Bone
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Orthopedic joint prostheses may loosen because of localized bone resorption. Despite initial optimism, there are no reports showing that bisphosphonates can stop the progression of prosthetic loosening once it has begun. This might be due to the strong resorptive stimulus, which continuously recruits new osteoclasts. ⋯ Both alendronate doses reduced serum levels of tartrate-resistant acid phosphatase isoform 5b to a similar extent, demonstrating that the lower dose was able to reduce resorption in the normally remodeling skeleton, although not in the osteolytic lesions caused by instability. Osteoclast numbers in the lesion were increased by the lower bisphosphonate dose and reduced by OPG-Fc. The results suggest the possibility of targeting osteoclast recruitment via the RANKL system in patients with impending prosthetic loosening.
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This multicenter study assessed the safety and efficacy of teriparatide 20 microg/day in Japanese men and women with osteoporosis at high risk of fracture during a 12-month, randomized, double-blind, placebo-controlled treatment period followed by second and third treatment periods (to 18 and 24 months, respectively,) in which all subjects received open-label teriparatide. Subjects (93% female; median age 70 years) were randomized 2:1 to teriparatide versus placebo (randomized at baseline, teriparatide n=137, placebo-teriparatide n=70; entering the second period, teriparatide n=119, placebo-teriparatide n=59; entering the third period, teriparatide n=102, placebo-teriparatide n=50). For subjects with measurements at 12 months, teriparatide significantly increased bone mineral density (BMD) at the lumbar spine L2-L4 (mean percent change+/-SD, teriparatide 10.04+/-5.23% versus placebo-teriparatide 0.19+/-4.33%), the femoral neck (teriparatide 2.01+/-4.63% versus placebo-teriparatide 0.44+/-3.97%), and the total hip (teriparatide 2.72+/-4.04% versus placebo-teriparatide -0.26+/-3.42%). ⋯ Serum procollagen I N-terminal pro-peptide (PINP) increased rapidly with teriparatide treatment (P<0.001 versus placebo at 1 month) and changed from baseline in the teriparatide and placebo-teriparatide groups at 12 months by a median of 78.95% and -17.23%, respectively, (P<0.001) and at 24 months by 49.24% and 76.12%, respectively. The incidence of treatment-emergent adverse events (TEAEs), serious TEAEs, and discontinuations due to TEAEs were comparable in the teriparatide and placebo-teriparatide groups. These data show that teriparatide 20 microg/day was well tolerated and stimulated bone formation in Japanese subjects with osteoporosis at high risk of fracture during 18 and 24 months of treatment.
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Bioactive glass (BAG)-S53P4 is an osteoconductive bone substitute with proven antibacterial and bone bonding properties. In a multicentre study 11 patients with verified chronic osteomyelitis in the lower extremity and the spine were treated with BAG-S53P4 as a bone substitute. The cavitary bone defect and the surrounding of a spinal implant were filled with BAG-S53P4. ⋯ Nine patients healed without complications. One patient who achieved good bone formation sustained a superficial wound infection due to vascular problems in the muscle flap, and one patient had an infection due to a deep haematoma. This study shows that BAG-S53P4 is a good and well-tolerated bone substitute, and can be used in treatment of osteomyelitis with good primary results.
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Earlier studies have shown that the influence of fixation stability on bone healing diminishes with advanced age. The goal of this study was to unravel the relationship between mechanical stimulus and age on callus competence at a tissue level. Using 3D in vitro micro-computed tomography derived metrics, 2D in vivo radiography, and histology, we investigated the influences of age and varying fixation stability on callus size, geometry, microstructure, composition, remodeling, and vascularity. ⋯ Varying fixator configurations in older individuals did not alter the dominant effect of advanced age on callus tissue mineralization, unlike in their younger counterparts. Age-associated influences appeared independent from stability. This study illustrates the dominating role of osteoclastic activity in age-related impaired healing, while demonstrating the optimization of fixation parameters such as stiffness appeared to be less effective in influencing healing in aged individuals.
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Bone defects in vertebral bodies (VB) usually occur after the reduction of fractures or are caused by bone disease. Besides the treatment of original disease, repair of the bone defect can restore the structure of VB and improve stabilization of the spine to protect the spinal cord nerves. To aid studies of the efficacy of bioengineering techniques for repair of VB, we developed a rat model with a critical size bone defect in VB. ⋯ This animal model has further utility for the study of different biomaterials for VB bone repair. Implantation of a bioactive PLGA scaffold carrying rhBMP2 allowed more successful repair of the VB defect. Although further characterization studies are needed, the bioactive PLGA scaffold developed in this study will likely adapt easily to other in vivo osteogenesis applications.