Spinal Alignments of Residual Lumbar Curve Affect Disc Degeneration after Spinal Fusion in Patients with Adolescent Idiopathic Scoliosis: Follow-up after 5 or More Years

Abstract

Introduction: Despite preserving lumbar disc mobility, spinal sagittal, and/or coronal alignment might ultimately impede surgical success. The purpose of this study was to elucidate the effects of spinal alignment on lumbar disc degeneration after 5 or more years in adolescent idiopathic scoliosis (AIS) patients who underwent spinal fusion.Methods: Subjects were 49 AIS patients who underwent posterior spinal fusion without lumbar curve fusion. The inclusion criteria were the following: 1) Lenke type 1A, 1B, 2A or 2B, 2) age 10 to 19 years at the time of operation, and 3) minimum 5-year follow-up. The exclusion criteria were the following: 1) diagnosed as other than AIS, 2) history of lumbar disc herniation and spondylolysis, 3) subsequent surgery, and 4) history of surgery before AIS surgery. Nineteen patients agreed to participate in this research. X-rays, lumbar MRI, and questionnaires were evaluated. Disc degeneration in nonfused segments was defined as Pfirrmann grade 3 or higher. Patients with disc degenerations at the final observation (DD[+] group) were compared to those without disc degenerations (DD[−] group).Results: There were no significant differences in the preoperative or postoperative 1-week X-ray parameters between both groups. The lumbar curve was significantly larger in the DD[+] group compared with the DD[−] group at the final observation (DD[+]: 16.8 degrees, DD[−]: 10.4 degrees, p = 0.035). The sagittal vertical axis (SVA) was significantly larger in the DD[+] group compared with the DD[−] group at the final observation (DD[+]: −4.4 mm, DD[−]: −34.3 mm, p = 0.006). SRS-22 function, self-image, and satisfaction scores were lower in the DD [+] group compared with the DD[−] group at the final observation.Conclusions: The patients with DD had significantly larger lumbar curve and SVA with lower SRS-22 function, selfimage, and satisfaction scores at the final observation. Even though the non-fused segments were preserved, spinal alignments of non-fused lumbar curve affect the DDs.

Does the Distal Level Really Matter in the Setting of Health-Related Quality of Life? Assessment of a Series of Adolescent Idiopathic Scoliosis Patients at More Than 7 Years Following Surgery

“…However, the importance of the correlation between disc degeneration and HRQOL after AIS fusion may be questioned at this follow-up point. 21,22 We may hypothesize that if disc degeneration may lead to back pain and radiculopathy when AIS fused patients aged, the main restriction and cause of pain 10 years after surgery could be lumbar amplitude restriction. Indeed, no implant failure or lack of fusion to the LIV were seen in the cohort at follow-up on radiographic assessments, even though they may lack sensibility to detect early loosening.…”

Half of the adolescent idiopathic scoliosis patients may have lumbar adjacent segment degeneration following spinal fusion: A systemic review and meta-analysis

“…However, the group with LIV ≤L4 tends to have a larger interbody tilt angle and less lumbar lordosis, factors that have been associated with degeneration. 31,33,35 It’s important to note that patients with LIV at a lower position more frequently experience back pain. Therefore, it may be advisable to consider placing the LIV at a higher position, as recommended by previous research.…”

“…Additionally, several risk factors, which remain a subject of debate, such as surgery age, BMI, radiographic parameters in the coronal and sagittal planes, preoperative disc conditions, osteoporosis, physical activity, were not considered due to data limitations. 31,33,37,60–64 Lastly, it’s important to note that high heterogeneity is often unavoidable in meta-analyses of epidemiological studies, despite our efforts to conduct subgroup analyses to address this issue.…”

Comparable rates of lumbar disc degeneration at long-term following adolescent idiopathic scoliosis spinal fusion extended to L3 or L4: systematic review and meta-analysis

“…The above-mentioned condition differs from the acceleration of physiological disc degeneration processes that also occur in healthy individuals over long time span and affects all unfused discs, but predominantly the lumbosacral junction, with L5-S1 being the most affected level which is naturally more vulnerable due to the frequent concomitance of AIS with low pelvic incidence morphotypes [ 26 , 39 ].…”