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Naoto Endo

Publications and source records attributed to Naoto Endo.

At least 19 recordsLinked to original sources
PubMed2006

Three-dimensional knee motion before and after high tibial osteotomy for medial knee osteoarthritis.

BACKGROUND: High tibial osteotomy (HTO) is an established surgical option for treating medial knee osteoarthritis. HTO moves the mechanical load on the knee joint from the medial compartment to the lateral compartment by changing the leg alignment, but the effects of the operation remain unclear. The purpose of this study was to evaluate the change in three-dimensional knee motion before and after HTO, focusing on lateral thrust and screw home movement, and to investigate the relationship between the change in knee motion and the clinical results. METHODS: A series of 19 patients with medial knee osteoarthritis who had undergone HTO were evaluated. We performed a clinical assessment, radiological evaluation, and motion analysis at 2.4 years postoperatively. The clinical assessment was performed using the Japanese Orthopaedic Association knee score. RESULTS: The score was significantly improved in all patients after operation. Motion analysis revealed that lateral thrust, which was observed in 18 of the 20 knees before operation, was reduced to 7 knees after operation. Regarding active terminal extension of the knee, three patterns of rotational movement were observed before operation: screw home movement (external rotation), reverse screw home movement (internal rotation), and no rotation. By contrast, after operation, only reverse screw home movement and no rotation were observed; the screw home movement disappeared in all patients. In the knees with reverse screw home movement after operation, the preoperative score was significantly lower than those in the knees with no rotation after operation. CONCLUSIONS: Kinetically, HTO was useful for suppressing lateral thrust in medial knee osteoarthritis, although the rotational movement of the knee joint was unchanged.

Adult↗
PubMed2006

Nitric oxide in cerebrospinal fluid and local inducible nitric oxide synthase after cauda equina compression in rats.

We investigated the time course of changes in nitric oxide metabolite (NO2- plus NO3-: NOx) levels in the cerebrospinal fluid and the expression of local inducible nitric oxide synthase following cauda equina compression in rats. Cerebrospinal fluid NOx levels were significantly increased from 12 h to 3 days after compression, and decreased thereafter. Histologically, inducible nitric oxide synthase immunoreactivity was observed in macrophages that infiltrated the dura mater on days 1 and 3 after compression, but not in foamy macrophages in the parenchyma of the cauda equina observed afterwards. The pattern of NOx levels coincided with the appearance of inducible nitric oxide synthase labeled macrophages, indicating a critical role of these cells as the main synthesizers of NOx in the acute stage of cauda equina compression.

Animals↗
PubMed2006

Osteoinduction with highly purified beta-tricalcium phosphate in dog dorsal muscles and the proliferation of osteoclasts before heterotopic bone formation.

The aim of the study was to examine the chronological histology of osteoinduction of highly purified beta-tricalcium phosphate (beta-TCP) implanted in dog dorsal muscles. Specimens were harvested on days 14, 28, 42, 56, 112 and 168 after implantation, and were analyzed by hematoxylin and eosin (HE) staining, tartrate-resistant acid phosphatase (TRAP) staining, immunohistochemistry, in situ hybridization, and silver impregnation. After day 28, abundant TRAP- and cathepsin K-positive multinucleated cells adhered to beta-TCP, suggesting that these cells are osteoclasts that can resorb beta-TCP. On day 56, new bone was formed and alpha1 chain of type I procollagen mRNA-positive osteoblasts lined the newly formed bone. Silver impregnation showed abundant collagen fibrils within the beta-TCP micropores. These results suggest that micropores function as a storage space for extracellular matrix components, including collagen. Newly formed bone never degenerated in the late stage, suggesting that beta-TCP has good biocompatibility and this material retains the conditions appropriate for osteointegration and bioresorption. In conclusion, beta-TCP has osteoinductivity after implantation in dog dorsal muscles without use of bone marrow cells or osteoinductive cytokines. The appearance of a large number of active osteoclasts precedes new bone formation.

