Effect of PKP on Sagittal Balance of the Whole Spine in Patients with Single Segment OVCF

Abstract：Objective To investigate the effect of PKP on sagittal balance of the whole spine in patients with single seg-ment OVCF. Methods A retrospective analysis of experimental group of 65 cases of patients with single-level osteoporotic vertebral compression fracture(OVCF)in the period from February 2014 to October 2015. All patients have undergone percu-taneous balloon kyphoplasty(PKP). The natural standing position of the whole spine(including bilateral femoral head)positive lateral position X-ray films were taken at pre-and post-operation to measure the pelvic incidence(PI),pelvic tilt(PT),sacral slope(SS),lumbar lordosis(LL),thoracic kyphosis(TK),local sagittal Cobb angle,and C7 ~ S1 SVA;the visual analogue scale (VAS)and Oswestry disability index(ODI)were recorded. The relationship between preoperative spine-pelvis sagittal parame-ters and those of normal control group were assessed. And the changes of the sagittal parameters and the occurrence of compli-cations after operation in the study group were analyzed. Results All patients were followed up. At the last follow-up,the VAS score and ODI score of the study group were significantly improved compared with the preoperative(P < 0. 05). The preopera-tive C7 ~ S1 SVA values of the study group were larger than those in the normal control group,of which the difference was sta-tistically significant(P < 0. 05);preoperative TK values of the study group were larger than those of normal control group,the difference was statistically significant(P < 0. 05). In pelvis-related parameters,the differences of PI values of the study group between those of normal control group showed no significant whilst the corresponding PT,SS changes were both statistically sig-nificant(P < 0. 05). Post-operative C7 ~ S1 SVA was reduced compared with the pre-operative ones,of which the difference was statistically significant(P < 0. 05);In spine-related parameters,there were an increase in post-operative LL value preopera-tive than the postoperative ones and a decrease in post-operative TK values compared with the preoperative ones,of which the differences were statistically significant(P < 0. 05);In pelvis related parameters,there was no statistical significance in thepre-and post-operative differences of PI,PT,SS values(P > 0. 05)whilst the post-operative local Cobb angle was significantly reduced compared to the pre-operative onces,of which the difference was statistically significant(P < 0. 05). There was no ob-vious correlation between local Cobb angle and C7 ~ S1 SVA. However,the change of the local Cobb angle was significantly re-lated to the change of C7 ~ S1 in the sagittal plane(SVA C7 ~ S1 ). No serious complications were found during the operation and postoperative follow-up. Conclusion For patients with osteoporotic vertebral compression fractures,a percutaneous bal-loon kyphoplasty(PKP)is a considerable and effective minimally-invasive surgical approach,which can not only relieving frac-ture-caused pain,but also improve agittal alance through alleviation of local kyphosis.