title: Does Zoledronate Prevent Femoral Head Collapse from Osteonecrosis? A Prospective, Randomized, Open-Label, Multicenter Study.
abstract: BACKGROUND
  Osteonecrosis of the femoral head frequently leads to collapse of the necrotic portion and subsequent degenerative joint disease of the hip, which is the most common diagnosis leading to total hip arthroplasty in young adults. Bisphosphonate therapy has been reported to potentially retard the collapse. We conducted a two-year prospective, randomized, open-label, multicenter study to determine whether zoledronate prevents the collapse and reduces the need for total hip arthroplasty.
  
  
  METHODS
  We randomly assigned patients who had Steinberg stage-I or II nontraumatic osteonecrosis of the femoral head with a necrotic area of ≥30% to either the zoledronate group or the control group. Patients in the zoledronate group received 5 mg of zoledronate intravenously per year for two years, while patients in the control group did not receive this medication. The primary efficacy outcome was the survival rate in terms of the occurrence of collapse (≥2 mm). The patients were observed for a minimum of two years after enrollment.
  
  
  RESULTS
  A total of 110 patients (110 hips) underwent randomization; fifty-five patients were assigned to the zoledronate group and fifty-five, to the control group. During the two-year follow-up, twenty-nine femoral heads in the zoledronate group and twenty-two in the control group collapsed (p > 0.05). Nineteen hips in the zoledronate group and twenty in the control group underwent total hip arthroplasty (p > 0.05).
  
  
  CONCLUSIONS
  Zoledronate for Steinberg stage-I or II osteonecrosis of the femoral head, with a medium to large necrotic area, did not prevent the collapse of the femoral head or reduce the need for total hip arthroplasty.
  
  
  METHODS
  Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.
authors.affiliation: Seoul National University Bundang Hospital, Seoul National University College of Medicine, 82 Gumi-ro 173 beon-gil, Bundang-gu, Seongnam 463-707, South Korea. E-mail address for Y.-K. Lee: ykleemd@gmail.com. E-mail address for K.-H. Koo: khkoo@snu.ac.kr.
authors.forename: Young-Kyun
authors.initials: YK
authors.lastname: Lee
authors.affiliation: Department of Orthopaedic Surgery, Chung-Ang University College of Medicine, 224-1 Heukseok-dong, Dongjak-gu, Seoul 156-755, South Korea. E-mail address: hayongch@naver.com.
authors.forename: Yong-Chan
authors.initials: YC
authors.lastname: Ha
authors.affiliation: College of Medicine, Kyung Hee University, 1 Hoegi-dong, Dongdaemun-gu, Seoul 130-702, South Korea. E-mail address: yjcho@khmc.or.kr.
authors.forename: Yoon Je
authors.initials: YJ
authors.lastname: Cho
authors.affiliation: Pusan National University Yangsan Hospital, Pusan National University School of Medicine, 20 Geumo-ro, Mulgeum-eup, Yangsan 626-770, South Korea. E-mail address: kuentak@pusan.ac.kr.
authors.forename: Kuen Tak
authors.initials: KT
authors.lastname: Suh
authors.affiliation: School of Medicine, Kyungpook National University, 680 Gukchaebosang-ro, Jung-gu, Daegu 700-842, South Korea. E-mail address: syukim@knu.ac.kr.
authors.forename: Shin-Yoon
authors.initials: SY
authors.lastname: Kim
authors.affiliation: Ajou University School of Medicine, San 5, Woncheon-dong, Yeongtong-gu, Suwon 443-721, South Korea. E-mail address: thrtkr@ajou.ac.kr.
authors.forename: Ye-Yeon
authors.initials: YY
authors.lastname: Won
authors.affiliation: Keimyung University Dongsan Medical Center, 194 Dongsan-dong, Jung-gu, Daegu 700-712, South Korea. E-mail address: min@dsmc.or.kr.
authors.forename: Byung-Woo
authors.initials: BW
authors.lastname: Min
authors.affiliation: Chonnam National University Hwasun Hospital, 322 Seoyong-ro, Hwasun-eup, Hwasun-gun, Jeonnam 519-809, South Korea. E-mail address: tryoon@chonnam.ac.kr.
authors.forename: Taek Rim
authors.initials: TR
authors.lastname: Yoon
authors.affiliation: Seoul National University Hospital, Seoul National University College of Medicine, 101 Daehak-ro, Jongno-gu, Seoul 110-744, South Korea. E-mail address: oskim@snu.ac.kr.
authors.forename: Hee Joong
authors.initials: HJ
authors.lastname: Kim
authors.affiliation: Seoul National University Bundang Hospital, Seoul National University College of Medicine, 82 Gumi-ro 173 beon-gil, Bundang-gu, Seongnam 463-707, South Korea. E-mail address for Y.-K. Lee: ykleemd@gmail.com. E-mail address for K.-H. Koo: khkoo@snu.ac.kr.
authors.forename: Kyung-Hoi
authors.initials: KH
authors.lastname: Koo
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D019644:Arthroplasty, Replacement, Hip; D050071:Bone Density Conservation Agents / Q000627:therapeutic use*; D004164:Diphosphonates / Q000627:therapeutic use*; D005260:Female; D005270:Femur Head / Q000473:pathology*; D006801:Humans; D007093:Imidazoles / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D010020:Osteonecrosis / Q000188:drug therapy* / Q000473:pathology*; D011446:Prospective Studies; D016896:Treatment Outcome; D000077211:Zoledronic Acid
chemical_list: D050071:Bone Density Conservation Agents; D004164:Diphosphonates; D007093:Imidazoles; D000077211:Zoledronic Acid