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Featured researches published by Toshiki Iwase.


Journal of Bone and Joint Surgery, American Volume | 2002

Eccentric rotational acetabular osteotomy for acetabular dysplasia follow-up of one hundred and thirty-two hips for five to ten years

Yukiharu Hasegawa; Toshiki Iwase; Shinji Kitamura; Ken-ichi Yamauchi; Shinji Sakano; Hisashi Iwata

Background: Eccentric rotational acetabular osteotomy for the operative treatment of acetabular dysplasia consists of a spherical but eccentric osteotomy and rotation of the acetabulum that moves the center of rotation of the head of the femur medially and distally. No bone graft is needed. The reorientation of the acetabular fragment not only improves acetabular coverage but also restores the center of rotation of the subluxated hip. The purpose of this paper was to describe eccentric rotational acetabular osteotomy for the treatment of acetabular dysplasia and to evaluate its clinical and radiographic outcomes.Methods: We performed this procedure consecutively in 132 hips in 126 patients with dysplasia of the hip. Eighteen hips had no osteoarthritis, fifty-three had early osteoarthritis, and sixty-one had advanced osteoarthritis. Seven patients were male, and 119 were female. The average age was 36.5 years at the time of the index operation, and the average duration of follow-up was 7.5 years. Twenty-three hips in twenty-two patients were also treated with intertrochanteric valgus osteotomy to further improve joint congruency at the time of the acetabular osteotomy.Results: The average preoperative Harris hip score of 71 points improved to an average score of 89 points at the time of the latest follow-up. The average center-edge angle improved from 0° to 36°. An apparent change in the stage of the arthritis was observed in seven hips (5%), one of which had had early-stage disease and six of which had had advanced disease preoperatively.Conclusions: Eccentric rotational acetabular osteotomy appears to be a good treatment option for young patients with either early or advanced hip osteoarthritis secondary to dysplasia.


Journal of Biomedical Materials Research | 1997

Macrophage activation and migration in interface tissue around loosening total hip arthroplasty components.

Naoki Ishiguro; T. Kojima; Takayasu Ito; Shinsuke Saga; Hideki Anma; Kazutoshi Kurokouchi; Yuusuke Iwahori; Toshiki Iwase; Hisashi Iwata

The bone-cement interface tissue of failed total hip arthroplasty (THA) has inflammatory characteristics, such as the presence of prostaglandin E2 and interleukin 1 (IL-1). We considered that the bone-cement interface tissue could be the site of granulomatous inflammation caused by a foreign-body reaction. It has been demonstrated that inflammatory cytokines and chemokines have an important role in granulomatous inflammation. Bone-cement interface tissue was obtained at revision from nine patients with failed cemented THA, and the role of macrophages was assessed by immunohistochemistry, electron microscopy, and molecular biological techniques. We used the reverse-transcriptional polymerase chain reaction to examine the expression of mRNA for IL-1 alpha, IL-1 beta, tumor necrosis factor alpha (TNF alpha), macrophage inflammatory protein (MIP)-1 alpha, MIP-1 beta, IL-8, and monocyte chemoattractant protein. Polyethylene debris surrounded by macrophages and phagocytosis of debris by macrophages was frequently observed in the interface tissue. Macrophage activation and the production of inflammatory cytokines such as IL-1 and TNF alpha might induce the development of interface tissue. Expression of chemokine mRNAs was also commonly seen, suggesting that this led to recruitment of macrophages into the bone-cement interface tissue. Debris released from implants appears to cause activation of macrophages and the production of inflammatory cytokines and chemokines that induce cellular recruitment into interface tissue. This mechanism might form a vicious cycle that aggravates THA loosening.


Clinical Orthopaedics and Related Research | 1996

Twenty years' followup of intertrochanteric osteotomy for treatment of the dysplastic hip

Toshiki Iwase; Yukiharu Hasegawa; Kouichi Kawamoto; Seiki Iwasada; Kenji Yamada; Hisashi Iwata

A followup study of more than 15 years of intertrochanteric osteotomy for osteoarthrosis of the dysplastic hip was performed in 52 hips of 42 patients with varus osteotomy and in 58 hips of 53 patients with valgus osteotomy. Varus osteotomy was indicated for predegenerative or early degenerative stages of osteoarthrosis, and valgus osteotomy was indicated for progressive or end stage disease. The average age at time of varus and valgus osteotomies was 25 and 37 years, respectively, and the average followup period was 21 and 20 years, respectively. Using Kaplan-Meiers method (end point, Harris Hip Score < 70 points or salvage operation), the 10- and 15-year survival rates for varus osteotomy were 89% and 87% and for valgus osteotomy were 66% and 38%, respectively. Radiographic measurements of the postoperative acetabular head index and center edge angle in varus osteotomy were better in the group with good results than those in the group with poor results. There were no differences in radiographic measurements between the group with good results and the group with poor results of valgus osteotomy. Intertrochanteric varus and valgus osteotomy delayed the need for total hip arthroplasty in young patients with osteoarthrosis of the dysplastic hip.


