A review of lumbosacral transitional vertebrae and associated vertebral numeration

A Whole Spine MRI Based Study of the Prevalence, Associated Disc Degeneration and Anatomical Correlations of Lumbosacral Transitional Vertebra

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

Lumbosacral transitional vertebra (LSTV) results in numerical alterations of the lumbar and sacral segments. Literature concerning true prevalence, associated disc degeneration, and variation in numerous anatomical landmarks concerning LSTV is lacking.

METHODS

This is a retrospective cohort study. The prevalence of LSTV was determined in whole spine MRIs of 2011 poly-trauma patients. LSTV was identified as sacralization (LSTV-S) or lumbarization (LSTV-L) and further sub-classified into Castellvi's and O'Driscoll's type respectively. Disc degeneration was evaluated using Pfirmann grading. Variation in important anatomical landmarks was also analysed.

RESULTS

Prevalence of LSTV was 11.6% with 82% having LSTV-S. Castellvi's type 2A and O'Driscoll type 4 were the commonest sub-types. LSTV patients demonstrated considerably advanced disc degeneration. The median termination level of conus medullaris (TLCM) in non- LSTV and LSTV-L groups was at middle L1 (48.1% and 40.2%) while in the LSTV-S group, it was at upper L1 (47.2%). The median level of right renal artery (RRA) in non- LSTV patients was at middle L1 in 40.0% of individuals while in the LSTV-L and LSTV-S groups, it was at upper L1 level in 35.2% and 56.2% respectively. The median level of abdominal aortic bifurcation (AA) in non-LSTV and LSTV-S patients was at middle L4 in 83.3% and 52.04% respectively. However, in the LSTV-L group, the most common level was middle L5 (53.6%).

CONCLUSION

The overall prevalence of LSTV was 11.6%, with sacralization accounting for more than 80%. LSTV is associated with disc degeneration and a variation in the levels of important anatomical landmarks.

The Clinical Significance of Lumbar Transverse Process Lengths Associated with Lumbosacral Transitional Vertebrae: A Landmark for Lumbar Spine Enumeration

OBJECTIVE

This study aimed to identify which lumbar vertebral level above a lumbosacral transitional vertebra (LSTV) demonstrated the longest transverse process (TVP) lengths.

METHODS

In this exploratory quantitative osteological cohort study using a digital Vernier caliper, dried human cadaveric lumbar TVPs were measured for linear horizontal length at each lumbar vertebra, left and right sides. Data collection was conducted in South Africa at the Raymond A. Dart Collection of Modern Human Skeletons and the Pretoria Bone Collection. The LSTV cohort consisted of 110 spinal columns and an LSTV-free control cohort of a sex-balanced randomized selection of 30 male and 30 female spinal columns.

RESULTS

Compared with the control cohort, the LSTV cohort demonstrated longer TVPs for every vertebral level, particularly L3, while the left side demonstrated longer TVPs overall. There were no statistical differences in TVP length within the LSTV cohort when comparing all levels (P > 0.05). The L3 TVPs demonstrated the longest mean lengths in both control (65%) and LSTV (58%) cohorts. The general trend was that the TVPs of L3 had the longest mean length for both the left and the right sides in both cohorts and both sexes.

CONCLUSIONS

In the absence of whole-spine imaging, these findings indicate that L3 TVPs may offer an alternative bony landmark, which may aid in spinal enumeration estimation in the setting of LSTV. This is of value for radiograph appraisal and may aid with correct-level intervention.

3D U-Net Neural Network Architecture-Assisted LDCT to Acquire Vertebral Morphology Parameters: A Vertebral Morphology Comprehensive Analysis in a Chinese Population

To evaluate the feasibility of acquiring vertebral height from chest low-dose computed tomography (LDCT) images using an artificial intelligence (AI) system based on 3D U-Net vertebral segmentation technology and the correlation and features of vertebral morphology with sex and age of the Chinese population. Patients who underwent chest LDCT between September 2020 and April 2023 were enrolled. The Altman and Pearson's correlation analyses were used to compare the correlation and consistency between the AI software and manual measurement of vertebral height. The anterior height (Ha), middle height (Hm), posterior height (Hp), and vertebral height ratios (VHRs) (Ha/Hp and Hm/Hp) were measured from T1 to L2 using an AI system. The VHR is the ratio of Ha to Hp or the ratio of Hm to Hp of the vertebrae, which can reflect the shape of the anterior wedge and biconcave vertebrae. Changes in these parameters, particularly the VHR, were analysed at different vertebral levels in different age and sex groups. The results of the AI methods were highly consistent and correlated with manual measurements. The Pearson's correlation coefficients were 0.855, 0.919, and 0.846, respectively. The trend of VHRs showed troughs at T7 and T11 and a peak at T9; however, Hm/Hp showed slight fluctuations. Regarding the VHR, significant sex differences were found at L1 and L2 in all age bands. This innovative study focuses on vertebral morphology for opportunistic analysis in the mainland Chinese population and the distribution tendency of vertebral morphology with ageing using a chest LDCT aided by an AI system based on 3D U-Net vertebral segmentation technology. The AI system demonstrates the potential to automatically perform opportunistic vertebral morphology analyses using LDCT scans obtained during lung cancer screening. We advocate the use of age-, sex-, and vertebral level-specific criteria for the morphometric evaluation of vertebral osteoporotic fractures for a more accurate diagnosis of vertebral fractures and spinal pathologies.

Lumbar sacralization and L4-L5 microdiscectomy, a prospective cohort study on radiologic and clinical outcomes

Aim

To evaluate the role of lumbar sacralization (LS) on the surgical outcomes of L4-L5 microdiscectomy.

