MULTIPLE OSTEONECROSIS IN PATIENTS WITH STEROID-RELATED, ALCOHOL-RELATED, AND IDIOPATHIC OSTEONECROSIS OF THE FEMORAL HEAD
Takashi Sakai MD*, Nobuhiko Sugano MD**, Takashi Nishii MD**,
Hidenobu Miki MD**, Nobuo Nakamura MD**, Yuki Kishida MD**,
Kenji Ohzono MD***, Hideki Yoshikawa MD**
*Dept of Orthopaedic Surgery, Ikeda Municipal Hospital, Ikeda, JAPAN
**Dept of Orthopaedic Surgery, Osaka University Medical School, Suita, JAPAN
***Dept of Orthopaedic Surgery, Osaka National Hospital, Osaka, JAPAN

The purpose of the present study was to investigate the incidence of multiple osteonecrosis (MON), that is defined as disease involving two or more separate anatomic sites, in patients with steroid-related, alcohol-related, and idiopathic osteonecrosis of the femoral head (ONFH). A total of 375 patients with ONFH were reviewed clinically and radiologically. There were 197 females and 178 males. MON was diagnosed based on the findings of plain radiographs, MRI, bone scintigraphy, and/or histology for the symptomatic joints.

Osteonecrosis affected bilateral hips in 200 out of 258 steroid-related (78%), 46 out of 73 alcohol-related (63%), and 19 out of 44 idiopathic patients (43%). MON was found in 87 patients (23%), who consisted of 77 steroid-induced (29%), and 10 alcohol-related patients (14%). There was no MON in 44 idiopathic ONFH patients. The knee region was most common (81 patients, 22%), followed by the shoulder (21 patients, 6%), the ankle (6 patients, 2%), and the hand (2 patients, 0.5%). Between MON patients and non-MON patients, there were significant differences in age at diagnosis (MON: 36 vs non- MON: 43 years), gender (M/F; 38/49 vs 16 9/119), and related factors (steroid/alcohol/idiopathic; 77/10/0 vs 181/63/44). The collapse rate was 32% for the knee, 29% for the shoulder, and 33% for the ankle.

Steroid-related and alcohol-related osteonecrosis tended to develop in multiple joints, whereas idiopathic osteonecrosis did not develop as MON. Besides, the rate of bilateral involvement was lower in idiopathic osteonecrosis patients than in steroid-induced and alcohol-related osteonecrosis patients.