Sakae Tanaka

The University of Tokyo, Tōkyō, Japan

Are you Sakae Tanaka?

Claim your profile

Publications (238)911.53 Total impact

  • Takumi Matsumoto · Sakae Tanaka ·
    [Show abstract] [Hide abstract]
    ABSTRACT: Significant advancement in pharmacological treatment including biological agents has gradually changed the role and content of surgical treatments for patients with rheumatoid arthritis. The number of joint replacements in the large joints of lower limbs has decreased, while the number of surgeries in the small joints of hand and feet has increased. Favorable disease control by pharmacological treatment has changed the needs of patients for surgeries and expanded the options of operative procedures for surgeons. The changing needs of patients demanding the higher level of quality of life may seek a change in the surgical treatments.
    Clinical calcium 11/2015; 25(12):1809-1816.

  • PLoS ONE 11/2015; 10(11):e0143350. DOI:10.1371/journal.pone.0143350 · 3.23 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Incidences of cervical laminoplasty in the elderly are increasing; the influence of other age-related complications and neurological status must be considered for justifying surgery. This study identified the aforementioned influence on long-term outcomes of cervical laminoplasty in patients aged ≥75 years. Thirty-seven of 38 consecutive patients aged ≥75 years who underwent cervical laminoplasty were retrospectively evaluated. Minimum 5-year follow-up was acceptable if patients were complication-free. Follow-up was terminated when neurological evaluation was not possible, owing to death or other serious complications affecting activities of daily living (ADL). Postoperative neurological changes and newly developed severe complications were investigated. Postoperatively, one patient died of acute pneumonia, one remained nonambulatory owing to cerebral infarction, and 35 were ambulatory and were discharged. At a mean follow-up of 78 months, three patients died and nine developed serious complications severely affecting ADL. Of the 25 remaining patients, 23 remained ambulatory at mean follow-up of 105 months. Cox proportional hazard analysis revealed that postoperative motor upper and lower extremities JOA scores of ≤2 and ≤1, respectively, were risk factors for mortality or other severe complications. Postoperative neurological status can be maintained in the elderly if they remain complication-free. Poorer neurological status significantly affected their ADL and mortality.
    11/2015; 2015(2):1-7. DOI:10.1155/2015/713952
  • [Show abstract] [Hide abstract]
    ABSTRACT: Objective: Prevalence of ankle osteoarthritis (OA) is lower than that of knee OA, however, the molecular mechanisms underlying the difference remain unrevealed. In the present study, we developed mouse ankle OA models for use as tools to investigate pathophysiology of ankle OA and molecular characteristics of ankle cartilage. Design: We anatomically and histologically examined ankle and knee joints of C57BL/6 mice, and compared them with human samples. We examined joints of 8-week-old and 25-month-old mice. For experimental models, we developed three different ankle OA models: a medial model, a lateral model, and a bilateral model, by resection of respective structures. OA severity was evaluated eight weeks after the surgery by safranin O staining, and cartilage degradation in the medial model was sequentially examined. Results: Anatomical and histological features of human and mouse ankle joints were comparable. Additionally, the mouse ankle joint was more resistant to cartilage degeneration with aging than the mouse knee joint. In the medial model, the tibiotalar joint was markedly affected while the subtalar joint was less degenerated. In the lateral model, the subtalar joint was mainly affected while the tibiotalar joint was less altered. In the bilateral model, both joints were markedly degenerated. In the time course of the medial model, TUNEL staining and Adamts5 expression were enhanced at early and middle stages, while Mmp13 expression was gradually increased during the OA development. Conclusion: Since human and mouse ankles are comparable, the present models will contribute to ankle OA pathophysiology and general cartilage research in future.