Methods

This prospective cohort study was conducted in a university referral hospital. The patients with L4-L5 disc herniation and eligible for microdiscectomy were enrolled and allocated in G1 (with LS) and G2 (no LS). After the L4-L5 microdiscectomy patients were followed, clinical and radiological parameters were collected to investigate the influence on the outcomes. Recurrence, low back outcome score (LBOS), and the Oswestry disability index (ODI) were defined as main outcomes.

Results

Two hundred and forty patients (n = 120, each), were reviewed in the final analysis. There was no difference between groups regarding baseline characteristics. Postoperative radicular and back pain was more severe in LS(P < 0.05). Univariate analysis showed recurrence was significantly higher in LS with a direct correlation with postoperative back pain persistence and low LBOS (p = 0.001). Age had a negative impact on G2 recurrence(p = 0.008). LS had a negative impact on LBOS and ODI scores. Postoperative radicular pain and higher lumbar lordosis were associated with a higher disability (ODI) index.

Conclusion

L4-L5 microdiscectomy in patients with lumbar sacralization was associated with higher recurrence rates, worse ODI and LBOS scores, persistent postoperative axial back pain, and radicular pain. Postoperative axial back pain and poor LBOS results could effectively predict a higher recurrence rate following L4-L5 microdiscectomy in lumbar sacralization.

Analysis of Spinopelvic Parameters and Lumbar Lordosis in Patients with Transitional Lumbosacral Vertebrae, with Special Reference to Sacralization and Lumbarization

BACKGROUND

Transitional lumbosacral vertebra presents in 2 forms based on its origin: sacralization and lumbarization. These patients have 2 options for sacral endplates (upper and lower) and consequently, 2 sets of values for spinopelvic parameters and lumbar lordosis (LL). This study aimed to evaluate these parameters in asymptomatic patients with sacralization and lumbarization and compare them with each other and normative values.

METHODS

Spinopelvic parameters and LL according to upper and lower endplate were measured using abdominal computed tomography in 1420 asymptomatic patients, of which 108 had Transitional lumbosacral vertebra. These parameters were compared among patients with lumbarization and sacralization and with normal controls. In addition, correlations between the upper and lower endplate parameters were determined.

RESULTS

As compared to the control group, upper endplate measurements yielded lower spinopelvic parameters and LL values while lower endplate values yielded higher values. While these values were significantly different from normative values, these parameters were similar in both lumbarization and sacralization groups. Furthermore, most spinopelvic parameters of both upper and lower endplates were strongly correlated, and the differences between the upper and lower PI and LL values are relatively constant (27° and 14°, respectively.

CONCLUSIONS

Upper and lower endplate parameters are comparable in patients with sacralization and lumbarization; therefore, the average spatial position of a sacralized L5 and a lumbarized S1 within the pelvis is similar and either parameter can be used for radiological measurements. Further studies with symptomatic patients are warranted to confirm these results.

Comparison of whole trunk muscle mass between healthy and lumbar herniated nucleus pulposus patients using abdominal pelvic computed tomography

Background

Paraspinal muscle asymmetry is associated with low back pain (LBP) problems. This study aimed to analyze skeletal muscle areas around the lumbar vertebra and compare the ratio of anterior and posterior muscles between patients with lumbar herniated nucleus pulposus (HNP) and healthy individuals using abdominal pelvic computed tomography (APCT).

Methods

After propensity score matching, 122 HNP patients and 122 non-HNP individuals were finally used for analyses. In APCT, axial cut images were collected at the level of the third lumbar vertebra lower end plate and only the muscle structure was obtained. After obtaining the muscular portion of their image, we measured the skeletal muscle area (SMA). Second, for analysis relation of sarcopenia and HNP, the status of low skeletal muscle mass was determined using a previously reported criteria based on APCT scans in the Republic of Korea.

Results

From the analysis of the anterior-posterior muscles, the ratio of anterior SMA was statistically significantly larger in the HNP group than in the non-HNP group. Regarding the anatomical classification of trunk muscles, a statistically significant left-right imbalance to peripheral muscle in HNP men was observed. Regarding the status of low skeletal muscle mass, no statistical difference in prevalence between the two groups were observed. Moreover, no statistical difference in the prevalence of low skeletal muscle mass obesity was observed.

Conclusion

The lumbar flexor muscle was larger in HNP than others, showing trunk muscle imbalance. However, low skeletal muscle mass is not associated with HNP.

The anatomical feasibility of anterior intra- and extra-bifurcation approaches to L5-S1: an anatomic study based on lumbar MRI

BACKGROUND CONTEXT

The anterior approach at L5-S1 has many advantages, however, vascular complications are challenging for spinal surgeons who may not be familiar with the variability of vascular anatomy. There are three different anterior approaches (intra-bifurcation approach and extra-bifurcation: left-, and right-sided prepsoas approaches) described in previous studies to respond to the variability of anterior vascular anatomy for reduction in vascular injury, while no guidance for the choice of approach preoperatively.

PURPOSE

To analyze the anatomical feasibility of three anterior approaches to access the L5-S1 disc space according to a practical framework.

STUDY DESIGN

Retrospective study.

PATIENT SAMPLE

Lumbar magnetic resonance imaging (MRI) from patients who visited our outpatient clinic were reviewed, with 150 cases meeting the inclusion criteria.

OUTCOME MEASURES

The following radiographic parameters were measured on axial T2-weighted MRI at the lower endplate of L5 and the upper endplate of S1: width of the vascular corridor, position of the left and right common iliac vein (CIV), and presence of perivascular adipose tissue (PAT). Moreover, we designed a safe line to evaluate the feasibility of left- and right-sided prepsoas approaches. Cases of lumbosacral transitional vertebrae were identified.

