Lumbosacral transitional vertebrae and its prevalence in the Australian population

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.

Relationship between lumbosacral transitional vertebra and postoperative outcomes of patients with Lenke 5C adolescent idiopathic scoliosis: a minimum 5-year follow-up study

PURPOSE

To assess the incidence of lumbosacral transitional vertebra (LSTV) in Lenke 5C adolescent idiopathic scoliosis (AIS) and evaluate the relationship between postoperative outcomes and LSTV when the lowest instrumented vertebra (LIV) is fixed at L3.

METHODS

The study included 61 patients with Lenke 5C AIS who underwent fusion surgery of L3 as the LIV who were followed-up for a minimum of 5 years. Patients were divided into two groups: LSTV + and LSTV-. Demographic, surgical, and radiographic data, including L4 tilt and thoracolumbar/lumbar (TL/L) Cobb angle, were obtained and analyzed.

RESULTS

LSTV was observed in 15 patients (24.5%). The L4 tilt was not significantly different between the two groups preoperatively (P = 0.54); however, it was significantly greater in the LSTV group postoperatively (2 weeks: LSTV +  = 11.7 ± 3.1, LSTV -  = 8.8 ± 3.2, P = 0.013; 2 years: LSTV +  = 11.5 ± 3.5, LSTV -  = 7.9 ± 4.1, P = 0.006; 5 years: LSTV +  = 9.8 ± 3.1, LSTV -  = 7.3 ± 4.5,  P= 0.042). The postoperative TL/L curve was greater in the LSTV + group, with significant differences at 2 weeks and 2 years postoperatively (preoperative: LSTV +  = 53.5 ± 11.2, LSTV -  = 51.7 ± 10.3,P = 0.675; 2 weeks: LSTV +  = 16.1 ± 5.0, LSTV- = 12.2 ± 6.6, P = 0.027; 2 years: LSTV +  = 21.7 ± 5.9, LSTV -  = 17.6 ± 5.9, P = 0.035; 5 years: LSTV +  = 18.7 ± 5.8, LSTV -  = 17.0 ± 6.1, P = 0.205).

CONCLUSION

The prevalence of LSTV in Lenke 5C AIS patients was 24.5%. Lenke 5C AIS patients with LSTV with the LIV at L3 had a significantly greater postoperative L4 tilt than those without LSTV and retained the TL/L curve.

Prevalence of Lumbosacral Transition Vertebrae in Symptomatic Adults and the Levels of Degeneration in the Suprajacent Disc

Lumbosacral transition vertebra (LSTV) is a common occurrence and its prevalence ranges from 2.6% to 35.6%. Our aim is to study this phenomenon in the adult Singaporean population and assess the level of degeneration of the suprajacent disc in those with LSTV. Retrospectively, 545 patients (Age = 57.6 ± 18.3 years; Male = 277; Female = 268) who underwent radiographic evaluation of the lumbar spine for lower back pain or radicular symptoms were shortlisted. LSTV was found to be present in 106 patients (19.4%) with sacralization of L5 and lumbarization of S1 occurring in 96 patients (17.6%) and 10 patients (1.8%), respectively. The most common form of LSTV was Castellvi type IIA (46 patients; 43.4%). Based on Pfirrmann grading, Grade IV disc degeneration was most common in both the LSTV level (63%) and the unfused suprajacent level (77%) in those with LSTV. There was a significantly higher number of patients with grade IV and above degeneration in the suprajacent disc level among those with LSTV when compared to the last unfused (L5-S1) disc level in those without LSTV (84% vs. 65%; p = 0.0001). This suprajacent disc degeneration seen in patients with LSTV may contribute to low back pain and related problems in these patients.

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%).

Surgical Pitfalls in Bertolotti's syndrome management: A case report

RATIONALE

Bertolotti's syndrome is one of the differential causes of low back pain, especially within young people. The etiopathogenesis of the typical paramedian low back pain, associated with Bertolotti's syndrome remains controversial, and there is no worldwide acceptance of treatment.

PATIENT CONCERNS

This article presents the authors experience with surgical treatment of symptomatic patients with Bertolotti's syndrome.

DIAGNOSES

Retrospective study of a selected series of patients with symptomatic Bertolotti's syndrome submitted to surgical treatment.

INTERVENTIONS

This study included 16 patients, being 8 submitted to the new modified mini-open tubular microsurgical transverse processectomy, Among those patients, intraoperative fluoroscopy was used in 6 surgeries to locate the base of the enlarged transverse process (6/8); intraoperative neuromonitoring was used in 6 patients (6/8), 3D intraoperative advanced spinal image (O-arm) with neuronavigation was used to localize the base of the pseudojoint to be removed and to check the final bone resection for the last 5 cases (5/8).

OUTCOMES

The average paramedian lower back pain before surgery on the visual analogue scale for pain in the 8 patients was 6.6 (range: 5-8) and reduced to 1.5 (range: 0-3) at the latest follow-up after surgery, while the average pain score of the radicular pain on the right or left side before the surgery was 1.3 (range: 0-6) and reduced to 0.6 (range: 0-7) after the surgery.

