Implant placement increases bone remodeling transiently in a rat model1. Issue 5 (31st December 2012)

• Record Type: Journal Article
• Authors: Irish, John; Virdi, Amarjit S.; Sena, Kotaro; McNulty, Margaret A.; Sumner, Dale R.
• Is Part Of: Journal of orthopaedic research. Volume 31:Issue 5(2013:May)
• Page Start: 800
• Page End: 806
• Publication Date: 2012-12-31
• Subjects: Orthopedics -- Periodicals; Musculoskeletal system -- Periodicals; 616.7
• DOI: 10.1002/jor.22294
• Languages: English
• ISSNs: 0736-0266

Abstract

<abstract abstract-type="main" xml:lang="en"> <title>Abstract</title> <p>To examine bone remodeling following implant placement, 88 female Sprague–Dawley rats underwent either sham ovariectomy (sham‐ovx) or ovariectomy (ovx) at 4.5 months. At 11 months, 17 baseline control animals were euthanized, while 71 rats received bilateral intramedullary femoral implants. Implanted rats were randomized to 4‐, 8‐, or 12‐week follow‐up times. Microcomputed tomography was used to assess cortical area and trabecular architecture in all rats. Dynamic and static histomorphometry were performed in a subset to examine the trabecular and endocortical bone in the distal femoral metaphysis adjacent to the implant and the periosteal surface at the midshaft superior to the implant (<italic>n</italic> = 59). Implantation did not affect bone volume in either sham‐ovx or ovx rats compared to baseline controls. Implant placement significantly increased mineralizing surface, mineral apposition rate, and bone formation rate in both sham‐ovx and ovx rats at the trabecular and endocortical surfaces at four and sometimes 8 weeks, with a return to baseline values by 12 weeks. At the periosteal surface, implant placement increased bone formation at 4 weeks with a return to baseline levels by 8 weeks. Thus, implant placement increases bone remodeling transiently without affecting bone volume in sham‐ovx and ovx rats. © 2012 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 31: 800–806, 2013</p> </abstract>