Several studies have reported the assessment of the femoral head coverage on plane radiograph and CT data in supine position, though young patients with the dysplastic hip often have symptoms during activities such as standing, walking, and running. On the other hand, some investigators have used a method of CT which allows standardization of the femoral head coverage against an anterior pelvic plane based on the anterior superior iliac spines and the pubic tubercle. We believe both the weight-bearing position and the standardized position to be more relevant for diagnosis and preoperative surgical assessment. So, we show the femoral head coverage in standardized position using 3D-CT method and in weight-bearing position using the plane radiograph and the three-dimensional lower extremity alignment assessment system before and after Curved periacetabular osteotomy (CPO). Especially the covered volume of the femoral head, a new concept, using the three-dimensional lower extremity alignment assessment system which differs from the affected area and is measured by the ratio of the covered area in the medial part of the line connecting the anterior point of the acetabulum with the posterior to the femoral head area in each axial slice, superior slices than the slice passing through the femoral head center, obtained from the reproduced 3D model of the pelvis and the femur in standing position allows us to integrate various measurements reported by past researchers. We studied the consecutive 16 patients treated with CPO. In standardized position the sagittal sectional angles on the slice passing through the femoral head center using 3D-CT method gave us how the anterior, lateral, and posterior coverage was lack compared with normal subjects and whether the adequate transfer of the rotated fragment was performed after operation. The covered volume of the femoral head decides generally the deficiency or the adequateness. In standing position, though the pelvic tilt changes, the femoral head coverage on plane radiograph, representation by the CE angle, the VCA angle, AHI and ARO, was significantly improved, and the covered volume of the femoral head was significantly improved from 25.7% preoperatively to 51.1% postoperatively. Our study showed the improvement of the femoral head coverage, including the covered volume of the femoral head as a new concept, after CPO in weight-bearing and standardized position. The morphological and functional assessment of the femoral head coverage on both pre- and post-CPO should be performed because we can obtain the objective information in standardized position and the femoral head coverage in standing position is closely connected with the pain

Introduction. The treatment of trochanteric femoral fractures with the use of short femoral nails has become an established method. The fixation is required that lag screw be centered to prevent complications. But correct positioning of the device may difficult because of anatomical feature. This study evaluated the femoral morphology three-dimensionally using computed tomography (CT) images. Methods. Seventy eight patients (mean age 75)who underwent total knee arthroplasty were included. After three-dimensional reconstruction of the CT images, the anterior deviation from the femoral neck axis to proximal shaft axis was measured. The proximal shaft axis was defined as a line between center of the cross-section underneath the lesser trochanter and the center of diaphysis. The connection of center in narrow section of the neck and femoral head center was defined as neck axis. Results. The femoral neck axis and shaft axis were not coplanar. The anterior deviation of the axes was 7.5 mm (1.7 to 18.4 mm). The neck-shaft angle was 124° (110–142°). Discussion. Our results indicate that the nail and screw could not be center in current nail system, because of the non-crossing of the femoral axes. The large variation of neck-shaft angle would lead error in preoperative planning using traditional 2-D template system. Our study suggests needs for three-dimensional template system and newly femoral nail device

Cam type femoroacetabular impingement (FAI) is due to an aspheric femoral head, which is best quantified by the alpha angle described on MRI and CT-scan. Radiographic measurement of the alpha angle is not well codified and studies from the literature cannot conclude on the best view to measure it. Most authors also describe a mixed type FAI which associates an aspheric femoral head with an excessive anterior acetabular coverage of the femoral head. Anterior center edge (ACE) angle has been described on the false profile view to measure anterior acetabular coverage in hip dysplasia and has never been evaluated in FAI. In this study, we developed a new lateral hip view which associates a lateral view of the femoral neck and a false profile view of the acétabulum, which we called profile view in impingement position (PVIP). Twenty six patients operated for FAI had CT-scan, the PVIP and the false profile view of one or two hips according to pain. A control group of 19 patients who did not suffer from the hip had the PVIP. Alpha angles were measured twice on 17 CT scan of FAI patients by two observers and compared with the alpha angles measured on the corresponding hip PVIP by a correlation analysis. Alpha angles were measured twice on 45 PVIP in FAI patient and on 19 PVIP in the control group by three observers. ACE angles were measured once on 15 PVIP and on 15 false profile views. Means were compared by two tail paired t-tests, intra- and inter-observer reliability were measured by intraclass correlation coefficient. Mean alpha angle on CT scan was 65.8° and 65.6° for observers 1 and 2 respectively (p>0.05). It was 63.6° and 64.3° on the PVIP (p>0.05). No significant difference was found between CT scan and radiographic measurements, and Pearson's correlation coefficients were good at 0.74 and 0.8. ICC was 0.86 for inter-rater reliability, and 0.91 for intra-rater reliability for CT-scan alpha angle measures. ICC for PVIP measures varied from 0.82 to 0.9 for intra-rater reliability and from 0.6 to 0.9 for inter-rater reliability. Mean alpha angle measured on PVIP in FAI patients was 63.3° and was 44.9° in control subjects and the difference was significant (p<0.001) for the three observers. None of the FAI patients and 88% of the control subjects had an alpha angle < 50°. Mean ACE angle was 26.8° on PVIP and 32.8° on the false profile view, the difference was significant (p=0.015), and the Pearson's correlation coefficient was moderate (r=0.58). The PVIP is a reliable radiographic view to measure the alpha angle. It allows a good quantification of the alpha angle comparable to CT-scan measurements and permits to differentiate patients from control subjects. PVIP is not a good view to quantify anterior edge angle probably because of acetabular retroversion due to the hip flexion needed in this view. Mean ACE angle measured on the false profile view in FAI patient was comparable to ACE angle in general population reported in the literature

Aims

To evaluate the outcomes of cemented total hip arthroplasty (THA) following a fracture of the acetabulum, with evaluation of risk factors and comparison with a patient group with no history of fracture.