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Dive into the research topics where Yuji Takazawa is active.

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Featured researches published by Yuji Takazawa.


Scandinavian Journal of Medicine & Science in Sports | 2008

ST/G ACL reconstruction: double strand plus extra-articular sling vs double bundle, randomized study at 3-year follow-up

Stefano Zaffagnini; Danilo Bruni; Alessandro Russo; Yuji Takazawa; M. Lo Presti; Giovanni Giordano; M. Marcacci

Several investigators have reported the presence of biomechanical, kinematic, anatomic, fiber orientation patterns and biological differences between the anteromedial bundle and the posterolateral bundle of ACL. The purpose of this prospective randomized study was to compare the clinical, instrumental and X‐ray outcome of two ACL reconstruction techniques with hamstring tendons: one with a single intra‐articular bundle associated to an extra‐articular sling, the second with a more anatomic double‐bundle technique that reproduces better the native ACL function. From an initial group of 100 patients who underwent ACL reconstruction, 72 patients (35 single bundle plus lateral plasty and 37 double bundle) were evaluated with IKDC, Tegner score, KT2000 arthrometer, Activity Rating Scale, Psychovitality Questionnaire and Ahlback radiographic score at a mean 3 years follow‐up. Double‐bundle group showed significantly better results regarding IKDC, ROM, Activity Rating Scale and time to return to sport. Also KT 2000 showed significant differences in objective stability. The double‐bundle technique for ACL reconstruction described in this paper has demonstrated significantly better subjective, objective and functional results compared with a double‐stranded hamstrings plus extra‐articular sling at a minimum 3‐year follow‐up.


Clinical Rheumatology | 2010

Correlation between synovitis detected on enhanced-magnetic resonance imaging and a histological analysis with a patient-oriented outcome measure for Japanese patients with end-stage knee osteoarthritis receiving joint replacement surgery

L. Liu; Muneaki Ishijima; I. Futami; H. Kaneko; Mitsuaki Kubota; Takayuki Kawasaki; Toshiharu Matsumoto; Hidetake Kurihara; Liang Ning; Zhuo Xu; Hiroshi Ikeda; Yuji Takazawa; Yoshitomo Saita; Yuta Kimura; Shouyu Xu; Kazuo Kaneko; Hisashi Kurosawa

Osteoarthritis (OA) is a disease that primarily results in the degeneration and destruction of the articular cartilage. However, synovitis that occurs secondarily by this primary phenomenon is crucial for both the structural and symptomatic progression of the disease. The Japanese Knee Osteoarthritis Measure (JKOM) was created as an outcome measure for Japanese patients with knee OA. This study was conducted to determine whether synovitis in knee OA correlates with the current disability of patients with knee OA who required total knee arthroplasty (TKA). Thirty-four Japanese patients with end-stage knee OA who required TKA were included in this study. The visual analog scale (VAS, 0–100) for pain and the JKOM score, as well as the Western Ontario and McMaster Universities Arthritis Index (WOMAC), were examined before the operation. Synovial samples were taken at the time of the operation. A histological analysis and gadolinium-enhanced magnetic resonance imaging (Gd-MRI) were conducted to evaluate synovitis. Correlations between the synovitis score evaluated by histological analysis and Gd-MRI with either the pain VAS score or the JKOM score were examined using Spearman’s rank correlation coefficient. Neither the synovitis scores evaluated by the histological analysis nor those by a Gd-MRI correlated with the pain VAS score (n = 34, r = 0.25, p = 0.18 and r = 0.08, p = 0.75, respectively) and WOMAC (n = 14, r = 0.35, p = 0.22 and r = 0.45, p = 0.16, respectively) of the patients. However, they significantly correlated with the JKOM score of the patients (n = 34, r = 0.55, p = 0.001 and r = 0.71, p = 0.001, respectively). The severity of synovitis in OA was closely correlated with the current functional impairment and disability of the patients receiving TKA with end-stage knee OA.


Journal of Orthopaedic Science | 2009

Therapeutic home exercise versus intraarticular hyaluronate injection for osteoarthritis of the knee: 6-month prospective randomized open-labeled trial

Takayuki Kawasaki; Hisashi Kurosawa; Hiroshi Ikeda; Yuji Takazawa; Muneaki Ishijima; Mitsuaki Kubota; Hajime Kajihara; Yuichiro Maruyama; Sung-Gon Kim; Hiroaki Kanazawa; Tokuhide Doi