Animals↗
PubMed2006

High dose glucocorticoid hampers bone formation and resorption after bone marrow ablation in rat.

We analyzed the effect of glucocorticoid on bone regeneration after bone marrow ablation in tibiae of 8-week-old rats. Methylprednisolone sodium succinate (MPSS) was injected intramuscularly at a dose of 100 mg/kg/day for 3 days. Tibiae on days 1, 3, 5, 7, 10, 12, and 14 after ablation were subjected to tartrate-resistant acid phosphatase staining, immunohistochemistry, in situ hybridization, and transmission electron microscopy (TEM), and measurement of the volume of newly-formed bone and the osteoclast number. MPSS significantly decreased the newly-formed bone volume on day 7, and immature bone still remained on day 10 in the MPSS-treated group. The volume of this bone was significantly higher than that in the control group. However, there were no differences between the groups in the osteoclast number, the expression of mRNAs for osteoblast differentiation markers, and alkaline phosphatase and cathepsin K judged by immunohistochemistry. TEM findings showed no difference in the form of osteoblasts, whereas osteoclasts in the MPSS-treated group had less developed ruffled borders, compared to those in the control group. These results suggest that MPSS treatment affects neither the differentiation nor the shape of osteoblasts, and does not change the osteoclast number or the cathepsin K level. However, high dose MPSS inhibits both bone formation and resorption during bone regeneration after rat tibial bone marrow ablation, and inhibits ruffled border formation in osteoclasts. These data will be useful to develop bone regenerative therapies for bone diseases due to high dose steroid administration.

Alkaline Phosphatase↗
PubMed2006

Risk factors for vertebral fracture in menopausal or postmenopausal Japanese women with rheumatoid arthritis: a cross-sectional and longitudinal study.

The occurrence of vertebral fracture was examined cross-sectionally and longitudinally over a 4-year interval in 117 menopausal and postmenopausal Japanese women with rheumatoid arthritis (RA), whose ages ranged from 50 to 64 years. Patients treated with bisphosphonate were excluded. Vertebral fracture was diagnosed by lateral thoracic and lumbar spine radiography at the start and end of a 4-year period. Bone mineral density (BMD) at L2-L4 according to dual-energy X-ray absorptiometry (DXA), the administration of corticosteroids or methotrexate, and urinary excretion of N-telopeptide of type I collagen (NTx) were also recorded. In the cross-sectional study, the prevalence of vertebral fracture in the initial radiographs of RA patients was 21%, while it was 5% in healthy age-matched controls. Among RA patients treated with corticosteroids, 33% had vertebral fracture, which was a significantly higher prevalence than that in RA patients without steroid administration. In the longitudinal study, vertebral fracture prevalence was also increased in patients more than 60 years old. RA patients having steroid treatment and a BMD/YAM (young adult mean) ratio below 70% had higher risk of vertebral fracture than patients with a BMD/YAM ratio of 70%-80%, which in turn exceeded the risk with a BMD of 80% or more. No adverse effect of low-dose methotrexate on vertebral fracture was found. Urinary NTx was high in RA patients, as reported previously, and did not differ between patients with or without new fracture after 4 years. In conclusion, Japanese RA patients more than 60 years old who were treated with corticosteroid or had a BMD below 80% had high risk of vertebral fracture.

Aged↗
PubMed2006

Report on the Japanese Orthopaedic Association's 3-year project observing hip fractures at fixed-point hospitals.

