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Dive into the research topics where Masaru Kadowaki is active.

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Featured researches published by Masaru Kadowaki.


Archives of Orthopaedic and Trauma Surgery | 2012

A “sandwich” method of reconstruction of the medial patellofemoral ligament using a titanium interference screw for patellar instability in skeletally immature patients

Nobuyuki Kumahashi; Suguru Kuwata; Taku Tadenuma; Masaru Kadowaki; Yuji Uchio

BackgroundNo standard surgical procedure for medial patellofemoral ligament (MPFL) reconstruction exists in skeletally immature patients with patellar instability. This study aimed to evaluate the clinical effectiveness of a novel reconstruction technique for the MPFL in patients with patellar instability because of non-closure of the epiphyseal line.MethodsThe “sandwich” method was fixation of the patella between a double-stranded semitendinosus tendon through the posterior third of the femoral insertion of the medial collateral ligament (MCL) as a pulley with a titanium interference screw in a single patellar tunnel. Five knees in five patients were studied: four with recurrent and one with habitual patellar dislocations. Subjects underwent MPFL reconstruction with or without lateral release. Patients were evaluated using pre-operative and post-operative physical and radiographic examinations, including apprehension testing, assessment of tilting and congruence angles, medial and lateral shift ratios under stress measured using X-ray imaging, and Kujala and Lysholm scores.ResultsNo patient experienced recurrent post-operative episodes of dislocation or subluxation. By the final follow-up, patellar apprehension had disappeared in all patients. In addition, all patients showed significant improvement in the following: tilting angle, congruence angle, lateral shift ratio, Kujala score, and Lysholm score.ConclusionsThe MPFL reconstruction methods, using a double-stranded semitendinosus autograft and sparing the femoral physeal line in non-closure of the epiphyseal line, provide acceptable short-term results for the treatment of patellar instability.


Pain | 2016

Dose–response relationship between sports activity and musculoskeletal pain in adolescents

Masamitsu Kamada; Takafumi Abe; Jun Kitayuguchi; Fumiaki Imamura; I-Min Lee; Masaru Kadowaki; Susumu S. Sawada; Motohiko Miyachi; Yuzuru Matsui; Yuji Uchio

Abstract Physical activity has multiple health benefits but may also increase the risk of developing musculoskeletal pain (MSP). However, the relationship between physical activity and MSP has not been well characterized. This study examined the dose–response relationship between sports activity and MSP among adolescents. Two school-based serial surveys were conducted 1 year apart in adolescents aged 12 to 18 years in Unnan, Japan. Self-administered questionnaires were completed by 2403 students. Associations between time spent in organized sports activity and MSP were analyzed cross-sectionally (n = 2403) and longitudinally (n = 374, students free of pain and in seventh or 10th grade at baseline) with repeated-measures Poisson regression and restricted cubic splines, with adjustment for potential confounders. The prevalence of overall pain, defined as having pain recently at least several times a week in at least one part of the body, was 27.4%. In the cross-sectional analysis, sports activity was significantly associated with pain prevalence. Each additional 1 h/wk of sports activity was associated with a 3% higher probability of having pain (prevalence ratio = 1.03, 95% confidence interval = 1.02-1.04). Similar trends were found across causes (traumatic and nontraumatic pain) and anatomic locations (upper limbs, lower back, and lower limbs). In longitudinal analysis, the risk ratio for developing pain at 1-year follow-up per 1 h/wk increase in baseline sports activity was 1.03 (95% confidence interval = 1.02-1.05). Spline models indicated a linear association (P < 0.001) but not a nonlinear association (P ≥ 0.45). The more the adolescents played sports, the more likely they were to have and develop pain.


Knee | 2013

A comparison of patient-reported outcomes and arthroscopic findings between drilling and autologous osteochondral grafting for the treatment of articular cartilage defects combined with anterior cruciate ligament injury.

Shinji Imade; Nobuyuki Kumahashi; Suguru Kuwata; Masaru Kadowaki; Takaaki Tanaka; Hiroshi Takuwa; Yuji Uchio

BACKGROUND To compare the patient-reported outcomes and arthroscopic findings between drilling and autologous osteochondral grafting (AOG) for the treatment of articular cartilage defects combined with anterior cruciate ligament (ACL) injuries. METHODS The subjects were 40 patients who had articular cartilage defects in the weight-bearing part of the medial and lateral femur condyle combined with ACL injuries that were treated by drilling (20 patients) or AOG (20 patients) at the same time as ACL reconstruction was performed. In the drilling group patients, lesions were penetrated with multiple 1.2-mm Kirschner wires, and in the AOG group patients, grafts were made to cartilage defects from one to three osteochondral pegs harvested from the less-weight-bearing periphery of the articular surface of the femoral condyle. The patient-reported outcomes were assessed using the International Knee Documentation Committee (IKDC) subjective knee examination score. Second-look arthroscopy was performed to evaluate the repaired cartilage macroscopically. RESULTS The median follow-up duration was 25 (range, 12-42) months. The IKDC scores were significantly improved from 64.4 to 95.4 points in the drilling group and from 52.3 to 94.3 points in the AOG group, with no difference between the two groups, although there was a difference in the repaired cartilage findings of arthroscopy. CONCLUSION In this study, no differences in IKDC scores were found in patients with a concomitant ACL rupture and an osteochondral lesion treated by drilling or AOG at a minimum follow-up of 1year, regardless of the differences at arthroscopic grading of the ICRS classification. LEVEL OF EVIDENCE Case-control study (LEVEL III).


