A histological study of the necrotic area after transtrochanteric anterior rotational osteotomy for osteonecrosis of the femoral head.
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We studied nine patients who had had a transtrochanteric anterior rotational osteotomy, as developed by Sugioka, for osteonecrosis of the femoral head. At a mean of 2.5 years after the initial operation we carried out a histological study of the previously necrotic femoral head which had not shown collapse of the new primary weight-bearing site. In seven joints, there was proliferation of fibrous tissue in the dead trabeculae with vascular ingrowth. New bone covering dead trabeculae created the characteristic appearance of 'creeping substitution'. However, these changes were limited and did not extend over the entire necrotic area. Dead bone remained in all the cases. In the other two heads we did not observe proliferation of fibrous tissue or vascular ingrowth, only dead trabeculae and dead bone marrow. (+info)
Femoroacetabular impingement and the cam-effect. A MRI-based quantitative anatomical study of the femoral head-neck offset.
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We have observed damage to the labrum as a result of repetitive acetabular impingement in non-dysplastic hips, in which the femoral neck appears to abut against the acetabular labrum and a non-spherical femoral head to press against the labrum and adjacent cartilage. In both mechanisms anatomical variations of the proximal femur may be a factor. We have measured the orientation of the femoral neck and the offset of the head at various circumferential positions, using MRI data from volunteers with no osteoarthritic changes on standard radiographs. Compared with the control subjects, paired for gender and age, patients showed a significant reduction in mean femoral anteversion and mean head-neck offset on the anterior aspect of the neck. This was consistent with the site of symptomatic impingement in flexion and internal rotation, and with lesions of the adjacent rim. Furthermore, when stratified for gender and age, and compared with the control group, the mean femoral head-neck offset was significantly reduced in the lateral-to-anterior aspect of the neck for young men, and in the anterolateral-to-anterior aspect of the neck for older women. For patients suspected of having impingement of the rim, anatomical variations in the proximal femur should be considered as a possible cause. (+info)
Short stature as a screening test for endocrinopathy in slipped capital femoral epiphysis.
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Slipped capital femoral epiphysis may be associated with hypothyroidism and other endocrinopathies. Routine screening for such abnormalities is unlikely to be cost-effective since the overall incidence of these disorders, in association with slipped capital femoral epiphysis, is low. The identification of a presenting characteristic which would predict the chance of an associated endocrinopathy would allow only selected children to be screened. Our aim was to determine if certain characteristics were useful as a screen for patients with an underlying endocrinopathy who presented with slipped capital femoral epiphysis. Between January 1988 and December 1996 we recorded gender, age, height, unilateral or bilateral involvement and an associated diagnosis of endocrinopathy for all patients who were treated for slipped capital femoral epiphysis. Of 166 such patients 13 (7.8%) had an endocrinopathy. Height was the only useful screening characteristic, although bilateral involvement was more likely in those with an endocrinopathy. Most (90.9%) of this latter group were below the tenth percentile for height compared with only 5.4% in those who did not have an endocrinopathy (p < 0.005). The sensitivity and negative predictive value of detecting an underlying endocrinopathy in a patient presenting with a slipped capital femoral epiphysis and short stature (tenth percentile or less) were 90.2% and 98.6%, respectively. Patients who are on or below the tenth percentile for height at the time of presentation should be screened for a possible endocrine abnormality using measurement of thyroid-stimulating hormone and free thyroxine as a preliminary screening test. These hormones are most likely to be abnormal in the presence of endocrine dysfunction. (+info)
Selective reduction of bone blood flow by short-term treatment with high-dose methylprednisolone. An experimental study in pigs.
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Treatment with corticosteroids is a risk factor for non-traumatic avascular necrosis of the femoral head, but the pathological mechanism is poorly understood. Short-term treatment with high doses of methylprednisolone is used in severe neurotrauma and after kidney and heart transplantation. We investigated the effect of such treatment on the pattern of perfusion of the femoral head and of bone in general in the pig. We allocated 15 immature pigs to treatment with high-dose methylprednisolone (20 mg/kg per day intramuscularly for three days, followed by 10 mg/kg intramuscularly for a further 11 days) and 15 to a control group. Perfusion of the systematically subdivided femoral head, proximal femur, acetabulum, humerus, and soft tissues was determined by the microsphere technique. Blood flow in bone was severely reduced in the steroid-treated group. The reduction of flow affected all the segments and the entire epiphysis of the femoral head. No changes in flow were found in non-osseous tissue. Short-term treatment with high-dose methylprednisolone causes reduction of osseous blood flow which may be the pathogenetic factor in the early stage of steroid-induced osteonecrosis. (+info)
A systematic approach to the quantitative description of musculo-skeletal geometry.
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1. A systematized computer technique of centroid analysis has been developed to evaluate the precise geometric relationship between a muscle and a bone and it has been applied to the abductor mechanism of the human hip joint. 2. The validity of the traditional use of straight lines for displaying the line of action of a muscle is open to serious question, although in the case of the gluteus medius the straight line simplification is not unmeasurable. 3. The determination of the precise interactions of muscles and bones is of major importance in the consideration of various orthopaedic procedures. (+info)
Femoral head fractures.
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This report includes six patients with femoral head fractures. Five were associated with posterior hip dislocation, of which one also had an ipsilateral trochanteric fracture. All were young adults who had been injured in automobile accidents. The protocol for management, indications for surgery and guidelines for evaluation of results are described. (+info)
The assessment of contact stress in the hip joint after operative treatment for severe slipped capital femoral epiphysis.
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We determined contact stress on the articular surface of the hip joint in a group of patients who underwent operative treatment for severe slipped capital femoral epiphysis. Two different procedures were considered: the modified osteotomy of Dunn-Fish and the osteotomy of Imhauser. In order to determine the stress distribution, a three-dimensional mathematical model was used taking into account the geometrical parameters of the pelvis and hip, which were measured from standard antero-posterior radiographs. We found that the Dunn-Fish procedure produced lower peak stress than the Imhauser procedure. (+info)
Volumetric analysis of osteonecrosis of the femur. Anatomical correlation using MRI.
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We tested the accuracy of MRI for the precise quantification of the volume of osteonecrosis in 30 hips (stage III). The values were compared with direct anatomical measurements of the femoral heads obtained after total hip replacement. When the area of osteonecrosis was determined visually, and manually outlined on each slice, the accuracy of the measurement of volume was satisfactory, and the mean absolute deviation between MRI and anatomical measurements was similar to that between two MRI data sets. For ten of the hips which were measured by MRI, both before and after collapse, the volume did not appear to change significantly. Our findings suggest that the volume of osteonecrosis can be determined with accuracy by MRI, both before and after collapse. (+info)