METHODS

The feasibility of the intra-bifurcation approach was determined by the width of the vascular corridor, presence of PAT, and the position of the CIV. The feasibility of the prepsoas approach was determined by the relative position of the CIV to the safe line, presence of PAT, and the intersection point of the CIV and vertebral body.

RESULTS

Sixty-eight percent, 64.7%, and 75.3% cases allowed the intra-bifurcation, left-, and right-sided prepsoas approach to L5-S1, respectively. The cases in this study had at least one of three anterior approaches to access L5-S1 disc space, and 74% of cases had more than one anatomical feasibility of anterior approach. The right-sided prepsoas approach was feasible in the majority of cases because of the vertical course of the right CIV with a significantly higher proportion of presence of PAT. Patients with lumbosacral transitional vertebrae (24 cases) may prefer the prepsoas approaches, and only six cases (25.0%) were determined to be feasible for the intra-bifurcation approach.

CONCLUSIONS

Our study proposes a practical framework to determine whether the three different anterior approaches are feasible access at L5-S1. According to the framework, all cases had the anatomical feasibility of using an anterior approach to access L5-S1, and three-fourths of cases had a replaceable anterior approach when encountering intraoperative difficulties.

First description of frequent occurrence of supernumerary lumbar ribs and transitional vertebrae in children with Williams-Beuren syndrome

BACKGROUND

Williams-Beuren syndrome is a rare multisystemic genetic disorder with an incidence of 1 in 7,500 live births. Because these children often have scoliosis, they undergo routine radiographic examinations of the spine. During these examinations we have found many children with supernumerary lumbar ribs arising from the first lumbar vertebra, often associated with lumbosacral transitional vertebrae.

OBJECTIVE

To describe the incidence of supernumerary ribs and transitional vertebrae in children with Williams-Beuren syndrome and compare it to the incidence in a general population. Our hypothesis is that these findings are common, but they have not been described in the literature concerning Williams-Beuren syndrome.

MATERIALS AND METHODS

From January 2015 to October 2021, 308 patients (138 male) with Williams-Beuren syndrome were treated at our hospital. Of these, 106 (47 male) underwent diagnostic imaging, mostly for suspected scoliosis. Panoramic radiographs of the whole spine were performed in 88 patients and radiographs of regions of the spine, chest radiographs, CT, MRI or fluoroscopy in 18 patients. We retrospectively analysed the images concerning the number of ribs and vertebrae. We correlated the frequency of lumbar ribs and transitional vertebrae in comparison to a general population as described in the literature.

RESULTS

After exclusions for insufficient imaging, we analysed imaging in 91 patients. Of these, 67 patients (73.6%) had 13 ribs, of which 85% were located on both sides, 9% on the right and 6% on the left side. Of the 67 patients with supernumerary lumbar ribs, 38 (57%) also had transitional vertebrae.

CONCLUSION

Supernumerary lumbar ribs arising from the first lumbar vertebra, often accompanied by lumbosacral transitional vertebrae, are common in children with Williams-Beuren syndrome.

Anterior spinal fusion (ALIF/OLIF/LLIF) with lumbosacral transitional vertebra: A systematic review and proposed treatment algorithm

•Key anterior approaches differences in LSTV include vascular (aortic bifurcation/iliocaval confluence), muscular (psoas) and osseus anatomy (inter-crestal tangent/pubic symphysis), when compared to non-LSTV.•There are increased surgical deviations but not significantly greater complications for anterior approaches in LSTV.•Vascular awareness while accessing L45 will be in the presence of a more cephalad ABF and ICC with sacralized L5, and access to the deeper L56 level will be in the presence of a more caudal ABF and ICC in lumbarized S1.

If you look this way, you will see it: cranial shift in adolescent idiopathic scoliosis

INTRODUCTION

Anatomical variations in the spine can be seen in each transitional border, either toward the skull as 'cranial shifts' or away as caudal shifts. Cranial shifting (CS) occurs when there is presence of occipitalization, C7 cervical costae or prominent transverse processes, thoracolumbar transitional vertebrae (TLTV) at T12 level, L5 sacralization, and sacrococcygeal fusion. We termed the coexistence of sacralization of L5 and absence or remarkable reduction of T12 rib size in AIS as Abul cranial shift (ACS). In this descriptive clinical study, primary aim was to investigate the incidence of ACS in AIS.

METHODS

Retrospective analysis of 187 surgically treated AIS cases was performed. Demographic data were recorded. The incidence of the specific set of anatomic variations including lumbosacral transitional vertebrae, TLTV, transverse process changes in C7 vertebrae, and posterior lumbosacral neural arch cleft formations (NACf) were evaluated in the radiological images.

RESULTS

36 (19%) of 187 cases had ACS. ACS was detected in only 1 of 19 male cases (5%), while in 35 of 168 female cases (21%). Forty-one cases had sacralization of L5 (22%). There were only eleven pair of ribs in 14 (7%) of 187 cases and 10 (28%) of 36 ACS cases. Forty cases had NACf (21%). ACS and NACf coexistence were observed in 8 (22%) of 36 ACS cases.

CONCLUSION

Accurate spinal column assessment is critical in adolescent idiopathic scoliosis (AIS). ACS may be observed in up to one in five AIS cases and its presence should not be neglected to avoid wrong level surgery.

Prevalence of lumbosacral transitional vertebra among 4816 consecutive patients with low back pain: A computed tomography, magnetic resonance imaging, and plain radiographic study with novel classification schema

Study Design

A retrospective single-center study.

