Hip-Spine Syndrome

This study was designed to investigate the changes of low back pain and saggital pelvic inclination over time after total hip arthroplasty (THA) in osteoarthrosis (OA) of the hip. Fifty OA cases were classified into three groups according to age: Adult; 40 to 64 years of age, 19 hips; Young-Old; 65 to 74 years of age, 16 hips; Old-Old; 75 years of age ∼16 hips. The incidence of low back pain before THA was about 60% in all groups, but the transition of low back pain after THA was that the low back pain tended to improve more in the younger group. No improvement was seen in the “Old-Old” group. The degree of saggital pelvic inclination was calculated from the transverse axis length (b/a) ratio of the radiological shape of the pelvic cavity in antero-posterior radiographs. As a result, we found that the pelvis tended to incline posteriorly with increasing age. Therefore, pelvic anterior inclination was found in all “Adult patients” and pelvic posterior inclination in most “Old-Old patients”. After THA, the pelvis in most patients tended to slightly incline posteriorly over time.