BACKGROUND: The aim of this study was to assess the disability and mortality of hip fractures 1 year after initial visit (postoperatively) at fixed-point hospitals selected by the Japanese Orthopaedic Association Committee on Osteoporosis. METHOD: A total of 158 core orthopedic hospitals were selected for participation in this research. Subjects were all aged 65 years and older with hip fractures at the selected hospitals between January 1, 1999 and December 31, 2001. A prognostic survey of activities of daily living (ADL), assessed by the long-term care insurance criteria established by the Ministry of Health, Labour, and Welfare of Japan was performed 1 year after the initial visit. RESULTS: A total of 1992 hip fractures in patients aged 65 to 111 years were treated over the 3 years from 1999 to 2001. Among the 1992 patients, 4537 had femoral neck fractures and 6217 had trochanteric fractures. Surgical treatment was chosen for 85.6% of the femoral neck fractures and 88.2% of the trochanteric fractures. The mean duration from fracture to admission was 3.1 days, and the mean duration from admission to surgery was 11.2 days. The mean duration from surgery to discharge over the 3-year period was 49.8 days. Before hip fracture, the ratio of patients with J1 ("able to go out freely utilizing public transportation") or J2 ("able to visit immediate neighbors independently") on the long-term care insurance criteria was 50.9%. At 1 year after the initial visit, that result represented a decrease of 24.1 percentage points before hip fracture. A total of 70 patients died before undergoing surgery. In the present study, the 1-year mortality rate for the entire patient population over the 3-year period was 10.1%. CONCLUSIONS: Hip fracture patients show a decrease in the ADL score 1 year after the initial visit. Compared to other countries, the duration of hospitalization is longer in Japan, but the mortality rate is lower.

Age Distribution↗
PubMed2006

Effects of unipedal standing balance exercise on the prevention of falls and hip fracture among clinically defined high-risk elderly individuals: a randomized controlled trial.

BACKGROUND: The aim of this study was to assess the effectiveness of the unipedal standing balance exercise for 1 min to prevent falls and hip fractures in high-risk elderly individuals with a randomized controlled trial. This control study was designed as a 6-month intervention trial. SUBJECTS: Subjects included 553 clinically defined high-risk adults who were living in residences or in the community. They were randomized to an exercise group and a control group. METHODS: Randomization to the subjects was performed by a table of random numbers. A unipedal standing balance exercise with open eyes was performed by standing on each leg for 1 min three times per day. As a rule, subjects of the exercise group stood on one leg without holding onto any support, but unstable subjects were permitted to hold onto a bar during the exercise time. Falls and hip fractures were reported by nurses, physical therapists, or facility staff with a survey sheet every month. This survey sheet was required every month for both groups. RESULTS: Registered subjects were 553 persons ranging in age from 37 to 102 years (average, 81.6 years of age). Twenty-six subjects dropped out. The number of falls and hip fractures for the 6-month period after the trial for 527 of the 553 subjects for whom related data were available were assessed. The exercise group comprised 315 subjects and the control group included 212 subjects. The cumulative number of falls of the exercise group, with 1 multiple faller omitted, was 118, and the control group recorded 121 falls. A significant intergroup difference was observed. However, the cumulative number of hip fractures was only 1 case in both groups. This difference was not statistically significant. CONCLUSIONS: The unipedal standing balance exercise is effective to prevent falls but was not shown to be statistically significant in the prevention of hip fracture in this study.

Accidental Falls↗
PubMed2006

Sprouting of sensory neurons in dorsal root ganglia after transection of peripheral nerves.

Morphological reaction of sensory neurons of dorsal root ganglia after peripheral nerve transection was investigated by a nerve tracing method using E. coli lacZ (beta-galactosidase) gene recombinant adenovirus. The sciatic nerve of the rat was transected and inoculated with the gene recombinant adenovirus from the cutting end of nerve fibers. The fixation was accomplished from one to six weeks after inoculation. A whole mount specimen was observed after the reaction in a X-galactocidase substrate. Newly formed sprouting processes of dorsal root ganglion (DRG) cells appeared, all of them sprouting from the primary segment of DRG cells. Developed branches were morphologically categorized in to two types: one was the "linear type" which showed diverged branches running straightly along the major axis of the DRG; the other was the "winding type" which exhibited a random running pattern to the original axons and wound and extended in all directions in dorsal root ganglia with many branches. Many of this type encircled other cell bodies and formed a ring-like structure. There was no difference in the size of cell bodies in either type or between the ring-like structure forming the cells and those cells encircled by them.

Adenoviridae↗
PubMed2006

[Up-date of cartilage repair technique].

