Abstract
Background: In surgical correction of adult spinal deformity (ASD), pelvic incidence (PI)-lumbar lordosis (LL) plays a key role to restore normal sagittal alignment. Recently, it has been found that postoperative lordosis morphology act as an important factor in preventing mechanical complications. However, there have been no studies on the effect of postoperative lordosis morphology on the restoration of sagittal alignment. The primary objective of this study was to evaluate the effect of postoperative lordosis morphology on achievement of optimal sagittal alignment. The secondary objective was to find out which radiographic or morphologic parameter affects sagittal alignment in surgical correction of ASD. Methods: 228 consecutive patients with lumbar degenerative kyphosis who underwent deformity correction and long-segment fixation from T10 to S1 with sacropelvic fixation and follow-up over 2 years were enrolled. Patients were divided according to whether optimal alignment was achieved (balanced group) or not (non-balanced group) at last follow-up. We analyzed the differences of postoperative radiographic parameters and morphologic parameters between two groups. Correlation analysis and stepwise multiple linear regression analysis was performed to predict the effect of PI-LL and morphologic parameters on the sagittal vertical axis (SVA). Results: Of 228 patients, 195 (85.5%) achieved optimal alignment at last follow-up. Two groups significantly differed in postoperative and last follow-up LL (p < 0.001 and p = 0.028, respectively) and postoperative and last follow-up PI-LL (p < 0.001 and p = 0.001, respectively). Morphologic parameters did not significantly differ between the two groups except lower lordosis arc angle (=postoperative sacral slope). In correlation analysis and stepwise multiple linear regression analysis, postoperative PI-LL was the only parameter which had significant association with last follow-up SVA (R2 = 0.134, p < 0.001). Morphologic parameters did not have any association with last follow-up SVA. Conclusions: When planning spine reconstruction surgery, although considering postoperative lordosis morphology is necessary, it is still very important considering proportional lordosis correction based on individual spinopelvic alignment (PI-LL) to achieve optimal sagittal alignment.
Highlights
The goal of surgical treatment for adult spinal deformity (ASD) is to restore sagittal alignment and achieve a solid arthrodesis in order to improve the patient’s quality of life [1]
For deformity correction and sagittal alignment restoration, 116 patients underwent pedicle subtraction osteotomy (PSO), and the accessory rod technique was performed with PSO to prevent pseudarthrosis, while 112 patients underwent multilevel lateral lumbar interbody fusion (LLIF) with posterior column osteotomy (PCO) [14]
In the stepwise multiple linear regression analysis, parameters showing multicollinearity were excluded, and the results showed that only postoperative pelvic incidence (PI)-lumbar lordosis (LL) was significantly linearly associated with the last follow-up sagittal vertical axis (SVA) (R2 = 0.134, p < 0.001)
Summary
The goal of surgical treatment for adult spinal deformity (ASD) is to restore sagittal alignment and achieve a solid arthrodesis in order to improve the patient’s quality of life [1]. Many studies have reported the standard for lordosis correction, and currently, the Schwab formula, which quantitatively corrects the pelvic incidence (PI) and lumbar lordosis (LL) mismatch, is widely used According to this formula, the PI-LL must be corrected within ±10◦ postoperatively in order to achieve optimal sagittal alignment and improve clinical symptoms, such as health-related quality of life [6,7]. To achieve such surgical goal, various surgical methods are used, including pedicle subtraction osteotomy (PSO), Smith–Petersen osteotomy, posterior column osteotomy (PCO), and posterior vertebral column resection [8,9,10]. Conclusions: When planning spine reconstruction surgery, considering postoperative lordosis morphology is necessary, it is still very important considering proportional lordosis correction based on individual spinopelvic alignment (PI-LL) to achieve optimal sagittal alignment
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
