title: Evidence for using bisphosphonate to treat Legg-Calvé-Perthes disease.
abstract: BACKGROUND
  The rationale for using bisphosphonate (BP) therapy for Legg-Calvé-Perthes disease (LCPD) is the potential to prevent substantial femoral head deformity during the fragmentation phase by inhibiting osteoclastic bone resorption. However, it is unclear whether BP therapy decreases femoral head deformity.
  
  
  OBJECTIVE
  In this systematic review, we answered the following questions: (1) Does bisphosphonate (BP) therapy decrease femoral head deformity and improve pain and function in LCPD or other juvenile osteonecrotic conditions? And (2) does BP therapy decrease femoral head deformity in experimental studies of juvenile femoral head osteonecrosis?
  
  
  METHODS
  We searched the literature from 1966 to 2011 for clinical and experimental studies on BP therapy for juvenile femoral head osteonecrosis. Studies specifically addressing clinical and/or radiographic/histologic outcomes pertaining to pain and function and femoral head morphology were analyzed.
  
  
  RESULTS
  Three Level IV clinical studies met our inclusion criteria. Only one study initiated BP therapy during the precollapsed stage of osteonecrosis and reported prevention of femoral head deformity in nine of 17 patients. All studies noted subjective improvements of pain and gait in patients treated with intravenous BPs. Of the eight experimental studies reviewed, seven reported reduced femoral head deformity and six found better preservation of trabecular framework in animals treated with BPs.
  
  
  CONCLUSIONS
  Clinical evidence lacks consistent patient groups and drug protocols to draw definitive conclusions that BP therapy can decrease femoral head deformity in juvenile osteonecrotic conditions. Experimental studies suggest BP therapy protects the infarcted femoral head from deformity, but it lacks bone anabolic effect. Further basic and clinical research are required to determine the potential role of BPs as a medical treatment for LCPD.
authors.affiliation: Texas Scottish Rite Hospital for Children, UT Southwestern Medical Center, Dallas, TX, USA.
authors.forename: Megan L
authors.initials: ML
authors.lastname: Young
authors.forename: David G
authors.initials: DG
authors.lastname: Little
authors.forename: Harry K W
authors.initials: HK
authors.lastname: Kim
mesh_terms: D000818:Animals; D018771:Arthralgia / Q000209:etiology / Q000517:prevention & control; D001696:Biomechanical Phenomena; D050071:Bone Density Conservation Agents / Q000627:therapeutic use*; D016723:Bone Remodeling / Q000187:drug effects*; D004164:Diphosphonates / Q000627:therapeutic use*; D004195:Disease Models, Animal; D019317:Evidence-Based Medicine; D005270:Femur Head / Q000000981:diagnostic imaging / Q000187:drug effects* / Q000503:physiopathology; D006801:Humans; D007873:Legg-Calve-Perthes Disease / Q000150:complications / Q000000981:diagnostic imaging / Q000188:drug therapy* / Q000503:physiopathology; D011859:Radiography; D020127:Recovery of Function; D016896:Treatment Outcome
chemical_list: D050071:Bone Density Conservation Agents; D004164:Diphosphonates