) in ten patients, four joints (hip, knee, shoulder, and ankle) in six patients, four joints (hip, knee, shoulder, and wrist) in two patients, and five joints (hip, knee, shoulder, ankle, and wrist) in four patients. All 39 patients, except two had femoral head involvement. Overall, 288 joints were involved (7.6 lesions per patients). Bilaterality was common. Corticosteroid dose in patients with multifocal ON was higher than patients with single joint ON.
Conclusion
We found that the patients with ON who had peripheral joints (shoulder, elbow, ankle, wrist) involved also were diagnosed hip and knee ON (both or either). Patients with hip or knee joint ON can exist in isolation. Multifocal ON was increased with higher doses of corticosteroid administration. Vigilance is important in the diagnosis of multifocal ON. The MRI is a sensitive and specific method for diagnosing multifocal ON.
