[Short and medium term follow-up study on the changes of spine pelvic parameters in patients with hip-spine syndrome after total hip arthroplasty].

OBJECTIVE To investigate the influence of total hip arthroplasty on the changes of spine pelvic parameters in patients with hip spine syndrome. METHODS From January 2013 to October 2014, 22 patients (26 hips) with hip spine syndrome accompanied by necrosis of femoral head, hip osteoarthritis and congenital dysplasia of hip were treated with total hip arthroplasty. There were 12 males and 10 females with an average age of 58.4 years (range, 45 to 76 years). The course of disease was 1.5 to 25 years with an average of 12.8 years. Before and after the operation, the anteroposterior, full length radiographs of both lower limbs, thoracolumbar spine and pelvis in standing position were routinely taken. The balance parameters of spine pelvis coronal plane and sagittal plane before and after the replacement were measured. Visual analogue scale (VAS), Oswestry Disability Index (ODI) and Harris score were performed before and after the operation. RESULTS All cases were followed up for 21 to 52 (32±8) months. No infection, prosthesis subsidence, loosening, prosthesis dislocation were found in the last follow up. After total hip arthroplasty, sagittal vertical axis(SVA), thoracic kyphosis(TK), lumbar lordosis(LL), pelvic tilt (PT) were significantly reduced(P 0.05); PT and scoliosis (coronal position) were significantly decreased after operation(P<0.05); VAS score of waist, VAS score of hip joint and ODI score of waist were significantly decreased before and after operation (P<0.05). Harris score of hip joint increased significantly after operation, and thedifference was statistically significant (P<0.05). CONCLUSION After total hip arthroplasty, the coronal and historical balance parameters of spine and pelvis are significantly improved, and the short term and medium-term effects are satisfactory.