LESSONS

The mini-open tubular microsurgical transverse processectomy seems to be potentially safe and effective for the surgical treatment of selected symptomatic patients with Bertolotti's syndrome.

Lumbosacral transitional vertebrae: prevalence in a southern European population and its association with low back pain

PURPOSE

Lumbosacral transitional vertebra (LSTV) is a congenital anomaly of the lumbosacral junction. Its prevalence is variable in the literature such as its association with low back pain. The aim of this study was to identify the prevalence of LSTV in a southern European population, and its correlation with low back pain.

METHODS

A retrospective review of 639 thoraco-abdomino-pelvic consecutive CT-scans between January 2019 and November 2020 was performed. The presence of LSTV was classified into type II, III, IV based on Castellvi's classification. To investigate the association with low back pain, Oswestry Low Back Disability Questionnaire (ODI) and the EuroQol-5D-3L questionnaire was applied.

RESULTS

The prevalence of LSTV was 24.9% (142 of 571). 37,3% were type IIb, 31,0% were type IIa, 13,4% were type IIIa, 9.9% were type IIIb and 8.5% were type IV. Individuals with LSTV were more likely to report low back pain and have a higher ODI score (OR:0.392, 95% CI:0.192-0.802, p = 0.010), (OR: 1050, 95% CI: 1029-1072, p < 0.01). Castellvi's type IV showed a significantly higher ODI when compared to type II (OR:1059, 95% CI:1019-1100, p = 0,04). There was no statistical difference in the EuroQol-5D-3L score between two groups (OR:1085, 95% CI: 0.459-2.560, p = 0.852).

CONCLUSION

This population-based study adds to the literature the prevalence of LSTV in a southern European population. LSTV was associated with low back pain. However, this difference did not translate into a loss of quality life. Type IV was associated with higher functional disability when compared with type II.

Lumbosacral transitional vertebrae alter the distribution of lumbar mobility–Preliminary results of a radiographic evaluation

Background

Lumbo-sacral transitional vertebrae (LSTV) are one of the most common congenital variances of the spine. They are associated with an increased frequency of degeneration in the cranial adjacent segment. Hypermobility and concomitant increased loads are discussed as a possible reason for segmental degeneration. We therefore examined the lumbar and segmental motion distribution in patients with LSTV with flexion-extension radiographs.

Methods

A retrospective study of 51 patients with osteochondrosis L5/S1 with flexion and extension radiographs was performed. Of these, 17 patients had LSTV and were matched 1:1 for age and sex with patients without LSTV out of the collective of the remaining 34 patients. The lumbar and segmental range of motion (RoM) by segmental lordosis angle and the segmental wedge angle were determined. Normal distribution of parameters was observed by Kolmogorov-Smirnov-test. Parametric data were compared by paired T-test. Non-parametric data were compared by Wilcoxon-rank-sum-test. Correlations were observed using Spearman’s Rank correlation coefficient. A p-value <0.05 was stated as statistically significant.

Results

Patients with LSTV had mean age of 52.2±10.9, control group of 48.9±10.3. Both groups included 7 females and 10 males. Patients with LSTV presented with reduced RoM of the lumbar spine (LSTV 37.3°±19.2°, control 52.1°±20.5°, p = 0.065), however effects were statistically insignificant. LSTV significantly decreased segmental RoM in the transitional segment (LSTV 1.8°±2.7°, control 6.7°±6.0°, p = 0.003). Lumbar motion distribution differed significantly; while RoM was decreased in the transitional segment, (LSTV 5.7%, control 16.2%, p = 0.002), the distribution of lumbar motion to the cranial adjacent segment was increased (LSTV 30.7%, control 21.6%, p = 0.007).

Conclusion

Patients with LSTV show a reduced RoM in the transitional segment and a significantly increased motion distribution to the cranial adjacent segment in flexion-extension radiographs. The increased proportion of mobility in the cranial adjacent segment possibly explain the higher rates of degeneration within the segment.

Sacralization of Coccygeal Vertebra: A Descriptive Observational Study in Bangladesh

Background: In the sacrococcygeal region, anatomical variation is due to the sacralization of the coccygeal vertebra, which is the due union of/fusion of the fifth sacral with the first coccygeal vertebra of five couples of sacral foramina under-detected or asymptomatic beyond radiological assessment. That is why it is challenging to know the cause of coccydynia, caudal block failure, the difficult second stage of labor, and perineal tears. The present study aims to improve knowledge about the anatomical variation of sacralization of the coccygeal vertebra. Additionally, to find the prevalence of sacralization of coccygeal vertebra in Sylhet, Bangladesh.

Methods: This study was performed on 60 parched, totally calcified, typical sacra of mature-age individuals of undetermined sexes, fulfilling the inclusion criteria from the bone bank of the osteology museum of the Department of Anatomy, Sylhet MAG Osmani Medical College, Sylhet, Bangladesh, from July 2017 to June 2018. Sex determination of the collected unknown sacra was conducted using discriminant function analysis. It was found that 50% (30) were male and 50% (30%) were female. The unpaired t-tests and chi-square were utilized to determine the statistical significance.

