Lumbosacral Transitional Vertebra: Possible Role in the Pathogenesis of Adolescent Lumbar Disc Herniation

Lumbar disc herniation in juveniles: A case-control study of MRI characteristics and etiological insights

Lumbar disc herniation (LDH) is rare in juveniles. LDH occurring at age 20 years or younger is referred to as juvenile disc herniation (JDH). While adult LDH is regarded as an advanced stage of disc degeneration, it remains unclear why intervertebral discs rupture in youth. This study aimed to characterize magnetic resonance imaging (MRI) findings of JDH and investigate possible etiological factors. From 2013 to 2020, JDH patients and controls were identified and interviewed to assess demographics, general lifestyles, and family histories. MRIs were evaluated for disc degeneration, epiphyseal ring separation, Modic changes and endplate lesions. The relationships between JDH and suspected risk factors were examined. A total of 297 JDH patients (199 boys and 98 girls, age 17.3 ± 2.1 years) and 185 controls (age 17.1 ± 2.4 years) were studied. Age, body mass index, exposures to daily physical labor, regular exercise, and daily sitting time were similar between JDH cases and controls. A family medical history of serious back pain was more common in JDH patients than in controls (59.4% vs. 26.5%, p < 0.001), as well as family history of clinically established LDH (45.0% vs. 12.4%, p < 0.001). Epiphyseal ring separation was identified in 102 (29.2%) herniated discs in 91 (36.4%) JDH patients, while occurring in only 5 (1.4%) control participants (p < 0.001). Overall, severe disc degeneration was not a prominent finding in JDH patients. In conclusion, epiphyseal ring separation was a common magnetic resonance feature in JDH. Findings suggest a genetically mediated developmental model of JDH, rather than a model of premature disc degeneration.

Transforaminal Endoscopic Lumbar Discectomy for Lumbosacral Junction Adolescent Lumbar Disc Herniation with High Iliac Crests

Objective

To investigate the clinical results of transforaminal endoscopic lumbar discectomy for lumbosacral junction adolescent lumbar disc herniation with high iliac crest.

Methods

From February 2014 to September 2020, a retrospective analysis of 96 patients less than 21 years old with intervertebral disc herniation was carried out. We enrolled 44 patients diagnosed with lumbosacral junction disc herniation with high iliac crest who required transforaminal endoscopic lumbar discectomy. Pain in the back and the lower extremity was scored on Numeric Rating Scales (NRS) scores. Patient outcomes were graded as excellent, good, fair, and poor using modified MacNab criteria. The NRS scores before and after the operation were compared using the Wilcoxon two‐sample test.

Results

There were 30 male patients and 14 females. One patient underwent repeat surgery for an intervertebral disc pseudocyst. The NRS scores decreased significantly in both early and late follow‐up evaluations (p < 0.05). At the last follow‐up, 42 patients (95.45%) had an excellent outcome, one patient (2.27%) had a good outcome, and one patient (2.27%) had a fair outcome. The overall success rate was 97.7%.

Conclusion

This study's data suggest that targeted individualized foraminoplasty can effectively overcome the lumbosacral anatomical obstacles, and transforaminal endoscopic lumbar discectomy is an effective and valid option for lumbosacral junction adolescent lumbar disc herniation with high iliac crest.

The effect of transitional vertebrae and spina bifida occulta on disc herniation, disc degeneration, and end-plate changes in pediatric patients with low back pain

The aim of the study is to investigate the assumption whether lumbosacral transitional vertebrae (LSTV) and spina bifida occulta (SBO) cause lumbar disc herniation (LDH), intervertebral disc degeneration (IDD), and vertebral endplate changes / Modic changes (MCs) in children and adolescents with low back pain (LBP). Four hundred patients (aged 10-17) with LBP persisting for at least six weeks were included in the study. Lumbosacral X-rays were examined for the presence of LSTV and SBO. The prevalence of IDD/MCs and LDH at L4-5 and L5-S1 levels were investigated by evaluating the lumbosacral MRI of the patients with and without LSTV-SBO. The study population consisted of 219 girls and 181 boys with mean age 14.9±1.9. LSTV was determined in 67 (16.8%) patients and SBO in 62 (15.5%). No significant difference was observed in the prevalence of IDD, MCs, and LDH in patients with and without LSTV/SBO. LSTV and SBO were not observed in approximately 80% of patients without LDH and IDD/MCs. The presence of LSTV and SBO does not appear to represent a risk factor for early degeneration in lumbar spine and LDH in children and adolescents with LBP.

