The Experts below are selected from a list of 315 Experts worldwide ranked by ideXlab platform
Hidekji Tsutsui - One of the best experts on this subject based on the ideXlab platform.
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transtrochanteric anterior rotational osteotomy for idiopathic and steroid induced necrosis of the femoral head indications and long term results
Clinical Orthopaedics and Related Research, 1992Co-Authors: Yoichi Sugioka, Takao Hotokebuchi, Hidekji TsutsuiAbstract:Abstract From 1972 until 1988, transtrochanteric rotational osteotomy was used to treat 474 hips in 378 patients with idiopathic and steroid-induced osteonecrosis of the femoral head. Two hundred twenty-nine of 295 hips with anterior rotation and follow-up periods ranging from three to 16 years had excellent surgical results (success rate, 78%). Outcome was chiefly dependent on the ratio of transposed intact posterior articular surface to the acetabular weight-Bearing Area after osteotomy. This relationship suggested that the transposed intact Area should occupy more than 36% of the acetabular weight-Bearing Area by adequate rotation and intentional varus position in addition to rotation, especially for extensive lesions. Salvage operations, such as total hip arthroplasty, were performed on 18 hips, of which ten hips were cases of either relative indication for extensive lesions in young patients or other misindications for rotational osteotomy. Four hips sustained neck fracture, including three hips after 180 degrees of posterior rotation; two hips were complicated with avascular necrosis, and another two hips developed osteoarthrosis. Histologically, femoral heads with osteoarthrosis removed at the time of salvage operation showed complete healing of the necrotic lesion. The overall findings indicate that healing of the necrotic lesion of the femoral head may be brought about by rotational osteotomy if it spares the vulnerable site from the brunt of mechanical stress.
Yoichi Sugioka - One of the best experts on this subject based on the ideXlab platform.
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transtrochanteric anterior rotational osteotomy for idiopathic and steroid induced necrosis of the femoral head indications and long term results
Clinical Orthopaedics and Related Research, 1992Co-Authors: Yoichi Sugioka, Takao Hotokebuchi, Hidekji TsutsuiAbstract:Abstract From 1972 until 1988, transtrochanteric rotational osteotomy was used to treat 474 hips in 378 patients with idiopathic and steroid-induced osteonecrosis of the femoral head. Two hundred twenty-nine of 295 hips with anterior rotation and follow-up periods ranging from three to 16 years had excellent surgical results (success rate, 78%). Outcome was chiefly dependent on the ratio of transposed intact posterior articular surface to the acetabular weight-Bearing Area after osteotomy. This relationship suggested that the transposed intact Area should occupy more than 36% of the acetabular weight-Bearing Area by adequate rotation and intentional varus position in addition to rotation, especially for extensive lesions. Salvage operations, such as total hip arthroplasty, were performed on 18 hips, of which ten hips were cases of either relative indication for extensive lesions in young patients or other misindications for rotational osteotomy. Four hips sustained neck fracture, including three hips after 180 degrees of posterior rotation; two hips were complicated with avascular necrosis, and another two hips developed osteoarthrosis. Histologically, femoral heads with osteoarthrosis removed at the time of salvage operation showed complete healing of the necrotic lesion. The overall findings indicate that healing of the necrotic lesion of the femoral head may be brought about by rotational osteotomy if it spares the vulnerable site from the brunt of mechanical stress.
Mitsuo Ochi - One of the best experts on this subject based on the ideXlab platform.