Results: Out of 60 sacra, eight (13.33%) samples presented with sacralization. This study found that males had significantly higher straight (p=0.05) and curved (p=0.05) lengths of sacrococcygeal vertebrae. The sacrococcygeal curvature index (SCI) showed statistically significant (p=0.05) differences between the sexes.

Conclusion: Sacralization may exert an impact on the caudal block. It could extend the second stage of the labor process with perineal tears. Therefore, knowledge about the anatomical variation of the coccygeal vertebra is essential.

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.

The Association of Lumbosacral Transitional Vertebrae with Low Back Pain and Lumbar Degenerative Findings in MRI: A Large Cohort Study

STUDY DESIGN

A cross-sectional study of the Northern Finland Birth Cohort 1966 (NFBC1966).

OBJECTIVE

To evaluate the association of lumbosacral transitional vertebrae (LSTV) with low back pain (LBP) and associated degenerative findings using magnetic resonance (MR) imaging.

SUMMARY OF BACKGROUND DATA

LSTV is a common finding with a prevalence of 10% to 29%. LSTV causes biomechanical alterations leading to accelerated lumbar degeneration. However, its association with degenerative findings on MRI and LBP is unclear.

METHODS

One thousand four hundred sixty eight lumbar spine MRI scans from the NFBC1966 acquired at a mean age of 47 years were assessed for the presence of LSTV and degenerative changes. Castellvi classification was utilized to identify LSTV anatomy. Additionally, 100 controls without LSTV were collected. Self-reported LBP with a duration of more than 30 days in the past year was deemed clinically relevant. For the statistical analyses, chi square test, independent samples t test and multinomial logistic regression analyses were used.

RESULTS

LSTV was found in 310 (21.1%) subjects. After adjusting for age, sex, and disc degeneration (DD) sum, subjects with Castellvi type III reported prolonged LBP significantly more frequently than the controls (odds ratio [OR] = 8.9, P = 0.001). We observed a higher prevalence of facet degeneration (FD) at all levels from L3/L4 to L5/S1 in type I, and L3/L4 to L4/L5 in types II-IV. DD was more prevalent at L4/L5 in types II-IV. Disc protrusion/extrusion occurred more frequently at L3/L4 and L4/L5 in type II, and at L3/L4 in type III. Castellvi type II had a higher prevalence of type 1 Modic changes at levels from L3/L4 to L4/L5.

CONCLUSION

LSTVs were a common finding within this study, and Castellvi type III LSTVs were associated with LBP. Degenerative findings were associated with LSTV anatomy and occurred more commonly above the transitional level.Level of Evidence: 3.

[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.

Transitional vertebrae and numerical variants of the spine : prevalence and relationship to low back pain or degenerative spondylolisthesis

AIMS

Although lumbosacral transitional vertebrae (LSTV) are well-documented, few large-scale studies have investigated thoracolumbar transitional vertebrae (TLTV) and spinal numerical variants. This study sought to establish the prevalence of numerical variants and to evaluate their relationship with clinical problems.

METHODS

A total of 1,179 patients who had undergone thoracic, abdominal, and pelvic CT scanning were divided into groups according to the number of thoracic and lumbar vertebrae, and the presence or absence of TLTV or LSTV. The prevalence of spinal anomalies was noted. The relationship of spinal anomalies to clinical symptoms (low back pain, Japanese Orthopaedic Association score, Roland-Morris Disability Questionnaire) and degenerative spondylolisthesis (DS) was also investigated.

RESULTS

Normal vertebral morphology (12 thoracic and five lumbar vertebrae without TLTV and LSTV) was present in 531 male (76.7%) and 369 female patients (75.8%). Thoracolumbar transitional vertebrae were present in 15.8% of males and 16.0% of females. LSTV were present in 7.1% of males and 9.0% of females. The prevalence of the anomaly of 16 presacral mobile vertebrae (total number of thoracolumbar vertebrae and TLTV) without LSTV was 1.0% in males and 4.1% in females, and that of the anomaly of 18 vertebrae without LSTV was 5.3% in males and 1.2% in females. The prevalence of DS was significantly higher in females with a total of 16 vertebrae than in those with normal morphology. There was no significant correlation between a spinal anomaly and clinical symptoms.

CONCLUSION

Overall, 24% of subjects had anomalies in the thoracolumbar region: the type of anomaly differed between males and females, which could have significant implications for spinal surgery. A decreased number of vertebrae was associated with DS: numerical variants may potentially be a clinical problem. Cite this article: Bone Joint J 2021;103-B(7):1301-1308.

Prevalence of Lumbosacral Transitional Vertebrae in Patients With Symptomatic Femoroacetabular Impingement Requiring Hip Arthroscopy

PURPOSE

The primary aim of this study was to determine the prevalence of lumbosacral transitional vertebrae (LSTVs) in patients with symptomatic femoroacetabular impingement (FAI) requiring hip arthroscopy. The secondary aim was to determine whether there is an association between LSTV anatomy and patient-reported outcomes.

