Effects of Zoledronic Acid and Vitamin E on Surgical- Induced Osteonecrosis of the Femoral Head in Rabbit.

Abstract

Femoral head osteonecrosis is a progressive disease with disabling outcomes in hip joint if not treated. This study was designed to compare the effects of zoledronic acid plus vitamin E versus zoledronic acid alone in surgical induced femoral head osteonecrosis in rabbits. 26 Japanese white adult normal male rabbits at 28-32 weeks old were undertaken surgical femoral dislocation to devastate the femoral neck vessels; the femoral neck vessels were ligated and the hip was relocated. Next, the first 10 rabbits received zoledronic acid injections at 1^st and the 4^th weeks; the second group (10 rabbits) received zoledronic acid injections at 1^st and the 4^th week along with daily oral vitamin E for 12 weeks; and the third group was considered as non-treated control group. Radiographic and postmortem pathological assessments including the Ficat classification, epiphyseal quotient (EQ), new bone formation, and residual necrotic bone (RNB) were performed and compared after week 12. A significant difference was found between the combination therapy group and the control group in Ficat classification at 12^th weeks (<i>P=0.048</i>), but, the difference between monotherapy and combination therapy groups at 12^th weeks was nonsignificant (<i>P=0.37</i>). Also, both treated groups had significant difference with the control group for RNB (<i>P=0.015</i>). There were no significant differences between the three groups for Ficat classification at the 6^th week (<i>P=0.65</i>); EQ at 6^th (<i>P=0.59</i>) and 12^th week (<i>P=0.64</i>); and NBF (<i>P=0.55</i>). Although zoledronic acid therapy along with vitamin E could improve some radiologic and pathological indices related to femoral head osteonecrosis, vitamin E showed a relative impact. I.