EOS® is a low dose imaging system which allows the acquisition of coupled AP and lateral high-definition images while the patient is in standing position. HipEos has been developped to perform pre-surgical planning including hip implants selection and virtual positioning in functional weight-bearing 3D. The software takes advantage of the real size 3D patient anatomical informations obtained from the EOS exam. The aim of this preliminary study on 30 consecutive THP patients was to analyze the data obtained from HipEos planning for acetabular and femoral parameters and to compare them with pre and post-operative measurements on standing EOS images. Full body images were used to detect spino-pelvic abnormalities (scoliosis, pelvic rotation) and lower limbs discrepancies. One surgeon performed all THP using the same type of cementless implants (anterior approach, lateral decubitus). The minimum delay for post-op EOS controls was 10 months. A simulation of HipEos planning was performed retrospectively in a blinded way by the same surgeon after the EOS controls. All measurements were realized by an independent observer. Comparisons were done between pre and post-op status and the “ideal planning” taking in account the parameters for the restitution of joint offset and femur and global limb lengths according to the size of the selected implants. Regarding cup anteversion, the data included the anatomical anteversion (with reference to the anterior pelvic plane APP) and functionnal anteversion (according to the horizontal transverse plane in standing position).Introduction
Material and methods
The combination of spinal fusion and THP is not exceptional. Disorders of the pelvic tilt and stiffness of the lumbosacral junction modify the adaptation options while standing or sitting. Adjusting the cup can be difficult and THP instability is a potential risk. This study reports an experience with EOS® simultaneous measurements on AP and lateral views of spine and hips in THP patients. 29 men and 45 women were included in this prospective study. 21cases had bilateral THP. Patients were separated into two groups: long fusions including the thoraco-lumbar junction (group 1) and shorter fusions below L1 (group 2). We analyzed the impact of the arthrodesis on the position of the pelvis by measuring variations of the sacral slope (SS) and APP angle. Cup position was defined by coronal inclination and functional anteversion in the horizontal plane standing and sitting. We compared the data to a previous series of 150 THP patients with asymptomatic and non fused spine.Introduction
Material and methods