Background

The prevalence of the lumbosacral anomalies remains controversial. The existing classification to characterize these anomalies is more complex than necessary for clinical use.

Purpose

To assessment of the prevalence of lumbosacral transitional vertebra (LSTV) in patients with low back pain and the development of clinically relevant classification to describe these anomalies.

Materials and Methods

During the period from 2007 to 2017, all cases of LSTV were preoperatively verified, and classified according to Castellvi, as well as O'Driscoll. We then developed modifications of those classifications that are simpler, easier to remember, and clinically relevant. At the surgical level, this was assessed intervertebral disc and facet joint degeneration.

Results

The prevalence of the LSTV was 8.1% (389/4816). The most common L5 transverse process anomaly type was fused, unilaterally or bilaterally (48%), to the sacrum and were O'Driscoll's III (40.1%) and IV (35.8%). The most common type of S1-2 disc was a lumbarized disc (75.9%), where the disc's anterior-posterior diameter was equal to the L5-S1 disc diameter. In most cases, neurological compression symptoms (85.5%) were verified to be due to spinal stenosis (41.5%) or herniated disc (39.5%). In the majority of patients without neural compression, the clinical symptoms were due to mechanical back pain (58.8%).

Conclusions

LSTV is a fairly common pathology of the lumbosacral junction, occurring in 8.1% of the patients in our series (389 out of 4,816 cases). The most common types were Castellvi's type IIA (30.9%) and IIIA (34.9%) and were O'Driscoll's III (40.1%) and IV (35.8%).

Definition of normal vertebral morphometry using NHANES‐II radiographs

A robust definition of normal vertebral morphometry is required to confidently identify abnormalities such as fractures. The Second National Health and Nutrition Examination Survey (NHANES‐II) collected a nationwide probability sample to document the health status of the United States. Over 10,000 lateral cervical spine and 7,000 lateral lumbar spine X‐rays were collected. Demographic, anthropometric, health, and medical history data were also collected. The coordinates of the vertebral body corners were obtained for each lumbar and cervical vertebra using previously validated, automated technology consisting of a pipeline of neural networks and coded logic. These landmarks were used to calculate six vertebral body morphometry metrics. Descriptive statistics were generated and used to identify and trim outliers from the data. Descriptive statistics were tabulated using the trimmed data for use in quantifying deviation from average for each metric. The dependency of these metrics on sex, age, race, nation of origin, height, weight, and body mass index (BMI) was also assessed. There was low variation in vertebral morphometry after accounting for vertebrae (eg, L1, L2), and the R² was high for ANOVAs. Excluding outliers, age, sex, race, nation of origin, height, weight, and BMI were statistically significant for most of the variables, though the F‐statistic was very small compared to that for vertebral level. Excluding all variables except vertebra changed the ANOVA R² very little. Reference data were generated that could be used to produce standardized metrics in units of SD from mean. This allows for easy identification of abnormalities resulting from vertebral fractures, atypical vertebral body morphometries, and other congenital or degenerative conditions. Standardized metrics also remove the effect of vertebral level, facilitating easy interpretation and enabling data for all vertebrae to be pooled in research studies. © 2022 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.

Lumbosacral Transitional Vertebra Contributed to Lumbar Spine Degeneration: An MR Study of Clinical Patients

We aimed to comprehensively characterize degenerative findings associated with various types of lumbosacral transitional vertebra (LSTV) on magnetic resonance images. Three hundred and fifty patients with LSTV (52.3 ± 10.9 years), including 182 Castellvi type I, 107 type II, 43 type III, and 18 type IV, and 179 controls without LSTV (50.6 ± 13.1 years), were studied. Discs, endplates, and posterior vertebral structures were assessed and compared to those of controls for the most caudal three discs on MRIs. There were no differences in degenerative findings between patients with type I LSTV and controls. For types III and IV, the transitional discs had smaller sizes, lower Pfirrmann scores, and lower rates of disc bulging (2.3% and 5.6% vs. 39.1%), osteophytes (2.3% vs. 15.1%), disc herniation (2.3% and 5.6% vs. 31.8%), and Modic changes (2.3% and 5.6% vs. 16.8%) than controls. However, the cranial discs had more severe Pfirrmann scores, disc narrowing and spinal canal narrowing, and greater rates of disc herniation (41.9% and 50.0% vs. 25.7%), endplate defects (27.9% and 33.3% vs. 14.4%) and spondylolisthesis (18.6% vs. 7.3%) than controls. Type II LSTV was associated with degenerative findings in the cranial segments but to a lesser degree, as compared with type III/IV LSTV. Thus, Castellvi type III/IV LSTV predisposed the adjacent spinal components to degeneration and protected the transitional discs. Type II LSTV had significant effects in promoting transitional and adjacent disc degeneration. Type I LSTV was not related to spinal degeneration.

The morphological consequences of segmentation anomalies in the human sacrum

OBJECTIVES

Despite the high frequency of segmentation anomalies in the human sacrum, their evolutionary and clinical implications remain controversial. Specifically, inconsistencies involving the classification and counting methods obscure accurate assessment of lumbosacral transitional vertebrae. Therefore, we aim to establish more reliable morphological and morphometric methods for differentiating between sacralizations and lumbarizations in clinical and paleontological contexts.

MATERIALS AND METHODS

Using clinical CT data from 145 individuals aged 14-47 years, vertebral counts and the spatial relationship between the sacrum and adjoining bony structures were assessed, while the morphological variation of the sacrum was assessed using geometric morphometrics based on varied landmark configurations.

