[CORRELATION ANALYSIS OF CHANGES OF SPINE-PELVIC SAGITTAL PARAMETERS BEFORE AND AFTER OPERATION AND EFFECTIVENESS IN...

To investigate the correlation between the effectiveness and the changes of spine-pelvic sagittal parameters for patients with spondylolisthesis before and after operation.

A retrospective analysis was made on the clinical data of 32 patients with single segmental degenerative lumbar spondylolisthesis at L4 who accorded with the inclusion criteria between June 2011 and January 2014 (trial group). There were 13 males and 19 females, aged 51-67 years (mean, 59 years). According to Meyerding degree, there were 21 cases of degree I, 10 cases of degree II, and 1 case of degree III. All patients were treated with transforaminal lumbar interbody fusion (TLIF) surgery. Thirty-five healthy adults at the age of 46-67 years (mean, 57 years) were enrolled as normal controls (control group). The standing position lumbar lateral X-ray films (T12-S1, bilateral femoral head) were taken at pre- and post-operation to measure the pelvic incidence (PI), pelvic tilt (PT), sacral slope (SS), lumbar lordosis (LL), disc height (DH), and slip percentage (SP); the visual analogue scale (VAS) and Oswestry disability index (ODI) were recorded. Pearson correlation analysis was used to analyze the correlation between the preoperative various spine-pelvic sagittal parameters and the VAS score and the ODI. After operation, Pearson correlation analysis was used to evaluate the correlation between the changes of these parameters and the improve rates of VAS score and ODI.

All patients of trial group were followed up 15 - 22 months (mean, 18 months). At last follow-up, the VAS score, ODI, PT, SS, LL, SP, and DH were significantly improved when compared with preoperative values (P < 0.05), except for PI (t = -1.445, P = 0.158). There was no significant difference in PT, SS, LL, and DH between trial and control groups at last follow-up (P > 0.05); PI was slightly bigger than that of control group (t = 8.531, P = 0.043). Pearson correlation analysis showed that there was a correlation between spine-pelvic sagittal parameters of PI, PT, SS, and LL (P < 0.05); preoperative parameters (except for LL and DH) had correlation with ODI and VAS scores (P < 0.05). Postoperative parameters (except for PI) had correlation with the improve rates of ODI and VAS scores (P < 0.05), especially for the changes of PT and the improvements of ODI and VAS scores.

There is a correlation between the changes of spine-pelvic sagittal parameters at pre- and post-operation and effectiveness in patients with lumbar spondylolisthesis. The correlation between the changes of PT and the improvement rates of ODI and VAS scores is more marked. The good effectiveness is closely related with the improved PT.