Network


Latest external collaboration on country level. Dive into details by clicking on the dots.

Hotspot


Dive into the research topics where Tetsuo Masui is active.

Publication


Featured researches published by Tetsuo Masui.


Journal of Spinal Disorders & Techniques | 2005

Natural history of patients with lumbar disc herniation observed by magnetic resonance imaging for minimum 7 years.

Tetsuo Masui; Yasutsugu Yukawa; Shigeru Nakamura; Gakuji Kajino; Yuji Matsubara; Fumihiko Kato; Naoki Ishiguro

Objective: The aim of this work was to elucidate the relation between the clinical course and morphologic changes of lumbar disc herniation on magnetic resonance imaging (MRI). Methods: Twenty-one patients with lumbar disc herniation treated nonsurgically were followed for a minimum of 7 years and investigated with regard to their clinical outcome and the initial, 2-year, and final stage MRI findings. The space-occupying ratio of herniation to the spinal canal and the degree of disc degeneration were evaluated on serial MRI. Results: The mean space-occupying ratio of herniation showed significant reduction both on the 2-year and on the final scans. Progression of degeneration of the intervertebral disc was seen in all patients at the final investigation. Comparing patients with and without symptoms, no factors were detected on the initial and 2-year MR images capable of distinguishing patients who were and were not destined to develop lumbago and/or sciatica in the future. Morphologic changes of lumbar disc herniation continued to occur even after 2 years. Conclusions: Clinical outcome did not depend on the size of herniation or the grade of degeneration of the intervertebral disc in the minimum 7-year follow-up.


Osteoporosis International | 2006

ALDH2 polymorphisms and bone mineral density in an elderly Japanese population

Jin Yamaguchi; Yukiharu Hasegawa; Masashi Kawasaki; Tetsuo Masui; Toshiya Kanoh; Naoki Ishiguro; Nobuyuki Hamajima

IntroductionOsteoporosis is a multifactorial genetic disease which greatly increases the risk of bone fracture in elderly persons.MethodsFour hundred and three recipients of a community health screening program were examined for the presence/absence of osteoporosis and 11 kinds of gene polymorphisms as a means of determining the relation between these gene polymorphisms and osteoporosis. The gene polymorphisms screened were: alcohol sensitivity-associated polymorphisms of alcohol dehydrogenase (ADH2) Arg47His, aldehyde dehydrogenase (ALDH2) Glu487Lys, smoking sensitivity-associated polymorphisms of glutathione S transferase (GST) M1, (GST)T1, NAD(P)H quinone oxidoreductase 1 (NQO1) C609T, inflammation-associated polymorphisms of interleukin-1β (IL-1B)T-31C, tumor necrosis factor α (TNF-α) T-1031C, endothelial constitutive nitric oxide synthase (ecNOS) Glu298Asp, longevity-associated polymorphism of mitochondrial DNA (mtDNA) 5178 A/C, allergy-associated polymorphism of interleukin-4 (IL-4), and immunity-associated polymorphism of CD14.ResultsA significant association was found between the ALDH2Glu478Lys gene polymorphisms and osteoporosis. In the osteoporosis group of patients, a significant difference was noted between the Lys/Lys group and the group comprising Glu/Lys and Glu/Glu groups (namely, the genotypes including Glu alleles). In the Lys/Lys group, after age, sex, BMI, smoking history and alcohol consumption history had been adjusted for, the morbidity rate was significantly elevated [odds ratio (OR): 3.33; 95% confidence interval (95% CI): 1.28–8.71; p=0.014], and the effect was even more evident in the sub-group of women with osteoporosis (OR: 4.31; 95% CI: 1.24–14.92; p=0.021).ConclusionsThe present results suggest that active prophylactic interventions such as dietary, exercise, and pharmacological therapies should be offered to non-carriers of the Glu allele (Lys/Lys).


Clinical Orthopaedics and Related Research | 2007

Factors leading to osteoarthritis after eccentric rotational acetabular osteotomy.

