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Dive into the research topics where Naoki Takeda is active.

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Featured researches published by Naoki Takeda.


Spine | 1997

Risk factors and probability of vertebral body collapse in metastases of the thoracic and lumbar spine

Hiroshi Taneichi; Kiyoshi Kaneda; Naoki Takeda; Kuniyoshi Abumi; Shigenobu Satoh

STUDY DESIGN The associations between vertebral body collapse and the size or location of the metastatic lesions were analyzed statistically to estimate the critical point of collapse. OBJECTIVES To determine risk factors for collapse, to estimate the predicted probability of collapse under various states of metastatic vertebral involvement, and to establish the criteria of impending collapse. SUMMARY OF BACKGROUND DATA Pathologic vertebral collapse brings about severe pain and paralysis in patients with cancer. Prevention of collapse plays a significant role in maintaining or improving their quality of life. Because no previous study has clarified the critical point of vertebral collapse, however, the optimum timing for prophylactic treatment has been unclear. METHODS The size and location of metastatic tumor from Th1 to L5 were evaluated radiologically for 100 thoracic and lumbar vertebrae with osteolytic lesions. The correlations between collapse and the following risk factors (x1-x4) were determined by means of a multivariate logistic regression model: x1, tumor size (the percentage of tumor occupancy in the vertebral body [% TO]); x2, pedicle destruction, x3, posterior element destruction; and x4, costovertebral joint destruction. RESULTS Significant risk factors were costovertebral joint destruction (odds ratio, 10.17; P = 0.021) and tumor size (odds ratio of every 10% increment in %TO, 2.44; P = 0.032) in the thoracic region (Th1-Th10), whereas, tumor size (odds ratio of every 10% increment in %TO, 4.35; P = 0.002) and pedicle destruction (odds ratio, 297.08; P = 0.009) were main factors in the thoracolumbar and lumbar spine (Th10-L5). The criteria of impending collapse were: 50-60% involvement of the vertebral body with no destruction of other structures, or 25-30% involvement with costovertebral joint destruction in the thoracic spine; and 35-40% involvement of vertebral body, or 20-25% involvement with posterior elements destruction in thoracolumbar and lumbar spine. CONCLUSIONS With respect to the timing and occurrence of vertebral collapse, there is a distinct discrepancy between the thoracic and thoracolumbar or lumbar spine. When a prophylactic treatment is required, the optimum timing and method of treatment should be selected according to the level and extent of the metastatic vertebral involvement.


Acta Obstetricia et Gynecologica Scandinavica | 2002

Multivariate analysis of histopathologic prognostic factors for invasive cervical cancer treated with radical hysterectomy and systematic retroperitoneal lymphadenectomy

Naoki Takeda; Noriaki Sakuragi; Mahito Takeda; Kazuhira Okamoto; Michiya Kuwabara; Hiroaki Negishi; Mamoru Oikawa; Ritsu Yamamoto; Hideto Yamada; Seiichiro Fujimoto

Background.  The aim of this study was to identify the independent histopathologic prognostic factors for patients with cervical carcinoma treated with radical hysterectomy including paraaortic lymphadenectomy.


Spine | 2004

A longitudinal study of congruent sagittal spinal alignment in an adult cohort.

