Nobuhiko Sugano

The single slice CT method has sufficient accuracy for use, provided the slice is taken just below the femoral head. In cases with a femoral head deformity or a valgus neck or where difficulty is encountered in positioning the patient, 3D reconstruction appears essential for accurate measurement of anteversion.

We studied the morphometry of 35 femora from 31 female patients with developmental dysplasia of the hip (DDH) and another 15 from 15 age- and sex-matched control patients using CT and three-dimensional computer reconstruction models. According to the classification of Crowe et al 15 of the dysplastic hips were graded as class I (less than 50% subluxation), ten as class I/III (50% to 100% subluxation) and ten as class IV (more than 100% subluxation). The femora with DDH had 10 to 14 degrees more

The purpose of the current study was to evaluate whether safe acetabular component position depends on differences in pelvic location between the supine, standing, and sitting positions. The subjects of the current study were 101 patients who had total hip arthroplasty. Anteroposterior radiographs of the pelvis with the patients in the supine, standing, and sitting positions were obtained preoperatively and 1 year after total hip arthroplasty. Computed tomography images of the pelvis were obtain

Various systems of computer-assisted orthopaedic surgery (CAOS) in total hip arthroplasty (THA) were reviewed. The first clinically applied system was an active robotic system (ROBODOC), which performed femoral implant cavity preparation as programmed preoperatively. Several reports on cementless THA with ROBODOC showed better stem alignment and less variance in limb-length inequality on radiographic evaluation, less incidence of pulmonary embolic events on transesophageal cardioechogram, and le

We have developed a CT-based navigation system using infrared light-emitting diode markers and an optical camera. We used this system to perform cementless total hip replacement using a ceramic-on-ceramic bearing couple in 53 patients (60 hips) between 1998 and 2001. We reviewed 52 patients (59 hips) at a mean of six years (5 to 8) postoperatively. The mid-term results of total hip replacement using navigation were compared with those of 91 patients (111 hips) who underwent this procedure using

Abstract For the proper diagnosis or treatment of hip joint disorders caused by anatomical abnormalities, the normal hip joint morphology must be studied to understand its influence on the maximum range of motion (ROM) until bony impingement by focusing on gender differences. Acetabular and femoral morphologies were analyzed from 3D CT images of 106 normal hip joints from elderly men ( n = 36 joints) and women ( n = 70 joints), and measurements of ROM until bony impingement were made in four dir

From 1981 to 1983, we implanted Bioceram type-4 and type-5 prostheses in 61 hips in 54 patients with osteoarthritis secondary to acetabular dysplasia, congenital subluxation, or congenital dislocation of the hip. Fifty-seven hips in 50 patients were followed for a mean of 11.1 years (10 to 13). The mean age of the patients at operation was 53 years (31 to 70). Functional evaluation using the Merle d'Aubigné and Postel hip score showed a 77% success rate. Radiological loosening occurred in three

Six major and seven minor diagnostic criteria have been developed by the Japanese Investigation Committee for osteonecrosis of the femoral head (ONFH). We have carried out a multicentre study to clarify these. We studied prospectively 277 hips in 222 patients, from six hospitals, who had ONFH and other hip pathology and from whom histological material was available. We identified five criteria with high specificity: 1) collapse of the femoral head without narrowing of the joint space or acetabul

Thirty-five patients (54 hips) with osteonecrosis of the femoral head without collapse or only with a crescent sign were followed up for at least 5 years to clarify the natural course of osteonecrosis. During the followup, 28 hips (52%) in 21 patients collapsed including nine hips in nine patients with small necrotic lesions occupying less than the medial (2/3) of the weightbearing area. Cessation of collapse then was observed in 15 (14 patients) of the 28 hips (54%), especially in eight of the

To detect and prognosticate osteonecrosis of the femoral head in the preradiographic stage, 60 patients with systemic lupus erythematosus who had normal hip radiology were followed prospectively for a mean period of 5 years (range, 3-7 years) using magnetic resonance imaging (MRI). The first MRI scans showed a low intensity band in the femoral head of normal fat intensity on T1 weighted images in 16 hips of 9 patients. The MRI findings were used to classify the lesions into three categories. Typ

Level III, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.

We reviewed 41 hips in 40 patients at three to 11 years (average 6.3 years) after Sugioka transtrochanteric rotational osteotomy for non-traumatic avascular necrosis of the femoral head. The clinical results were excellent or good in 23 hips (56%) and the radiological success rate was 56%. Failure was due to fracture of the femoral neck, nonunion of the osteotomy, secondary collapse, or osteoarthritis. Nonunion and femoral neck fracture were more common after the use of the large screws describe