There are two major conditions which require cartilage repair, one is partial cartilage defect due to trauma or osteochondritis dissecanse and the other is cartilage degeneration and loss induced by osteoarthritis. In this section, we introduce several surgical techniques which are available in clinical cases. In patient with relatively small traumatic cartilage defect, microfracture technique, autologous osteochondral graft transplantation, or autologous cultured chondrocytes transplantation are performed. In patients with osteoarthritis, which usually larger region is affected than traumatic cartilage defect, cell based technique and osteochondral transplantation are not sufficient to cover the region, therefore abrasion arthroplasty is performed accompanied with osteotomy to correct mechanical property in the joint.

Cartilage↗
PubMed2006

[The relationship between vitamin D insufficiency and hip fracture].

Recently the relationship of vitamin D insufficiency and fracture is noticed in elderly people. Vitamin D nutritional status is evaluated by measuring serum 25 (OH) D. Higher prevalence of vitamin D insufficiency is observed in the patients with hip fracture. This suggests that vitamin D insufficiency is one of fracture risk factor and improvement of vitamin D status reduce fracture risk. With the results of recent studies, we would like to discuss about fractures from the viewpoint of vitamin D insufficiency.

Aged↗
PubMed2005

Histological assessment in grafts of highly purified beta-tricalcium phosphate (OSferion) in human bones.

Prominent osteoconductive activity and the biodegradable nature of commercially available beta-tricalcium phosphate (beta-TCP, OSferion) have been documented in animal experiments. We analyzed four cases of involving grafted OSferion in human bone with respect to histological features by routine hematoxylin and eosin staining, silver impregnation, immunohistochemistry and in situ hybridization. OSferion affords early bioresorption by osteoclasts, vascular invasion of macropores and osteoblastic cell attachment on the surface on the ceramic surface 14 days after grafting. Prominent bone formation and direct bone connection between preexisting bone and OSferion were evident 28 days after grafting. Nearly the entire TCP surface was covered by lamellar bone; additionally, active osteoblastic lining and attachment of the osteoclast-like giant cells were not observed 72 weeks after grafting. Silver impregnation revealed the presence of collagen fibrils within probable micropores of OSferion.

Adolescent↗
PubMed2005

Use of the scoliosis research society outcomes instrument to evaluate patient outcome in untreated idiopathic scoliosis patients in Japan: part I: comparison with nonscoliosis group: preliminary/limited review in a Japanese population.

STUDY DESIGN: This preliminary study evaluates untreated Japanese patients with idiopathic scoliosis using the Scoliosis Research Society Outcomes Instrument (SRS-24). OBJECTIVES: To determine the baseline patient outcome score using the SRS-24 for untreated Japanese scoliosis patients compared with a nonscoliosis group. SUMMARY OF BACKGROUND DATA: The SRS instrument with 24 questions was developed to help evaluate patient-perceived outcomes of idiopathic scoliosis treatment. Evaluation of untreated Japanese idiopathic scoliosis patients using the SRS instrument has not been reported. METHODS: Japanese idiopathic scoliosis patients (n = 141) (mean age, 13.6 years; range, 10-17 years) with a Cobb angle of more than 20 degrees who were not treated with a brace or surgery, were evaluated in comparison with a nonscoliosis group (healthy junior high school students; n = 72) using the SRS-24. The scoliosis group was categorized as mild deformity group with a major curve Cobb angle of less than 30 degrees, moderate deformity group with 30 degrees to 49 degrees, and severe deformity group with more than 50 degrees. The patients were evaluated using section 1 (15 questions) of the SRS-24, which was divided into four domains: total pain, general self-image, general function, and activity. Reliability, as determined by internal consistency, was validated using Cronbach's alpha for these domain scales. RESULTS: The severe deformity group had the lowest scores compared with the other deformity groups and the nonscoliosis group in pain (P < 0.0001) and self-image (P < 0.05) domains. The scores for questions 3 (P < 0.0001) and 5 (P < 0.0001), evaluation of self-image of back appearance, were significantly lower in the scoliosis group than those in the nonscoliosis group. This tendency was more significant in the patients with greater curve magnitude. Scores for questions 14 and 15, evaluation of general self-image, in the scoliosis group were, however, higher than those in the nonscoliosis group. Internal consistency using Cronbach's alpha was 0.57 (pain), 0.27 (general self-image), -0.08 (general function), and 0.15 (overall level of activity). CONCLUSION: Untreated scoliosis patients with severe deformity were inclined to complain of being self-conscious or distressed regarding their back appearance compared with age- and sex-matched control adolescents. The control group was inclined to have, however, a negative general self-image compared with the patients group. Internal consistency using Cronbach's alpha for all domains was considerably low. The baseline of the SRS-24 scores in the Japanese population might differ from that of the Western population because of differences in national culture. Therefore, further study is necessary to clarify the validity of the SRS-24 domains for Japanese patients.