RESULTS

The prevalence of lumbosacral and sacrococcygeal segmentation anomalies was 40%. Lumbarizations and sacralizations were reliably distinguishable based on the spatial relationship between the iliac crest and the upward or downward trajectory of the linea terminalis on the sacrum. Different craniocaudal orientations of the alae relative to the corpus of the first sacral vertebra were also reflected in the geometric morphometric analyses. The fusion of the coccyx (32%) was frequently coupled with lumbarizations, suggesting that the six-element sacra more often incorporate the coccyx rather than the fifth lumbar vertebra.

CONCLUSIONS

Our approach allowed the consistent identification of segmentation anomalies even in isolated sacra. Additionally, our outcomes either suggest that homeotic border shifts often affect multiple spinal regions in a unidirectional way, or that sacrum length is highly conserved perhaps due to functional constraints. Our results elucidate the potential clinical, biomechanical, and evolutionary significance of lumbosacral transitional vertebrae.

Quantitative measurements at the lumbosacral junction are more reliable parameters for identifying and numbering lumbosacral transitional vertebrae

OBJECTIVES

To evaluate quantitative parameters to identify the anatomic variation lumbosacral transitional vertebrae (LSTV) and compare them with the landmarks commonly used at present.

METHODS

A total of 2,845 PET/CT scans were reviewed, and the patients with 23 and 25 presacral vertebrae were included. The quantitative parameters, including the anterior-edge vertebral angle (AVA) of the lowest lumbar-type vertebra, the ratio of the length of the inferior endplate to that of the superior endplate (RISE) of the uppermost sacral-type vertebra and the lumbosacral intervertebral disc angle (LSIVDA), and the anatomical landmarks, including the iliac crest tangent (ICT) level, the iliolumbar ligament (ILL) origin level and psoas proximal insertion, were all evaluated to determine their ability to identify LSTV.

RESULTS

The values of AVA and RISE were significantly different between the LSTV group and the control group, and between subgroups of LSTV. The cutoff value for AVA was 73.0°, with an accuracy, sensitivity, and specificity of 91.1%, 77.5%, and 88.3%, and that for RISE was 0.79, with an accuracy, sensitivity, and specificity of 90.3%, 77.5%, and 94.2%, while that for LSIVDA was 14.15°, with an accuracy, sensitivity, and specificity of 75.9%, 65.7%, and 78.3%, to differentiate L5 sacralization from S1 lumbarization. For differentiating the controls from LSTV, the accuracy, sensitivity, and specificity of the ICT level and proximal psoas insertion were 78.0%, 70.2%, and 95.0%, versus 71.7%, 61.7%, and 94.0%.

CONCLUSIONS

Compared with the anatomical landmarks, the quantitative measurements at the lumbosacral junction, including AVA and RISE, may be more helpful for differentiating subgroups of LSTV especially if only lumbar spine imaging is available.

KEY POINTS

• The quantitative parameters, the anterior-edge vertebral angle (AVA) of the lowest lumbar-type vertebra and the ratio of the length of the inferior endplate to that of the superior endplate (RISE) of the uppermost sacral-type vertebra, are more helpful for distinguishing L5 sacralization from S1 lumbarization than the previously proposed anatomic landmarks. • AVA and RISE represent relevant changes in the curvature at the lumbosacral region and the shape of the transitional vertebral body, respectively. • AVA and RISE are easily assessed, with high intra- and inter-reader reliability.

Anterior column reconstruction of the lumbar spine in the lateral decubitus position: anatomical and patient-related considerations for ALIF, anterior-to-psoas, and transpsoas LLIF approaches

PURPOSE

Circumferential (AP) lumbar fusion surgery is an effective treatment for degenerative and deformity conditions of the spine. The lateral decubitus position allows for simultaneous access to the anterior and posterior aspects of the spine, enabling instrumentation of both columns without the need for patient repositioning. This paper seeks to outline the anatomical and patient-related considerations in anterior column reconstruction of the lumbar spine from L1-S1 in the lateral decubitus position.

METHODS

We detail the anatomic considerations of the lateral ALIF, transpsoas, and anterior-to-psoas surgical approaches from surgeon experience and comprehensive literature review.

RESULTS

Single-position AP surgery allows simultaneous access to the anterior and posterior column and may combine ALIF, LLIF, and minimally invasive posterior instrumentation techniques from L1-S1 without patient repositioning. Careful history, physical examination, and imaging review optimize safety and efficacy of lateral ALIF or LLIF surgery. An excellent understanding of patient spinal and abdominal anatomy is necessary. Each approach has relative advantages and disadvantages according to the disc level, skeletal, vascular, and psoas anatomy.

CONCLUSIONS

A development of a framework to analyze these factors will result in improved patient outcomes and a reduction in complications for lateral ALIF, transpsoas, and anterior-to-psoas surgeries.

[Analysis of unfavorable postoperative outcomes in patients with lumbosacral junction anomalies]

BACKGROUND

The absence of a unified diagnostic approach and heterogeneous treatment strategies in patients with lumbosacral transitional vertebra contribute to registration of contradictory data on postoperative outcomes in these patients.

OBJECTIVE

A retrospective analysis of postoperative outcomes in patients with degenerative lumbar spine diseases associated with lumbosacral junction anomalies and causes of unfavorable results.

MATERIAL AND METHODS

Lumbosacral transitional vertebra was preoperatively verified and classified according to Castellvi A.E. in 352 cases between 2007 and 2017. Full-time examination, phone and e-mail survey covered 314 (89.2%) patients throughout 5.2-year follow-up period. There were unfavorable clinical outcomes in 42 cases. We analyzed the causes of these results and relationship of surgical strategy with the type of lumbosacral junction anomaly.