    Osteoarthritis and Cartilage 11/2015; DOI:10.1016/j.joca.2015.11.008 · 4.17 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Background: The objective of this study was to clarify the association of quadriceps muscle strength with knee pain using a large-scale, population-based cohort of the Research on Osteoarthritis/osteoporosis Against Disability (ROAD) study. Methods: From the 2566 subjects at the third visit of the ROAD study, the present study analyzed 2152 subjects who completed radiographic examinations and measurements of muscle strength and mass (690 men and 1462 women; mean age, 71.6 ± 12.2 years). Knee pain was assessed by an experienced orthopedist. Knee osteoarthritis (OA) was defined according to Kellgren-Lawrence (KL) grade. Quadriceps muscle strength and muscle mass at the lower limbs were measured by the Quadriceps Training Machine (QTM-05F, Alcare Co., Ltd. Tokyo, Japan) and the Body Composition Analyzer MC-190 (Tanita Corp., Tokyo, Japan), respectively. Results: Quadriceps muscle strength and weight bearing index (WBI: quadriceps muscle strength by weight) were significantly associated with knee pain after adjustment for age and body mass index, whereas grip strength and muscle mass at the lower limbs were not. The significant association of quadriceps muscle strength with knee pain was independent of radiographic knee OA. Conclusion: The present cross-sectional study showed an independent association of quadriceps muscle strength with knee pain.
    BMC Musculoskeletal Disorders 10/2015; 16(1):305. DOI:10.1186/s12891-015-0737-5 · 1.72 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Background: Currently, there are few reports regarding predictors of postoperative complications and short-term mortality after surgery for pathological femur fracture related to bone metastasis. Methods: Using data from the Japanese Diagnosis Procedure Combination Database from 2007 to 2012, we retrospectively identified 1497 patients who underwent internal fixation (n = 1073) or proximal femur resection and endoprosthetic reconstruction of the proximal femur (n = 424) for pathological femur fracture related to bone metastasis. Multivariable logistic regression analysis was performed to examine the relationship of various factors with postoperative complications and 30-day mortality. Results: The overall 30-day mortality after surgery was 2.6 %, and the proportion of postoperative complications was 12.1 %. Multivariable logistic regression analysis showed that postoperative complications overall were significantly associated with older age [odds ratio (OR), 2.15; 95 % confidence interval (CI) 1.23-3.74 for age ≥80 vs. ≤59 years]; lung carcinoma (OR 2.05; 95 % CI 1.47-2.86); esophageal carcinoma (OR 4.41; 95 % CI 1.57-12.43); higher Charlson Comorbidity Index (OR 1.50; 95 % CI 1.03-2.18 for ≥9 vs. 8); and blood transfusion (OR 1.57; 95 % CI 1.14-2.15). Thirty-day mortality also was significantly higher in patients with rapid-growth tumors, visceral metastasis, internal fixation, and no postoperative chemotherapy in the univariate analysis. Conclusions: Older age, type of primary tumor, higher Charlson Comorbidity Index, and blood transfusion were associated with higher morbidity. These findings can provide important information to assess perioperative risk in patients with pathological femur fracture related to bone metastasis.