Adolescent↗
PubMed2005

Use of the scoliosis research society outcomes instrument to evaluate patient outcome in untreated idiopathic scoliosis patients in Japan: part II: relation between spinal deformity and patient outcomes.

STUDY DESIGN: This study clarifies the relation between the results of the Scoliosis Research Society Outcomes Instrument (SRS-24) and radiographic parameters of back deformity in Japanese idiopathic scoliosis patients. OBJECTIVES: To investigate the relation between magnitude of back deformity and results of the SRS-24 in untreated patients. SUMMARY OF BACKGROUND DATA: In idiopathic scoliosis, it is necessary to clarify the relation between patient-perceived outcomes of the deformity and magnitude of back deformity before considering treatment. The relation between the magnitude of spinal deformity and outcomes of untreated patients, however, has not been fully investigated. METHODS: Patients (n = 166) under 30 years of age with untreated scoliosis were evaluated. Radiologic examination included Cobb angle, rotation angle of apical vertebrae, and translation of C7 vertebra from the central sacral line (C7 translation) on the coronal plane. Patient evaluation using section 1 (15 questions) of the SRS-24 was compared with radiologic findings using Spearman's correlation coefficient by rank (rs). RESULTS: The average pain domain score was 27.0 +/- 2.2 points, general self-image 9.9 +/- 1.7 points, general function 12.7 +/- 1.1 points, and overall level of activity 14.9 +/- 0.6 points. In radiologic deformity, the average Cobb angle and rotation angle of the thoracic curve were 35.8 degrees +/- 12.1 degrees (range, 17 degrees-73 degrees) and 13.9 degrees +/- 8.2 degrees (range, 0 degrees-38 degrees), respectively. The average Cobb and rotation angle of the lumbar curve were 31.4 degrees +/- 9.3 degrees (range, 13 degrees-56 degrees) and 15.4 degrees +/- 9.7 degrees (range, 2 degrees-36 degrees), respectively. The mean C7 translation was 12.4 +/- 9.7 mm (range, 0-48 mm). Comparison between individual domains and radiologic measurements revealed that the total pain (rs = -0.33; P < 0.0001) and general self-image (rs = -0.25; P = 0.0024) domain scores had a significant inverse correlation with thoracic curve Cobb angle. Comparison between the scores of individual questions and radiologic measurements revealed that the scores of question 3 (total pain domain) had a significant inverse correlation with thoracic curve Cobb angle (rs = -0.36; P < 0.0001). The scores of question 5 (general self-image domain) had a significant inverse correlation with thoracic curve Cobb angle (rs = -0.41; P < 0.0001) and rotation angle (rs = -0.30; P = 0.0006). CONCLUSION: The patients did not have negative self-image regarding back appearance when the thoracic curve Cobb angle was less than 30 degrees but had a negative self-image when the thoracic curve Cobb angle was more than 40 degrees and the rotation angle was more than 20 degrees. On the other hand, the lumbar curve Cobb angle and the rotation angle did not correlate with patient self-image. The results of the present study will help to define the parameters for the initiation of active treatment and physicians should maintain or reduce scoliotic deformity so that the thoracic curve Cobb angle is less than 40 degrees and the rotation angle is less than 20 degrees in idiopathic scoliosis.