METHODS

This retrospective study included patients aged 18 to 45 years with symptomatic FAI who underwent arthroscopy between March 2010 and March 2016 and had anteroposterior pelvic radiographs. The exclusion criteria included lack of an FAI diagnosis, hip osteoarthritis (Tönnis grade ≥ 2), prior spinal fusion surgery, prior total hip arthroplasty, indications for total hip arthroplasty, and revision surgery on the affected hip. All radiographs were assessed by an interventional spine and sports fellow. The primary outcome was the prevalence of LSTVs, classified using the criteria of Castellvi et al. Secondary outcomes included the modified Harris Hip Score, Hip Outcome Score, and International Hip Outcome Tool 33 score.

RESULTS

A total of 1,880 patients were included. Review of the patients' radiographs yielded 262 LSTVs, for an overall prevalence of 13.9% (type IA in 104 [5.5%], type IB in 53 [2.8%], type IIA in 60 [3.2%], type IIB in 25 [1.3%], type IIIA in 8 [0.4%], type IIIB in 0 [0%], and type IV in 12 [0.64%]). The prevalence of type II, III, and IV LSTVs was 5.6% (n = 105). Unilateral LSTV sidedness did not correlate with symptom laterality (κ = 0.07). There were no differences in patient-reported outcomes between patients with LSTV anatomy and those without it.

CONCLUSIONS

In this large cohort of 1,880 patients with symptomatic FAI, the prevalence of LSTVs was 13.9%. There was no correlation between sidedness of unilateral LSTVs and the symptomatic hip. Furthermore, there was no association between LSTV anatomy and patient-reported outcomes. The prevalence of LSTVs in this cohort was similar to the prevalence rates previously reported in patients with low-back pain.

LEVEL OF EVIDENCE

Level IV, case series.

Development of a novel in vitro cadaveric model for analysis of biomechanics and surgical treatment of Bertolotti syndrome

BACKGROUND CONTEXT

Bertolotti syndrome (BS) is caused by pseudoarticulation between an aberrant L5 transverse process and the sacral ala, termed a lumbosacral transitional vertebra (LSTV). BS is thought to cause low back pain and is treated with resection or fusion, both of which have shown success. Acquiring cadavers with BS is challenging. Thus, we combined 3D printing, based on BS patient CT scans, with normal cadaveric spines to create a BS model. We then performed biomechanical testing to determine altered kinematics from LSTV with surgical interventions. Force sensing within the pseudojoint modeled nociception for different trajectories of motion and surgical conditions.

PURPOSE

This study examines alterations in spinal biomechanics with LSTVs and with various surgical treatments for BS in order to learn more about pain and degeneration in this condition, in order to help optimize surgical decision-making. In addition, this study evaluates BS histology in order to better understand the pathology and to help define pain generators-if, indeed, they actually exist.

STUDY DESIGN/SETTING

Model Development: A retrospective patient review of 25 patients was performed to determine the imaging criteria that defines the classical BS patient. Surgical tissue was extracted from four BS patients for 3D-printing material selection. Biomechanical Analysis. This was a prospective cadaveric biomechanical study of seven spines evaluating spinal motions, and loads, over various surgical conditions (intact, LSTV, and LSTV with various fusions). Additionally, forces at the LSTV joint were measured for the LSTV and LSTV with fusion condition. Histological Analysis: Histologic analysis was performed prospectively on the four surgical specimens from patients undergoing pseudoarthrectomy for BS at our institution to learn more about potential pain generators.

PATIENT SAMPLE

The cadaveric portion of the study involved seven cadaveric spines. Four patients were prospectively recruited to have their surgical specimens assessed histologically and biomechanically for this study. Patients under the age of 18 were excluded.

OUTCOME MEASURES

Physiological measures recorded in this study were broken down into histologic analysis, tissue biomechanical analysis, and joint biomechanical analysis. Histologic analysis included pathologist interpretation of Hematoxylin and Eosin staining, as well as S-100 staining. Tissue biomechanical analysis included stiffness measurements. Joint biomechanical analysis included range of motion, resultant torques, relative axis angles, and LSTV joint forces.

METHODS

This study received funding from the American Academy of Neurology Medical Student Research Scholarship. Three authors hold intellectual property rights in the simVITRO robotic testing system. No other authors had relevant conflicts of interest for this study. CT images were segmented for a representative BS patient and cadaver spines. Customized cutting and drilling guides for LSTV attachment were created for individual cadavers. 3D-printed bone and cartilage structural properties were based on surgical specimen stiffness, and specimens underwent histologic analysis via Hematoxylin and Eosin, as well as S-100 staining. Joint biomechanical testing was performed on the robotic testing system for seven specimens. Force sensors detected forces in the LSTV joint. Kruskal-Wallis tests and Dunnett's tests were used for statistical analysis with significance bounded to p<.05.