Role of the Lumbosacral Transition Vertebra and Vertebral Lamina in the Pathogenesis of Lumbar Disc Herniation

OBJECTIVE

To investigate the prevalence of lumbosacral transition vertebrae (LSTVs) in both the normal population and the lumbar disc herniation (LDH) population and to determine the risk factors for LDH.

METHODS

Between January 2019 and September 2020, all patients aged 18-39 years and underwent an anteroposterior (AP) X-ray of the lumbar vertebrae were retrospective reviewed in our institution. Those patients who were diagnosed with LDH were eligible for inclusion in the LDH group. During the same period, those patients admitted to our hospital who underwent an anteroposterior X-ray of the lumbar spine and had not been diagnosed with LDH were included in the control group. Those patients with disease that might affect the lumbar anatomy were excluded from both groups. The type of LSTV was classified according to the Castellvi classification. The height of the lumbar vertebral lamina was evaluated through the h/H index. The inter- and intra-observer reliability was evaluated by one senior radiologist and one senior orthopedist using intraclass correlation coefficient (ICC). The association between the LSTV and the herniation level was also investigated. Binary logistic regression was used to explore the association of different factors between the LDH group and the control group.

RESULTS

Two hundred LDH patients (115 male and 85 female) and 200 individuals (108 male and 92 female) were investigated retrospectively. The prevalence of LSTVs was 71.5% (n = 143) in the LDH group and 34.0% (n = 68) in the control group. The most frequent LSTV types were type Ib and type IIa. The inter- and intra-observer ICCs of the measurement of "h/H" index and the classification of LSTV were all "excellent" (ICC > 0.90). The median h/H index in the control group was significantly higher than that in the LDH group (0.28 (0.26, 0.31) vs 0.34 (0.31, 0.37), P = 0.000). The distribution of the Castellvi classification in the L4/5 and L5/S1 herniation patients was significantly different (P = 0.048). LSTVs, BMI and the h/H index were closely associated with LDH, with odds ratios of 3.06 (95% CI: 2.12-4.43), 1.23 (95% CI: 1.13-1.33) and 0.09 (95% CI: 0.05-0.15), respectively. The incidence of L4/5 disc herniation in patients with an LSTV was significantly more common than that in patients with L5/S1 disc herniation (P = 0.048).

CONCLUSION

The prevalence of LSTVs was 34.0% in the control group and 71.5% in the LDH group; LSTVs and BMI were positively correlated with LDH, and h/H was negatively correlated with LDH.

Lumbosacral Transitional Vertebrae in Adolescents: Effects on the Short-Term Outcomes of Percutaneous Endoscopic Lumbar Discectomy

Objective

To investigate whether lumbosacral transitional vertebrae (LSTV) affects the clinical outcomes of percutaneous endoscopic lumbar discectomy (PELD) in adolescent patients with lumbar disc herniation (LDH).

Methods

This was a retrospective study with two groups. Group A was made up of 22 adolescent LDH patients with LSTV (18 males and 4 females). Group B was made up of 44 adolescent LDH patients without LSTV (36 males and 4 females), who were matched to group A for age, sex, and body mass index. All patients underwent PELD at the L4/5 or L5/S1 single level and were followed up at 18 months after surgery. We identified LSTV on radiographs and computed tomography and assessed the imaging characteristics of all patients. Outcomes were evaluated through a numerical rating scale (NRS), the Oswestry Disability Index (ODI), the modified MacNab grading system, and the incidence of additional lumbar surgery.

Results

At 18 months after PELD, both groups had significant improvements in the mean NRS scores of low back pain (LBP) or leg pain and the ODI scores. In terms of the MacNab criteria, 90.9% in group A and 93.2% in group B showed excellent or good outcomes. The mean NRS scores of LBP or leg pain, ODI score, and MacNab grade after surgery were not significantly different between the 2 groups. Two patients (one patient had a recurrence; one patient had a new lumbar disc herniation) in group A and 3 patients (one patient had a recurrence; two patients had new lumbar disc herniations) in group B underwent additional lumbar surgery.

Conclusions

Our study suggests that in terms of pain relief, life function improvement, and the incidence of additional lumbar surgery, LSTV has no effect on the short-term clinical outcomes of PELD in adolescents. A new lumbar disc herniation is an important reason for additional surgery in adolescents, regardless of the LSTV status.

Nomograms for Predicting Recurrent Herniation in PETD with Preoperative Radiological Factors

Purpose

To investigate the preoperative radiological risk factors for recurrent lumbar disc herniation (rLDH) within 1 year after percutaneous endoscopic transforaminal discectomy (PETD).