American Journal of Sports Medicine | 2014

Clinical Outcomes of Revision Meniscal Repair A Case Series

Shinji Imade; Nobuyuki Kumahashi; Suguru Kuwata; Masaru Kadowaki; Syuji Ito; Yuji Uchio

Background: Meniscal preservation results in better clinical outcomes than meniscectomy; however, no studies have evaluated the results of revision meniscal repair. Hypothesis: Revision meniscal repair can achieve good clinical outcomes. Study Design: Case series; Level of evidence, 4. Methods: The study participants were 16 patients with symptomatic meniscal retears of a total of 96 patients who underwent primary arthroscopic meniscal repair. Fifteen of these 16 patients underwent revision meniscal repair. The mean age at revision was 27 years, and the mean duration between the primary operation and revision was 27 months. Eight patients had degenerative changes of the meniscus at revision. Clinical outcomes were assessed using the Lysholm score and the Tegner sports activity score, and image assessment was performed using magnetic resonance imaging. Results: Five patients had re-retears of a resutured meniscus, and the mean duration between revision and the re-retear was 25 months (range, 8-68 months). The mean follow-up of patients without re-retears was 41 months (range, 24-74 months), and the mean Lysholm score in those without re-retears significantly improved from 81.4 points (range, 73-89 points) at pre-revision to 97.4 points (range, 90-100 points) at the final survey (P = .0001). Degenerative changes of the meniscus at the revision site were observed in all 5 patients with re-retears but in only 3 of the 10 patients without re-retears. Conclusion: Revision meniscal repair should be considered in the setting of a retorn meniscus without degenerative changes.


Clinical Orthopaedics and Related Research | 2017

Brain Activity Changes in Somatosensory and Emotion-Related Areas With Medial Patellofemoral Ligament Deficiency

Masaru Kadowaki; Taku Tadenuma; Nobuyuki Kumahashi; Yuji Uchio

BackgroundPatellar instability with medial patellofemoral ligament (MPFL) deficiency is a common sports injury among young people. Although nonoperative and surgical treatment can provide stability of the patella, patients often have anxiety related to the knee. We speculate that neural dysfunction may be related to anxiety in these patients; however, the mechanism in the brain that generates this anxiety remains unknown.Questions/purposes(1) How does brain activity in patients with MPFL deficiency change in the areas related to somatic sensation against lateral shift of the patella? (2) How does patella instability, which can lead to continuous fear or apprehension for dislocation, influence brain activity in the areas related to emotion?MethodsNineteen patients with MPFL deficiency underwent surgical reconstruction in our hospital from April 2012 to March 2014. Excluding seven patients with osteochondral lesions, 12 patients (five males and seven females; mean age, 20 years) with MPFL deficiency were sequentially included in this study. Eleven control subjects (four males and seven females; mean age, 23 years) were recruited from medical students who had no history of knee injury. Diagnosis of the MPFL deficiency was made with MR images, which confirmed the rupture, and by proving the instability with a custom-made biomechanical device. Brain activity during passive lateral stress to the patella was assessed by functional MRI. Functional and anatomic images were analyzed using statistical parametric mapping. Differences in functional MRI outcome measures from the detected activated brain regions between the patients with MPFL deficiency and controls were assessed using t tests.ResultsIntergroup analysis showed less activity in several sensorimotor cortical areas, including the contralateral primary somatosensory areas (% signal change for MPFL group 0.49% versus 1.1% for the control group; p < 0.001), thalamus (0.2% versus 0.41% for the MPFL versus control, respectively; p < 0.001), ipsilateral thalamus (0.02% versus 0.27% for the MPFL versus control, respectively; p < 0.001), and ipsilateral cerebellum (0.82% versus 1.25% for the MPFL versus control, respectively; p < 0.001) in the MPFL deficiency group than in the control group. In contrast, the MPFL deficiency group showed more activity in several areas, including the contralateral primary motor area (1.06% versus 0.6% for the MPFL versus control, respectively; p < 0.001), supplementary motor area (0.89% versus 0.52% for the MPFL versus control, respectively; p < 0.001), prefrontal cortex (1.09% versus 1.09% for the MPFL versus control, respectively; p < 0.001), inferior parietal lobule (0.89% versus 0.62% for the MPFL versus control, respectively; p < 0.001), anterior cingulate cortex (0.84% versus 0.08% for the MPFL versus control, respectively; p < 0.001), visual cortex (0.86% versus 0.14% for the MPFL versus control, respectively; p < 0.001), vermis (1.18% versus 0.37% for the MPFL versus control, respectively; p < 0.001), and ipsilateral prefrontal cortex (1.1% versus 0.75% for the MPFL versus control, respectively; p < 0.001) than did the control group.ConclusionsLess activity in the contralateral somatosensory cortical areas suggested that MPFL deficiency may lead to diminished somatic sensation against lateral shift of the patella. In contrast, increased activity in the anterior cingulate cortex, prefrontal cortex, and inferior parietal lobule may indicate anxiety or fear resulting from patellar instability, which is recognized as an aversion similar to that toward chronic pain.Clinical RelevanceThis study suggests that specific brain-area activity is increased in patients with MPFL deficiency relative to that in controls. Further longitudinal research to assess brain activity and proprioception between patients pre- and postreconstructive knee surgery may reveal more regarding how patella instability is related to brain function. We hope that based on such research, a neural approach to improve patella-instability-related brain function can be developed.


