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.
The Institute of Orthopaedics and Musculoskeletal Science, University College London, The Royal National Orthopaedic Hospital Trust, Brockley Hill, Stanmore, Middlesex HA7 4LP, United Kingdom.
Allen E
AE
Goodship
Gordon W
GW
Blunn
Jonathan
J
Green
Melanie J
MJ
Coathup
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