BackgroundTreatment for osteoarthritis (OA) of the knee is controversial. Only a few studies have compared the effects of intraarticular injection of hyaluronate with those of home exercise for knee OA. We prospectively evaluated the therapeutic effects of each treatment.MethodsA total of 102 female subjects (mean age 70.4 years) were randomly divided into two groups and followed up to the 24th week. The primary outcome measure was judged by three pain/function scales as follows: a visual analogue scale, the Japanese Knee Osteoarthritis Measure, and the Outcome Measures in Rheumatology Clinical Trials and Osteoarthritis Research Society International criteria. For secondary outcome measures, all data were categorized for logistic regression analysis and the chi-squared test to address factors affecting these outcomes.ResultsThe two treatment groups demonstrated equal improvement regarding all three scales, and there was statistically no difference in between-group analyses, although there seemed to be better improvement in range of motion at 24 weeks in the home exercise group. In categorical analysis, OA stage was classified as early and advanced OA at 3 mm of joint space width obtained from standing anteroposterior radiographs. Logistic regression analysis revealed that the OA stage at the baseline of the knee affected these improvements. For early OA the improvement rate regarding hydrops was significantly higher in the home exercise group, whereas for advanced OA there was a tendency for the rate of improvement in ROM to be inferior in the hyaluronidate group.ConclusionsTaking into account the cost, convenience, and invasiveness to patients, exercise is thought to have some advantage over intraarticular injection of hyaluronate for the therapy of OA of the knee.


Journal of Bone and Mineral Metabolism | 2008

Additive effects of glucosamine or risedronate for the treatment of osteoarthritis of the knee combined with home exercise: a prospective randomized 18-month trial

Takayuki Kawasaki; Hisashi Kurosawa; Hiroshi Ikeda; Sung-Gon Kim; Aki Osawa; Yuji Takazawa; Mitsuaki Kubota; Muneaki Ishijima

We have previously demonstrated the efficacy of therapeutic exercise for osteoarthritis (OA) of the knee. This study was performed to examine the additive effects of glucosamine or risedronate on the exercise therapy. In this study, 142 female patients with moderate OA of the knee, who had been recommended to undergo home exercise at the first visit to the hospital, were randomly given glucosamine hydrochloride, risedronate, or no additive. Although improvement after 18 months was observed in all groups using individual scales for evaluation of pain and function of the knee, no significant differences were observed between the groups regarding any of the scales, indicating no significant additive effect of glucosamine or risedronate. One reason for the lack of effect of glucosamine or risedronate on OA of the knee may be that the effect of these agents was occluded by the effect of therapeutic exercise to improve pain and function of the knee. This finding means that even if glucosamine and risedronate were to have an effect on OA of the knee, the effect would not be greater than the effect of knee exercise to improve the symptoms.


American Journal of Sports Medicine | 2012

Headless Compression Screw Fixation of Jones Fractures An Outcomes Study in Japanese Athletes

Masashi Nagao; Yoshitomo Saita; So Kameda; Hiroaki Seto; R. Sadatsuki; Yuji Takazawa; Masafumi Yoshimura; Yukihiro Aoba; Hiroshi Ikeda; Kazuo Kaneko; Masahiko Nozawa; Sung-Gon Kim; Hiroki Nakajima; Norifumi Fukushi

Background: Internal fixation is advocated as the primary treatment for fifth metatarsal Jones fractures in athletes; however, screw insertion site discomfort and refracture can occur especially in competitive athletes. The ideal implant has not been determined. Hypothesis: Headless compression screw fixation of proximal fifth metatarsal Jones fractures is an effective treatment approach especially in competitive athletes. Study Design: Case series; Evidence level, 4. Methods: We studied 60 athletes treated surgically with a headless compression screw for fifth metatarsal Jones fractures (mean age, 19 years). The mean follow-up time was 178 weeks. We evaluated the clinical and radiographic outcomes of headless compression screw fixation of Jones fractures. Results: All athletes returned to full activity. The mean time to start running after surgery was 6.3 weeks (range, 3-12.7 weeks), and the mean time to full activity after surgery was 11.2 weeks (range, 6-25 weeks). One athlete suffered a delayed union, which healed uneventfully. One athlete suffered a nonunion and underwent reoperation for a screw exchange to an autogenous bone graft harvested from the iliac crest. No screw breakage was reported. No athlete suffered a refracture or discomfort in the screw insertion site. Conclusion: Headless compression screw fixation of fifth metatarsal Jones fractures provided excellent results, allowing athletes to return to full activity without both screw insertion site irritation and clinical refracture.


