The aim of this investigation was to examine the effect of short-term immobilization on subchondral cortical and trabecular bone tissue in the rat tibia and to determine whether there was any difference when the knee was immobilized in extension or flexion. Thirty-six male rats were used in this study, and in 18 the knee was fixed in extension and in 18 in flexion. The time of immobilization was for 1, 2 and 3 weeks, with 12 animals in each group and 6 knees in extension and 6 in flexion. The following parameters were measured: (1) the mean thickness of subchondral and both periosteal cortices; (2) cortical porosity; (3) trabecular bone volume; (4) relative osteoid volume, and (5) relative osteoid surface. The mean cortical thickness decreased during the period of immobilization and the cortical porosity significantly increased. The trabecular bone volume was unaltered in the first week, but after 3 weeks it had decreased. The relative osteoid volume decreased significantly during the three weeks, and the relative osteoid surface moderately increased. No relationship was found between the quantitative osteopenic alteration of subchondral bone and the position of immobilization.
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http://dx.doi.org/10.1007/BF00266984 | DOI Listing |
Bone
January 2025
Division of Nephrology-Hypertension, Department of Medicine, School of Medicine, University of California, San Diego, La Jolla, CA, USA; Veterans Affairs San Diego, La Jolla, CA, USA.
Introduction: Tetracycline labeling for bone biopsy facilitates quantification of the pace of new bone production. As tetracycline labeling needs to be done prior to biopsy, it cannot be used to assess bone turnover in patients presenting with fractures, yet knowing turnover rate in patients experiencing fractures - especially in those with chronic kidney disease (CKD) - may guide appropriate medical therapy after surgical repair. Therefore, we sought to determine the diagnostic accuracy of static markers of bone turnover relative to tetracycline labeling in a pediatric and adult cohort of patients with chronic kidney disease (CKD) undergoing iliac crest biopsy with histomorphometry.
View Article and Find Full Text PDFObjective: To investigate whether Parathyroid hormone (PTH) can promote mandibular distraction osteogenesis by regulating macrophage polarization and the underlying mechanisms of this phenomenon.
Methods: Forty-eight Rabbits were used to establish the mandibular distraction osteogenesis experimental model, randomly divided into 2 groups. Intermittent post-operative injections of 20 μg/kg PTH and normal saline were administered to the experimental and control groups, respectively.
Although bone tumors (BT) are relatively uncommon among the human neoplasm, they constitute the most frequent tumors in children and adolescents (CAA). Little information is available about the epidemiologic features of BT in CAA. We aimed to present and discuss epidemiological characteristics of BT in CAA in southern Tunisia, regarding the different histological types.
View Article and Find Full Text PDFAm J Case Rep
June 2024
Faculty of Medicine, University of Medicine and Pharmacy at Ho Chi Minh City, Ho Chi Minh City, Vietnam.
BACKGROUND Monostotic fibrous dysplasia is a benign proliferation of fibrous and osseous tissues that expand medullary bone to cause symptoms due to compression of adjacent organs and anatomical structures. Focal seizures are rarely the first sign of this kind of lesion. This report describes a young female patient with left-sided focal motor seizures associated with fibrous dysplasia presenting as a mass in the right parietal bone.
View Article and Find Full Text PDFJBMR Plus
May 2024
Department of Orthopaedic Surgery, Spine Section, Chang Gung Memorial Hospital, Linkou, Taiwan and College of Medicine, Chang Gung University, Taoyuan 33305, Taiwan.
Nonunion resulting from early bone resorption is common after bone transplantation surgery. In these patients, instability or osteoporosis causes hyperactive catabolism relative to anabolism, leading to graft resorption instead of fusion. Systemic zoledronate administration inhibits osteoclastogenesis and is widely used to prevent osteoporosis; however, evidence on local zoledronate application is controversial due to osteoblast cytotoxicity, uncontrolled dosing regimens, and local release methods.
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