Bending rod is unnecessary in single-level posterior internal fixation and fusion in treatment of lumbar degenerative diseases

Background Bending rod is a routine in lumbar fusion and fixation surgery, but there is no study investigating whether bending rod in one level is necessary. Methods Patients receiving 1 level lumbar fixation and fusion between May 2018 and September 2020 were included with a minimum 6-month follow-up. The routine of bending rod was omitted during fixation. Preoperative and postoperative radiological parameters were compared. Results There were 67 patients included in the study. Segment lordosis angle increased obviously from 10° (1–39°) to 14° (2–30°) immediately after operation (p = 0.000). T5-T12 increased from 22.97 ± 12.31° to 25.52 ± 11.83° by the 3rd months after surgery (p = 0.011). SS decreased from 35.45 ± 10.47 to 32.19 ± 11.37 in 6-month follow-up (p = 0.038), and PI dropped from 56.97 ± 14.24 to 53.19 ± 12.84 (p = 0.016). ROM of SLA decreased from 4.13 ± 3.14° to 1.93 ± 1.87° at that time point (p = 0.028). Those changes were not seen at 12-month follow-up. No evidence of adjacent vertebral disc degeneration was observed at any time point. Conclusions No sagittal imbalance, dynamic instability or adjacent vertebral degeneration was observed by the 12th month after single-segment posterior lumbar fusion with the use of unbent rods. Bending rod could be omitted in 1-level lumbar fusion to simplify the procedure and reduce operating time.

AB0970 THE RELATION BETWEEN CONGENITAL STRUCTURAL MALFORMATIONS, DISC-VERTEBRA DEGENERATION AND DISC HERNIATION IN THE PEDIATRIC AGE GROUP

Background:Disc/vertebral degeneration and disc herniation are rare causes of low back pain in childhood. Their relationship with congenital anomalies were reviewed in few studies in literature (1-3).Objectives:To examine the relation between congenital structural malformations in the lumbar spine, early degeneration and lumbar disc herniation in pediatric age group patients with low back pain, and to determine the incidence of congenital structural malformations, disc/vertebral degeneration, and disc herniation.Methods:Four hundred patients with LBP persisting for at least six weeks were included in the study. Demographic characteristics, physical examination findings, and laboratory and imaging results were recorded for all patients. Severity of pain was determined using a visual analog scale (VAS). Lumbosacral X-rays were examined for the presence of lumbosacral transitional vertebrae (LSTV) and spina bifida occulta (SBO). The incidence of disc/vertebral degeneration and disc herniation was investigated at the L4-5 and L5-S1 level in lumbosacral magnetic resonans imaging of patients with and without congenital malformation (LSTV-SBO).Results:The study population consisted of 219 girls and 181 boys aged 10-17 years (mean age 14.9±1.9). Presentation symptoms were low back pain in 90.5% (n= 362), and low back-leg pain in 9.5% (n=38). The mean VAS score was 5.3±1.0. LSTV was determined in 67 (16.8%) patients and SBO in 62 (15.5%). Disc herniation was determined in 68 patients, at the L4-5 level in 26.5% (n=18), at the L5-S1 level in 48.5% (n=33), and at both levels in 25% (n=17). Vertebral degeneration was present at the L4-5 level in 14 (8.6%) patients and at the L5-S1 level in 39 (23.9%), while disc degeneration was present at the L4-5 level in 21 (12.8%) patients and at the L5-S1 level in 31 (19.0%). No significant difference was observed in the incidence of disc/vertebral degeneration and disc herniation in patients with congenital malformation. Disc herniation was significantly more common in patients with disc degeneration (p=0.003, p<0.001). Congenital malformations were not observed in approximately 80% of patients without disc herniation and disc/vertebral degeneration.Conclusion:The presence of congenital malformations does not appear to represent a risk factor for early degeneration and disc herniation in pediatric age group. Congenital malformations, early degeneration, and disc herniation may constitute an underlying pathology in pediatric patients with persistent low back pain.References:[1]Milicić G, et al. Causal connection of non-specific low back pain and disc degeneration in children with transitional vertebra and/or Spina bifida occulta: role of magnetic resonance--prospective study. Coll Antropol. 2012.[2]Dang L, et al. Lumbar Disk Herniation in Children and Adolescents: The Significance of Configurations of the Lumbar Spine. Neurosurgery. 2015.[3]Zhang B, et al. Lumbosacral Transitional Vertebra: Possible Role inthe Pathogenesis of Adolescent Lumbar Disc Herniation. World Neurosurg. 2017.Disclosure of Interests:None declared

Effect of vertebral degeneration on the instability of spine

Insufficient exploration of the dependence between diseases of degenerative bones and the range of motion (ROM) during torsion, flexion and lateral bending limits further understanding about the lumbar biomechanics and treating of the lumbar related dysfunction. The objective of this study was to determine the effect of vertebral degradation on the instability of spine 2 motion L2–L4 segments during torsion, flexion and lateral bending by the finite element method (FEM). Three different 3D FE models comprising the healthy state and the degradation of trabecular bone and cortical bone were developed. Nonlinear numerical analyses of lumbar spine stability discovered that osteoporotic degradation can lead to critical segmental ROM and intervertebral shearing values, which results in the loss of spine stability for the case of flexion loading. Instability is caused by microscopic changes in the thickness of cortical shell. This analysis of the intervertebral shearing and ROM may be further used to diagnose such translation abnormalities like hypomobility or hypermobility.

Appendix I: Report on the Cremations from Sarn-Y-Bryn-Caled, Welshpool, Powys

The adults appear to be healthy and relatively young. None has vertebral degeneration nor any trace of osteoarthritis. There is no dental pathology. As for age deduced from dental attrition, only the primary cremation from the timber circle (site 1) and cremation 3 from site 2 have useful molar crown fragments (either first or second). Both show some flattening of die occlusal surface but with wear limited to level 3. This would give an age of 17-25 if first molars and 25-35 if second - in any case an upper limit of 35. The secondary cremation in the timber circle (site 1) and cremation 1 in the floor of the southern ditch terminal of site 2 arc young adults between 17 and 25.The sexing of cremations in general has to be prefaced with a ‘probable’ because of the absence of the relevant pelvic remains, Le. the complete girdle with sub-pubic angle, etc.