    Annals of Surgical Oncology 10/2015; DOI:10.1245/s10434-015-4881-9 · 3.93 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Background: Although a few studies on perioperative stroke following spinal surgery have been reported, differences in the incidence of perioperative stroke among various surgical procedures have not been determined. The purpose of this retrospective analysis was to investigate the incidence of perioperative stroke during hospitalization in patients undergoing elective spinal surgery, and to examine whether the incidence varied according to the surgical procedure. Methods: A retrospective analysis of data from the Diagnosis Procedure Combination database, a nationwide administrative impatient database in Japan, identified 167,106 patients who underwent elective spinal surgery during 2007-2012. Patient information extracted included age, sex, preoperative comorbidity, administration of blood transfusion, length of hospitalization, and type of hospital. Clinical outcomes included perioperative stroke during hospitalization, and in-hospital death. Results: The overall incidence of perioperative stroke was 0.22 % (371/167,106) during hospitalization. A logistic regression model fitted with a generalized estimating equation showed perioperative stroke was associated with advanced age, a history of cardiac disease, an academic institution, and resection of a spinal tumor. Patients who underwent resection of a spinal cord tumor (reference) had a higher risk of stroke compared with those undergoing discectomy (odds ratio (OR), 0.29; 95 % confidence interval (CI), 0.14-0.58; p = 0.001), decompression surgery (OR, 0.44; 95 % CI, 0.26-0.73; p = 0.001), or arthrodesis surgery (OR, 0.55; 95 % CI, 0.34-0.90); p = 0.02). Advanced age (≥80 years; OR, 5.66; 95 % CI, 3.10-10.34; p ≤ 0.001), history of cardiac disease (OR, 1.58; 95 % CI, 1.10-2.26; p = 0.01), diabetes (OR, 1.73; 95 % CI, 1.36-2.20; p ≤ 0.001), hypertension (OR, 1.53; 95 % CI, 1.18-1.98; p = 0.001), cervical spine surgery (OR, 1.44; 95 % CI, 1.09-1.90; p = 0.01), a teaching hospital (OR, 1.36; 95 % CI, 1.01-1.82; p = 0.04), and length of stay (OR, 1.008; 95 % CI, 1.005-1.010; p ≤ 0.001) were also risk factors for perioperative stroke. Conclusions: Perioperative stroke occurred in 0.22 % of patients undergoing spinal surgery. Resection of a spinal cord tumor was associated with increased risk of perioperative stroke as well as advanced age, comorbidities at admission, cervical spine surgery, surgery in a teaching hospital, and length of stay.
    BMC Musculoskeletal Disorders 10/2015; 16(1):276. DOI:10.1186/s12891-015-0743-7 · 1.72 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Background context: Although the negative aspects of blood transfusion are increasingly recognized, less is known about transfusion-related risks in spinal surgery. Purpose: This study was designed to determine whether perioperative allogeneic blood transfusion is associated with increased risk of infectious complications after elective spinal surgery. Study design: Retrospective cohort study with propensity score matched analysis. Patient sample: Data of patients with spinal canal stenosis and spondylolisthesis who underwent elective lumbar surgeries (decompression and/or fusion) were obtained from the Diagnosis Procedure Combination database, a nationwide administrative impatient database in Japan. Outcome measures: Clinical outcomes included in-hospital death and the occurrence of infectious complications (surgical site infection, respiratory tract infection, urinary tract infection and sepsis). Methods: Patients' clinical information, including sex, age, type of hospital, preoperative comorbidities, duration of anesthesia, cell saver use and volume of allogeneic blood transfused, were investigated. Patients transfused with > 840 mL (6 units) were excluded. Propensity scores for receiving transfusion were calculated, with one-to-one matching based on estimated propensity scores to adjust for patients' baseline characteristics. The proportions of complications were compared in patients with and without transfusions. This study was funded by grants from the Ministry of Health, Labour and Welfare, Japan. The authors declare that they have no conflicts of interest. Results: Of the 84,650 patients identified, 5,289 patients (6.1%) received transfusions, with 4,436 (5.2%) receiving up to 840 mL. One-to-one propensity score matching resulted in 4,275 pairs with and without transfusion. Patients transfused were at increased risk of surgical site infection (odds ratio [OR], 1.9; 95% confidence interval [CI], 1.4-2.5; p < 0.001), and urinary tract infection (OR, 2.5; 95% CI, 1.5-4.2; p < 0.001) than those not transfused. Conclusions: Allogeneic blood transfusion after elective lumbar surgery was associated with increased risks of surgical site infection and urinary tract infection.
    The spine journal: official journal of the North American Spine Society 10/2015; 15(10):S204. DOI:10.1016/j.spinee.2015.07.280 · 2.43 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Objectives: We investigated the effect of cartilage degeneration on ultrasound speed in human articular cartilage in vitro. Methods: Ultrasound speed was calculated by the time-of-flight method for twenty-two femoral condyle osteochondral blocks obtained from osteoarthritis patients. In parallel, histological evaluation of specimens was performed using the modified Mankin and OARSI scores. Results: The mean ultrasound speed was 1757 ± 109 m/s. Ultrasound speed showed significant negative correlation with OARSI score, and a decreasing tendency with high Mankin scores. Good correlation was found between the optically measured and the calculated cartilage thickness. Conclusion: Our results show that articular cartilage degeneration has relatively little influence on ultrasound speed. In addition, morphological evaluation of articular cartilage using a preset value of ultrasound speed seems to offer relatively accurate results.
