Effect of combined exercise training on bone, body balance, and gait ability: a randomized controlled study in community-dwelling elderly women.

The purpose of this study was to investigate whether a 48-week multicomponent exercise program could improve the risk factors for fall and hip fracture. Fifty elderly women 65-70 years of age participated. These participants were divided into an exercise group (25 subjects) that attended an exercise program and a control group (25 subjects) that did not. The exercise program included stretching for 9 min, strength training for 10 min followed by 23 min of weight-bearing exercise at an intensity above 65%-75% of the maximal heart rate, and 18 min of balance and posture correction training. The program was conducted three times per week for 48 weeks. The 10-m maximal walk time, maximal step length, and eyes-open-one-legged-stand time in the exercise group improved significantly (P < 0.05). Concerning deoxypyridinoline, the exercise group achieved a significant improvement (P < 0.05) after the 48 weeks. Bone mineral density (BMD) of the femoral neck and trochanter in the exercise group was significantly increased after the exercise program; also body sway was significantly improved (P < 0.05). In conclusion, a multi-component exercise program with weight-bearing exercise at a moderate intensity and gait training may be effective in offsetting a decline in BMD and improving aggravation of bone resorption in this population. In addition, this program has a positive effect on postural stability and gait ability.

Effect of bone marrow grafting on the titanium porous-coated implant in bilateral total knee arthroplasty.

BACKGROUND AND PURPOSE: Poor bone ingrowth into the porous coating of tibial components has been reported. We hypothesized that iliac marrow grafting might be useful to enhance bone ingrowth into a porous-coated implant. The first part of this study was to examine the presence of fibroblast colony-forming units (CFUF) containing osteogenic precursor cells in tibial bone marrow and iliac bone marrow. The second aim was to compare the clinical and radiographic results after bilateral total knee arthroplasty (TKA) with and without autologous bone marrow transplantation to the bone-implant interface. METHODS: Simultaneous bilateral TKA was performed in 21 patients with osteoarthritis. Aspirated iliac bone marrow was transplanted to the interface of one randomly selected porous-coated tibial component in each patient, and contralateral knees served as controls. All of the 21 patients were followed for 5 years. RESULTS: The average number of CFU-F was significantly lower in tibial marrow than in iliac marrow (p = 0.008). The final fluoroscopically-guided radiographs revealed a decrease in the number of knees with radiolucent lines after marrow grafting compared to those without grafting (p = 0.004). INTERPRETATION: Iliac bone marrow is useful as a bone grafting material to enhance the biological fixation in porous-coated implants.

Clinical factors as predictors of the risk of falls and subsequent bone fractures due to osteoporosis in postmenopausal women.

In Japan, the "bedridden state" is one of the most serious problems the aged face, and it is becoming a social problem. The main causes of the bedridden state are cerebrovascular disorders and bone fractures following falls. The purpose of this study was to predict risk factors for falls and resultant bone fracture due to osteoporosis. We explored mobility parameters for possible fall prevention. In order to examine the correlation between the risk of falling and resultant bone fracture due to osteoporosis, logistic regression analysis was performed between bone mass (independent variable) and various factors dependent variables: body mass index [BMI], body fat percentage, atherogenic index, presence of transformation-related osteoarthritis of knee, presence of transformation-related osteoarthritis of spine, maximum step length, single-leg stance with open eyes, and hip-joint flexion motion angle); predictive factors were then examined. Predictive factors were determined by the stepwise method. Subjects who could not perform the "single-leg stance with open eyes" test had a risk of falling and bone fracture 2.49 times as large as that of subjects who could. The "single-leg stance with open eyes" test may be considered a useful method for the early detection of the risk of falling and bone fracture associated with osteoporosis. As a first step to identify factors predicting the occurrence of falls and bone fractures due to osteoporosis, we intended to discover an indicator that would help to detect incipient osteoporosis.

Gene expression of bone-resorbing cytokines in rat osteolysis model.

Osteolysis after single-injection polyethylene (PE) administration has been analyzed, but this experimental model did not reflect the clinical postoperative condition. Therefore, we investigated the bone-resorbing cytokines interleukin and tumor necrosis factor (IL-1alpha, IL-6, TNFalpha) produced by continuous PE administration using histomorphologic findings and the reverse transcription polymerase chain reaction. TNFalpha mRNA was continuously detected in the PE continuous-infusion group, whereas it was not expressed in the PE single-injection group. IL-1alpha and IL-6 mRNA were detected in both groups. As for histomorphological findings, in the PE continuous-infusion group proliferating fibrous tissue penetrated subchondral bone and the interface membrane around the K-wire inserted into the femur. Numerous osteoclasts were observed in the vicinity of resorbed bone. In the PE single-injection group, proliferation of fibrous tissue with bone resorption was not observed. TNFalpha may play a major role in fibrous tissue formation and osteoclastic bone resorption caused by PE debris. This osteolysis model is useful for investigating osteolysis associated with bone-resorbing cytokines under conditions similar to those seen with a human prosthesis.

A novel bisphosphonate inhibits inflammatory bone resorption in a rat osteolysis model with continuous infusion of polyethylene particles.

This study examined the inhibitory effect of a new bisphosphonate (TRK-530) on wear debris-mediated bone resorption in a rat osteolysis model involving continuous infusion of high density polyethylene (HDPE) particles. TRK-530 (TRK) is a novel synthetic bisphosphonate that has been shown to decrease the level of tumor necrosis factor alpha (TNF-alpha) in the bone marrow of rats with adjuvant arthritis. Forty Wistar rats were randomized to two groups (n = 20 each). In each rat, a Kirshner (K) wire was inserted into the femur and HDPE particles were continuously infused into the knee joint. Thereafter, the animals were subcutaneously injected with saline (control group) or 1 mg/kg of TRK (TRK group) every second day, and were sacrificed at 4 or 8 weeks after surgery. Radiographs obtained at the time of sacrifice were evaluated for periprosthetic osteolysis. We also examined the thickness of the reactive membrane as well as the number of osteoclast-like cells around the K-wire. In addition, we examined the expression of genes for bone-resorbing cytokines in the reactive membrane. Radiographic peri-implant osteolysis was more frequent in the control group compared with the TRK group at each time of assessment (p < 0.01). The interfacial membrane was significantly thinner in the TRK group compared with the control group (p < 0.01) and the average number of osteoclast-like cells around the K-wire was significantly fewer in the TRK group (p < 0.01). In addition, the expression of interleukin 1-alpha messenger ribonucleic acid (IL-1alpha mRNA) and TNF-alpha mRNA was suppressed in the TRK group at each time of assessment. We conclude that the TRK can inhibit the formation of inflammatory peri-implant osteolysis induced by HDPE particles.