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The clinical and radiographic results of intertrochanteric curved varus osteotomy for idiopathic osteonecrosis of the femoral head
Archives of Orthopaedic and Trauma Surgery, 2014Co-Authors: Michio Hamanishi, Yuji Yasunaga, Takuma Yamasaki, Ryo Mori, Takeshi Shoji, Mitsuo OchiAbstract:Purpose In this study, postoperative results of intertrochanteric curved varus osteotomy (CVO) for idiopathic osteonecrosis of the femoral head (ION) were studied retrospectively and optimal indication of CVO was considered. Methods Between 1995 and 2011, CVO was performed in 51 patients (53 hips) for the treatment of ION in our department. The patients who had the potential to obtain acetabular coverage of more than one-third of the intact articular surface on pre-operative AP hip radiographs in maximum abduction were considered suitable for this operation. For radiological assessment, a ratio of necrotic volume, a ratio of postoperative intact surface on the weight-Bearing Area, progression of collapse, shortening length of the lower limb, and lateralization of great trochanter were evaluated. Results The mean ratio of necrotic volume was 16.9 %. The mean ratio of postoperative intact surface on the weight-Bearing Area of the femoral head was 51.7 %. The progression of collapse was observed in two hips (ratio of necrotic volume 10.4, 39.8 %; ratio of postoperative intact Area 36.5, 38.1 %). The mean shortening length of the lower limb was 9 mm, and the mean lateralization of great trochanter was 3 mm. One hip (ratio of necrotic volume 11.6 %, ratio of intact Area 35.8 %) was converted to THA because of the progression of osteoarthritis at 55 months after CVO. Conclusion The results of CVO for ION were successful, if this procedure was indicated for cases with intact load-Bearing Area more than 40 %.
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progressive collapse of transposed necrotic Area after transtrochanteric rotational osteotomy for osteonecrosis of the femoral head induces osteoarthritic change
Archives of Orthopaedic and Trauma Surgery, 2004Co-Authors: Takashi Hisatome, Yuji Yasunaga, Kazuhiro Takahashi, Mitsuo OchiAbstract:Osteonecrosis of the femoral head is usually progressive, and once collapse of the femoral head develops, joint destruction almost invariably follows. Therefore, for partial osteonecrosis of the femoral head, various types of osteotomies have been developed in an attempt to save the femoral head and maintain the natural function of the hip joint. We reviewed 25 hips in 21 patients for a mean follow-up period of 6.4 years after Sugioka’s transtrochanteric anterior rotational osteotomy for osteonecrosis of the femoral head. The clinical results were excellent or good in 20 hips (80%), and radiological success was observed in 15 hips (60%) with an absence of both collapse of the newly established weight-Bearing Area of the femoral head and narrowing of the joint space. Progressive collapse of the transposed necrotic Area was noted in 10 hips (40%), and of these 10 hips, narrowing of the joint space was observed in 7 (70%) at follow-up. A significant correlation was demonstrated between progressive collapse of the transposed necrotic Area and narrowing of the joint space. Growth of an osteophyte of the femoral head was observed postoperatively in 16 hips (64%), particularly at anterior and lateral sites of the femoral head. Though collapse of a new weight-Bearing Area can be prevented, progressive collapse of the transposed necrotic Area induces anterior joint instability, giving rise to osteoarthritic change. It is therefore concluded that prevention of the collapse of the transposed necrotic Area is important for satisfactory long-term results.
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Progressive collapse of transposed necrotic Area after transtrochanteric rotational osteotomy for osteonecrosis of the femoral head induces osteoarthritic change
Archives of Orthopaedic and Trauma Surgery, 2004Co-Authors: Takashi Hisatome, Yuji Yasunaga, Kazuhiro Takahashi, Mitsuo OchiAbstract:Introduction Osteonecrosis of the femoral head is usually progressive, and once collapse of the femoral head develops, joint destruction almost invariably follows. Therefore, for partial osteonecrosis of the femoral head, various types of osteotomies have been developed in an attempt to save the femoral head and maintain the natural function of the hip joint. Materials and methods We reviewed 25 hips in 21 patients for a mean follow-up period of 6.4 years after Sugioka’s transtrochanteric anterior rotational osteotomy for osteonecrosis of the femoral head. Results The clinical results were excellent or good in 20 hips (80%), and radiological success was observed in 15 hips (60%) with an absence of both collapse of the newly established weight-Bearing Area of the femoral head and narrowing of the joint space. Progressive collapse of the transposed necrotic Area was noted in 10 hips (40%), and of these 10 hips, narrowing of the joint space was observed in 7 (70%) at follow-up. A significant correlation was demonstrated between progressive collapse of the transposed necrotic Area and narrowing of the joint space. Growth of an osteophyte of the femoral head was observed postoperatively in 16 hips (64%), particularly at anterior and lateral sites of the femoral head. Conclusions Though collapse of a new weight-Bearing Area can be prevented, progressive collapse of the transposed necrotic Area induces anterior joint instability, giving rise to osteoarthritic change. It is therefore concluded that prevention of the collapse of the transposed necrotic Area is important for satisfactory long-term results.
