title: A single dose zoledronic acid enhances pin fixation in high tibial osteotomy using the hemicallotasis technique. A double-blind placebo controlled randomized study in 46 patients.
abstract: BACKGROUND
  Bisphosphonates have been shown to reduce osteoclastic activity and enhance pin fixation in both experimental and clinical studies. In this prospective, randomized study of high tibial osteotomy using the hemicallotasis (HCO) technique, we evaluate whether treatment by one single infusion of zoledronic acid can enhance the pin fixation.
  
  
  METHODS
  46 consecutive patients (35-65 years) were operated on for knee osteoarthritis by the HCO technique. After the osteotomy, two hydroxyapatite-coated pins were inserted in the metaphyseal bone and two non-coated pins in the diaphyseal bone. The insertion torque was measured by a torque force screw driver. Four weeks postoperatively, the patients were randomized to either one infusion of zoledronic acid or sodium chloride intravenously. At time for removal of the pins, the extraction torque forces of the pins were measured.
  
  
  RESULTS
  All osteotomies healed and no difference was found in time to healing. The mean extraction torque force in the non-coated pins in the diaphyseal bone was doubled in the zoledronic treated group (4.5 Nm, SD 2.1) compared to the placebo group (2.4 (SD 1.0, p<0.0001). The mean extraction torque forces of the hydroxyapatite-coated pins in the metaphyseal bone were similar in the zoledronic acid group (4.7 Nm, SD 1.3) and in the placebo group (4.0 Nm, SD 1.3).
  
  
  CONCLUSIONS
  A single infusion of zoledronic acid improved twofold the fixation of non-coated pins in diaphyseal bone. Bisphosphonates might be an alternative to hydroxyapatite-coated pins in nonosteoporotic bone.
authors.affiliation: Department of Orthopedics, Clinical Sciences Lund University and Lund University Hospital, SE-221 85 Lund, Sweden. anna_kajsa.harding@med.lu.se
authors.forename: Anna Kajsa
authors.initials: AK
authors.lastname: Harding
authors.forename: Sören
authors.initials: S
authors.lastname: Toksvig-Larsen
authors.forename: Magnus
authors.initials: M
authors.lastname: Tägil
authors.forename: Annette
authors.initials: A
authors.lastname: W-Dahl
mesh_terms: D000328:Adult; D001858:Bone Nails; D020099:Coated Materials, Biocompatible / Q000008:administration & dosage / Q000009:adverse effects; D004164:Diphosphonates / Q000008:administration & dosage*; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D007093:Imidazoles / Q000008:administration & dosage*; D007262:Infusions, Intravenous; D008297:Male; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000188:drug therapy / Q000601:surgery; D010027:Osteotomy / Q000295:instrumentation* / Q000379:methods; D053831:Surgical Fixation Devices; D013977:Tibia / Q000187:drug effects* / Q000601:surgery*; D000077211:Zoledronic Acid
chemical_list: D020099:Coated Materials, Biocompatible; D004164:Diphosphonates; D007093:Imidazoles; D000077211:Zoledronic Acid