Tetsuya Kobayashi; Yuji Atsuta; Takeo Matsuno; Naoki Takeda

Study Design. A 10+-year longitudinal study of 100 adult volunteers. Objectives. To identify congruent lumbar lordosis in association with other sagittal spinopelvic parameters. Summary of Background Data. The aging spine poses difficult problems in determining appropriate lumbar lordosis. The concept of congruent spinal alignment is preferred over that of normal spinal alignment, yet the definition of sagittal spinal congruity in elderly population has not been well documented. Methods. A population-based recruitment of adult volunteers and follow-up of 10+ years was conducted. A total of 100 healthy volunteers with baseline age of 50+ years were subjected to standing entire spine radiographs. Radiologic parameters included lumbar lordosis, sacral inclination, sagittal spinal balance, and other sagittal alignments. Results. Average age of the subjects was 62.0 years at baseline and 73.9 years at follow-up. Lumbar lordosis with <5° change during observation was defined as stable lumbar lordosis (n = 34). Regression analyses of the baseline parameters revealed that sacral inclination was the sole predictor of stable lumbar lordosis (lumbar lordosis = 0.8 * sacral inclination, r = 0.94, P < 0.0001). Baseline lumbopelvic congruity, determined as 0.7 ≤ lumbar lordosis/sacral inclination ≤ 0.9, was associated with minimum alterations in sagittal spinal alignment, whereas subjects with incongruent lumbopelvic relationships were predisposed to developing kyphosis and spinal imbalance. Conclusions. Our study substantiates previous results showing that the strongest determinant of lumbar lordosis is sacral alignment. Appropriate lumbar lordosis was estimated to be 80% of sacral inclination using standing radiographs, and the proposed lumbopelvic congruity could measure stability in sagittal spinal alignment. This study provides practical data for the assessment of sagittal spinal alignment in the aging spine.


Spine | 2006

A prospective study of de novo scoliosis in a community based cohort.

Tetsuya Kobayashi; Yuji Atsuta; Masakazu Takemitsu; Takeo Matsuno; Naoki Takeda

Study Design. A 12-year prospective study of de novo scoliosis in a community based cohort. Objective. To investigate factors associated with development of de novo scoliosis. Summary of Background Data. De novo scoliosis is becoming one of the most prevalent findings in the aging spine, and this condition is associated not only with severe back or leg symptoms but also with complicated surgical outcomes. Cross-sectional studies were limited in distinguishing de novo scoliosis from preexisting deformities, and there had been controversies over the etiology of degenerative scoliosis. Methods. Community based volunteers were recruited, then examined by orthopedic physicians. Radiologic measurements using entire spine radiographs included the angle of scoliosis and sagittal spinal curvatures, sagittal spinal balance, grade of bone atrophy, number of degenerated discs, and vertebral fractures. We defined radiologic parameters, the disc index, and lateral osteophyte difference to evaluate the asymmetrical spinal degeneration. Results. A total of 60 subjects aged 50–84 years and without scoliosis at baseline were selected and followed for a mean of 12.0 years. De novo scoliosis ≥10° developed in 22 subjects, and logistic regression analysis revealed that the baseline disc index and lateral osteophyte difference values were independent predictors (P < 0.05). Conclusions. Incidence of de novo scoliosis was predictable by assessing asymmetric disc degeneration in frontal radiograph. More than 20% decrease in unilateral disc height or more than 5 mm longer osteophyte on one side led to increased incidence of de novo scoliosis, which might also influence long-term results of spinal surgery.


Spine | 2005

A Novel Back School Using a Multidisciplinary Team Approach Featuring Quantitative Functional Evaluation and Therapeutic Exercises for Patients With Chronic Low Back Pain : The Japanese Experience in the General Setting

Osamu Shirado; Toshikazu Ito; Toyo Kikumoto; Naoki Takeda; Akio Minami; Thomas E. Strax

Study Design. A prospective cohort study. Objectives. To introduce a novel back school for the treatment of patients with chronic low back pain (CLBP), and to report its clinical results. Summary of Background Data. Although back school is one of the treatment methods for patients with CLBP, its efficacy and appropriate style remain controversial. No studies have been published regarding the combined program of back school with a multidisciplinary team approach. Methods. A total of 182 patients with CLBP (74 men and 108 women; average age, 43.8 years) participated in this study. All patients were enrolled in the back school using a multidisciplinary team approach featuring quantitative functional evaluation and therapeutic exercises. The following outcome measures were evaluated at the baseline, and 6 and 12 months after the enrollment: the level of pain evaluated with a Visual Analog Scale (VAS), flexibility of trunk and hamstrings (finger-floor distance, straight leg raising), trunk muscle strength and endurance, frequency of therapeutic exercises, and self-reported patient satisfaction. Results. An averaged VAS score was 6.2 before enrollment in the program and 2.8 at follow-up. The pain improved in 141 patients (80.8%), did not change in 27 (15.4%), and was aggravated in 7 (3.8%). There was statistically significant improvement of finger-floor distance, trunk muscle strength, and endurance in the patients whose pain was relieved after enrollment in the program (P < 0.05). The compliance with the exercise program was significantly correlated with the clinical results (P < 0.05). Conclusions. We developed a novel back school using a multidisciplinary team approach, featuring quantitative functional evaluation and therapeutic exercises. The current study demonstrated that our program could provide a satisfactory result for the treatment of patients with CLBP. The quantitative functional evaluation was a worthwhile outcome measure when evaluating the efficacy of the treatment program. Teaching body mechanics and performing the therapeutic exercises through the multidisciplinary team approach are essential to managing CLBP in a general setting.