    Modern Rheumatology 09/2015; DOI:10.3109/14397595.2015.1097012 · 2.40 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Idiopathic osteonecrosis of the talus is a rare but severe condition that directly affects the ability to walk and is difficult to treat either conservatively or surgically. We report the case of a 72-year-old female with idiopathic necrosis of the talus treated with total talar replacement surgery. A custom-made aluminum-ceramic total talar prosthesis was prepared using the mirror image of the computed tomography and radiographic data from the contralateral ankle. The talus was exposed and removed using an anterior approach, and the total talar prosthesis was inserted. The prosthesis was placed in a stable position between the tibia, calcaneus, and navicular, with no signs of instability with ankle joint movement. The ankle was immobilized in a short-leg cast for 3 weeks. At the latest follow-up examination, 2 years after surgery, the patient was walking without pain. Examination of the left ankle showed 20° of dorsiflexion and 40° of plantar flexion. The American Orthopaedic Foot and Ankle Society ankle/hindfoot score was 90, which had improved from a preoperative score of 45. Radiographic examination showed that the prosthesis was in a stable position in the ankle mortise, and no degenerative or destructive changes were observed in the surrounding bones. This is the first reported case of total talar replacement with a prosthesis for idiopathic talar necrosis. Although the long-term outcome is still unknown, this procedure could provide a good treatment option for idiopathic necrosis of the talus.
    The Journal of foot and ankle surgery: official publication of the American College of Foot and Ankle Surgeons 09/2015; DOI:10.1053/j.jfas.2015.07.015 · 0.85 Impact Factor

  • Global Spine Journal 09/2015; DOI:10.1055/s-0035-1563725
  • [Show abstract] [Hide abstract]
    ABSTRACT: Introduction: Mortality following hip fracture surgery is higher in patients with dementia than those without; however, few large-scale studies have investigated postoperative in-hospital complications in such patients. The aim of this study was to elucidate the complications that occur after hip fracture surgery in patients with and without dementia using a large national database. Materials and methods: We retrospectively identified patients aged ≥70 years who underwent hemiarthroplasty, osteosynthesis for femoral neck fracture or osteosynthesis for intertrochanteric fracture, and compared the occurrence of postoperative complications between patients with and without dementia. Multivariate logistic regression analysis was performed to adjust for patient characteristics and hospital factors. Results: A total of 87,654 patients were included in this study, including 9419 with dementia. Compared with the non-dementia group, the dementia group showed a higher incidence of overall postoperative complications [odds ratio (OR) 1.45; p < 0.001), surgical site infection (OR 1.58; p = 0.004), urinary tract infection (OR 1.87; p < 0.001) and respiratory complications (OR 1.49; p < 0.001). The rate of postoperative complications was higher for all types of hip fracture surgery. The occurrence of a postoperative complication was significantly higher in patients aged ≥80 years (OR 1.37; p < 0.001) and those with dementia (OR 1.45; p < 0.001), any type of malignancy (OR 1.42; p < 0.001), a history of cardiovascular disease (OR 1.33; p < 0.001), a history of cerebrovascular disease (OR 1.15; p = 0.029), chronic renal failure (OR 1.36; p < 0.001), liver cirrhosis (OR 1.41; p < 0.001) or blood transfusion after surgery (OR 1.49; p < 0.001). Conclusions: Our results highlight the need to pay particular attention to surgical site infection, urinary tract infection and respiratory complications in patients with preoperative dementia after hip fracture surgery. These results provide additional useful evidence to inform the management of these patients.