RESULTS

LSTV significantly reduces motion at the L5-S1 level, particularly in lateral bending and axial rotation. Meanwhile, the LSTV increases adjacent segment motion significantly at the L2-L3 level, whereas other levels have nonsignificant trends toward increased motion with LSTV alone. Fusion involving L4-S1 (L4-L5 and L5-S1) to treat adjacent level degeneration associated with an LSTV is associated with a significant increase in adjacent segment motion at all levels other than L5-S1 compared to LSTV alone. Fusion of L5-S1 alone with LSTV significantly increases L3-L4 adjacent segment motion compared to LSTV alone. Last, ipsilateral lateral bending with or without ipsilateral axial rotation produces the greatest force on the LSTV, and these forces are significantly reduced with L5-S1 fusion.

CONCLUSIONS

BS significantly decreases L5-S1 mobility, and increases some adjacent segment motion, potentially causing patient activity restriction and discomfort. Ipsilateral lateral bending with or without ipsilateral axial rotation may cause the greatest discomfort overall in these patients, and fusion of the L5-S1 or L4-S1 levels may reduce pain associated with these motions. However, due to increased adjacent segment motion with fusions compared to LSTV alone, resection of the joint may be the better treatment option if the superior levels are not unstable preoperatively.

CLINICAL SIGNIFICANCE

This study's results indicate that patients with BS have significantly altered spinal biomechanics and may develop pain due to increased loading forces at the LSTV joint with ipsilateral lateral bending and axial rotation. In addition, increased motion at superior levels when an LSTV is present may lead to degeneration over time. Based upon results of LSTV joint force testing, these patients' pain may be effectively treated surgically with LSTV resection or fusion involving the LSTV level if conservative management fails. Further studies are being pursued to evaluate the relationship between in vivo motion of BS patients, spinal and LSTV positioning, and pain generation to gain a better understanding of the exact source of pain in these patients. The methodologies utilized in this study can be extrapolated to recreate other spinal conditions that are poorly understood, and for which few native cadaveric specimens exist.

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.

Lumbosacral Transitional Vertebrae: A Cadaveric Investigation of Prevalence and Relation to Lumbar Degenerative Disease

STUDY DESIGN

This is a retrospective cohort study.

OBJECTIVE

The objective of this study was to verify the prevalence of lumbosacral transitional vertebrae (LSTV) in the general population and measure the resulting spinal arthritic changes.

SUMMARY OF BACKGROUND

LSTV are a morphologic variation within the lumbar spine that has potentially significant clinical implications. LSTV prevalence has been investigated using nonrandom volunteer samples and patient populations presenting with medical complaints such as abdominal or lumbar pain warranting computed tomography and magnetic resonance imaging scans. The examination of LSTV prevalence and variations using a true random population to our knowledge has yet to be conducted, and the relation between LSTV and spinal arthritis has not been rigorously examined.

MATERIALS AND METHODS

A total of 560 cadaveric skeletons were obtained from the Hamann-Todd osteological collection. The transverse processes of the terminal lumbar vertebrae were examined and measured, since the classification at times is based on examination and at times is based on measurement. The lumbar degenerative disease was graded on each specimen.

RESULTS

Our search revealed 489 (87.3%) nontransitional vertebrae and 71 (12.7%) transitional vertebrae, with the majority of these Castellvi type IA (N=28), type IB (N=19), and type IIA (N=11). Transitional vertebrae as a whole (standardized β=0.090, P=0.015), and in particular type Ia showed a correlation to osteoarthritis in the L4-L5 vertebral level (standardized β=0.089, P=0.015).

CONCLUSIONS

This cadaveric study aids in establishing the prevalence of LSTV (12.7%) in a random population and the frequency of the various Castellvi LSTV morphologies. An association was found between type Ia morphology and L4-L5 osteoarthritis which has not been reported in the past, suggesting that mild LSTV may carry more significance to lumbar pathology than previously considered.

Understanding quality of life and treatment history of patients with Bertolotti syndrome compared with lumbosacral radiculopathy

OBJECTIVE

Bertolotti syndrome is a rare spinal condition that causes low-back pain due to a lumbosacral transitional vertebra (LSTV), which is a pseudoarticulation between the fifth lumbar transverse process and the sacral ala. Bertolotti syndrome patients are rarely studied, particularly with regard to their quality of life. This study aimed to examine the quality of life and prior treatments in patients with Bertolotti syndrome at first presentation to the authors' center in comparison with those with lumbosacral radiculopathy.

METHODS

This study was a retrospective cohort analysis of patients with Bertolotti syndrome and lumbosacral radiculopathy due to disc herniation seen at the authors' institution's spine center from 2005 through 2018. Diagnoses were confirmed with provider notes and imaging. Variables collected included demographics, diagnostic history, prior treatment, patient-reported quality of life metrics, and whether or not they underwent surgery at the authors' institution. Propensity score matching by age and sex was used to match lumbosacral radiculopathy patients to Bertolotti syndrome patients. Group comparisons were made using t-tests, Fisher's exact test, Mann-Whitney U-tests, Cox proportional hazards models, and linear regression models where variables found to be different at the univariate level were included as covariates.