Spine | 1998

Pathologic features of spinal disorders in patients treated with long-term hemodialysis.

Manabu Ito; Kuniyoshi Abumi; Naoki Takeda; Shigenobu Satoh; Kyoichi Hasegawa; Kiyoshi Kaneda

Study Design. Pathologic features of hemodialysis‐associated spinal disorders were evaluated using preoperative radiographic images and histologic findings of the spinal lesions resected during surgery. Objectives. To investigate the pathology of hemodialysis‐related spinal disorders and to determine the role of amyloidosis in the establishment of severe destruction of the spine. Summary of Background Data. The pathologic events leading to hemodialysis‐associated spinal disorders are poorly understood. The distribution of amyloid deposits in the spine also has not been clarified. Methods. Twenty patients with hemodialysis‐associated spinal disorders were investigated regarding pathologic features of neural compression and spinal destruction. Preoperative radiographic images such as plain radiography, tomography, computed tomography, magnetic resonance imaging, and scintigraphy were assessed for the existence of an intracanal mass, hypertrophy of the ligamentum flavum, and destructive changes of the spinal components. Histologic examination also was conducted by light microscopy and scanning electron microscopy to determine the distribution pattern of amyloid deposits in the spinal components. Results. Six patients with no destructive changes in the spine showed spinal canal stenosis. In the cervical spine, a main factor associated with spinal canal stenosis was the presence of intracanal amyloid deposits in three patients. In the lumbar spine, a main factor associated with spinal canal stenosis was hypertrophied ligamentum flavum in three patients. Destructive changes of the facet joints, intervertebral disc, and vertebral body were seen in the other 14 patients. Amyloid deposits were densely distributed at the enthesis of capsular fibers to the bone and in anular tears in the intervertebral discs. Vertebral end plates were destroyed by penetration of amyloid granulation into the vertebral body. Osteoclast activity in the destroyed vertebral bodies was enhanced, with no evidence of new bone formation. Conclusions. Amyloid deposits played an important role in the progression of spinal destruction and severe instability.


Journal of Orthopaedic Science | 2009

Changes in the sagittal spinal alignment of the elderly without vertebral fractures: a minimum 10-year longitudinal study

Naoki Takeda; Tetsuya Kobayashi; Yuji Atsuta; Takeo Matsuno; Osamu Shirado; Akio Minami

BackgroundThoracic hyperkyphosis, or loss of lumbar lordosis, is often equated with osteoporosis because vertebral fractures are assumed to be a major causative factor. However, recent evidence suggests that up to one-half of the patients with hyperkyphosis have no evidence of underlying vertebral fracture. The shape characteristics of the intervertebral discs and their role in determining kyphotic curvature have been investigated. The spinal sagittal parameters and segmental disc angles of elderly subjects were examined during a longitudinal follow-up.MethodsA total of 53 subjects (20 men, 33 women) without vertebral fractures during a more than 10-year follow-up were included in this study, undergoing standing lateral radiographs of the spine using 36-inch film at baseline and final follow-up. The mean age of the subjects was 63 years (range 50–77 years) at baseline and 75 years (range 62–88 years) at follow-up; and the mean follow-up period was 11 years 11 months.ResultsThe lumbar lordosis and the sacral inclination angle decreased and the C7-plumbline distance increased with age. Among a total of 664 discs, 70 discs (10.5%) showed anterior wedging over 5° at follow-up. In contrast, 39 discs (5.9%) showed posterior wedging over 5°. The subjects had only discs with anterior wedging, decreased total lumbar lordosis, and the C7 plumbline displaced anteriorly. However, when the subjects had discs with posterior wedging, the C7 plumbline and sagittal spinal balance tended to be maintained. This compensatory mechanism was seen in younger subjects.ConclusionsA decrease in the total lumbar lordosis and the sacral inclination angle occurred with age. Increasing age correlated with a more forward sagittal vertical axis, depending on a decrease in the total lumbar lordosis. The cause of loss of lumbar lordosis in the subjects without vertebral fracture was anterior wedging of the segmental discs. Posterior wedging of the thoracic and lumbar segmental discs then could occur, compensating for the loss of lumbar lordosis.