    Archives of Orthopaedic and Trauma Surgery 09/2015; 135(11). DOI:10.1007/s00402-015-2321-8 · 1.60 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Dumbbell-shaped tumors consisting of 2 different tumors are extremely rare. Herein, the authors present a case of concurrent spinal schwannoma and meningioma mimicking a single cervical dumbbell-shaped tumor. A 64-year-old man presented with a 5-year history of gradually exacerbating left occipital pain without clinical evidence of neurofibromatosis. Magnetic resonance imaging showed an extradural tumor along the left C-2 nerve root with a small intradural component. The tumor was approached via a C-1 hemilaminectomy. The intradural tumor was resected together with the extradural tumor after opening the dura mater. The intradural tumor was attached to the dura mater around the exit point of the C-2 nerve root. Intraoperative biopsy revealed that the extradural tumor was a schwannoma and that the intradural tumor was a meningioma. The dura mater adjacent to the tumor was then coagulated and resected. Postoperative pathological examination confirmed the same diagnoses with no evidence of continuity between the intra- and extradural components. The patient's postoperative clinical course was uneventful. Clinicians should be aware that cervical dumbbell-shaped tumors can consist of 2 different tumors.
    Journal of neurosurgery. Spine 08/2015; DOI:10.3171/2015.3.SPINE141315 · 2.38 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Rheumatoid arthritis (RA) is an autoimmune destructive arthritis associated with CD4(+) T cell-mediated immunity. Although expanded CD4(+) T cell clones (ECs) has already been confirmed, the detailed characteristics of ECs have not been elucidated in RA. Using combination of a single-cell analysis and next-generation sequencing (NGS) in TCR repertoire analysis, we here revealed the detailed nature of ECs by examining peripheral blood (PB) from 5 RA patients and synovium from 1 RA patient. When we intensively investigated the single-cell transcriptome of the most expanded clones in memory CD4(+) T cells (memory-mECs) in RA-PB, senescence-related transcripts were up-regulated, indicating circulating ECs were constantly stimulated. Tracking of the transcriptome shift within the same memory-mECs between PB and the synovium revealed the augmentations in senescence-related gene expression and the up-regulation of synovium-homing chemokine receptors in the synovium. Our in-depth characterization of ECs in RA successfully demonstrated the presence of the specific immunological selection pressure, which determines the phenotype of ECs. Moreover, transcriptome tracking added novel aspects to the underlying sequential immune processes. Our approach may provide new insights into the pathophysiology of RA.
    Scientific Reports 08/2015; 5:12937. DOI:10.1038/srep12937 · 5.58 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Although hip osteoarthritis (OA) is a major cause of hip pain and disability in elderly people, few epidemiologic studies have been performed. We investigated the prevalence of radiographic hip OA and its association with hip pain in Japanese men and women using a large-scale population of a nationwide cohort study, Research on Osteoarthritis/osteoporosis Against Disability (ROAD). From the baseline survey of the ROAD study, 2,975 participants (1,043 men and 1,932 women), aged 23-94 years (mean 70.2 years), living in urban, mountainous, and coastal communities were analyzed. The radiographic severity at both hips was determined by the Kellgren/Lawrence (K/L) grading system. Radiographic hip OA was defined as K/L ≥2, and severe radiographic hip OA as K/L ≥3. The crude prevalence of radiographic hip OA was 18.2% and 14.3% in men and women, respectively, that of severe radiographic hip OA was 1.34% and 2.54%, and that of symptomatic K/L ≥2 OA was 0.29% and 0.99%, respectively. The crude prevalence of hip OA, including severe OA, was not age-dependent in men or women. Male sex was a risk factor for radiographic hip OA, whereas female sex was a risk factor for severe radiographic hip OA and hip pain. Compared with K/L = 0/1, hip pain was significantly associated with K/L ≥3, but not with K/L=2. The present cross-sectional study revealed the prevalence of radiographic hip OA and severe hip OA in Japanese men and women. Hip pain was strongly associated with K/L ≥3. Copyright © 2015. Published by Elsevier Ltd.