RESULTS

The final cohort included 22 patients with Bertolotti syndrome who had patient-reported outcomes data available and 46 propensity score-matched patients who had confirmed radiculopathy due to disc herniation. The authors found that Bertolotti syndrome patients had significantly more prior epidural steroid injections (ESIs) and a longer time from symptom onset to their first visit. Univariate analysis showed that Bertolotti syndrome patients had significantly worse Patient-Reported Outcomes Measurement Information System (PROMIS) mental health T-scores. Adjustment for prior ESIs and time from symptom onset revealed that Bertolotti syndrome patients also had significantly worse PROMIS physical health T-scores. Time to surgery and other quality of life metrics did not differ between groups.

CONCLUSIONS

Patients with Bertolotti syndrome undergo significantly longer workup and more ESIs and have worse physical and mental health scores than age- and sex-matched patients with lumbosacral radiculopathy. However, both groups of patients had mild depression and clinically meaningful reduction in their quality of life according to all instruments. This study shows that Bertolotti syndrome patients have a condition that affects them potentially more significantly than those with lumbosacral radiculopathy, and increased attention should be paid to these patients to improve their workup, diagnosis, and treatment.

Are high lumbar punctures safe? A magnetic resonance imaging morphometric study of the conus medullaris

A high lumbar puncture (LP) at L2-L3 or above is often necessary to consider on technical grounds, but complications of conus medullaris (CM) damage during high LP are potentially concerning. We hypothesized that a high LP might be safer than previously thought by accounting for movements of the CM upon patient positional changes. We retrospectively reviewed standard normal supine lumbar spine magnetic resonance imaging of 58 patients and used electronic calipers on axial images at the T12-L1, L1-L2, and L2-L3 disc levels to measure the transverse diameter of the CM relative to the size of the dorsal thecal sac space (DTSS) through which a spinal needle could be inserted. On 142 axial images, the means for CM diameters were 8.2, 6.0, and 2.9 mm at the three levels, respectively. We then used known literature mean CM displacement values in the legs flexed and unflexed lateral decubitus position (LDP) to factor in CM shifts to the dependent side. We found that at all three levels, the likely positional shift of the CM would be too small and insufficient to displace the entire CM out of the DTSS. However, if needle placement could be confined to the midsagittal plane, an LP in the unflexed LDP would theoretically be entirely safe at both L1-L2 and L2-L3, and almost so at L2-L3 in the legs flexed LDP. Thus, high LPs at L1-L2 and L2-L3 are in theory likely safer than considered previously, more so in the legs unflexed than in the flexed LDP. Clin. Anat. 32:618-629, 2019. © 2019 Wiley Periodicals, Inc.

Asymmetric sacroiliac joint anatomy in partial lumbosacral transitional variations: Potential impact on clinical testing in sacral dysfunctions

Lumbosacral transitional vertebrae (LSTV) anomalies may present as bio-mechanical dysfunctions leading to low back pain (LBP). Unilateral or incomplete/partial LSTVs have been documented to be associated with significant sacroiliac joint (SIJ) joint asymmetries. Objective evaluation of outcomes from routine clinical testing for sacral dysfunctions on these subsets of LSTV cannot be found in the literature. Based on quantitative studies available on LSTV-associated anatomical variations at the SIJ, this study hypothesizes probable outcomes of standard palpatory clinical tests used to evaluate sacral dysfunctions in unilateral LSTV anomalies. Since LSTV is reported in a sizeable percentage in the general population and due to its proposed etiological relationship with LBP, these entities warrant attention in terms of the anatomical bases of related clinical assessments and their outcomes, as proposed in this hypothesis.

Interpretation of Spinal Radiographic Parameters in Patients With Transitional Lumbosacral Vertebrae

STUDY DESIGN

Retrospective radiographic review.

OBJECTIVES

To understand the effect of variability in sacral endplate selection in transitional lumbosacral vertebrae (TLSV) and its impact on pelvic, regional, and global spinal alignment parameters.

BACKGROUND

TLSV can have the characteristics of both lumbar and sacral vertebrae. Difficulties in identification of the S1 endplate may come from nomenclature, number of lumbar vertebrae, sacra, and morphology and may influence the interpretation and consistency of spinal alignment parameters.

METHODS

Patients with TLSV were identified and radiographic measurements including pelvic incidence (PI), pelvic tilt (PT), sacral slope (SS), lumbar lordosis (LL), sagittal vertical axis (SVA), T1-pelvic angle (TPA), pelvic incidence-lumbar lordosis (PI-LL) mismatch, thoracic kyphosis (TK), and spinal inclination (T1SPi) were obtained. Radiographic measurements were performed twice with the sacral endplate at the cephalad and caudal options. Paired t tests assessed the difference between different selection groups.