Adolescent↗
PubMed2005

Bone formation and resorption of highly purified beta-tricalcium phosphate in the rat femoral condyle.

The aim of this study was to examine the chronological histology associated with highly purified beta-tricalcium phosphate (beta-TCP) implanted in the rat femoral condyle. Specimens were harvested on days 4, 7, 14, 28 and 56 after implantation, and were analyzed by tartrate-resistant acid phosphatase (TRAP) staining, immunohistochemistry of the ED1 protein as a marker of the phagocyte system, and in situ hybridization with digoxigenin-labeled alpha1 chain of type I procollagen (COL1A1), osteopontin and osteocalcin. beta-TCP was resorbed in a chronological manner. Although new bone was not observed on day 4, fibroblast-like cells around beta-TCP were positive for COL1A1 and osteopontin mRNA. New bone formation presented after day 7. In the double-staining for OPN and ED1 on day 7, most cells around beta-TCP were positive for either osteopontin mRNA or ED1 protein. However, there were some doubly positive multinucleated cells, suggesting that they belonged to the mononuclear phagocyte system. After day 28, the implanted region was replaced with bone marrow. Multinucleated TRAP-positive and ED1-positive cells which adhered to beta-TCP at all stages seemed to be osteoclasts and they continuously resorbed beta-TCP. beta-TCP has a good biocompatibility since both bioresorption and bone formation started at an early stage after implantation.

Absorbable Implants↗
PubMed2005

A study on a micro mover driven by ultrasonic waves.

In developing a mobile micro robot, it is important to realize an effective energy supply method. The existing general method is to supply energy from outside through a cable. However, supplying energy through a cable adds weight and restricts movement. Mounted energy sources, such as batteries, also add weight. We therefore propose a method of supplying energy to a robot externally without using a cable. Using the radiation of ultrasonic waves as a wave energy source, we devised a mover that can receive and use wave energy for propulsion. We investigated and clarified the movement this prototype mover through various experiments. Consequently, we proved the use of ultrasonic waves to be effective as a cable-free energy supply.

Journal Article↗
PubMed2005

Comparison of hydroxyapatite and beta tricalcium phosphate as bone substitutes after excision of bone tumors.

Long-term results are reported in 23 patients and short-term results in 30 patients presenting with bone tumors treated by curettage or resection followed by implantation of hydroxyapatite (HA) or highly purified beta-tricalcium phosphate (beta-TCP), respectively. Mean follow-up was 97 and 26 months in cases involving HA implantation and beta-TCP implantation, respectively. Radiographs revealed HA incorporation into host bone in all but two cases; moreover, no obvious evidence of HA biodegradation was observed. A single patient exhibited late deformity following implantation of HA. All grafted beta-TCP was, at least partially, absorbed and replaced by newly formed bone. The mean period required for the disappearance of radiolucent zones between the ceramics and host bone was 17 weeks in HA and 9.7 weeks in beta-TCP. Highly purified beta-TCP appears to be advantageous relative to HA for surgical intervention in bone tumors consequent to the nature of remodeling and superior osteoconductivity.

Adolescent↗
PubMed2005

Ischial weight-bearing brace after the infection of megaprosthesis a salvage method for resection arthroplasty.

We report a case of successful control of the infection of megaprosthesis in the distal femur. Deep infection occurred 5 years after the resection of the osteosarcoma and reconstruction with cementless megaprosthesis. Multiple debridement and intravenous administration of antibiotics did not eradicate the infection. He developed aortitis syndrome (Takayasu's arteritis) and needed to undergo steroid therapy. Total removal of the prosthesis achieved good control of the infection, and the patient had started prednisolone therapy. The patient can walk alone with an ischial weight-bearing brace. Removal of the endoprosthesis and application of ischial weight-bearing brace may be a possible option for the treatment of infected megaprosthesis.

Adult↗