Yukiharu Hasegawa; Tetsuo Masui; Jin Yamaguchi; Kiyoharu Kawabe; Sadao Suzuki

We performed eccentric rotational acetabular osteotomy consecutively in 273 hips in 248 patients with hip dysplasia. Twenty-one patients were male and 227 were female. The average age was 37.7 years at the time of the index operation. Twenty-two hips had no osteoarthritis, 129 had early osteoarthritis, 117 had advanced osteoarthritis, and five had end-stage osteoarthritis. Twenty-six hips also were treated with concomitant intertrochanteric valgus osteotomy. Patients were followed for a minimum of 5 years after surgery. The average Harris hip score improved from 71 points preoperatively to 92 points at the final followup. Nine hips were converted to total hip arthroplasty as a result of deterioration after surgery. Kaplan-Meier survivorship analysis 15 years after the index operation indicated 97% in pre- and early stages and 87% in advanced and end stages when the end point was total hip arthroplasty. Risk factors identified by multivariate analysis for development of osteoarthritis of the hip 5 years after the index operation were body mass index (24 kg/m2 or more), concomitant valgus osteotomy, operative year between 1989 and 1992, a postoperative center-edge angle of Wiberg less than 25°, and a postoperative horizontal distance of the femoral head from the tear drop (40 mm or more).Level of Evidence: Level IV, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.


Journal of Arthroplasty | 2010

Accurate Acetabular Component Orientation After Total Hip Arthroplasty Using an Acetabular Alignment Guide

Toshiya Kanoh; Yukiharu Hasegawa; Tetsuo Masui; Jin Yamaguchi; Kiyoharu Kawabe; Naoki Ishiguro

Between February 2005 and August 2006, we recorded acetabular component orientation in 90 patients (100 hips) who underwent primary total hip arthroplasty (THA), to determine whether using an alignment guide ensures accurate acetabular positioning. In the alignment-guide group (46 patients; 48 hips), a guide was placed on the pelvis, a Kirschner wire (K-wire) was attached to the guide, and orientation of the acetabular component was confirmed by both the surgeon and an assistant. In the control group (44 patients; 52 hips), a K-wire was not used and the angle was confirmed by the surgeon alone. Radiographic acetabular component inclination and anteversion and computed tomography anteversion were determined. There was no significant difference in mean component orientation between the 2 groups. However, the SD was significantly smaller in the alignment-guide group, showing that consistent acetabular component orientation in primary THA is highly reproducible when an acetabular alignment guide with an attached K-wire is used.


Journal of Orthopaedic Science | 2008

Quality of life following femoral osteotomy and total hip arthroplasty for nontraumatic osteonecrosis of the femoral head

Taisuke Seki; Yukiharu Hasegawa; Tetsuo Masui; Jin Yamaguchi; Toshiya Kanoh; Naoki Ishiguro; Kiyoharu Kawabe

BackgroundNontraumatic osteonecrosis of the femoral head (NOFH) frequently develops in active young persons. The affected femoral head collapses owing to weight-bearing, and the individual’s quality of life (QOL) can be predicted to deteriorate greatly with time. We undertook to determine the efficacy of surgery and to clarify whether patient QOL differs according to differences in the surgical method employed.MethodsWe cross-sectionally compared QOL in NOFH patients treated with femoral osteotomy, total hip arthroplasty (THA), or nonoperatively. A total of 81 cases were available for study, comprising 41 with osteotomy, 19 with THA, and 21 in the nonoperative group. The mean age was significantly higher in the THA group than in the other two groups. The Japanese Orthopaedic Association (JOA) hip score and Visual Analogue Scale (VAS) regarding hip pain were compared among the groups. These groups were also analyzed for their health-related QOL using the Short Form Health Survey (SF-36) with analysis of variance for age adjustment.ResultsThe mean JOA score was significantly lower in the nonoperative group than in the osteotomy group. The mean VAS scores showed no significant difference between any of the three groups. Regarding the subscales of SF-36, the physical functioning subscale in the nonoperative group showed a significantly lower value than was seen in the osteotomy group (P = 0.003). The physical component summary (PCS) scores were 39.4 (osteotomy group), 39.1 (THA group), and 27.8 (nonoperative group), with a significant difference between the osteotomy and nonoperative groups (P = 0.027). There was also a trend for a better PCS scores in the THA group than in the nonoperative group (P = 0.056). The mental component summary scores were 49.6 (osteotomy group), 50.3 (THA group), and 48.3 (nonoperative group), with no significant difference found among any of the three groups.ConclusionsAmong patients with NOFH, physical function impairment was a more potent factor than pain for decreasing QOL in the nonoperative group than in the surgical groups. Furthermore, osteotomy and THA were similar in regard to the evaluation of the postoperative QOL score if the indications for osteotomy were strictly applied.