Journal of Orthopaedic Science | 2014

Medial ankle impingement syndrome with talocalcaneal coalition treated by arthroscopy-assisted resection: a case report

Masaru Kadowaki; Shinji Imade; Yuji Uchio

Ankle impingement syndromes are common disorders of the ankle. They are pathologic conditions involving painful restriction of movement at the tibiotalar joint caused by osseous or soft tissue overgrowth or the presence of accessory ossification centers [1]. Osseous impingement can result from spur formation along the anterior margin of the distal tibia and talus [2]. Generally, medial ankle impingement syndrome results from injury to the deltoid ligament complex, leading to scar formation and synovitis along the anteromedial joint line. Talocalcaneal coalition is characterized by nonspecific symptoms such as vague pain of the hindfoot, but most patients with talocalcaneal coalition have no symptoms and thus generally require no treatment [3]. On the other hand, several authors have reported that restriction of the subtalar joint increases mechanical stress on the talocrural joint, which may lead to disruption of the talocrural joint [4, 5]. Here, we report a case of medial ankle impingement syndrome with a talocalcaneal coalition that was treated by arthroscopy-assisted resection. To our knowledge, this is the first report of a case in which a spur that formed on the medial malleolus without being induced by injury was the cause of medial ankle impingement syndrome.


Journal of Foot & Ankle Surgery | 2018

Atraumatic Spontaneous Achilles Tendon Rupture in Patients Receiving Oral Corticosteroids Treated With the Modified Side-Locking Loop Suture Technique

Kiminori Ushio; Shinji Imade; Hiroshi Takuwa; Masaru Kadowaki; Yuji Uchio

Atraumatic spontaneous Achilles tendon ruptures sometimes occur in patients receiving oral corticosteroids. In general, these cases are treated surgically; however, delayed postoperative management can lead to impaired activities of daily living. The modified side-locking loop suture (SLLS) technique is a useful suture method for safe and early active mobilization. Three cases of spontaneous Achilles tendon ruptures were treated with the modified SLLS technique with good clinical results. The modified SLLS technique is a useful method with a short rehabilitation period for treating atraumatic spontaneous Achilles tendon rupture in patients undergoing corticosteroid therapy.


Journal of Pediatric Orthopaedics B | 2017

Sporadically occurred bilateral osteochondritis dissecans on the trochlea of the femur: case report.

Nobuyuki Kumahashi; Akinori Matsumoto; Suguru Kuwata; Masaru Kadowaki; Yuji Uchio

We report the case of a 13-year-old boy with bilateral osteochondritis dissecans in the lateral femoral trochlea of the knees. They were classified as grade 4 in the right knee and grade 1 in the left knee on the basis of the Nelson classification within 1 year after first consultation. In the right knee, the fragment was surgically fixed, but the left knee healed with conservative treatment. This case indicates the possibility that osteochondritis dissecans of the lateral femoral trochlea may develop bilaterally at different times and present at different stages. The case shows the importance of early diagnosis and appropriate treatment on the basis of the stage.


Archives of Gerontology and Geriatrics | 2012

Mortality in patients with hip fracture aged over 90 years: a report from a progressively aging island.

Masaru Kadowaki; Michihaya Kono; Kaoru Nishiguchi; Hiroyuki Kakimaru; Yuji Uchio


Archives of Orthopaedic and Trauma Surgery | 2008

A case of symptomatic tumoral calcinosis on the great toe and review of the literature

Masaru Kadowaki; Kohei Naito; Masatoshi Tobita; Nobuyuki Kumahashi; Michihaya Kono; Masato Takao

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Jun Kitayuguchi

Tokyo University of Agriculture

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