title: Prevention of postoperative osteopenia using IV pamidronate: a pilot study.
abstract: BACKGROUND
  Postoperative bone mineral density (BMD) loss, especially after cast immobilization and/or non-weight-bearing, is a well-known phenomenon in children that can cause fracture. Children with marginal bone density are at greatest risk. This prospective randomized control trial compared the effect of single-dose intravenous (IV) pamidronate versus placebo to prevent postoperative BMD loss.
  
  
  METHODS
  Children between the ages of 4 and 18 were included in the study; inclusion criteria included a predisposition to low bone density and hip or lower extremity surgery that would require cast immobilization or non-weight-bearing for at least 4 weeks. Dual-energy x-ray absorptiometry (DXA) scans of the lumbar spine and bilateral distal femora were performed preoperatively and at least 4 weeks postoperatively. Subjects were randomized to receive either a single, low dose of IV pamidronate (1 mg/kg) or placebo, given during the immediate postoperative period. Changes in the BMD were compared using the Mann-Whitney test for significance in the lumbar spine. A multivariate general linear model was used to compare the effect of surgery, DXA region, and treatment on BMD.
  
  
  RESULTS
  A total of 24 subjects were included in the study, and 20 completed the protocol. Pamidronate-treated subjects showed a statistically significant difference with a median gain in BMD of 0.029 gm/cm in the lumbar spine compared with the control group, which showed a median loss of 0.025 gm/cm. Treatment did not have a statistically significant effect on BMD loss in the distal femur but trended toward decreased BMD loss (treatment=0.0331 gm/cm, control=0.0416 gm/cm). There were no complications or adverse reactions.
  
  
  CONCLUSIONS
  This small pilot study shows that single-dose postoperative pamidronate mitigated postoperative BMD loss in at-risk children, which may in turn decrease postoperative fracture risk. Further investigation into the use of IV pamidronate in postoperative patients is warranted.
  
  
  METHODS
  Level 1 double-blinded randomized control trial.
authors.affiliation: *Department of Orthopaedics and Rehabilitation †University of New Mexico School of Medicine, 1 University of New Mexico ‡Department of Orthopaedics and Rehabilitation, University of New Mexico Carrie Tingley Hospital, Albuquerque, NM.
authors.forename: Bryon D
authors.initials: BD
authors.lastname: Hobby
authors.forename: Samuel
authors.initials: S
authors.lastname: Dominguez-Bartmess
authors.forename: Elizabeth A
authors.initials: EA
authors.lastname: Szalay
mesh_terms: D015502:Absorptiometry, Photon; D061605:Administration, Intravenous; D000293:Adolescent; D015519:Bone Density; D050071:Bone Density Conservation Agents / Q000008:administration & dosage / Q000627:therapeutic use*; D001851:Bone Diseases, Metabolic / Q000209:etiology / Q000517:prevention & control*; D002648:Child; D002675:Child, Preschool; D004164:Diphosphonates / Q000008:administration & dosage / Q000627:therapeutic use*; D005260:Female; D006801:Humans; D016014:Linear Models; D008297:Male; D015999:Multivariate Analysis; D000077268:Pamidronate; D010865:Pilot Projects; D011183:Postoperative Complications / Q000517:prevention & control*; D011446:Prospective Studies; D018709:Statistics, Nonparametric; D016896:Treatment Outcome
chemical_list: D050071:Bone Density Conservation Agents; D004164:Diphosphonates; D000077268:Pamidronate