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Publications (6)3.34 Total impact

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    Hiroyuki Kawaji · Masaji Ishii · Yasunobu Tamaki · Kan Sasaki · Michiaki Takagi ·
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    ABSTRACT: Fatal pulmonary thromboembolism is the most serious complication following surgery. Patients undergoing major orthopedic surgeries, including total hip replacement, total knee replacement, and hip fracture surgery, represent a group at particularly high risk of venous thromboembolism. Therefore, prophylaxis for thromboembolic events has been of great concern to surgeons. Edoxaban is a novel, orally available, and highly specific and direct factor Xa inhibitor. This new agent was approved for the prevention of venous thromboembolism in patients undergoing major orthopedic surgery, including total hip replacement, total knee replacement, and hip fracture surgery, by the Japanese Ministry of Health, Labor, and Welfare in 2011. Preclinical and Phase I clinical trials demonstrated several promising properties. Its rapid absorption and short life-time in blood are known. Edoxaban inhibits factor Xa activity directly and selectively. It also has a strong antithrombotic effect without any influence of food intake. Coagulation monitoring is not required. Edoxaban has predictable linear pharmacokinetic and pharmacodynamic profiles. Phase II and III clinical trials have been completed to examine its efficacy and safety in patients undergoing major orthopedic surgery. In these clinical trials, oral administration of edoxaban showed efficacy superior to that of oral placebo or subcutaneously administered dalteparin or enoxaparin. Edoxaban can be regarded as a first choice to prevent venous thromboembolism after major orthopedic surgery.
    Orthopedic Research and Reviews 11/2011; 4. DOI:10.2147/ORR.S24583
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    ABSTRACT: The aim of this study was to estimate the effective administration procedure of fondaparinux for prevention of venous thromboembolism after cemented total hip replacement (THR) in Japanese patients. The study included 471 Japanese patients. The dose regimens were 2.5 mg daily for 14 days (2.5 mg/14 day group) or 10 days (2.5 mg/10 day group), 1.5 mg daily for 10 days (1.5 mg group), 2.5 mg daily for the first 3 postoperative days and 1.5 mg daily for the subsequent 7 days (Mixed group), and no administration of fondaparinux (Control group). Deep venous thrombosis (DVT) was diagnosed by ultrasonography on postoperative day 3 or 4 and day 14. The 2.5 mg/14 day, 2.5 mg/10 day and Mixed groups were regarded as one group in the assessment on postoperative day 3 or 4, and denoted as the 2.5 mg group. The incidence of DVT on postoperative day 3 or 4 in the 2.5 mg group was significantly lower than that in the Control and 1.5 mg groups. On postoperative day 14, the incidence of DVT in the 1.5 mg and Mixed groups was significantly lower than that in the Control group in both the intention-to-treat and per-protocol analyses. The incidence in the 2.5 mg/10 day and 2.5 mg/14 day groups was significantly lower than that in the Control group in only the per-protocol analysis. The results suggest that the administration protocol of the Mixed group is effective in preventing DVT in Japanese patients undergoing cemented THR.
    Modern Rheumatology 07/2011; 22(2):216-22. DOI:10.1007/s10165-011-0496-6 · 2.40 Impact Factor
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    ABSTRACT: The geometry of the proximal femur is one of the important factors for choosing the suitable stem. We have been applied cemented collarless polished tapered (CPT) stem to the patients with small femur. Radiographic evaluation was performed to access the clinical feature of the stem in early stage of the follow-up. One hundred total hip arthroplasties with CPT system were performed between October 2004 to February 2006. This study focused on the 53 cases to whom size 1 or smaller sized stem were implanted, and its post-operative period was 41 months (30-46 months). Morphologic classification of preoperative proximal femur, stem alignment, thickness of the cement mantle, cementing technique, subsidence of the stem, improvement in the bone-cement interface, and stress shielding were assessed. The size of the inserted stem was X-SMALL in one case, SMALL in two cases, SIZE 0 in 12 cases, and SIZE 1 in 38 cases. Canal shape of proximal femur was stovepipe type in five cases, normal type in 43 cases, and champagne-flute type in five cases. There was no subsidence in eight cases. 44 stems subsided within 1 mm, one stem subsided 1 to 2 mm, and no stem subsided over 2 mm. In 39 of 45 cases, subsidence was appeared within six months after operation. Marked progressive and excessive subsidence was not seen after the two years of follow-up. Short term radiographic results of THA with CPT stem to small femur were satisfactory with less unfavorable radiographic findings, which imply contribution to longer survivorship of the stem.
    The Open Orthopaedics Journal 03/2010; 4(1):147-51. DOI:10.2174/1874325001004010147
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    ABSTRACT: Periprosthetic infection is one of the serious complications after total hip arthroplasty (THA). This study analyzed the perioperative and postoperative status of patients who underwent antibiotics-impregnated cement spacer technique in the first step of the two-stage revision. Ten joints of the nine patients (mean age, 65 years; seven women, two men) received two-stage revision as a result of infection that appeared after primary THAs in seven joints, aseptic revision in one, and recurrent type in two. An antibiotics-impregnated cement spacer made by a mold system was applied in the femoral side of all joints. An acetabular spacer was made by hand using a cup gauge in eight joints with extensive tissue loss. The change of leg length after the first stage was -2.2 mm, and range of hip flexion was 72 degrees on average, respectively. Patients could walk with crutches after the first stage, except one patient with simultaneous infections of both hips and one with fracture of the cement spacer. One fracture of femoral cement spacer, and one dislocation of femoral spacer accompanied by fracture of acetabular cement spacer and curable recurrent infection, were found. In all cases of the second-stage procedure, the acetabular side was reconstructed with allogeneic bone graft with cross plate and that of the femur was by impaction bone grafting method. In the latest follow-up, reconstructed implants were stable. Seven patients could walk without any supportive devices and two could walk with the support of a T-cane. An antibiotics-impregnated cement spacer in the first step of the two-stage revision was effective not only to compensate tissue loss after removal of the implants and to minimize discrepancy of leg length, but also to contribute to improvement of perioperative and postoperative daily activities of the patient's life as well as treatment of the infection.
    Journal of Orthopaedic Science 11/2009; 14(6):704-10. DOI:10.1007/s00776-009-1406-z · 0.94 Impact Factor
  • Masaji ISHII · Hiroyuki KAWAJI · Yasunobu TAMAKI · Makoto HAMASAKI ·

    The Japanese Journal of Rehabilitation Medicine 01/2009; 46(10):638-643. DOI:10.2490/jjrmc.46.638
  • Masaji Ishii · M. Takagi · H. Ida · S. Kobayashi · H. Kawaji · M. Hamasaki ·
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    ABSTRACT: Clinical application of alumina ceramic to femoral head of prostheses has been performed with possible advantage of lower friction of ceramic head / ultra-high molecular weight polyethylene (UHMWPE) or ceramic head /ceramic cup articulations, when compared to that of metal head / UHMWPE cup. Although favorable clinical results of alumina ceramic head / UHMWPE cup combination has been known, breakage of alumina ceramic head has been reported. In this study, we investigated the series of total hip arthroplasties (THAs) with alumina ceramic head, and reported breakage of alumina ceramic head combined with UHMWPE cup and critical clinical problems after tiny modification of the taper system between alumina ceramics head and metal neck.
    Bioceramics and Alternative Bearings in Joint Arthroplasty, 12/2006: pages 303-309;