MusculoskeletalA novel rat model of osteonecrosis of the femoral head induced by periarticular injection of vascular endothelial growth factor receptor 2 antibody

BackgroundTraditional methods to establish animal model of osteonecrosis of the femoral head (ONFH) are not satisfactory because of the undefined underlying mechanism, low rate of the disease, and high incidence of mortality. The present study was to induce ONFH in a rat model through periarticular injection of vascular endothelial growth factor (VEGF) receptor 2 antibody.Materials and methodsEighty Sprague-Dawley rats were divided into four groups randomly and equally. VEGF receptor 2 antibody solution with a concentration of 50 μg/mL (group A), 25 μg/mL (group B), and 12.5 μg/mL (group C) was injected periarticularly to the capsular attachment to proximal femur, respectively. The injection lasted 4 continuous days, with a total volume of 2 mL. The rats in the fourth group were treated by saline for control (group D). Two weeks after the first injection, histologic and micro-computed tomographic examinations were used to investigate the presence of ONFH.ResultsHistologically, there were 90% of rats that developed ONFH in group A, 60% in group B, and 20% in group C, whereas no ONFH was found in group D. The density of intraosseous vessels was suppressed significantly by the antibody. Radiologically, the features of ONFH including deformation of the femoral head were revealed. There was no occurrence of lethal complications.ConclusionsVEGF receptor 2 antibody can induce ONFH in the rat with a high incidence of the disease. Local blockage of angiogenesis can be used as an effective method to establish animal model of ONFH.