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Dive into the research topics where Daichi Ishimaru is active.

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Featured researches published by Daichi Ishimaru.


Osteoarthritis and Cartilage | 2014

Alterations in the chondroitin sulfate chain in human osteoarthritic cartilage of the knee.

Daichi Ishimaru; Nobuo Sugiura; Haruhiko Akiyama; Hideto Watanabe; Kazu Matsumoto

OBJECTIVE To determine whether the structure of chondroitin sulfate (CS) in cartilage is reflected by the degree of cartilage degeneration in patients with osteoarthritis (OA) of the knee and to determine how CS biosynthesis affects cartilage degeneration. DESIGN Two osteoarthritic cartilage samples were obtained from medial femoral condyle (MFC) and lateral femoral condyle (LFC) of 24 knees with end-stage OA. The samples were assigned to two groups as follows: lesion and remote cartilage were adjacent to and remote from the osteoarthritic cartilage, respectively. Histological grade was determined according to the Mankin score. The CS concentration and chain length were determined using high-performance liquid chromatography (HPLC) and gel filtration chromatography, respectively. Expression of the gene encoding CS glycosyltransferase was evaluated using a real-time quantitative polymerase chain reaction (qPCR) assay. These results were compared between lesion and remote cartilage. RESULTS The Mankin score indicated that lesion cartilage was more degraded compared with remote cartilage. Although the CS levels varied among individuals, the mean CS concentration and chain length were significantly lower and shorter in lesion cartilage than in remote cartilage, respectively (concentration: 12.04 vs 14.84 μg/mg wet weight, P = 0.021; chain length: 5.36 vs 6.19 kDa, P = 0.026). Three genes encoding CS glycosyltransferases (CHPF, CSGALNACT1, CSGALNACT2) were expressed at lower levels in lesion cartilage. CONCLUSIONS In the osteoarthritic knee, the CS concentration and chain length were reduced closer to the more degraded cartilage with decreasing CS glycosyltransferase gene expression. Inhibition of CS glycosyltransferase gene expression may reduce CS chain length, which may contribute to OA progression.


British Journal of Sports Medicine | 2012

Hip pads reduce the overall risk of injuries in recreational snowboarders

Daichi Ishimaru; Hiroyasu Ogawa; Kazuhiko Wakahara; Hiroshi Sumi; Yasuhiko Sumi; Katsuji Shimizu

Objective The purpose is to determine common injuries in recreational snowboarding as targets of preventive strategy and protective gear that reduces the overall risk of these injuries. Methods The subjects comprised 5561 injured recreational snowboarders. On the basis of patients’ self-reporting form, ‘the common snowboarding injuries’ (cut-off point >2.0% in prevalence) were decided, and all injured snowboarders were categorised into two groups: common injuries and the other injuries (control). Several factors such as age, gender, self-reported skill level, experienced seasons, experienced days, previous snowboarding school attendance and the use of protective gears (helmet, elbow pads, wrist guards, backbone guard, hip pads and knee pads) were recorded. Multiple logistic regression analysis was conducted to investigate which type of protective gear reduced the overall risk of the common injuries. Results The common snowboarding injuries consisted of eight types, in which distal radial fracture was the most common (17.7%), followed by head injury (9.4%) and clavicle fracture (6.5%). In univariate regression analysis, skill level, experienced seasons, experienced days and the use of hip pads and knee pads were manifested potential risk factors on the common injuries. In subsequent multivariate regression analysis, the use of hip pads was related with a lower overall risk of these common injuries (OR, 0.84; 95% CI, 0.75 to 0.95), specifically that of distal radial fracture and glenohumeral dislocation. Conclusions The use of hip pads is recommended for snowboarders as it reduces the overall risk of common snowboarding injuries.


Case reports in orthopedics | 2012

Intertrochanteric Fracture of the Ankylosed Hip Joint Treated by a Gamma Nail: A Case Report

Daichi Ishimaru; Satoshi Nozawa; Masato Maeda; Katsuji Shimizu

We herein report a rare case of an intertrochanteric fracture complicated with an ankylosed hip joint in a 76-year-old man. Generally, operative treatment is performed for elderly people with intertrochanteric fractures to prevent general complications, maintain mobility, and release pain. However, intertrochanteric fractures of ankylosed hip joints are rare, and the optimal surgery for this condition is unknown. In addition, surgical fracture repair is challenging because unusual instability of the fracture site is suspected owing to the long lever arm of the lower extremity. Nevertheless, we successfully treated this rare fracture using a gamma nail, which may be a useful implant with which to treat this type of fracture if the status of the arthrodesed hip joint allows.


Orthopedics | 2011

Surgical treatment of an infant with Bacille Calmette-Guérin osteomyelitis extending across the growth plate.