Orthopaedic Journal of Sports Medicine | 2013

ACL Reconstruction Preserving the ACL Remnant Achieves Good Clinical Outcomes and Can Reduce Subsequent Graft Rupture

Yuji Takazawa; Hiroshi Ikeda; Takayuki Kawasaki; Muneaki Ishijima; Mitsuaki Kubota; Yoshitomo Saita; H. Kaneko; Sung-Gon Kim; Hisashi Kurosawa; Kazuo Kaneko

Background: Although anterior cruciate ligament (ACL) reconstruction techniques that preserve remnant tissues have been described, complete preservation may be difficult, with little known about its clinical advantages. Purpose: To compare clinical outcomes in patients undergoing ACL reconstruction with and without ACL remnant preservation. Study Design: Case-control study. Methods: Of 372 patients who underwent surgical treatment of an ACL injury between September 2006 and July 2010, 154 had no remaining identifiable ligament tissue and were excluded from this study. Attempts were made to preserve the ACL remnant as much as possible in the remaining 218 patients. These patients were divided into 2 groups: those in whom the remnant was preserved (group 1, n = 85) and those in whom the remnant was not preserved (group 2, n = 98). Patients were followed for at least 24 months. Outcomes, including graft rupture, were compared in the 2 groups. Results: Time from injury to surgery was significantly shorter (7.3 ± 16.3 vs 16.0 ± 30.3 months; P < .05) and the preinjury Tegner activity was significantly higher (7.6 ± 1.4 vs 7.1 ± 1.2; P < .05; 95% confidence interval, 1.2-13.7) in group 1 than in group 2. The postoperative negative ratio of the pivot-shift test was similar in the 2 groups (87% vs 81%). Anterior stability of the knee, as measured by a KT-2000 arthrometer, was significantly better in group 1 than in group 2 (1.0 ± 0.8 vs 1.3 ± 1.0 mm; P < .05). ACL graft rupture occurred in 1 patient (1.1%) in group 1 and in 7 patients (7.1%) in group 2 (P < .05). Regression analysis showed that preservation of the remnant decreased the likelihood of graft rupture (odds ratio, 11.2; 95% confidence interval, 1.2-101.7). Conclusion: These findings confirmed that preserving the remnant tissue of the ACL may facilitate recovery of function and decrease graft rupture after primary reconstruction.


Journal of Orthopaedic Science | 2010

A longitudinal study of the relationship between the status of bone marrow abnormalities and progression of knee osteoarthritis

Mitsuaki Kubota; Muneaki Ishijima; Hisashi Kurosawa; L. Liu; Hiroshi Ikeda; Aki Osawa; Yuji Takazawa; Takayuki Kawasaki; Yoshitomo Saita; Yuta Kimura; Kazuo Kaneko

BackgroundBone marrow abnormalities (BMAs) detected on magnetic resonance imaging (MRI) are suggested to be involved in the pathogenesis of osteoarthritis (OA), and the size of the BMAs is associated with the progression of OA. However, it still remains unclear as to whether the associations of BMA size and OA severity are observed equally or whether they differ from early to advanced stages of OA. In the present study we examined whether BMA enlargement and OA progression differed according to the severity of OA.MethodsOne hundred and eighty patients with knee OA were enrolled in the present study, and 122 of these patients completed this study. Radiography and knee MRI were done two times in all patients, at the baseline and 6 months or later at the time of patient follow-up. The severity of OA was evaluated by radiography using the Kellgren-Lawrence (K-L) grade. The patients who showed a deterioration in the K-L grade during the follow-up examination (59/122) were defined as the deterioration group. T2-weighted fat-suppressed MR images were used to score the size of the BMAs according to the whole-organ magnetic resonance imaging score (WORMS). A new scoring system, the spacial BMA score (s-score) was defined to assess the size of the BMAs three-dimensionally.ResultsIn patients with K-L grade 2, the s-score changes during the follow-up period in the deterioration group were significantly increased in comparison to those in the no-change group (P = 0.04), and no significant s-score changes were observed in patients with either K-L grade 1 or 3 (P = 0.07 and 0.57) between the deterioration group and the no-change group during the follow-up examination. In patients with K-L grade 3, the s-score at the baseline in the deterioration group was higher than that in the no-change group (P = 0.05).ConclusionsThe relationship between the size and enlargement of BMAs and the progression of OA changed depending upon the severity of OA.


Journal of Shoulder and Elbow Surgery | 2014

Incidence of and risk factors for traumatic anterior shoulder dislocation: an epidemiologic study in high-school rugby players

Takayuki Kawasaki; Chihiro Ota; Shingo Urayama; Nobukazu Maki; Masataka Nagayama; Takefumi Kaketa; Yuji Takazawa; Kazuo Kaneko

