title: Administration of pamidronate alters bone-titanium attachment in the presence of endotoxin-coated polyethylene particles.
abstract: Bisphosphonates are promising in the treatment of periprosthetic osteolysis induced by particulate wear debris. The in vivo effects of pamidronate with different doses and durations of administration on bone-titanium attachment in the presence of endotoxin-coated polyethylene particles were examined in a rat model in this study. Titanium pins and endotoxin-coated polyethylene particles were introduced into rat femoral canals followed by intraperitoneal injection of pamidronate every other day. The treatment varied in the dose from 0 to 40 microg/kg and the duration of either 10 days or 6 weeks. Bilateral femurs were harvested after 6 weeks and examined by bone densitometer and MicroCT scan. Pamidronate increased the bone density of the left, unoperated femurs in a dose and duration dependent manner. Bone-titanium attachment significantly increased in all treatment groups compared to the control group. When pamidronate was administered for 10 days, the increase of bone-titanium attachment was significantly dose-dependent. However, when pamidronate was given for 6 weeks at 4 microg/kg, the bone-titanium attachment was significantly (p < 0.001) lower compared to the 10 day treatment of the same dose, although it was significantly higher than controls. Our results suggest that pamidronate effectively increase bone-titanium attachment even in the presence of endotoxin-coated polyethylene particles. However, long-term administration may reduce its efficacy.
authors: Department of Orthopaedic Surgery, University of Tennessee--Campbell Clinic, Memphis, Tennessee 38163, USA. zhiqingx@orthosurg.ucsf.edu
authors: Zhiqing
authors: Z
authors: Xing
authors: Karen A
authors: KA
authors: Hasty
authors: Richard A
authors: RA
authors: Smith
mesh_terms: D015502:Absorptiometry, Photon; D000818:Animals; D050071:Bone Density Conservation Agents / Q000008:administration & dosage*; D001842:Bone and Bones / Q000737:chemistry / Q000000981:diagnostic imaging / Q000187:drug effects; D004164:Diphosphonates / Q000008:administration & dosage*; D004731:Endotoxins / Q000009:adverse effects; D005260:Female; D005269:Femur / Q000737:chemistry / Q000000981:diagnostic imaging / Q000187:drug effects*; D006622:Hip Prosthesis / Q000009:adverse effects*; D007274:Injections, Intraperitoneal; D010014:Osteolysis / Q000139:chemically induced / Q000188:drug therapy*; D000077268:Pamidronate; D020959:Polyethylene / Q000009:adverse effects* / Q000737:chemistry; D051381:Rats; D017207:Rats, Sprague-Dawley; D014025:Titanium / Q000009:adverse effects* / Q000737:chemistry
chemical_list: D050071:Bone Density Conservation Agents; D004164:Diphosphonates; D004731:Endotoxins; D020959:Polyethylene; D014025:Titanium; D000077268:Pamidronate