Association of Sagittal Spinopelvic Realignment with Correction in Lower Lumbar Lordosis after Surgical Treatment in Degenerative Lumbar Scoliosis

Objective To assess the effect that correction of lower lumbar lordosis (3L) has on global spine realignment due to the key role of 3L for scoliosis surgery in patients with degenerative lumbar scoliosis (DLS). Methods This study is a retrospective review performed between June 2018 and January 2020, including consecutive patients with DLS. Only patients age ≥ 45 years who had already undergone a selective root block operation and had the procedure of long‐fusion extending to pelvis and posterior lumbar interbody fusion (PLIF) at lower lumbar spine (L4‐S1) were retained for analysis. Spinopelvic parameters measured included thoracic kyphosis (TK), lumbar lordosis (LL), 3L, pelvic incidence (PI), pelvic tilt (PT), sacral slope (SS), T1 pelvic angle (TPA), and sagittal vertical axis (SVA) at pre‐operation and the third month follow‐up. The mismatch (PI‐LL) was calculated subsequently. Pearson correlation and linear regression analysis were performed to explore the association of the changes in global spinopelvic parameters with 3L correction. Results Thirty‐nine patients (five males, 34 females) with the average age of 63.84 years (SD 7.53; range, 45–75 years) at the time of surgery were identified. All patients had the surgical procedure of long‐fusion (≥4 vertebras) with PLIF at lower lumbar spine between L4 and S1 spine. Lower instrumented vertebras (LIV) fused to pelvis (S1, 14; S2, 18; ilium, 7) were operated in all patients. Seventeen patients were with upper instrumented vertebras (UIV) at thoracolumbar spine (L2‐T11), and 22 patients at thoracic spine (T10 and above). The median of instrumented segments was 10 (5–14). 3L significantly increased (P = 0.02) after surgical treatment by mean change of 4.21° (range, −19.7° to +22.2°). Perioperatively, all spinopelvic parameters regarding to TK, LL, SS, PT, TPA, SVA, and mismatch (PI‐LL) had significant changes (P
Scatterplots showing the change in lumbar lordosis correlated with changes in spinopelvic parameters. The linear regression formulas are as follows: d‐LL = 14.977+ 0.636*d‐3L, (R 2 = 0.596); d‐(PI‐LL) = 16.575 + 0.62*d‐3L, (R 2 = 0.183); d‐TPA = −7.284 to 0.358*d‐3L, (R 2 = 0.193); d‐SVA = −30.556 to 2.639*d‐3L, (R 2 = 0.347).