BACKGROUND The incidence of reinjuries due to glenohumeral instability and the major risk factors for primary anterior shoulder dislocation in youth rugby players have been unclear. PURPOSE The purpose of this study was to investigate the incidence, mechanisms, and intrinsic risk factors of shoulder dislocation in elite high-school rugby union teams during the 2012 season. METHODS A total of 378 male rugby players from 7 high-school teams were investigated by use of self-administered preseason and postseason questionnaires. RESULTS The prevalence of a history of shoulder dislocation was 14.8%, and there were 21 events of primary shoulder dislocation of the 74 overall shoulder injuries that were sustained during the season (3.2 events per 1000 player-hours of match exposure). During the season, 54.3% of the shoulders with at least one episode of shoulder dislocation had reinjury. This study also indicated that the persistence of glenohumeral instability might affect the players self-assessed condition, regardless of the incidence during the current season. By a multivariate logistic regression method, a history of shoulder dislocation on the opposite side before the season was found to be a risk factor for contralateral primary shoulder dislocation (odds ratio, 3.56; 95% confidence interval, 1.27-9.97; P = .02). CONCLUSIONS High-school rugby players with a history of shoulder dislocation are not playing at full capacity and also have a significant rate of reinjury as well as a high risk of dislocating the other shoulder. These findings may be helpful in deciding on the proper treatment of primary anterior shoulder dislocation in young rugby players.


BMC Musculoskeletal Disorders | 2013

Reference intervals of serum hyaluronic acid corresponding to the radiographic severity of knee osteoarthritis in women

H. Kaneko; Muneaki Ishijima; Tokuhide Doi; I. Futami; L. Liu; R. Sadatsuki; A. Yusup; S. Hada; Mitsuaki Kubota; Takayuki Kawasaki; Yoshitomo Saita; Yuji Takazawa; Hiroshi Ikeda; Hisashi Kurosawa; Kazuo Kaneko

BackgroudWhile serum levels of hyarulonic acid (sHA) is known to be useful for a burden of disease biomarker in knee OA, it is far from practical. The reference intervals must be established for biomarkers to be useful for clinical interpretation. The aim of this study was to establish the reference intervals of sHA corresponding to the radiographic severity of knee OA for elucidating whether sHA can be useful as a burden of disease marker for individual patient with knee OA.Methods372 women with Kellgren & Lawrence grade (K/L) 1 through 4 painful knee OA were enrolled in this study. The patients included 54 with K/L 1, 96 with K/L 2, 97 with K/L 3, and 118 with K/L 4. Serum samples were obtained from all subjects on the day that radiographs taken. A HA binding protein based latex agglutination assay that employed an ELISA format was used to measure sHA. Age and BMI adjusted one way ANOVA was used to set the reference intervals of sHA.ResultsThe reference intervals for sHA corresponding to the patients with K/L 4 (49.6 – 66.5 ng/ml) was established without any overlap against to those with K/L 1, 2 and 3, while those with K/L 1, 2 and 3 showed considerable overlap.ConclusionsThese results indicate that sHA can be available as a burden of disease marker for the individuals with severe knee OA (K/L 4), while it is not for those with primary to moderate knee OA (K/L 1–3).


American Journal of Sports Medicine | 2015

Incidence of Stingers in Young Rugby Players

Takayuki Kawasaki; Chihiro Ota; Takeshi Yoneda; Nobukazu Maki; Shingo Urayama; Masashi Nagao; Masataka Nagayama; Takefumi Kaketa; Yuji Takazawa; Kazuo Kaneko

Background: A stinger is a type of neurapraxia of the cervical roots or brachial plexus and represents a reversible peripheral nerve injury. The incidence of and major risk factors for stingers among young rugby players remain uninvestigated. Purpose: To investigate the incidence, symptoms, and intrinsic risk factors for stingers in elite rugby union teams of young players. Study Design: Descriptive epidemiology study. Methods: A total of 569 male rugby players, including 358 players from 7 high school teams and 211 players from 2 university teams, were investigated using self-administered preseason and postseason questionnaires. Results: The prevalence of a history of stingers was 33.9% (95% CI, 30.3-37.9), and 20.9% (119/569) of players experienced at least 1 episode of a stinger during the season (34.2 [95% CI, 26.2-42.1] events per 1000 player-hours of match exposure). The reinjury rate for stingers per season was 37.3% (95% CI, 30.4-44.2). Using the multivariate Poisson regression method, a history of stingers in the previous season and the grade and position of the player were found to be risk factors for stingers during the current season. The mean severity of injury was 2.9 days, with 79.3% (191/241) of the players not losing any time from playing after sustaining a stinger injury and 5.8% (14/241) of the players recovering within more than 14 days. The most frequent symptom was numbness in the unilateral upper extremity, and the most severe symptom was weakness of grasping (mean severity, 6 days). A logistic regression analysis indicated that a history of stingers in the previous season and an injury with more than 3 symptoms, especially motor weakness, were correlated with the severity of injury. Conclusion: Young rugby players with a history of stingers have a significantly high rate of repeat injuries. Although nearly 80% of the players experienced only minimal (0-1 day) time loss injuries, neurological deficits sometimes last beyond 1 month. A history of stingers was identified to be the strongest risk factor for injuries and for lasting symptoms. This information may be useful for planning the proper treatment for stingers in young rugby players.

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L. Liu

Juntendo University

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