Patients and Methods

A retrospective case–control study was conducted. Between January 2013 and November 2019, a total of 1210 patients with single-level L4/5 LDH who underwent PETD were enrolled in the present study. In total, 62 rLDH patients were diagnosed and collected based on the clinical and radiological manifestations, and 224 non-rLDH controls were selected from the remaining 1148 patients. Preoperative radiological parameters were collected and measured. An age threshold to distinguish patients into subgroups was established using the Youden index. The relationships between the risk factors and rLDH were evaluated by univariate and multivariate analyses in two subgroups. Predictive models were established based on logistic analysis. The area under the curve (AUC) of receiver operating characteristic (ROC) curves, calibration plots, and decision curve analysis (DCA) were used to assess the predictive models.

Results

In the present study, logistic analysis identified six significant predictors associated with rLDH in the young group: superior endplate concave angle (ECA), sacral slope, Modic changes, sagittal range of motion (sROM), extension intervertebral angle (IVA), and lumbar lordosis. Four significant predictors were identified in the elderly group: disc height index (DHI), retrolisthesis (posterior spondylolisthesis), sROM, and extension IVA. Validation of both models demonstrated excellent model discrimination (AUC= 0.940 and 0.946, respectively). DCA also showed excellent clinical utility and benefits.

Conclusion

The nomograms that we constructed could accurately predict individual patient recurrence risk. Individualized measures should be taken for patients of different ages with the above risk factors, and tailored postoperative surveillance of patients who underwent PETD can be planned.

Comparison of Percutaneous Endoscopic Lumbar Discectomy and Open Lumbar Discectomy in the Treatment of Adolescent Lumbar Disc Herniation: A Retrospective Analysis

OBJECTIVE

To compare and analyze efficacy and safety of percutaneous endoscopic lumbar discectomy (PELD) and open lumbar discectomy (OLD) for adolescent lumbar disc herniation.

METHODS

Clinical data of 257 patients with single-segment adolescent lumbar disc herniation who underwent surgical treatment from January 2015 to December 2019 were retrospectively collected. The patients were divided into PELD and OLD groups based on the surgical method used. Propensity score matching was performed using preoperative baseline data of patients in both groups, and some patients in both groups were selected for comparative study. Clinical and follow-up data were assessed and compared.

RESULTS

There was no statistically significant difference in preoperative baseline data between the 2 groups of patients after propensity score matching. Visual analog scale and Oswestry Disability Index scores improved in both groups postoperatively and at each follow-up time point (P < 0.05). However, visual analog scale scores on the first postoperative day and Oswestry Disability Index scores at 3 months postoperatively were lower in the PELD group than in the OLD group (P < 0.05). Duration of surgery, intraoperative blood loss, and duration of postoperative hospitalization were lower in the PELD group than in the OLD group (P < 0.05). There was no statistically significant difference between the 2 groups when comparing complication and recurrence rates (P >0.05).

CONCLUSIONS

Both PELD and OLD are effective and safe surgical techniques for treatment of adolescent lumbar disc herniation. However, compared with OLD, PELD is more advantageous for rapid symptom relief and improving postoperative quality of life with a low rate of complications and recurrence.

Musculature adaption in patients with lumbosacral transitional vertebrae: a matched-pair analysis of 46 patients

OBJECTIVE

Even though lumbosacral transitional vertebrae (LSTV) are one of the most common congenital anomalies of the spine, their effect on surrounding soft tissues is not well-studied. We therefore aimed at analyzing the association between LSTV and changes in volume, mass, symmetry, and degeneration of lumbar and trunk muscles.

MATERIALS AND METHODS

Abdomen-pelvis CT scans were analyzed in patients with LSTV and a matched control group. LSTV were classified according to the Castellvi classification. Muscles were segmented from the remaining soft tissue and their cross-sectional area and volume were examined at five defined levels. Threshold segmentation was used to differentiate between muscle fibers and fat tissue. Matched pairs were compared using Wilcoxon rank sum tests. For comparison of categorical data, chi-squared tests were performed and for associations between the degree of fusion and muscle size and degeneration, Spearman's correlation coefficients were calculated. Inter- and intrarater reliabilities were evaluated by computing intraclass correlation coefficients.

RESULTS

Forty-six patients with LSTV and 46 controls were included. Muscle volume of the paraspinal and trunk muscles was significantly lower (707.0 cm³ vs. 809.7 cm³, p < 0.001) and fatty muscle changes were significantly increased in all but the caudal paravertebral muscles of LSTV patients (M. psoas p < 0.04, M. quadratus lumborum p < 0.001, paravertebral muscles p = 0.011, M. rectus abdominis p < 0.001, M. obliquus abdominis p < 0.001). Correlations between the degree of Castellvi classification and muscle volume were significant (p = 0.001).