A. Sethuramiah - One of the best experts on this subject based on the ideXlab platform.
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assessment of engine liner wear from Bearing Area curves
Wear, 2000Co-Authors: Rajesh Kumar, Braham Prakash, Salil Kumar, A. SethuramiahAbstract:Abstract This paper proposes a new procedure to evaluate engine liner wear volume and wear depth particularly for short duration engine tests. The method is based on the fact that honing depth is not removed when small amount of wear occurs. It was considered that 90% point of the Bearing Area curve is the same before and after wear. Then, the Bearing Area curve for the used liner was transformed by the depth differences at 90% and the Area between the two curves was calculated by numerical procedure. As the diameter of the liner is known, the wear volume was calculated for the various zones selected at different points from TDC and BDC. The methodology involved has been programmed in C++. The wear depth is obtained by the projection on the depth axis of the two Bearing Area curves, and then finding their difference. This method is considered superior to the usual method of gauging the changes in diameter as such determinations are influenced by the distortions that occur in the liner. The new procedure needs to be applied more extensively to improve confidence in repeatability and reproducibility and to determine the limits of applicability. Controlled laboratory wear tests and further measurements on cylinders from field engines are therefore proposed.
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Assessment of engine liner wear from Bearing Area curves
Wear, 2000Co-Authors: Rajesh Kumar, Braham Prakash, Salil Kumar, A. SethuramiahAbstract:This paper proposes a new procedure to evaluate engine liner wear volume and wear depth particularly for short duration engine tests. The method is based on the fact that honing depth is not removed when small amount of wear occurs. It was considered that 90% point of the Bearing Area curve is the same before and after wear. Then, the Bearing Area curve for the used liner was transformed by the depth differences at 90% and the Area between the two curves was calculated by numerical procedure. As the diameter of the liner is known, the wear volume was calculated for the various zones selected at different points from TDC and BDC. The methodology involved has been programmed in C + +. The wear depth is obtained by the projection on the depth axis of the two Bearing Area curves, and then finding their difference. This method is considered superior to the usual method of gauging the changes in diameter as such determinations are influenced by the distortions that occur in the liner. The new procedure needs to be applied more extensively to improve confidence in repeatability and reproducibility and to determine the limits of applicability. Controlled laboratory wear tests and further measurements on cylinders from field engines are therefore proposed. (C) 2000 Elsevier Science S.A. All rights reserved.
Takao Hotokebuchi - One of the best experts on this subject based on the ideXlab platform.
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transtrochanteric anterior rotational osteotomy for idiopathic and steroid induced necrosis of the femoral head indications and long term results
Clinical Orthopaedics and Related Research, 1992Co-Authors: Yoichi Sugioka, Takao Hotokebuchi, Hidekji TsutsuiAbstract:Abstract From 1972 until 1988, transtrochanteric rotational osteotomy was used to treat 474 hips in 378 patients with idiopathic and steroid-induced osteonecrosis of the femoral head. Two hundred twenty-nine of 295 hips with anterior rotation and follow-up periods ranging from three to 16 years had excellent surgical results (success rate, 78%). Outcome was chiefly dependent on the ratio of transposed intact posterior articular surface to the acetabular weight-Bearing Area after osteotomy. This relationship suggested that the transposed intact Area should occupy more than 36% of the acetabular weight-Bearing Area by adequate rotation and intentional varus position in addition to rotation, especially for extensive lesions. Salvage operations, such as total hip arthroplasty, were performed on 18 hips, of which ten hips were cases of either relative indication for extensive lesions in young patients or other misindications for rotational osteotomy. Four hips sustained neck fracture, including three hips after 180 degrees of posterior rotation; two hips were complicated with avascular necrosis, and another two hips developed osteoarthrosis. Histologically, femoral heads with osteoarthrosis removed at the time of salvage operation showed complete healing of the necrotic lesion. The overall findings indicate that healing of the necrotic lesion of the femoral head may be brought about by rotational osteotomy if it spares the vulnerable site from the brunt of mechanical stress.