Masamitsu Ezoe

St.Mary's Hospital (Fukuoka - Japan), Hukuoka, Fukuoka, Japan

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Publications (8)14.42 Total impact

  • Masamitsu Ezoe · Masatoshi Naito · Toshio Inoue
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    ABSTRACT: Acetabular retroversion can result from posterior wall deficiency in an otherwise normally oriented acetabulum or from excessive anterior coverage secondary to a malpositioned acetabulum, or both. Theoretically, a retroverted acetabulum, which adversely affects load transmission across the hip, may occur more frequently in hips with degenerative arthritis. The aim of this study was to assess the prevalence of acetabular retroversion in normal hips and in hips with osteoarthritis, developmental dysplasia, osteonecrosis, and Legg-Calvé-Perthes disease. We retrospectively examined anteroposterior radiographs of the pelvis of 250 patients (342 hips). Fifty-six patients (112 hips) had normal findings; sixty-six patients (seventy hips) had osteoarthritis; sixty-four (seventy-four hips), developmental dysplasia; thirty (thirty-six hips), osteonecrosis of the femoral head; and thirty-four (fifty hips), Legg-Calvé-Perthes disease. The sole criterion for a diagnosis of acetabular retroversion was the presence of a so-called cross-over sign on the anteroposterior radiograph of the pelvis. The prevalence of acetabular retroversion was 6% (seven of 112 hips) in the normal group, 20% (fourteen of seventy hips) in the osteoarthritis group, 18% (thirteen of seventy-four hips) in the developmental dysplasia group, 6% (two of thirty-six hips) in the group with osteonecrosis of the femoral head, and 42% (twenty-one of fifty hips) in the group with Legg-Calvé-Perthes disease. In patients with Legg-Calvé-Perthes disease, the prevalence of acetabular retroversion was 68% in twenty-five hips with Stulberg class-III, IV, or V involvement. In contrast, only four (16%) of twenty-five hips with Stulberg class-I or II involvement had acetabular retroversion. The difference was significant (p = 0.0002). Patients with osteoarthritis, developmental dysplasia, or Legg-Calvé-Perthes disease are significantly more likely to have acetabular retroversion than are normal subjects (p < 0.05). Acetabular retroversion occurs more commonly in association with a variety of hip diseases, in which the prevalence of subsequent degenerative arthritis is increased, than has been previously noted.
    No preview · Article · Mar 2006 · The Journal of Bone and Joint Surgery
  • Masamitsu Ezoe · Masatoshi Naito · Isao Asayama
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    ABSTRACT: We measured muscle strength after curved periacetabular osteotomy, one form of abductor-sparing periacetabular osteotomy, and then investigated the factors influencing postoperative muscle strength recovery. Curved periacetabular osteotomy was performed for acetabular dysplasia on 24 hips in 22 patients. All patients were females, with a mean age of 34.4 years. We based the severity of hip disease on the Tönnis classification. Isokinetic muscle strengths of the hips were measured preoperatively and 6 months and 12 months postoperatively. At 12 months postoperatively, the mean muscle strength (percentage difference to preoperative value) of the abductor was 42.2 Nm (129.6%), adductor 39.4 Nm (131.4%), flexor 48.4 Nm (121%), and extensor 45.8 Nm (130.5%), all of which exceeded the preoperative values. The 12-month postoperative muscle strength of patients with Grade 0 disease based on the Tönnis classification was greater in all directions than that of patients with Grades 1 and 2 disease. The preoperative stage was thought to be an essential factor in postoperative muscle strength recovery. Level of Evidence: Prognostic study, Level II (lesser quality prospective study--eg, patients enrolled at different points in their disease or < 80% followup). See the Guidelines for Authors a complete description of levels of evidence.
    No preview · Article · Mar 2006 · Clinical Orthopaedics and Related Research
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    ABSTRACT: The Bernese periacetabular osteotomy has a considerable rate of postoperative complications such as reflex sympathetic dystrophy, motor nerve palsy, heterotopic ossification, and delayed union of the ilium, which are assumed to be caused by extensive exposure or asphericity of the osteotomy surfaces. To address these issues, we developed the curved periacetabular osteotomy, a modification of the Bernese periacetabular osteotomy which limits dissection, prevents the outside of the ilium from being exposed, and produces osteotomy surfaces with the same curvature. Curved periacetabular osteotomies were done on 128 hips in 118 patients whose average age at the time of surgery was 35.2 years (range, 16-59 years). The average followup was 46 months (range, 24-99 months). The average center-edge angles were 4 degrees (range, -15 degrees -5 degrees ) preoperatively and 35 degrees (20 degrees -55 degrees ) postoperatively, and union of the iliac osteotomy was achieved in all hips. We experienced three asymptomatic pubic nonunions. Dysesthesias occurred in 27 patients along the lateral femoral cutaneous nerve and symptoms resolved in 23 patients within 1 year. The average Harris hip score improved from 72 to 93 points. There were no major complications such as sciatic nerve palsy, abductor dysfunction, or heterotopic ossification. LEVEL OF EVIDENCE: Therapeutic study, Level IV (case series--no, or historical control group). See the Guidelines for Authors for a complete description of levels of evidence.
    No preview · Article · May 2005 · Clinical Orthopaedics and Related Research
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    ABSTRACT: We devised a special instrument to assess intraoperative pelvic motion and used this device to measure intraoperative pelvic motion in three dimensions. A total of 100 total hip arthroplasties (THAs) were performed using this device. Two approaches were utilized: 52 THAs were performed with the posterolateral approach and the remaining 48 with the translateral approach. The average angle of pelvic tilt in the THAs with the translateral approach was less than that with the posterolateral approach. The average internal rotation angle was 1.75 degrees with the translateral approach and 14.25 degrees with the posterolateral approach. With the posterolateral approach, the internal rotation of the pelvis frequently occurred during retraction of the femur using a Hohmann's retractor placed at the anterior rim of the acetablum, with flexion and internal rotation of the affected hip.
    No preview · Article · Feb 2005 · Journal of Orthopaedic Science
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    ABSTRACT: In total hip arthroplasty (THA) in which the posterolateral approach is used, the pelvis can be easily inclined to roll both backward or forward on the operating table during the procedure. We prospectively studied 30 posterolateral-approach primary THA cases in which the surgeon used a specially devised goniometer that measured motions of the pelvis in the horizontal, frontal, and sagittal planes. We found that the pelvis primarily tilted forward during surgery, averaging 14.57 degrees of anterior tilt in the horizontal plane. The pelvic motion primarily occurred while the Hohman retractor was being applied to the femur to expose the acetabulum. Assessment of pelvic motion during surgery is an important component for successful positioning and placement of the acetabular cup with the posterolateral-approach THA.
    No preview · Article · Jan 2005 · The Journal of Arthroplasty

  • No preview · Article · Jan 2004
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    ABSTRACT: We reviewed 9 patients in which 9 shoulders were operated on because of internal impingement. The mean age of the patients at operation was 20.3 years (range; 16 to 28 years). All patients had undergone arthroscopic internal impingement test, followed by arthroscopic debridement. The clinical outcome was expressed using JOA score and JOA score for athletics. All postoperative JOA scores and athletic JOA scores were higher than preoperative scores. The average follow-up period was 11 months (range; 9 to 16 months). 8 cases were able to start playing baseball again, but the ninth case was not.
    No preview · Article · Jan 2001

  • No preview · Article · Jan 1999