CONCLUSION

LSTV are associated with a reduction in muscle volume and an increase in muscle degeneration of both lumbar and trunk muscles.

The Effect of Lumbosacral Transitional Vertebrae (LSTV) on Paraspinal Muscle Volume in Patients with Low Back Pain

RATIONALE AND OBJECTIVES

To determine if psoas, multifidus, and erector spina muscle volume at intervertebral disc levels differ in patients with lumbosacral transitional vertebrae (LSTV) and low back pain (LBP), and in LBP patients without LSTV.

MATERIALS AND METHODS

This retrospective study included 101 patients that underwent lumbar spinal MRI due to LBP. The patients were divided into two groups according to the presence of LSTV, as those with LSTV (LSTV group) and those without LSTV (control group). Those in the LSTV group were classified according to Castellvi classification, and whether or not LSTV was bilateral or unilateral. The lumbar lordosis angle was measured using sagittal T2-weighted MR images. Axial T2-weighted images were used to bilaterally measure psoas, multifidus, and erector spina muscle volume at intervertebral disc levels.

RESULTS

Among the 101 participants, 33 were male (32.7%) and 68 were female (67.3%). Left multifidus muscle volume at the L4-5 level was significantly lower in the LSTV group than in the control group (p = 0.033). Right and left erector spina muscle volume at the L5-S1 level was significantly lower in the LSTV group than in the control group (right side: p = 0.010; left side: p = 0.003). The mean lumbar lordosis angle was 47.54 ± 12.69° in the LSTV group, versus 35.34 ± 11.53° in the control group (p < 0.001). There were not any significant differences in psoas, multifidus, or erector spina muscle volume between the patients with unilateral and bilateral LSTV (p > 0.05).

CONCLUSION

The present findings indicate that paraspinal muscle volume can be used to understand LSTV symptomatology.

Is Lumbosacral Transitional Vertebra Associated with Degenerative Lumbar Spinal Stenosis?

The aim of this study was to shed light on the association between lumbosacral transitional vertebra (LSTV) and degenerative lumbar spinal stenosis (DLSS). A cross-sectional retrospective study was performed on 165 individuals that were diagnosed with clinical picture of DLSS (age range: 40-88 years; sex ratio: 80M/85F) and 180 individuals without DLSS related symptoms (age range: 40-99 years; sex ratio: 90M/90F). All participants had undergone high-resolution CT scan for the lumbar region in the same position. We also used the volume rendering method to obtain three-dimensional CT images of the lumbosacral area. Both males and females in the stenosis group manifest greater prevalence of LSTV than their counterparts in the control group (P<0.001). Furthermore, the presence of LSTV increases the likelihood of degenerative spinal stenosis (odds ratio= 3.741, P<0.001). In the control group, LSTV was more common in males, and sacral slope angle of males was significantly greater in LSTV group compared to non-LSTV. This study indicates that LSTV was significantly associated with symptomatic DLSS.

Association between lumbar sacralization and increased degree of vertebral slippage and disc degeneration in patients with L4 spondylolysis

OBJECTIVE

The aim of this study was to evaluate the effect of lumbar sacralization on the level of vertebral slip and disc degeneration in patients with L4 spondylolysis.

METHODS

The authors analyzed data from 102 cases in which patients underwent surgical treatment for L4 spondylolysis and spondylolisthesis at their institution between March 2007 and September 2016. Lumbar sacralization was characterized by the presence of pseudarthrosis and/or bony fusion between the L5 transverse process and sacrum, and the type of lumbosacral transitional vertebra (LSTV) was evaluated with the Castellvi classification. The amount of vertebral slippage was measured using the Taillard technique and Meyerding grade. Degeneration of the L4-5 segment was quantified using the Pfirrmann and Modic classifications. Patients were divided into 2 groups based on the presence or absence of sacralization, and the amount of vertebral slip and degeneration of the L4-5 segment was compared between groups.

RESULTS

Lumbar sacralization was present in 37 (36%) of 102 patients with L4 spondylolysis. The LSTV was type IIa in 10 cases, type IIb in 7, type IIIa in 2, and type IIIb in 18. The levels of vertebral slip and disc degeneration in the group of patients with sacralization were significantly greater than in the group without sacralization. No significant difference was found between the 2 groups with respect to Modic changes.

CONCLUSIONS

The increased stability between a sacralized L5 and the sacrum may predispose the L4-5 segment to greater instability and disc degeneration in patients with L4 spondylolysis.