Journal of Bone and Joint Surgery-british Volume | 2003

Pedicle bone grafting versus transtrochanteric rotational osteotomy for avascular necrosis of the femoral head

Yukiharu Hasegawa; Shinji Sakano; Toshiki Iwase; Seiki Iwasada; Shuhei Torii; Hisashi Iwata

Segmental collapse occurs in the early stage of avascular necrosis (AVN) of the femoral head, and is associated with a poor prognosis. Since it develops at a relatively young age, the long-term outcome after total hip replacement is a major concern. We have compared the long-term results of pedicle bone grafting (PBG) with those of transtrochanteric rotational osteotomy (TRO). In the PBG group there were 23 men (27 hips) and three women (4 hips) with a mean age at the time of surgery of 38 years and a mean follow-up of 13 years. In the TRO group there were 44 men (55 hips) and 19 women (22 hips) with a mean age at the time of surgery of 39 years and a mean follow-up of seven years. Failure was defined as a need for total hip replacement or a Harris hip score below 70. The long-term results were similar for the two groups. The survival rates at five and ten years were 85% and 67%, respectively, in the PBG group, and 71% and 61%, respectively, in the TRO group, according to Kaplan-Meier survivorship analysis. In the TRO group patients in stage II had significantly better results that those in stage III.


Archives of Orthopaedic and Trauma Surgery | 1997

Vascularized pedicle bone-grafting for nontraumatic avascular necrosis of the femoral head : A 5- to 11-year follow-up

Yukiharu Hasegawa; Hiroji Iwata; Shuhei Torii; Toshiki Iwase; Kouichi Kawamoto; Seiki Iwasada

We investigated the results of 31 hips in 26 patients with nontraumtic (n = 20) and steroid-induced (n = 6) avascular necrosis of the femoral head (ANFH) treated with vascularized iliac pedicle bone graft (PBG). The average age at operation was 38.3 years. Three were women and 23 men. The average follow-up was 8.0 years. The Harris hip score prior to operation and at latest follow-up improved from 62 to 83; one hip collapsed and was revised with a bipolar endoprosthesis. At the final follow-up, 19 hips (63%) were clinically rated as good to excellent, 4 fair, and 7 poor. At the final follow-up, 15 of 27 hips (56%) of stage II before operation showed progressive collapse after bone grafting. In steroid-induced ANFH, in three women, 2 of 4 hips showed poor results. These results are only slightly better than those of core decompression and no better than those obtained after decompression and simple nonvascularized grafts to provide support for the subchondral bone. We concluded that vascularized PBG is sometimes indicated for ANFH in an early stage before collapse of the femoral head.


Archives of Orthopaedic and Trauma Surgery | 1999

Osteonecrosis of the femoral head associated with pregnancy

Yoshinori Hasegawa; Toshiki Iwase; Seiki Iwasada; Shinji Kitamura; Hiroji Iwata

Abstract A 31-year-old pregnant woman suddenly complained of bilateral hip pain 2 weeks before delivery. She was delivered of triplets by Caesarean section. She had been treated with human menopausal gonadotropin and human chorionic gonadotropin (hMG-hCG) before pregnancy. Radiograms of the hip joint showed collapse of the femoral heads bilaterally. Magnetic resonance imaging revealed a band pattern of low signal intensity for both hips on T1- and T2-weighted images. She had no history of steroid therapy or alcohol abuse. Osteonecrosis of the femoral heads bilaterally associated with pregnancy was confirmed. Pathology of the femoral head showed typical empty lacunae and necrosis of the trabecula.


Journal of Arthroplasty | 2012

Total hip arthroplasty for Crowe type IV developmental dysplasia.

Yukiharu Hasegawa; Toshiki Iwase; Toshiya Kanoh; Taisuke Seki; Atsushi Matsuoka

The purposes of this study were to evaluate the midterm clinical and radiographic results of total hip arthroplasty (THA) in patients with Crowe type IV developmental dysplasia and to evaluate whether low back pain would improve after THA. Eighteen consecutive patients (20 hips) were included in this study. The average age at the time of surgery was 58.5 years. The average follow-up was 10.2 years. The socket was placed at the level of the true acetabulum, and a femoral shortening osteotomy was performed. The average Harris hip score before surgery was improved from 56 to 85 points at the final follow-up. Revision was performed in 4 hips due to loosening of the femoral component in 1 hip and osteolysis in 3 hips. The midterm outcomes of THA in patients with Crowe type IV developmental dysplasia were satisfactory. The severity of low back pain was significantly reduced after THA.