    Osteoarthritis and Cartilage 08/2015; DOI:10.1016/j.joca.2015.07.017 · 4.17 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Induced pluripotent stem cells (iPSCs) are a promising cell source for cartilage regenerative medicine. Meanwhile, the risk of tumorigenesis should be considered in the clinical application of human iPSCs (hiPSCs). Here, we report in vitro chondrogenic differentiation of hiPSCs and maturation of the differentiated hiPSCs through transplantation into mouse knee joints. Three hiPSC clones showed efficient chondrogenic differentiation using an established protocol for human embryonic stem cells. The differentiated hiPSCs formed hyaline cartilage tissues at 8 weeks after transplantation into the articular cartilage of NOD/SCID mouse knee joints. Although tumors were not observed during the 8 weeks after transplantation, an immature teratoma had developed in one mouse at 16 weeks. In conclusion, hiPSCs are a potent cell source for regeneration of hyaline articular cartilage. However, the risk of tumorigenesis should be managed for clinical application in the future.
    Biomedical Research 07/2015; 36(3):179-86. DOI:10.2220/biomedres.36.179 · 1.14 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: We investigated the serum levels of the phosphorylated form of the high molecular weight neurofilament subunit (pNF-H) in patients with cervical compressive myelopathy. pNF-H is becoming increasingly recognized as a biomarker for axonal injury, however, it remains unclear whether serum pNF-H is elevated in chronic spinal cord compression. We examined 26 patients who underwent surgery for cervical compressive myelopathy. Peripheral blood samples were obtained both preoperatively and 1week after surgery to evaluate the serum pNF-H levels using an enzyme-linked immunosorbent assay. A history of recent aggravation of myelopathy was also investigated. Of the 26 myelopathy patients, the preoperative serum pNF-H level was negative in 20 patients and moderately elevated in six. Patients who were positive for pNF-H were more likely to have had a recent aggravation of myelopathy compared with the pNF-H negative patients (83 versus 25%; p=0.02). All patients who were positive for pNF-H before surgery remained positive after surgery. Two patients who became positive after surgery demonstrated a neurologic deterioration associated with the surgery. In conclusion, the serum pNF-H level was negative in the majority of patients with cervical compressive myelopathy. Our results suggest that an elevated serum level of pNF-H is associated with an acute worsening of myelopathy and that a positive conversion of pNF-H after surgery is a marker of perioperative neural damage. Copyright © 2015 Elsevier Ltd. All rights reserved.
    Journal of Clinical Neuroscience 07/2015; 22(10). DOI:10.1016/j.jocn.2015.03.047 · 1.38 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Whiplash-associated disorders (WAD) are the most common injuries that are associated with car collisions in Japan and many Western countries. However, there is no clear evidence regarding the potential risk factors for poor recovery from WAD. Therefore, we used an online survey of the Japanese population to examine the association between potential risk factors and the persistence of symptoms in individuals with WAD. An online survey was completed by 127,956 participants, including 4,164 participants who had been involved in a traffic collision. A random sample of the collision participants (n = 1,698) were provided with a secondary questionnaire. From among the 974 (57.4%) respondents to the secondary questionnaire, we selected 183 cases (intractable neck pain that was treated over a period of 6 months) and 333 controls (minor neck pain that was treated within 3 months). Multivariable logistic regression analysis was used to evaluate the potential risk factors for prolonged treatment of WAD. Female sex, the severity of the collision, poor expectations of recovery, victim mentality, dizziness, numbness or pain in the arms, and lower back pain were associated with a poor recovery from WAD. In the present study, the baseline symptoms (dizziness, numbness or pain in the arms, and lower back pain) had the strongest associations with prolonged treatment for WAD, although the psychological and behavioral factors were also important. These risk factors should be considered when evaluating patients who may have the potential for poor outcomes.
