Efficacy of electrical polarization on a rat femoral bone defect model with a custom-made external fixator.

BACKGROUND: We have developed a technology to electrically polarize living bone. OBJECTIVE: The effects of stored electrical charge in electrical polarized bone on the facilitation of new bone formation were assayed. METHODS: Stimulated depolarized current measurement was performed in electrically polarized and nonpolarized femora of SD rats. These bone specimens were implanted into bone defects of the rat femora and fixed with a custom-made external fixator. X-ray imaging of the implant was performed every week. After 3 weeks, micro-CT scanning was performed to evaluate the displacement rate. Histological observation was performed, and the occupancy ratio of the newly formed bone was calculated from tissue specimens stained with Villanueva's Goldner method. RESULTS: There was a tendency for the displacement rate of the implant to be smaller and the occupancy ratio of the newly formed bone to be larger, especially at the distal end, in the polarized group compared with the nonpolarized group. The time of callus appearance was significantly earlier in the polarized group than in the nonpolarized group, and bridging callus grew from the distal to the proximal end. CONCLUSIONS: Bone specimens can be electrically polarized, and the stored electrical charge can work effectively to facilitate new bone formation.

Availability of ultrasound screening for asymptomatic elbow injuries in judo athletes.

OBJECTIVE: We conducted ultrasonography (US) examination for asymptomatic elbow injuries in judo athletes to confirm availability of US screening for elbow. MATERIALS AND METHODS: One hundred and thirty-two black belts in judo (85 males and 47 females; mean age, 20.0 ± 1.6 years) participated in this screening. Forty-eight participants had a history of elbow injury (elbow-injury group), and 84 did not (no-elbow-injury group). All participants completed a survey in the form of a questionnaire. Subsequently, US scanning of both elbows was performed. RESULTS: The maximal thickness of the medial collateral ligament of both elbows was significantly larger in the elbow-injury group than in the no-elbow-injury group. The width of the joint space was significantly larger in the right radiohumeral joint in the elbow-injury group than in the no-elbow-injury group. Combination injuries involving ligament and bone and those involving both the medial and lateral collateral ligaments were most commonly seen in both elbows in the elbow-injury group; however, these combined lesions of both elbows were also found in the no-elbow-injury group. CONCLUSIONS: Because US screening can reveal abnormalities of the asymptomatic elbow, US is recommended as a complementary imaging modality that is useful for evaluation of elbow injuries in athletes.

Effectiveness of bisphosphonate combined with activated vitamin D in patients with aromatase inhibitor-induced osteoporosis after breast cancer operation.

OBJECTIVES: We compared the effectiveness of bisphosphonates combined with activated vitamin D administered for therapy of aromatase inhibitor-induced osteoporosis after a breast cancer operation and primary postmenopausal osteoporosis through propensity score matching. METHODS: Forty-eight postmenopausal patients with estrogen receptor-positive early breast cancer, who had postoperative adjuvant treatment with aromatase inhibitors and whose T-score of bone mineral density (BMD) decreased below -2.5 (AI group), and 48 patients of primary postmenopausal osteoporosis (PO group) enrolled in this retrospective observational study. They were administered monthly risedronate or minodronate, and daily alfacalcitol or eldecalcitol were combined. Their BMD (L2-4, L-BMD), serum-corrected calcium, serum phosphate, tartrate-resistant acid phosphatase 5b (TRACP-5b), bone alkaline phosphatase (BAP), estimated glomerular filtration rate, urine calcium/creatinine ratio, intact-parathyroid hormone, and 25-hydroxy vitamin D were measured before treatment and until 24 months. RESULTS: L-BMD values increased with time compared with the baseline values in each group, and there was no significant difference in the groups. Percentage value of TRACP-5b decreased rapidly after 6 months and maintained low level until 24 months in both groups. Percentage value of BAP in the AI group decreased continuously until 24 months. In contrast, the percentage change in the PO group plateaued after 6 months. CONCLUSIONS: It is suggested that monthly oral bisphosphonate combined with activated Vitamin D is an effective therapy to increase BMD in the aromatase inhibitor-induced osteoporosis after breast cancer operation. Monitoring of kidney function and concentration of Ca in blood and urine may be necessary.

Development of a nerve scaffold using a tendon chitosan tube.

Bridge grafting (15 mm) into the sciatic nerve of SD rats was carried out using tendon chitosan tubes having either a circular or triangular cross-section, as well as triangular tubes combined with laminin, CDPGYIGSR, or CSRARKQAASIKVAVSAD (n = 15 in each group). As a control, isografting (15 mm) was carried out in the SD rats (n = 7). Specimens were taken after 1, 2, 4, 6, and 8 weeks for histology, and nerve regeneration was evaluated electro-physiologically and histologically after 12 weeks. The mechanical strength of triangular tubes was found to be higher than circular tubes, and the inner volume of a triangular tube tends to be larger than in circular tubes. Nerve tissue regeneration along the tube wall was found in both the laminin and laminin peptide groups. According to the result of percentage neural tissue in relation to evoked action potentials, the consecutive treatments of YIGSR and IKVAV was found to match the effectiveness of intact laminin.