RESULTS

Lumbosacral transitional vertebra Castellvi type IIA (30.9%) and IIIA (34.9%) prevailed. Unfavorable outcomes occurred in 7 cases after percutaneous interventions, in 12 patients after decompression surgery and in 23 patients after decompression and stabilization procedures. In all cases (n=42), redo surgery was performed: rigid fixation or extension of stabilization system in 16 cases, additional intracanal decompression in 10 patients, foraminal/extraforaminal decompression in 8 patients. Seven patients underwent repeated laser denervation. Of these, 5 patients underwent dorsal decompression without discectomy due to ineffective denervation. Correlation analysis showed the relationship between unfavorable outcomes after percutaneous procedures with L_V transverse process dysplasia and sacralization, decompressive interventions with additional articular joints and lumbarization, decompression/stabilization procedures with L_V transverse process dysplasia and sacralization.

CONCLUSION

Unfavorable outcomes occurred after percutaneous interventions for anomaly type IB and IIIB, decompressive procedures for anomaly type IIA, IIB and IV, decompression/ stabilization procedures for types IA and IIIA. It is the first report devoted to analysis of relationships between unsatisfactory postoperative outcomes, surgical technique and type of lumbosacral dysgenesis.

Diagnostic treatment-level discrepancies in patients with lumbosacral radicular pain and lumbar spine anomalies

BACKGROUND

Lumbosacral transitional vertebra can result in an anomalous number of lumbar vertebrae associated with wrong level treatment. The primary aim of this study was to characterize discrepancies between reported referring levels and levels from MRI reports with treated levels. The secondary aim was to analyze interobserver variability between a pain physician and a radiologist when determining levels and classifying lumbosacral transitional vertebrae.

METHODS

Between February 2016 and October 2019, a retrospective case series of prospectively collected data of the affected levels mentioned in referrals, MRI reports and treated levels was performed. The counting process, level determination, classification of lumbosacral transitional vertebrae and a secondary control were carried out by independent researchers using a standard methodology.

RESULTS

Of the 2443 referrals, 143 patients had an anomalous number of lumbar vertebrae; of these, 114 were included for analysis. The vertebral level noted in the patient's file, in the referral, and the reported level of treatment differed in 40% of these cases. The vertebral level between the MRI reports and treatment differed in 46% of cases. The interobserver reliability (radiologist vs pain physician) for classifying a transitional vertebra was fair ((κ=0.40) and was substantial (κ=0.70) when counting the vertebrae.

CONCLUSION

In the presence of lumbar spine anomalies, we report a high prevalence of discrepancies between referral levels and MRI pathological findings with treatment levels. Further research is needed to better understand clinical implications.

Association between lumbosacral transitional vertebrae and spinal pathologies based on T2 whole-spine sagittal magnetic resonance imaging

PURPOSE

To assess the association between 4, 5, or 6 lumbar spine vertebrae and the presence of lumbar spinal pathologies.

METHODS

We reviewed all MRI reports and images performed between August 1st, 2018 and July 31st, 2019. Lumbar spine pathologies such as disc herniation, lytic spondylolisthesis, and spinal stenosis were recorded. The reviewer studied the T2 sagittal screening of the entire spine and counted down manually from C2 to T12 on the assumption that there are seven cervical and twelve dorsal vertebrae. We then recorded whether there were four, five, or six lumbar vertebrae.

RESULTS

Our work incorporated a total of 1985 patients for whom T2-weighted entire spine sagittal MR images were obtainable. The study cohort's average age was 52.2 ± 15.9 years, comprising 944 males and 1041 females. One hundred and thirty-three patients (6.7%) had 4 lumbar-type vertebrae; 1799 (90.6%) had 5 lumbar-type vertebrae; and 53 (2.7%) had 6 lumbar-type vertebrae. There was a statistically significant difference between the rates of 6 lumbar-type vertebrae in males versus females (p < 0.05). There was a statistically significant difference with more spinal stenosis patients in the 6 lumbar-type vertebrae compared to the 4 or 5 lumbar-type vertebrae groups (p < 0.001).

CONCLUSION

Our study shows that spinal stenosis is significantly more common in patients with 6 lumbar-type vertebrae.

Establishing a common language for lumbar transforaminal epidural steroid injections

BACKGROUND

Patients presenting to spine surgeons for lumbar radiculopathy often undergo initial conservative treatment including medications, therapy, and lumbar transforaminal epidural steroid injections. Despite a growing number of spinal injections performed, there is a lack of available data regarding the occurrence of wrong-site injections. However, when examined, the discrepancies between ordering level and level of epidural steroid injection performed are immense. To aid with this issue, we propose that instead of ordering a lumbar transforaminal epidural steroid injections at a given level, it should be ordered to address a specific nerve root with laterality. This has the potential to reduce wrong-site procedures and improve patient outcomes.

METHODS

Retrospective chart review of 60 patients at a private orthopaedic spine practice under the care of spine surgeons or physician assistants over a 1-year period. The progress note, injection order form, procedure note, and procedural fluoroscopy were reviewed. If there were inconsistencies between one or more of these steps, it was deemed a failure. Results were analyzed to assess for any differences in outcomes between the two groups. We calculated our sample size prior to the study and powered it at 90%; descriptive statistics, Chi-square, Fisher's exact test, Student's t-test, and Wilcoxon rank sum tests were used where appropriate utilizing SAS v9.4.

