In the present study, we investigated the effects of fracture fixation on joint contracture and disuse muscle atrophy. We surgically fractured the right hind limbs of male Wistar rats, and then fixed the right ankle joints at maximal plantar flexion for two weeks using dorsal splints. Compared with immobilized healthy and sham operated joints, the fractured joints concomitantly showed highly restricted range of motion and significantly higher degrees of disuse atrophy in soleus muscle; decrease of muscle fiber cross sectional area, development of central core lesion and a change in myosin heavy chain isoforms from slow type myosin to fast type myosin. Therefore, it is suggested that orthopedic fracture fixation induces intense disuse muscle atrophy to aggravate joint contracture.

OBJECTIVES: To examine the effects of whole body vibration (WBV) on bone properties in growing rats, and to explore the optimal conditions for enhancing bone properties. METHODS: Thirty-six 4-week-old male rats were divided into 1 control and 5 experimental groups. Each experimental group underwent WBV at 15, 30, 45, 60, and 90 Hz (0.5 g, 15 min/d, 5 d/wk) for 8 weeks.We measured bone size, muscle weight and bone mechanical strength of the right tibia. Trabecular bone mass and trabecular bone microstructure (TBMS) of the left tibia were analyzed by micro-computed tomography. Serum levels of bone formation/resorption markers were also measured. RESULTS: WBV at 45 Hz and 60 Hz tended to enhance trabecular bone mass and TBMS parameters. However, there was no difference in maximum load of tibias among all groups. Serum levels of bone resorption marker were significantly higher in the 45-Hz WBV group than in the control group. CONCLUSIONS: WBV at 45–60 Hz may offer a potent modality for increasing bone mass during the period of rapid growth. Further studies are needed to explore the optimal WBV conditions for increasing peak bone mass and TBMS parameters. WBV modality may be a potent strategy for primary prevention against osteoporosis.
Animals ; Bone Resorption ; Humans ; Male ; Osteoporosis ; Primary Prevention ; Rats ; Tibia ; Vibration

OBJECTIVES: Type 2 diabetes mellitus (T2DM) increases fracture risk despite normal to high levels of bone mineral density. Bone quality is known to affect bone fragility in T2DM. The aim of this study was to clarify the trabecular bone microstructure and cortical bone geometry of the femur in T2DM model rats. METHODS: Five-week-old Otsuka Long-Evans Tokushima Fatty (OLETF; n = 5) and Long-Evans Tokushima Otsuka (LETO; n = 5) rats were used. At the age of 18 months, femurs were scanned with micro-computed tomography, and trabecular bone microstructure and cortical bone geometry were analyzed. RESULTS: Trabecular bone microstructure and cortical bone geometry deteriorated in the femur in OLETF rats. Compared with in LETO rats, in OLETF rats, bone volume fraction, trabecular number and connectivity density decreased, and trabecular space significantly increased. Moreover, in OLETF rats, cortical bone volume and section area decreased, and medullary volume significantly increased. CONCLUSIONS: Long-term T2DM leaded to deterioration in trabecular and cortical bone structure. Therefore, OLETF rats may serve as a useful animal model for investigating the relationship between T2DM and bone quality.
Animals ; Bone Density ; Diabetes Mellitus, Type 2 ; Femur ; Models, Animal ; Rats* ; Rats, Inbred OLETF

Objective：The aim of this study was to develop an 8-item Japanese Arthritis Self-Efficacy Scale (ASES-8J）and perform pilot testing of its face validity and internal consistency in patients with osteoarthritis of the knee.Methods：Translation of the ASES-8J from English into Japanese was performed via forward-translation, back-translation, review by the original developer, and production of the pre-final version. We calculated the mean and standard deviation and Cronbach's alpha coefficient to assess internal consistency. Face validity was assessed by reviewing the results of the pilot study and using in-depth questionnaires on the responders' understanding of the ASES-8J.Results：Forty-one patients with osteoarthritis of the knee participated in the pilot study, with 38 providing valid responses. The mean ± standard deviation was 5.7 ± 2.2. Cronbach's alpha coefficient was 0.96, indicating high internal consistency. Of the responders, 54.9％ stated that it the ASES-8J was very easy or easy to answer. The original developer reviewed ASES-8J to confirm its usefulness.Conclusion：The results indicate that ASES-8J is a useful tool to assess the self-efficacy of patients with osteoarthritis of the knee.

Objective：The aim of this study was to develop an 8-item Japanese Arthritis Self-Efficacy Scale (ASES-8J）and perform pilot testing of its face validity and internal consistency in patients with osteoarthritis of the knee.Methods：Translation of the ASES-8J from English into Japanese was performed via forward-translation, back-translation, review by the original developer, and production of the pre-final version. We calculated the mean and standard deviation and Cronbach's alpha coefficient to assess internal consistency. Face validity was assessed by reviewing the results of the pilot study and using in-depth questionnaires on the responders' understanding of the ASES-8J.Results：Forty-one patients with osteoarthritis of the knee participated in the pilot study, with 38 providing valid responses. The mean ± standard deviation was 5.7 ± 2.2. Cronbach's alpha coefficient was 0.96, indicating high internal consistency. Of the responders, 54.9％ stated that it the ASES-8J was very easy or easy to answer. The original developer reviewed ASES-8J to confirm its usefulness.Conclusion：The results indicate that ASES-8J is a useful tool to assess the self-efficacy of patients with osteoarthritis of the knee.