Daichi Ishimaru; Hiroyasu Ogawa; Yoshiki Ito; Katsuji Shimizu

Bacille Calmette-Guérin osteomyelitis in infants is a known complication of Bacille Calmette-Guérin vaccination. Treatment consists of antituberculosis chemotherapy after biopsy/curettage; however, in cases of Bacille Calmette-Guérin osteomyelitis extending to the growth plate and epiphysis, the extent and time of surgical treatment such as curettage/biopsy is unknown because of bone growth disturbances. This article presents a case of an infant with this type of Bacille Calmette-Guérin osteomyelitis at the proximal tibia. A metaanalytic review was performed for possible risk factors of its recurrence. In our patient, primary curettage of partial lesion, excluding the part extending to the growth plate and epiphysis, failed, and recurettage of the extended lesion involving the growth plate and epiphysis was required for its eradication, resulting in bone growth disturbance. In the metaanalysis, 7 literatures reporting 14 cases of Bacille Calmette-Guérin osteomyelitis extending to the growth plate and epiphysis were included. Although statistical analysis showed no significant risk factors associated with the recurrence, these cases showed high recurrence rate in approximately 55.6%, requiring reoperation. Generally, the smaller damage to the growth plate can minimize bone growth disturbance. Taken together, it is suggested that Bacille Calmette-Guérin osteomyelitis extending to the growth plate and epiphysis is associated with high recurrence rate, and early curettage of the entire lesion should be performed to eradicate it and avoid resulting complications.


Journal of Trauma-injury Infection and Critical Care | 2011

Lower extremity injuries in snowboarding

Daichi Ishimaru; Hiroyasu Ogawa; Hiroshi Sumi; Yasuhiko Sumi; Katsuji Shimizu

BACKGROUND In snowboarding, the upper extremity is known as the most common injury site and little information is available for lower extremity injuries. Here, we aim to discuss lower extremity injuries during snowboarding. METHODS We retrospectively analyzed the epidemiologic factors, injury types, and injury mechanisms for injured snowboarders (7,793 cases) between 2004-2005 and 2008-2009 seasons; information was gathered via questionnaires. Individuals were classified into a lower extremity injury group (961 cases) and a control group with other injuries (6,832 cases). RESULTS The incidence of lower extremity injuries in snowboarding was 0.16 per 1,000 participant days, accounting for 12.3% of all snowboarding injuries. The mean age of the lower extremity injury group and injured control group was 26.1 years ± 5.9 years and 25.1 years ± 5.6 years, respectively. Approximately 90% of snowboarders in both the groups were equipped with soft-shelled boots. Skilled snowboarders tended to sustain lower extremity injuries (p<0.0001). In lower extremity injuries, the most common injury type was lacerations/contusions (22.4%), resulting from collision with other snow sports participants. The most common fracture site was the ankle. Overall, in lower extremity injuries, the leading side was the most commonly injured (53.8%). CONCLUSIONS A typical lower extremity injury in snowboarding is lacerations/contusions caused by collision with other snow sport participants. Lower extremity injuries in snowboarding differ considerably from well-known upper extremity injuries in terms of injury types and mechanisms. The incidence of lower extremity injuries is high and deserves further attention.


Orthopedics | 2012

Outcomes of elderly patients with proximal femoral fractures according to positive criteria for surgical treatment.

Daichi Ishimaru; Hiroyasu Ogawa; Masato Maeda; Katsuji Shimizu

Proximal femoral fractures in elderly patients are a serious problem in the aging society. Recently, surgical indications have changed due to advancements in medical technology. The purpose of this study was to investigate the outcome of elderly patients with displaced proximal hip fractures according to our positive criteria for surgical treatment. Exclusion criteria included (1) terminal-stage malignancy; (2) a combination of an inability to walk, a severe mental disorder, and caregiver refusal of surgery; and (3) nonapproval of the anesthesiologist for surgery. The study group comprised 666 elderly patients. They were categorized into surgically and nonsurgically treated groups, and their treatment outcomes were retrospectively analyzed. The majority of patients were treated surgically (97.0% vs 3.0%). One-year survival rate was higher among surgically treated patients (82.2%-91.8%) than non-surgically treated patients (55%). The major cause of death in nonsurgically treated patients was deterioration of comorbidities (66.7%), whereas this was the cause of death in 18.9% of surgically treated patients. One-year survival rates were worse in both groups with a lower American Society of Anesthesiologists grade. The 1-year survival rate of our patients suggests that our surgical criteria offer a reasonable outcome in surgically and nonsurgically treated patients. American Society of Anesthesiologists grade and preexisting comorbidities were strongly correlated with patient outcome.


Orthopedics | 2011

Morcellized bone grafting for acetabular deficiency in cementless total hip arthroplasty.

Hiroyasu Ogawa; Yoshiki Ito; Mansho Itokazu; Nobuyuki Mori; Takashi Shimizu; Nobuo Terabayashi; Daichi Ishimaru; Katsuji Shimizu

Morcellized bone grafting was performed to significant acetabular deficiency in 35 hips of 29 patients in cementless total hip arthroplasty (THA). Bridging trabeculation across the graft-host interface, remodeling of the graft, and trabecular reorientation were observed at 4 weeks, 3.7 months, and 10.7 months postoperatively, respectively. These remodeling processes were observed in all cases. Morcellized bone grafting for acetabular deficiency in cementless THA stock, which is necessary to make the cup stable, revealed encouraging early trabecular reorientation and recovery of acetabular bone even in cases in which structural bone grafting is needed.