Clinical Orthopaedics and Related Research | 1999

Total hip arthroplasty after failed intertrochanteric valgus osteotomy for advanced osteoarthrosis

Toshiki Iwase; Yukiharu Hasegawa; Seiki Iwasada; Shinji Kitamura; Hisashi Iwata

Thirty hips that had undergone conversion total hip arthroplasty because of failed intertrochanteric valgus osteotomy for advanced osteoarthrosis were analyzed clinically and radiographically for more than 2 years. The average followup after total hip arthroplasty was 7 years (range, 2-18 years). The average age of the patients at the time of valgus osteotomy was 42 years (range, 30-63 years). The average age of the patients at the time of conversion total hip arthroplasty was 57 years (range, 43-76 years), and the average period between valgus osteotomy and conversion was 14 years (range, 3-24 years). Perioperative complications in conversion total hip arthroplasties were minimal, and intramedullary reaming was performed easily. Of the 30 conversion total hip arthroplasties, 12 cemented and 18 cementless components were used, respectively. Kaplan-Meiers survival analysis indicated that survivorship of cemented stems was significantly higher than that of conventional cementless stems. Cemented stems are preferable for conversion total hip arthroplasty after failed femoral valgus osteotomy.


Archives of Orthopaedic and Trauma Surgery | 1997

Transtrochanteric rotational osteotomy for osteonecrosis of the femoral head

Seiki Iwasada; Yukiharu Hasegawa; Toshiki Iwase; Shinji Kitamura; Hiroji Iwata

We reviewed 48 hips in 43 patients 3–7.1 years (average 4.6 years) after Sugioka transtrochanteric rotational osteotomy for osteonecrosis of the femoral head. The average age at operation was 41 years. Thirty-four patients were men and 9 women. Overall results at the final follow-up were satisfactory in 30 hips (62%). Kaplan-Meiers survivorship was 62% at 3 years and 60% at 5 years postoperatively. Six hips for which the ratio of the intact area of the articular surface on the preoperative lateral radiograph was less than 30% showed further collapse. Five hips were converted to bipolar hemiarthroplasties or total hip arthroplasties. Complications, such as varus deformity, subtrochanteric fracture, and ectopic bone formation, occurred in eight hips. Five of them were operated on in the first 2 years of this series. Three of these five operations had unsatisfactory results. We conclude that satisfactory results can be achieved using this osteotomy by maintaining exact surgical technique and by limiting the surgical indications to hips with an intact area of more than one-third of the entire articular surface on the lateral radiograph of the femoral head.


Journal of Bone and Joint Surgery, American Volume | 2014

Eccentric Rotational Acetabular Osteotomy for Acetabular Dysplasia and Osteoarthritis: Follow-up at a Mean Duration of Twenty Years

Yukiharu Hasegawa; Toshiki Iwase; Shinji Kitamura; Masashi Kawasaki; Jin Yamaguchi

BACKGROUND The aim of the eccentric rotational acetabular osteotomy is to correct the deficient acetabular coverage in the dysplastic hip in order to limit the development of secondary osteoarthritis. The purpose of this study was to investigate the results in patients managed with an eccentric rotational acetabular osteotomy after a mean of twenty years. METHODS The clinical and radiographic outcomes for the first 126 consecutive patients (132 hips) who underwent an eccentric rotational acetabular osteotomy at our institution were retrospectively evaluated. One hundred and twenty-four patients (130 hips) were evaluated; 117 were women (123 hips). The mean patient age was thirty-seven years (range, fifteen to fifty-nine years) at the time of surgery, and the average duration of follow-up was twenty years. Twenty-three hips in twenty-two patients were also treated with intertrochanteric valgus osteotomy at the time of the eccentric rotational acetabular osteotomy to further improve joint congruency. RESULTS The mean preoperative Harris hip score of 70 points (range, 51 to 90 points) improved to a mean of 88 points (range, 35 to 100 points) at the final follow-up. Thirty hips had a fair clinical outcome (Harris hip score, <80 points). In seventeen hips, the eccentric rotational acetabular osteotomy was converted to a total hip arthroplasty. The cumulative survivorship at fifteen years and at the final follow-up at twenty-three years was 97% and 80%, respectively. Four factors led to a poor outcome: a small (≤2.0-mm) preoperative minimum joint space, joint incongruence, simultaneous intertrochanteric valgus osteotomy, and lateral subluxation of the femoral head postoperatively. CONCLUSIONS Eccentric rotational acetabular osteotomy is an effective surgical procedure for treating symptomatic dysplastic hips before, and in the early stages of, osteoarthritis. The majority of patients maintained excellent or good native hip function at a mean of twenty years after surgery. LEVEL OF EVIDENCE Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

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Go Yoshida

University of Bordeaux

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Hiromi Otsuka

Aichi Medical University

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