Comparison Of The Balance Of The Sagittal-pelvic Sagittal Plane Between AS Hip Stiffness And Bilateral CroweⅣ Patients And Its Clinical Importance

Objective:The sagittal plane parameters of patients with bilateral hip joint stiffness and bilateral Crowe type IV DDH were measured and compared with the normal population to evaluate and investigate sagittal morphological abnormalities in patients with AS-induced hip stiffness and bilateral Crowe Ⅳ.Accroding to those sagittal morphological abnormalities and discuss their clinical importanceMethods:Collecting 20 patients with bilateral hip joint stiffness,20 patients with bilateral Crowe type IV DDH,20 patients with normal standing position,full-length lateral X-ray,thoracolumbar lateral X-ray,hip X Line lateral slices:(1)pelvic sagittal parameters:sacral slope(SS),sacrum pubic incidence(SPI);(2)spinal sagittal parameters:lumbar lordosis(lumbar Lordosis,LL);thoracic kyphosis angle(TK).ANOVA test was used to analyze the differences between the sagittal parameters of each group.Results:1、Genenal stiuation:There was no significant difference in age and genderdistribution between the three groups.2、Imaging parameters:① Characteristics of the spine-pelvic sagittal parameters of the AS group and the normal group.The TK parameters of the AS group(37.54±9.87)were larger than those of the normal control group(26.52±6.11),and the difference was statistically significant(P<0.05).The LL parameters of the AS group(27.39±10.82)were smaller than the normal control group(50.06±9.04),and the difference was statistically significant(P<0.05).The SS parameters of the AS group(24.27±8.36)were smaller than the normal control group(36,61±8.34),and the difference was statistically significant(P<0.05).The SPI parameters of the AS group(57.4±3.32)were smaller than the normal control group(62.24.±4.80),and the difference was statistically significant(P<0.05).②Characteristics of the spine-pelvic sagittal parameters in the CroweⅣ DDH group and the normal groupThe TK parameters of the DDH group(15.17±2.2)were smaller than those of the normal control group(26.52±6.11),and the difference was statistically significant(P<0.05).The LL parameters of the DDH group(34.89±8.41)were smaller than those of the normal control group(50.06±9.04),and the difference was statistically significant(P<0.05).The SS parameters of DDH group(55.55±5.98 were larger than the normal control group(36.61±8.34),the difference was statistically significant(P<0.05);The SPI parameters(70.3±4.44)in the CroweⅣ DDH group were larger than those in the normal control group(62.24.±4.80),and the difference was statistically significant(P<0.05).③Characteristics of the spine-pelvic sagittal parameters of the AS group and the bilateral Crowe IV DDH group.The TK parameters of the AS group(37.54±9.87)were larger than those of the DDH group(15.17±2.2),and the difference was statistically significant(P<0.05).The LL parameters of the AS group(27.39±10.82)were smaller than those of theDDH group(34.89±8.41),and the difference was statistically significant(P<0.05).The SS parameters of the AS group(24.27±8.36)were smaller than those of the DDH group(55.55±5.98),and the difference was statistically significant(P<0.05).The SPI parameters of the AS group(57.4±3.32)were smaller than those of the DDH group(70.3±4.44),and the difference was statistically significant(P<0.05).Conclusion:Spinal-pelvic sagittal imbalance is present in patients with hip stiffness caused by ankylosing spondylitis and bilateral Crowe type IV hip dysplasia.AS patients are more posteriorly inclined than DDH and normal patients,and thoracic kyphosis is increased.The lumbar spine is reduced and the hip joint is extended.Patients with DDH have pelvic anteversion,lumbar protrusion and kyphosis compared with normal subjects.These sagittal morphology of AS and bilateral crown IV DDH patients need to be considered in the design of total hip arthroplasty.