RESULTS

Of 1,869 patients, 70 (3.7%) were found to have TLSV on radiographic imaging. Fifty-eight (82.9%) had lumbarized sacral segments whereas 12 (17.1%) had sacralized lumbar segments. T1-SPi (mean: -1.77°) and TK (mean: 34.86°) did not vary from altering sacral endplate selection. Selection of the caudal TLSV as the sacral endplate resulted in an increase in all pelvic parameters (PI: 66.8° vs. 44.3°, PT: 25.1° vs. 12.7°, and SS: 41.6° vs. 31.6°), regional lumbar parameters (LL: -54.1° vs. 44.0°, PI-LL: 12.7° vs. 0.3°), and global parameters (SVA: 46.1 mm vs. 28.3 mm, TPA: 23.3° vs. 10.8°) as compared to selecting the cephalad TLSV. All mean differences between radiographic parameters were found to be statistically significant (p < .001).

CONCLUSIONS

Variation in sacral endplate selection in TLSV significantly affects spinal alignment parameter measurements. A standardized method for measuring TLSV is needed to reduce measurement error and ultimately allow more accurate understanding of alignment targets in patients with TLSV.

LEVEL OF EVIDENCE

Level III.

"Acquired" Type Castellvi-IIIa Lumbarization Transformed From Castellvi-IIa Following Discectomy and Fusion at Lumbosacral Level: A Case Report

STUDY DESIGN

A retrospective case report.

OBJECTIVE

To report a case that transformed from type Castellvi-IIa sacralization to type Castellvi-IIIa after decompression and fusion surgery at transitional disc (TD).

SUMMARY OF BACKGROUND DATA

Traditionally, lumbosacral transitional vertebra has been regarded as a congenital anomaly. No literature has ever reported that transformation from one type lumbosacral transitional vertebra to another would happen after birth.

METHODS

A 60-year-old man presented to our department with the complaint of low back pain and left sciatic pain, and was diagnosed of lumbar disc herniation at L4-5 and L5-S1 levels. Lumbar digital radiography revealed an anomalous articulation formed between sacrum and enlarged right L5 transverse process, exhibiting a typical Castellvi-IIa sacralization. Dynamic lateral radiographs showed mobilization existed at L5-S1 disc which was TD. The patient received posterior lumbar interbody fusion (PLIF) surgery at L4-5 and L5-S1 levels. Postoperative computed tomography examinations were taken to identify the progress of solid fusion at the operated segments.

RESULTS

After surgery, the patient's symptoms alleviated obviously. As solid fusion developed at intended interbody regions with time, we found that bony bridge passed through the patient's anomalous articulation region gradually, and finally, complete osseous fusion of the right L5 transverse process to the sacrum developed 1 year after surgery.

CONCLUSION

Following PLIF surgery at TD segment on a Castellvi-IIa Sacralization case, "acquired" transformation to Castellvi-IIIa might develop.

LEVEL OF EVIDENCE

5.

Lumbosacral transitional vertebrae: significance of local bone marrow edema at the transverse processes

OBJECTIVE

To evaluate the association between low back pain and bone marrow edema in lumbosacral transitional vertebra (LSTV) transverse processes, and to assess the prevalence of LSTV in a physically active population.

MATERIALS AND METHODS

Individuals with LSTV on coronal MRI studies were identified in a retrospective review by keyword search from PACS. In total, 140 cases were reviewed by two fellowship-trained musculoskeletal radiologists. Data on associated low back pain were collected from patient records at the time of the imaging.

RESULTS

Bone marrow edema was observed in 44% of the cases, but no correlation with low back pain was found. On coronal MRI, the prevalence of LSTV was 2.6%, with type II LSTV being the most common subtype.

CONCLUSIONS

No correlation with bone marrow edema at the transverse processes of the LSTV and low back pain was observed. In our selected study population, the prevalence of LSTV was low.

Determination of lumbosacral transitional vertebrae in kidney urinary bladder x-ray films in the Saudi population

OBJECTIVES

To investigated the rate of occurrence of lumbosacral transitional vertebrae (LSTV), spinal variant, in kidney urinary bladder (KUB) plain radiographs in a Saudi population.  Methods: Between January 2012 to January 2015, KUB plain films obtained from patients at King Abdulaziz University Hospital, Jeddah, Saudi Arabia, were reviewed, and the presence or absence of LSTV was documented and classified as incomplete or complete. Patients who had evidence of spinal surgery that would obscure the view were excluded.  Results: A total of 2078 patients underwent KUB examinations during the study period; LSTV anomalies were detected in 158 of these. Sacralization was present in 153 (96.8%) of this cohort, while lumbarization was present in 5 (3.2%). A total of 136 (86.1%) of the sacralized segments were of the incomplete type, whereas 17 (10.7%) were complete. Of the lumbarized vertebrae, 3 (1.8%) were incomplete, and 2 (1.2%) were complete. The most frequent type in men was type Ib (28.5%) for sacralized segments, and type IIb for lumbarized segments (0.6%). In women, type Ia was the most common form of sacralized segments (11.3%) and type IIb was the most common form of lumbarized segments (2.8%). Conclusion: The prevalence of LSTV in Saudi patients is 7.6%, with a higher incidence of sacralization than lumbarization. Further studies with larger sample sizes and longer follow-up time are needed to demonstrate the clinical significance thereof.