Applied Neuropsychology | 2004

Relation Between the Prefrontal Cortex and Cerebro-Cerebellar Functions: Evidence From the Results of Stabilometrical Indexes

Takeshi Hatta; Tetsuo Masui; Yasuhiro Ito; Emi Ito; Yukiharu Hasegawa; Yukihiro Matsuyama

The relation between prefrontal cortex and cerebro-cerebellar functions of 50 normal healthy elderly people was examined. The function of the prefrontal cortex was measured by means of a letter fluency test and the Digit Cancellation Test (D-CAT, a test for the assessment of attention). Two indexes of postural tremor measured by the stabilometer were employed for the indication of cerebello-thalamo-cortical circuit functions. The results of groups consisting of participants showing higher or lower scores than the mean of the norm on the stabilometer index measurements were compared with their D-CAT and letter fluency test performances. The results showed that 2 indexes of cerebello-thalamo-cortical circuit functions related to the attention function while the relation to the language function was rather weak. The results of the behavioral measures demonstrated a mutual relation between prefrontal cortex and cerebello-thalamo-cortical circuit functions and strongly suggest the notion that the human brain functions as a system, which includes neocortex, subcortex, and cerebellum.


Journal of Orthopaedic Science | 2008

Interleukin-1β gene polymorphism associated with radiographic signs of osteoarthritis of the knee

Toshiya Kanoh; Yukiharu Hasegawa; Tetsuo Masui; Jin Yamaguchi; Naoki Ishiguro; Nobuyuki Hamajima

BackgroundOsteoarthritis is recognized as a noninflammatory, progressive condition, the principal cause of which is regressive changes associated with aging and which pursues a chronic course. Recently, the involvement of genetic factors has been widely reported. The purpose of this study was to identify polymorphisms at particular risk of osteoarthritis of the knee for community-living middle-aged and elderly people.MethodsFocusing on 359 participants (ages 44–56 years) of the comprehensive health examination program (CHEP), we investigated the presence/absence of radiographic osteoarthritis (ROA) of the knee, and 11 types of gene polymorphisms and their association with ROA.ResultsInterleukin-1β (IL1B) T-31C polymorphism was found to be associated with ROA. In the case of IL1B T-31C polymorphism in the ROA group, a significant difference was found between the groups combining the C/C genotype, the C/T genotype, and the T/T genotype. In particular, the genotypes with the C allele differed from the T/T genotype, with the morbidity rate being higher in the T/T group (odds ratio (OR) 2.04, 95% confidence interval (95%CI) 1.05–1.98, P = 0.036).ConclusionOur results confirm that in IL1B T-31C with the T/T genotype, the rate of ROA was significantly higher than that with the C/C and C/T genotypes. It might be possible to implement active preventative measures, such as avoidance of obesity and excessive exercise loads, for carriers of IL1B T/T.


Clinical Orthopaedics and Related Research | 2007

Childbirth and sexual activity after eccentric rotational acetabular osteotomy

Tetsuo Masui; Yukiharu Hasegawa; Jin Yamaguchi; Toshiya Kanoh; Naoki Ishiguro

Pelvic osteotomy for symptomatic hip dysplasia usually is performed for young and adolescent females. Delivery after pelvic osteotomy is a concern for patients of childbearing age. We asked whether the clinical results differed before and after pregnancy, whether eccentric rotational acetabular osteotomy alters the bony birth canal, whether pelvic osteotomy impedes the ability to deliver vaginally, and whether sexual activity and quality of life improve if hip pain decreases after surgery. We retrospectively investigated 21 patients who experienced successful pregnancy and childbirth after eccentric rotational acetabular osteotomy. The mean age at the time of surgery was 25.7 years (range, 18-35 years) and 30.7 years (range, 23-40 years) at the initial delivery after surgery. Sixteen patients delivered 21 children vaginally and five patients delivered eight children by cesarean section. The clinical results were similar before and after childbirth. Eccentric rotational acetabular osteotomy caused no substantial difference in the bony birth canal before and after surgery. Vaginal delivery was possible in the majority of patients. Improvement of satisfaction with sexual activity and quality of life was related to less hip pain after surgery.Level of Evidence: Level IV, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.


Journal of Orthopaedic Science | 2006

Increasing postural sway in rural-community-dwelling elderly persons with knee osteoarthritis

Tetsuo Masui; Yukiharu Hasegawa; Jin Yamaguchi; Toshiya Kanoh; Naoki Ishiguro; Sadao Suzuki


Journal of Arthroplasty | 2005

Total Hip Arthroplasty After Failed Transtrochanteric Rotational Osteotomy for Avascular Necrosis of the Femoral Head

Masashi Kawasaki; Yukiharu Hasegawa; Shinji Sakano; Tetsuo Masui; Naoki Ishiguro

Collaboration


Dive into the Tetsuo Masui's collaboration.

Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Researchain Logo
Decentralizing Knowledge