Oncology | 1996

A Preliminary Report of Neoadjuvant Chemotherapy NSH-7 Study in Osteosarcoma: Preoperative Salvage Chemotherapy Based on Clinical Tumor Response and the Use of Granulocyte Colony-Stimulating Factor

Takuro Wada; Kazuo Isu; Naoki Takeda; Masamichi Usui; Seiichi Ishii; Shinya Yamawaki

Eleven patients with high-grade osteosarcoma of an extremity were treated with neoadjuvant chemotherapy with NSH-7 protocol. NSH-7 is a refinement of the T-12 Rosen protocol. Preoperative chemotherapy is initiated with a doxorubicin (ADM) and high-dose methotrexate combination. If the primary tumor progresses after the first cycle, the preoperative chemotherapy is switched to a combination of cisplatin and ADM. Postoperative adjuvant chemotherapy was selected based on histological response of the primary tumor. In addition, recombinant human granulocyte colony-stimulating factor was used to prevent leukocytopenia and to increase the dose intensity of the chemotherapy. In 1 patient, preoperative chemotherapy was switched to salvage treatment. Of the 156 courses given, there were 10 delays and 4 dose reductions. Leukocytopenia accounted for only 1 delay. All 11 patients completed the chemotherapy and 5 patients were fully able to tolerate the protocol without delay or dose reduction. Nine patients remained alive and continuously free of disease at an average follow-up of 35 months. The rate of continuous disease-free survival at 3 years was 81%, which was significantly better than that of the T-12 study of our group. These observations suggest that the NSH-7 protocol is a safe and effective treatment regimen for osteosarcoma.


Plastic and Reconstructive Surgery | 1997

Pelvic reconstruction with a free fillet lower leg flap

Yuhei Yamamoto; Hidehiko Minakawa; Naoki Takeda

The free fillet lower leg flap was applied for immediate reconstruction after hemipelvectomy including the overlying soft tissue and the internal and external iliac vessels. The flap, harvested from the amputated lower extremity, is a versatile reconstructive technique for such a large pelvic defect.


Clinical Orthopaedics and Related Research | 2005

Lumbar disc herniation associated with separation of the ring apophysis: is removal of the detached apophyses mandatory to achieve satisfactory results?

Osamu Shirado; Yasuhiro Yamazaki; Naoki Takeda; Akio Minami

There are three questions to be addressed in lumbar disc herniation with separation of the ring apophysis: does this lesion occur only in adolescents, does any trauma predispose this lesion, and is removal of the detached apophyses mandatory to achieve satisfactory results? We prospectively investigated 32 consecutive patients (22 men, 10 women; mean age, 25.4 years; mean followup, 4 years 8 months). This lesion occurred not only in adolescents, but also in adults older than 30 years. Eight patients (25%) were younger than 20 years, whereas 14 patients (43.8%) were in the third decade, and 10 (31.2%) were in the fourth decade. Only five patients (15.6%) had antecedent traumatic episodes. Resection of the fragment did not influence the clinical results. Excision of the herniated disc and mobile bony fragment was done in 11 patients (34.4%). Discectomy alone was done in 21 patients (65.6%) with immobile bony fragments. Satisfactory results were obtained in both groups. Lumbar disc herniation with detachment of the ring apophysis can occur, without any relationship to trauma, in adults and adolescents. Removal of the bony fragment is not always needed to achieve satisfactory results. Level of Evidence: Therapeutic study, Level IV (case series—no, or historical control group)

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Takeo Matsuno

Asahikawa Medical College

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Osamu Shirado

Saitama Medical University

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