Clinical Journal of Sport Medicine | 2016

Characteristics and risk factors of spinal fractures in recreational snowboarders attending an emergency department in Japan

Daichi Ishimaru; Kazu Matsumoto; Hiroyasu Ogawa; Hiroshi Sumi; Yasuhiko Sumi; Haruhiko Akiyama

Objective:The purpose of this study was to elucidate the characteristics of spinal fractures during recreational snowboarding and to determine the risk factors for these fractures. Design:Case series study. Setting:The Oku-mino ski area during the 7-year period between the 2005 to 2006 and 2011 to 2012 skiing seasons. Participants:Eight thousand seven hundred twenty-three snowboarders with injures. Interventions:Cases involved snowboarders with spinal fractures; controls were snowboarders without spinal fractures. Main Outcome Measures:The characteristics of spinal fractures were assessed using a standard form and patient records, including radiographs. Multivariate regression analysis was performed to investigate risk factors for spinal fractures, including age, type of slope, snow condition, accident cause, self-reported skill level, experience level, and the use of protective equipment. Results:Of 8723 snowboarders with injuries, 431 snowboarders presented with spinal fractures (4.9%). The most common spinal fracture was isolated transverse process fracture in the lumbar spine (33.2%, n = 143), followed by compression type fracture in the lumbar spine (25.1%, n = 108). Age (20-39 years), terrain slopes (half-pipe/box/kicker/rail), and jump-landing failure were associated with a significantly high risk of spinal fracture. Conclusions:Among the recreational snowboarders, isolated transverse process fracture in the lumbar spine was the most frequent spinal fracture. Age (20-39 year old), terrain slopes, and jump-landing failure were found to be risk factors for spinal fracture. Clinical Relevance:Identification of characteristics and risk factors for spinal fractures during snowboarding is useful information to create a preventive strategy for the fractures and make snowboarding a safer sport.


Clinical Journal of Sport Medicine | 2014

Comparison of Tibial Shaft Ski Fractures in Children and Adults

Tomo Hamada; Kazu Matsumoto; Daichi Ishimaru; Hiroshi Sumi; Katsuji Shimizu

Objective:To examine whether child and adult skiers have different risk factors or mechanisms of injury for tibial shaft fractures. Design:Descriptive epidemiological study. Setting:Prospectively analyzed the epidemiologic factors, injury types, and injury mechanisms at Sumi Memorial Hospital. Patients:This study analyzed information obtained from 276 patients with tibial fractures sustained during skiing between 2004 and 2012. Main Outcome Measures:We focused on 174 ski-related tibial shaft fractures with respect to the following factors: age, gender, laterality of fracture, skill level, mechanism of fracture (fall vs collision), scene of injury (steepness of slope), snow condition, and weather. Fracture pattern was graded according to Arbeitsgemeinschaft für Osteosynthesefragen (AO) classification and mechanical direction [external (ER) or internal rotation (IR)]. Results:Tibial shaft fractures were the most common in both children (89.3%) and adults (47.4%). There were no significant differences in gender, side of fracture, mechanism of fracture, snow condition, or weather between children and adults. Skill levels were significantly lower in children than in adults (P < 0.0001). Type A fractures were more dominant in children (73 cases, 72.3%) than in adults (39 cases, 53.4%). There was significantly more ER in children than in adults (P < 0.0001). Among children, female patients had significantly more IR than ER; in contrast, among adults, women were injured by ER. Conclusions:We found significant differences in some of these parameters, suggesting that child and adult skiers have different risk factors or mechanisms of injury for tibial shaft fractures.


Archives of Physical Medicine and Rehabilitation | 2008

Analysis of Muscle Atrophy After Hip Fracture in the Elderly

Hiroyasu Ogawa; Hidefumi Oshita; Daichi Ishimaru; Kazunari Yamada; Takashi Shimizu; Yoshinari Koyama; Atsushi Akaike; Hirohiko Hori

OBJECTIVES To examine the relationship between muscle atrophy, ambulatory ability, and fracture type, and to make a specific rehabilitation regimen for each fracture type. DESIGN Observational study. SETTING Public hospital. PARTICIPANTS Consecutive patients (N=53) with hip fracture (mean age, 83.6y) who underwent operative treatment. INTERVENTIONS Not applicable. MAIN OUTCOME MEASURES The ambulatory ability score and the cross-sectional areas of lower-limb muscles as measured on computed tomography scans. RESULTS Muscle atrophy was not related to fracture type. Although the mean ambulatory ability score decreased significantly from 4.5+/-0.3 points prior to injury to 3.0+/-0.6 points 1 month postadmission, the degree of muscle atrophy was not associated with the decrease in ambulatory ability. CONCLUSIONS It seems likely that other factors are more important than muscle atrophy and fracture type in determining recovery after surgical repair of a fracture and that there is no need for rehabilitation regimens based on fracture types.

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