RESULTS

Thirty-seven patients (37/60, 61.6%) were considered a failure. There were no failures when ordering an S1 nerve root injection. We identified one wrong-site procedure and one wrong-level order that was identified and corrected by the interventionalist.

CONCLUSIONS

There were multiple inconsistencies identified at various steps in the injection ordering process. This indicates a need to standardize the language used in this process to avoid wrong-site procedures. There were no inconsistencies in ordering an S1 injection, likely because this injection could only be ordered at the nerve root. It is also critical to utilize and save a localization film to ensure accuracy and accountability. We propose indicating the affected nerve root in all cases rather than the level of disc pathology would avoid confusion.

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.

Changes in Lumbosacral Anatomy and Vertebral Numbering in Patients with Thoracolumbar and/or Lumbosacral Transitional Vertebrae

The presence of a thoracolumbar transitional vertebra (TLTV) and/or lumbosacral transitional vertebra (LSTV) may cause wrong-site surgery and problems while measuring spinopelvic parameters, including pelvic incidence and lumbar lordosis. The Castellvi classification of LSTV addresses coronal images but not sagittal or axial images. Therefore, it is unclear how LSTV differs from the normal lumbosacral anatomy. We aimed to investigate the lumbosacral anatomy and vertebral numbering in patients with TLTV and/or LSTV. We performed computed tomography (CT) to identify TLTV, to number presacral vertebrae accurately, and to analyze morphological differences in each LSTV type.

Vascular anatomy and surgical approach in oblique lateral interbody fusion at lumbosacral transitional vertebrae

BACKGROUND

Oblique lateral interbody fusion (OLIF) at lumbosacral junction is typically performed on the central window between the bifurcations of iliac vessels. However, the central window of lumbosacral transitional vertebrae (LSTVs) is usually obstructed by the iliocaval venous structures. We aimed to describe the vascular anatomy and surgical approach in OLIF at LSTVs compared with those in OLIF at typical L5-S1 junction.

METHODS

Sixty-eight consecutive patients who underwent OLIF at lumbosacral junction were included. Of these, 31 patients had LSTVs and 37 patients had typical L5-S1 junction. The position of the iliocaval junction and the configuration of the left common iliac vein were compared using the preoperative CT and MR images of the lumbar spine. The surgical approach and intraoperative vascular findings were analyzed.

RESULTS

Almost 70% of LSTVs had the iliocaval junction at low or very low position. Mobilization of left common iliac vein for central window was potentially difficult in almost 74% of OLIF at LSTVs while it was not required or was potentially easy in almost 80% of OLIF at typical L5-S1. Vascular injury was identified in 2 (6.5%) patients with OLIF at LSTVs and in 3 (8.1%) patients with OLIF at typical L5-S1 junction (P = 0.904).

CONCLUSIONS

In our series, OLIF at LSTVs was performed through lateral window in 93.5% of the cases. Preoperative evaluation of the iliocaval junction using CT/MR of lumbar spine was reliable and valid in the determination of OLIF approach at lumbosacral junction.

Extra-articular Portion of the Sacroiliac Joint-Between the Sacral and Pelvic Tuberosities: An Anatomical Guide for the S2-Alar-Iliac Screw Trajectory

STUDY DESIGN

A novel technique for S2-alar-iliac (S2AI) screw placement was analyzed.

OBJECTIVES

Accurate confirmation of the S2AI screw trajectory with free-hand techniques is not simple, although some anatomical landmarks have been reported. To overcome the drawback, we aimed to introduce our technique for S2AI screw placement assisted with a guidewire using a new anatomical landmark.

METHODS

A total of 104 S2AI screws of 52 patients who underwent S2AI screw placement were investigated. Navigation software was used to simulate S2AI screw placement preoperatively. Screw placement was performed with the nonfluoroscopic free-hand technique. In this technique, a guidewire is inserted into the ilium from the extra-articular portion of the sacroiliac joint just lateral to the ideal screw entry point toward the tip of the greater trochanter and guides the screw trajectory. If the direction of the guidewire is satisfactory, all procedures of screw insertion are performed accordingly. The screw accuracy was assessed with computed tomography.

RESULTS

The modal size of the screw was 9.5 mm × 90 mm. The average horizontal angle was 42.0° (SD = 5.1°) on the right and 40.7° (SD = 4.7°) on the left. Of the 104 screws, 4 screws (3.9%) breached dorsally. No screw-related complication was observed.

CONCLUSIONS

Because the guidewire can be inserted at an angle according to the individual morphology of the sacroiliac joint, it will be a reliable guide for the screw trajectory. This technique with a guidewire would help improve the accuracy of S2AI screw placement.

Lumbosacral transitional vertebrae are associated with lumbar degeneration: retrospective evaluation of 3855 consecutive abdominal CT scans

Objectives

To assess the prevalence of lumbosacral transitional vertebra (LSTV) and associated spinal degenerative changes on abdominal CT scans in Caucasian population.

Material and methods

A total of 3855 abdominal CT scans of the year 2017 from a single hospital were retrospectively assessed for LSTV, disc degeneration (DD), and facet joint degeneration (FD). An age- and sex-matched 150-subject control group without LSTV was picked at random. Multivariable logistic regression was used for the analysis.

