A new set of angles measured on standard axial CT images of the hip joint is defined. The angles provide information on the support of the femoral head from the anterior and the posterior part of the acetabulum. These angles have been measured in 82 adult hips, and correlated to a set of established parameters commonly measured at conventional roentgenography and on CT images of the hip joint. The defined angles may prove to be valuable in the total appreciation of hip joint function and stability.

No abstract

We measured the intercondylar notch of the femur in female handball players from radiographs of 20 players with previous unilateral anterior cruciate ligament injury, and 26 controls without injury. The groups were comparable regarding age, height, weight and level of performance. Intercondylar fossa radiographs were obtained in a posteroanterior axial position. The anterior opening of the intercondylar notch was narrower in the healthy knee of the injured group compared to the controls. There was an increased risk of anterior cruciate ligament injury associated with decreasing notch opening: female handball players with 17 mm or less anterior notch width were 6 times more susceptible to anterior cruciate ligament injury compared to players with wider notch width.

A study has been performed to evaluate whether one or several levels are needed with computed tomography (CT) study to provide sufficient information regarding anteversion and acetabular support to the femoral head. A total of 23 hips in 14 adults with uni- or bilateral congenital hip dysplasia (center-edge angle less than 20 degrees) were assessed by obtaining 5-mm contiguous CT slices and performing acetabular measurements at four levels. Both anterior and posterior acetabular supports as quantified by the anterior and posterior acetabular sector angles were significantly lower than normal at all levels. The sector angles increased in the proximal cuts, whereas the acetabular anteversion increased caudally. Because no important additional information was gained by measuring at different levels, we conclude that CT study at one level is sufficient for acetabular measurements and suggest that the slice through the center of the femoral head is the most appropriate one.

The anteversion angle (AV-angle) of the femur was measured according to the method of Rippstein in a series of 50 patients with "primary" osteoarthritis of the hip, and in a control group of 30 individuals of the same age without hip disease. The median AV-angle of the hips in osteoarthritic patients was 17.5 degrees, and in the control group 13 degrees. Osteoarthritic patients had a significantly increased AV-angle in relation to the control group (P = 0.0028). The greatest AV-angle in the hips of the control group was 25 degrees. In 18 hips of osteoarthritic patients an AV-angle greater than 25 degrees was found. Osteoarthritis was found in 15 of these hips; there was no osteoarthritis in the remaining 3 hips. Our results lead to the conclusion that increased femoral anteversion is a predisposing factor for hip osteoarthritis. This implies that derotational osteotomy in children can be a prophylactic procedure.