Postural changes of the vertebral-pelvic balance in patients with hip-spine syndrome

Relevance It is known that the state of sagittal balance is strictly correlated with the quality of life of the patient. At the same time, reference values for correction of sagittal parameters of the spine are derived only from vertical radiographs. Current evidence shows that the use of only standardized sagittal parameters in the standing position for planning the volume of surgical reconstruction is erroneous. However, rare publications show the difference between the sagittal profile of the spine in the sitting and standing position related to age. There is no information on the profile in extended degenerative pathology of the spine. Aim of the study Comparative assessment of the variability of the parameters of the sagittal profile of patients with Hip-Spine syndrome in the standing and sitting positions and comparison with healthy subjects from the average population. Design A prospective case-control monocenter observational study with historical control. The study included 74 patients with "Hip-spine" syndrome at the age of 63 ± 9.9 (43 to 83) years at the time of examination. The recruitment period was 23 months. The main group was formed by 74 patients with Hip-Spine syndrome. The control group (58 subjects) was represented by healthy individuals from open sources on the average population. The criteria of the analysis were sagittal vertebral-pelvic parameters of the trunk - CL, TK, TLK, LL, PI, PT, SS, SVA. The calculation of sagittal parameters was performed with Surgimap Spine software. Results In all patients during the transition from standing to sitting, there was kyphotization of the thoracolumbar transition (mean TLK angle was 10.3° - 145 %), a decrease in lumbar lordosis (mean LL angle - 23° - 44.4 %) with pelvic retroversion (PT: 18.6° - 126.5 %, SS: 18.3° - 51.6 %) and an increase in forward SVA deviation (10.5 mm - 25.5 %). No significant changes in cervical lordosis and thoracic kyphosis were revealed. When comparing the average values of sagittal parameters of patients of the main and control groups, there were no significant differences. However, among all patients of the main group, there were 6 patients (8.1 %) in whom the difference in the parameters LL, SS, PT in the standing and sitting positions was less than 10°, which indicates a pronounced rigidity of the lumbosacral spine. Conclusion Postural sagittal vertebral-pelvic parameters of the trunk in the standing and sitting positions in patients with Hip-Spine syndrome differ significantly from each other. A key role in the changes is played by the position of the pelvis, which retains mobility, despite different severity of degenerative changes in the complex "hip joints-lumbosacral spine".