title: [Combined effects of NEL-like type 1 gene and zoledronate in preventing collapse of the femoral head].
abstract: OBJECTIVE
  To determine if combined therapy consisting of NEL-like type 1 gene (NELL-1) and zoledronate can prevent the collapse of the femoral head and stimulate the new bone formation in an animal model of osteonecrosis.
  
  
  METHODS
  Ischemic osteonecrosis was surgically induced in 24 SD rats, whicih were equally randomly divided into three groups: combination group, treated with both NELL-1 and zoledronate; sham operation group; and placebo group, treated with normal saline solution. The animals were killed 5 weeks after surgery. Radiography, MicroCT, histology, and immunohistochemistry were performed to analyze the results.
  
  
  RESULTS
  Morphologically, the femoral head was at good shape in the combination group, while mildly flattened femoral head was seen in the placebo group. No heterotopic ossifications were observed in each group. MicroCT assessment showed significantly higher total and bone mineral volume in the combination group than in the placebo group (P<0.01), whereas no such significant difference was found when compared with the sham operation group(P>0.05). Histological assessment showed more active osteoblast activity and reduced osteoclast activity in the combination group compared with placebo group.
  
  
  CONCLUSIONS
  A combination of NELL-1 and zoledronate can decrease the femoral head deformity while stimulating bone formation in a traumatic rat osteonecrois model, showing a potential to reverse the osteonecrosis.
authors.affiliation: Department of Orthopeadics, Tianjin First Center Hospital, Tianjin 300192, China; Institute of Orthopeadics, Chinese PLA General Hospital, Beijing 100853, China.
authors.forename: Meng
authors.initials: M
authors.lastname: Fan
authors.forename: Wen-xue
authors.initials: WX
authors.lastname: Jiang
authors.forename: Ai-yuan
authors.initials: AY
authors.lastname: Wang
authors.forename: Jiang
authors.initials: J
authors.lastname: Peng
authors.forename: Li
authors.initials: L
authors.lastname: Zhang
authors.forename: Wen-jing
authors.initials: WJ
authors.lastname: Xu
authors.forename: Shi-bi
authors.initials: SB
authors.lastname: Lu
mesh_terms: D000818:Animals; D004164:Diphosphonates / Q000627:therapeutic use*; D005271:Femur Head Necrosis / Q000188:drug therapy*; D007093:Imidazoles / Q000627:therapeutic use*; D008297:Male; D009419:Nerve Tissue Proteins / Q000627:therapeutic use*; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley; D000077211:Zoledronic Acid
chemical_list: D004164:Diphosphonates; D007093:Imidazoles; C484480:Nell1 protein, rat; D009419:Nerve Tissue Proteins; D000077211:Zoledronic Acid