The morphological relationship between lumbosacral transitional vertebrae and lumbosacral pedicle asymmetry

Introduction

The clinical significance of lumbosacral transitional vertebrae (LSTV) has been reported. However, the association between LSTV and lumbosacral pedicle anatomical anomaly has not been investigated. We hypothesized that LSTV might be associated with lumbosacral anatomical anomaly. The purpose of this study was to examine the morphological association between LSTV and lumbosacral pedicle asymmetry (PA) using computed tomography (CT).

Methods

A retrospective review of CT images of 347 lumbosacral degenerative disease patients was performed. We divided the subjects into two groups: the normal and LSTV groups. LSTV was classified based on Castellvi's classification. PA was defined as a difference of more than 20° between the right and left angles of the pedicle.

Results

Seventy out of 347 lumbosacral degenerative disease patients (20.17%) were diagnosed with LSTV. In the normal group, only a 0.54% incidence of PA was seen; however, with respect to the LSTV group, a 9.29% incidence of PA was seen. A significant difference in PA incidence was observed between the groups (p < 0.001). Type IIIa and Type IV in the LSTV group showed a statistically significant PA incidence rate (p = 0.004 and p = 0.039, respectively).

Conclusions

Our study demonstrated that there was a significant difference in the incidence of PA between LSTV subjects and normal subjects. Moreover, the incidence of PA was significantly higher in LSTV subjects with severe anomaly. These results suggested that lumbosacral spine anomaly might have a close relationship with the incidence of PA and lumbosacral nerve root asymmetry. Therefore, morphological evaluation of the pedicle is important for preoperative surgical management, especially in cases using pedicle screws. This information could lower the incidence of pedicle screw malposition when pedicle screws are inserted at the lumbosacral spine.

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

OBJECTIVE

To investigate the role of lumbosacral transitional vertebra (LSTV) in the pathogenesis of adolescent lumbar disc herniation (ALDH) and the association between LSTV type and the herniation level of ALDH.

METHODS

This study was a retrospective case-control analysis of roentgenographic images. All adolescent patients who received surgical treatment for L4/5 or L5/S1 single level lumbar disc herniation in our department from 2010 to 2015 were eligible for the ALDH group. All adolescent patients admitted to our hospital during the same period and who had ever undergone a plain anteroposterior radiologic examination of the abdomen and met the inclusion criteria that ensured the absence of any spinal disorders were selected into the control group. The anteroposterior lumbar or abdomen roentgenograms were collected to identify the LSTV. The incidence of LSTV in the ALDH group and the control group were compared. Among the ALDH group, the association between LSTV type (sacralization or lumbarization) and the herniation level of ALDH were evaluated.

RESULTS

A total of 80 adolescent patients were included in the ALDH group and 92 asymptomatic adolescents were included in the control group. LSTV was found in 24 patients (30%) in ALDH group compared with 7 patients (7.6%) in the control group (P < 0.001; odds ratio, 5.2; 95% confidence interval 2.1, 12.9). Among the adolescent patients with sacralization, the L4/5 disc herniation was significantly more common than L5/S1 (81.3% vs. 18.7%; P = 0.019).

CONCLUSIONS

The LSTV is associated with LDH in adolescents and the sacralization of L5 may contribute to the L4/5 disc herniation in adolescent patients.

Role of Anatomical Landmarks in Identifying Normal and Transitional Vertebra in Lumbar Spine Magnetic Resonance Imaging

Study Design

Retrospective study.

Purpose

Identification of transitional vertebra is important in spine imaging, especially in presurgical planning. Pasted images of the whole spine obtained using high-field magnetic resonance imaging (MRI) are helpful in counting vertebrae and identifying transitional vertebrae. Counting vertebrae and identifying transitional vertebrae is challenging in isolated studies of lumbar spine and in studies conducted in low-field MRI. An incorrect evaluation may lead to wrong-level treatment. Here, we identify the location of different anatomical structures that can help in counting and identifying vertebrae.

Overview of Literature

Many studies have assessed the vertebral segments using various anatomical structures such as costal facets (CF), aortic bifurcation (AB), inferior vena cava confluence (IC), right renal artery (RRA), celiac trunk (CT), superior mesenteric artery root (SR), iliolumbar ligament (ILL) psoas muscle (PM) origin, and conus medullaris. However, none have yielded any consistent results.

Methods

We studied the locations of the anatomical structures CF, AB, IC, RRA, CT, SR, ILL, and PM in patients who underwent whole spine MRI at our department.

Results

In our study, 81.4% patients had normal spinal segmentation, 14.7% had sacralization, and 3.8% had lumbarization. Vascular landmarks had variable origin. There were caudal and cranial shifts with respect to lumbarization and sacralization. In 93.8% of cases in the normal group, ILL emerged from either L5 alone or the adjacent disc. In the sacralization group, ILL was commonly seen in L5. In the lumbarization group, ILL emerged from L5 and the adjacent disc (66.6%). CFs were identified at D12 in 96.9% and 91.7% of patients in the normal and lumbarization groups, respectively. The PM origin was observed from D12 or D12–L1 in most patients in the normal and sacralization groups.

Conclusions

CF, PM, and ILL were good identification markers for D12 and L5, but none were 100% accurate.