Prevention of strain-related osteopenia in aseptic loosening of hip prostheses using perioperative bisphosphonate.
The hypothesis tested in this study was that perioperative administration of the bisphosphonate zoledronate will reduce strain protection-related calcar osteopenia and maintain functional integration of the femoral component in an ovine hemiarthroplasty model. Twelve sheep received a unilateral cemented hemiarthroplasty where six animals were given nine intravenous infusions of zoledronate (10 microg/kg) pre-, peri-, and postsurgery over 8 months. Control animals received physiological saline only. Implants remained in vivo for 9 months. Ground reaction force (GRF) was used to assess functional loading of the implanted limb, bone mineral density (BMD) was quantified using dual energy X-ray absorptiometry (DEXA). Cortical bone area, thickness, and viable osteocytes were assessed histologically. No significant differences in GRF data between groups was identified. Results demonstrated a significant drop in BMD values in the control group (9.7%) when compared with the bisphosphonate-treated group (3.2%) (p = 0.0159). Histological results showed that cortical area, thickness, and the percentage of lacunae with viable osteocytes was significantly greater in the bisphosphonate-treated group when compared with control (p = 0.002, p = 0.001, p = 0.003, respectively). The administration of zoledronate reduced cortical osteopenia in the calcar region of the proximal femur and this therapy could be used as a preventive measure to combat strain protection osteopenia and its contribution to associated aseptic loosening in total hip replacement surgery.
Goodship
Allen E
AE
The Institute of Orthopaedics and Musculoskeletal Science, University College London, The Royal National Orthopaedic Hospital Trust, Brockley Hill, Stanmore, Middlesex HA7 4LP, United Kingdom.
Blunn
Gordon W
GW
Green
Jonathan
J
Coathup
Melanie J
MJ
D000818:Animals; D019644:Arthroplasty, Replacement, Hip / Q000009:adverse effects*; D015519:Bone Density / Q000187:drug effects; D050071:Bone Density Conservation Agents / Q000494:pharmacology / Q000627:therapeutic use*; D001851:Bone Diseases, Metabolic / Q000175:diagnosis / Q000209:etiology / Q000517:prevention & control*; D004164:Diphosphonates / Q000494:pharmacology / Q000627:therapeutic use*; D005260:Female; D006621:Hip Joint / Q000473:pathology; D007093:Imidazoles / Q000494:pharmacology / Q000627:therapeutic use*; D008124:Locomotion / Q000187:drug effects; D008852:Microradiography; D011475:Prosthesis Failure; D011897:Random Allocation; D012756:Sheep; D013314:Stress, Mechanical; D000077211:Zoledronic Acid
D050071:Bone Density Conservation Agents; D004164:Diphosphonates; D007093:Imidazoles; D000077211:Zoledronic Acid