Effects of Teriparatide and Aerobic Exercise on Lumbar Spine Microstructure in Ovariectomized and Tail-Suspended Rats

Osteoporosis is an increasingly prevalent malady of the elderly that is associated with bone fragility and increased risk of fractures. Osteoporosis treatments focus on restoring bone strength and quality. Teriparatide (TPTD) is a therapeutic agent that has been shown to increase bone strength by improving the volume and connectivity of trabecular bone. Exercise is also known to have pro-osteogenic effects. Here we used a rat model of severe osteoporosis (ovariectomized and tail-suspension) to evaluate the effects of TPTD, exercise and a combination of TPTD and exercise on the microstructure of trabecular bone. TPTD mono-therapy and TPTD combined with exercise treatment significantly increased bone mineral density (BMD) in the whole body. Micro-computed tomography analysis revealed that a combination of exercise and TPTD treatment significantly decreased bone surface to volume and trabecular separation compared with those of the control and exercise groups. Node-strut analysis indicated that exercise or TPTD alone did not affect trabecular bone connectivity. However, the combination of exercise and TPTD treatment significantly decreased measures of trabecular bone connectivity (node number) that are consistent with a transition from rod-like to plate-like of trabecular bone microstructures. The combination treatment with exercise and TPTD improved microstructure of trabecular bone in the OVX and tail-suspended rats. These results indicate that combining exercise with TPTD represents a viable means to improve cancellous bone strength in osteoporosis populations.

Clinical Outcomes of Patients Who Perform High-Load Activities after Total Hip Arthroplasty in Snowy Agricultural Areas

Background: In snowy agricultural areas, weeding and snow shoveling are essential activities, and sports activities are common recreational activities. Clarifying the relationships between the degrees of these activities after total hip arthroplasty (THA) and the clinical outcomes may enable us to predict the results of THA for high-load activity patients. Methods: The subjects were 227 post-THA patients who were followed up between 2012 and 2014. Patient-reported outcomes were investigated by the Japanese Orthopaedic Association Hip Disease Evaluation Questionnaire (JHEQ) and a questionnaire on postoperative activity. In addition, the Japanese Orthopaedic Association Hip Score (JOA score) was used to quantify hip function. Results: Patients who resumed activities had significantly higher JOA and JHEQ scores than patients who had given up their activities. However, 25.8% of patients had not resumed weeding with a squatting posture. Furthermore, 20% had not resumed sports activities. The most common reason for giving up these activities was fear of implant failure. Conclusions: If the patients were informed that there is no problem restarting their activities after THA, the patients could resume activities and their clinical outcomes may be improved.

Effects of Povidone-Iodine or Ethanol Exposure on Bone Formation at the Osteotomy Site of the Proximal Tibia in Rats

Background: Povidone-iodine (PVI) irrigation is currently used to decrease the frequency of postoperative surgical site infections. Ethanol (EtOH) is sometimes applied to prevent local recurrence after curettage of benign bone tumors. However, the effects of PVI and EtOH on surrounding soft tissue and on bone union are unclear. The purpose of this study was to determine whether PVI or EtOH adversely affects the cancellous bone healing of the osteotomy site at the proximal tibia in rats. Methods: A cancellous bone osteotomy was performed at the right proximal tibia in 4-month-old, female, Sprague Dawley rats. Vehicle, 10% PVI, or 95% EtOH-soaked gauze was inserted into the osteotomy site and maintained for 6 minutes. The rats were euthanized 2 or 4 weeks after the osteotomy. Results: Two weeks after treatment, the bone union rate was significantly higher in the vehicle group than in the PVI group and the EtOH group (p < 0.001). However, the bone union rate was not significantly different between the PVI and EtOH groups. There was no significant difference among the three groups in the bone union rate 4 weeks after treatment. Conclusion: PVI or EtOH delayed bone union of the cancellous bone osteotomy site of the proximal tibia in the early phase (2 weeks), but not at 4 weeks, in rats.