Total hip arthroplasty for ankylosing spondylitis：the spine-pelvis sagittal balance and quality of life / 中国组织工程研究

ABSTRACT

BACKGROUND:Total hip arthroplasty is usualy taken to cure patients with ankylosing spondylitis combined with affected hip, to increase their life quality. But, its effects on sagittal balance of the spine-pelvis are not wel known. OBJECTIVE:To analyze the effects of total hip arthroplasty on sagittal balance of the spine-pelvis and life quality in patients with ankylosing spondylitis combined with affected hip. METHODS: Clinic data of 47 consecutive patients with ankylosing spondylitis combined with affected hip who had total hip arthroplasty and were folowed up for more than one year after operation from December 2008 to December 2013 were retrospectively analyzed. The spine-pelvis sagittal balancing parameters were measured. According to the SF-36 questionnaire, the dimensional scores were calculated to assess the life quality. Pearson correlation analysis was performed to analyze the correlation between the balancing parameters and SF-36 scores pre-operation, and the change of the balancing parameters and SF-36 scores pre- and post-operation were analyzed. RESULTS AND CONCLUSION:According to the data before total hip arthroplasty, sagittal vertical axis was negatively correlated with physiological function, body pain and vitality. Total kyphosis was negatively correlated with physiological function and general health. Lumbar lordosis was positively correlated with physiological function. Pelvic tilt angle was negatively correlated with the vitality and social function. Pelvic incident angle was negatively correlated with body pain, vitality and emotional role. No significant correlation was shown between sacral inclination angle and SF-36 items. After total hip arthroplasty, lumbar lordosis and sacral inclination angles were significantly increased, while sagittal vertical axis and pelvic tilt angle were significantly decreased compared with those before surgery. Total kyphosis and pelvic incident angle showed no significant differences before and after surgery. The SF-36 scores al got a statisticaly significant increase. Results showed that, sagittal vertical axis, total kyphosis, lumbar lordosis, pelvic incident angle and pelvic tilt angle are the potential factors influencing the life quality in patients with ankylosing spondylitis combined with affected hip. The total hip arthroplasty, which induces a better sagittal balance with an increased lumbar lordosis and sacral inclination angle, and a decreased sagittal vertical axis and pelvic tilt angle, can result in better life quality.