Coronal imbalance correction with distraction of distal convex side of lumbar scoliosis in degenerative lumbar scoliosis / 中华骨科杂志

ABSTRACT

Objective@#To investigate the effect of modified transforaminal lumbar interbody fusion (TLIF) on coronal degenerative lumbar scoliosis (DLS) in adults with mild Drum Tower Hospital Classification type B and C coronal imbalance.@*Methods@#From January 2011 to December 2015, 31 patients with mild coronal imbalance underwent long-segment fusion for DLS, 27 females and 4 males, with an average age of 63.1±5.5 years (52-76 years), were retrospectively analyzed. According to the coronal balance classification of Drum Tower degenerative scoliosis, there were 20 patients with type B and 11 patients with type C. The average follow-up time was 38.5±9.3 months. Sagittal parameters includingpelvic tilt (PT), PI-LL (pelvic incidence, PI; lumbar lordosis, LL), sagittal vertical axis (SVA) and coronal parameters includingCobb angle, coronal balance distance (CBD), lumbosacral inclination angle (when L 5 is the lower fusion vertebra, the angle between L4 upper endplate and horizontal line was measured; when S1 or S2 was the lower fusion vertebra, the angle between L 5 upper endplate and horizontal line is measured), and clinical scores including Visual Analogue Scale (VAS) and Oswestry Disability Index (ODI) (excluding sexual life assessment)were recorded before and during the last follow-up. Complications such as internal fixation displacement, fracture and loss of correction were evaluated at the last follow-up. The main method of surgical correction was the modified TLIF operation on the distal compensatory curve and concave side. After the soft tissue is released, the ipsilateral intervertebral fusion cage was implanted to distract the intervertebral space. SPSS 20.0 was used for statistical analysis. All data were expressed as mean ±standard deviation. Paired t-test was used to evaluate the imaging measurement and clinical scores. Independent sample t-test was used to compare the databetween type B and C. P value less than 0.05 has statistical significance.@*Results@#The mean operating time was 4.4±0.9 h (3.1-6.0 h) and the mean intraoperative bleeding was 777±249 ml (500-1 300 ml). For Sagittal balance, PI-LL was 21.7°±5.3° in 31 patients before operation, and the last follow-up was 7.4°±2.4° (t=16.41, P<0.001); PT was 32.6°±7.6° before operation, and the last follow-up was 24.1°±8.5° (t=15.32, P<0.001); SVA was 52.2±16.2 mm before operation, and the last follow-up was 25.5±13.8 mm (t=10.20, P<0.001). For coronal balance, the lumbosacral tilt angle was 8.8°±3.4°, and the last follow-up was 3.9°±2.1°. The average correction rate was 56.0%. The preoperative scoliosis Cobb angle was 41.5°±9.6°, and the last follow-up was 19.7°±6.7° (t=17.90, P <0.001). The average correction rate was 52.7%. The preoperative CBD was 4.3 ±0.7 mm, and last follow-up was 1.6 ± 0.8 mm (t=33.76, P < 0.001). In terms of clinical scores, the VAS score of 31 patients before operation was 6.5±1.0, and the last follow-up was 2.7±1.0 (t=15.97, P <0.001); the ODI score before operation was 34.8%+5.6%, and the last follow-up was 18.0%±5.4% (t=12.42, P <0.001). There were no significant differences in sagittal parameters, coronal parameters and clinical efficacy scores between group B and group C.@*Conclusion@#In adult DLS patients with mild coronal B-type and C-type imbalances, the application of modified TLIF interbody fusion and cage insertion in the distal convex side of lumbar scoliosis can achieve the levelization of lumbosacral region and correct coronal imbalance.