    PLoS ONE 07/2015; 10(7):e0132191. DOI:10.1371/journal.pone.0132191 · 3.23 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Sterilization using high-energy irradiation is an important aspect of implementing an ultra-high molecular weight polyethylene acetabular liner in total hip arthroplasty (THA). In this study, we evaluate the effects of extra irradiations such as gamma-ray or plasma irradiation during sterilization of the poly(2-methacryloyloxyethyl phosphorylcholine [MPC]) (PMPC) surface and cross-linked polyethylene (CLPE) substrate of a PMPC-grafted CLPE acetabular liner. The PMPC-grafted surface yielded high wettability and low friction properties regardless of the extra irradiations as compared with untreated CLPE. During a hip simulator test, wear resistance of the PMPC-grafted CLPE liner was maintained after extra irradiation, which is due to the high wettability characteristics of the PMPC surface. In particular, the PMPC-grafted CLPE liner treated with plasma irradiation showed greater wettability and wear resistance than that with gamma-ray irradiation. However, we could not clearly observe the changes in chemical properties and morphology of the PMPC surface after both extra irradiations. The physical and mechanical properties attributed to CLPE substrate performance were also unchanged. In contrast, PMPC-grafted CLPE treated with plasma irradiation showed improved oxidation resistance as compared to that treated with gamma-ray irradiation after accelerated aging. Thus, we conclude that PMPC-grafted CLPE with plasma irradiation has promise as a lifelong solution for bearing in THA. This article is protected by copyright. All rights reserved. © 2015 Wiley Periodicals, Inc.
    Journal of Biomedical Materials Research Part A 07/2015; DOI:10.1002/jbm.a.35538 · 3.37 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Total en bloc spondylectomy (TES) is accompanied by preoperative embolization of segmental arteries, which is limited to three consecutive levels to avoid the risk of spinal cord ischemia. We retrospectively examined the efficacy and safety of repeated TES with embolization of more than three levels of segmental arteries. Seven patients underwent TES twice for spinal metastases at different levels. Every patient underwent embolization of the bilateral segmental arteries before each surgery. We assessed the total number of segmental arteries embolized, the existence of Adamkiewicz arteries during the embolization procedure, intraoperative blood loss, and the motor function of the lower limbs, using the American Spinal Injury Association (ASIA) motor score. No patient experienced any motor deficit after embolization. During the embolization procedure, an Adamkiewicz artery was depicted in five patients, which precluded embolization at that level. The median number of segmental arteries embolized in total was 9 (9-11). Intraoperative blood loss (median, IQR) was 480 (420-630) ml during the first surgery and 520 (280-600) ml during the second surgery. The ASIA motor scores (median, IQR) were as follows; 100 (98-100) (first admission), 100 (100-100) (first discharge), 100 (98-100) (second admission), and 97 (94-100) (second discharge). No patients had developed statistically significant neurological deterioration, and there had been no local recurrence after a median follow-up of 17.8 months (range 1-51 months). Repeated TES procedures can be performed safely even if more than three levels of segmental arteries are embolized.
    European Spine Journal 07/2015; DOI:10.1007/s00586-015-4091-y · 2.07 Impact Factor

Publication Stats

8k Citations
911.53 Total Impact Points


  • 1997-2015
    • The University of Tokyo
      • • Department of Orthopaedic Surgery and Spinal Surgery
      • • Division of Sensory and Motor System Medicine
      • • School of Medicine
      Tōkyō, Japan
    • Tokyo Metropolitan Institute of Medical Science
      Edo, Tōkyō, Japan
  • 2009-2014
    • Tokyo Medical University
      • Department of Orthopedic Surgery
      Edo, Tōkyō, Japan
  • 2004-2014
    • Sagamihara National Hospital
      Йокосука, Kanagawa, Japan
  • 1992-2009
    • Showa University
      • • Department of Biochemistry
      • • School of Dentistry
      Shinagawa, Tōkyō, Japan
  • 2005
    • National Hospital Organization Sagamihara Hospital
      Sagamihara, Kanagawa, Japan