Results

LSTV was found in 1101 (29%) scans: Castellvi type I in 68%, type II in 16%, type III in 13%, and type IV in 3% of scans. Age- and sex-adjusted prevalence of DD was significantly higher in Castellvi type II and III groups at multiple lumbar levels, and in IV group at L4/5 than in control group (p < 0.001–0.034). At L5/S1, the prevalence of DD was significantly higher in the control group than in type II, III, or IV groups (p < 0.001–0.017). After combining Castellvi types II, III, and IV into one group, significant differences were found at all lumbar levels except L2/3 (p < 0.001–0.016). Prevalence of FD was significantly higher at L4/5 in Castellvi groups I, II, and III than in the control group (p < 0.001–0.002). When Castellvi types II, III, and IV were combined into one group, significant differences were found at lumbar levels L2/3, L3/4, and L4/5 (p < 0.001–0.021).

Conclusion

Lumbosacral vertebrae of Castellvi types II, III, and IV are associated with greater lumbar degeneration, warranting meticulous evaluation of spinal anatomy, even on CT.

Key Points

• Lumbosacral transitional vertebra is a common incidental finding on abdominal CT scans with a high prevalence of 29%.

• When assessing whole lumbar spine, lumbosacral vertebrae of Castellvi types II, III, and IV were associated with greater lumbar degeneration, warranting careful evaluation of the lumbar spine on abdominal CT scans.

Differences in prevalence and associated factors between mild and severe vertebral fractures in Japanese men and women: the third survey of the ROAD study

Vertebral fracture (VF) is a common osteoporotic fracture, while its epidemiology varies according to regions and ethnicities, little is known about it in Japan. Using whole-spine radiographs from a population-based cohort study, the Research on Osteoarthritis/Osteoporosis Against Disability study 3rd survey performed in 2012-2013, we estimated the sex- and age-specific prevalence of VF in the Japanese. Genant's semiquantitative method (SQ) was used to define VF; SQ ≥ 1 as VF, SQ = 1 as mild VF, SQ≥ 2 as severe VF. We also revealed accurate site-specific prevalence, and associated factors with mild and severe VF. The participants were 506 men [mean age 66.3 years, standard deviation (SD):13.0] and 1038 women (mean age 65.3 years, SD: 12.6). The prevalence of VF in participants aged under 40, in their 40s, 50s, 60s, 70s, and ≥ 80 years was 17.4, 7.9, 18.5, 25.6, 26.3, and 41.5%, respectively, in men, and 2.9%, 2.4%, 7,3, 10.3, 27.1, and 53.0%, respectively, in women. Men had a significantly higher prevalence of mild VF (21.2%) than women (10.0%, p < 0.001); whereas, severe VF was significantly more prevalent in women (9.1%) than in men (4.7%, p = 0.003). VF was distributed with 2 peaks regarding site; one large peak at the thoracolumbar region, and another at the middle thoracic lesion. Low back pain and decreased walking ability were independently associated with severe VF, but not with mild VF, after adjustment for participant characteristics. Decreased walking ability was associated with multiple VFs in women, but not in men.

Pedicle Stress Injury in Children and Adolescents With Low Back Pain

STUDY DESIGN

A cross-sectional, retrospective cohort study.

OBJECTIVE

To examine the prevalence of the pedicle stress injury, spondylolysis in children and adolescents with low back pain. And secondly, to test the hypothesis that these pathologies are associated with lumbar lordosis angle.

SUMMARY OF BACKGROUND DATA

The prevalence of the pedicle stress injury has not been investigated in children with low back pain. In recent studies, lumbar lordosis angle was associated with spondylolysis, on the other hand the pedicle stress injury was not investigated yet.

METHODS

In this retrospective study, 789 consecutive lumbar magnetic resonance imaging under 18 years of age were reviewed between January 2015 and July 2018. Seven hundred magnetic resonances imaging among them were included in the study (mean age: 14.87 ± 2.41 yrs; range: 4-17). Prevalence of spondylolysis, spondylolisthesis, pedicle stress injury, pedicle deformation, disc degeneration, and increased lordosis was investigated and compared in terms of sex. The relationship between increased lordosis and other pathologies was evaluated with risk ratio. Nominal variables were evaluated between the two groups using chi-square, Mann-Whitney U test.

RESULTS

Prevalence of pedicle stress injury (12.7%), spondylolysis (8.7%), spondylolisthesis (4.1%), pedicle deformation (3.1%), disc degeneration (24%), increase in lordosis (17.4%) was found. Spondylolysis and pedicle injury were more frequent in males (P = 0.025, P < 0.001, respectively). Increased lordosis was more frequent in females (P < 0.001). Pedicle stress injury was frequently observed between 13 to 17 years and often an isolated lesion (69.6%). Spondylolysis, spondylolisthesis, pedicle deformity were more frequent in increased lordosis (P < 0.001), whereas pedicle injury frequency was not found to be different (P = 0.997).

CONCLUSION

Pedicle stress injury is a common cause of back pain under 18 years of age, more common in males, and often an isolated lesion. No relationship was found between pedicle stress injury and increased lordosis, unlike other pathologies.

LEVEL OF EVIDENCE

3.

Lumbosacral Defects in a 16th-18th-Century Joseon Dynasty Skeletal Series from Korea

Paleopathological evidence for congenital and degenerative disorders of the lumbosacral vertebrae is informative about ancient individual lifeways and physical conditions. However, very few studies have focused on the paleopathology of the lumbosacral vertebrae in ancient skeletal series from East Asia. One reason for the lack of studies is that skeletal samples from East Asia are typically insufficient in size to represent populations for comparative studies within the continent. Here, we present the first comprehensive analysis of lumbosacral defects in an East Asian human skeletal sample, examining occurrences of spina bifida occulta (SBO), lumbosacral transitional vertebrae (LSTV), and spondylolysis in remains from Joseon tombs dating to the 16–18th centuries in Korea. In this study, we present an alternative methodology for understanding activities of daily life among ancient Koreans through paleopathological analysis.