The prevalence of transitional vertebrae in the lumbar spine

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.

A Whole-Spine Magnetic Resonance Imaging-Based Cross-Sectional Study of the Clinicoradiological Association of Lumbosacral Transitional Vertebra with Degenerative Disc Disease, End Plate Degeneration, Low Back Pain, and Facet Tropism

OBJECTIVE

To understand lumbosacral transitional vertebra (LSTV)-associated degenerative pathologies and their correlation to low back pain and radicular pain.

METHODS

Whole-spine magnetic resonance imaging was evaluated for disc degeneration using Pfirrmann grading, end plate changes using total end plate score (TEPS), and facet tropism in patients with low back pain and radicular pain, and their association with LSTV was analyzed.

RESULTS

In group 1, LSTV was seen in 15% of patients with 83% of these patients having sacralization. Disc degeneration was seen in 58%, 51%, and 63% of patients at levels C, B, and A, respectively; patients with sacralization had significant degeneration at all 3 levels. Similarly, the total end plate score and facet tropism were significantly higher in patients with sacralization. Facet tropism was observed in 31%, 40%, and 35% of patients with no -LSTV, patients with sacralization, and patients with lumbarization, respectively. In group 2, LSTV was seen in 17% of patients with sacralization accounting for 82%. Disc degeneration was seen in 44%, 36%, and 54% patients at levels C, B, and A, respectively. No significant difference was observed in the mean total end plate score between groups. Facet tropism was identified in 89% and 81% of patients with sacralization and patients with lumbarization, respectively, compared with only 19% of patients with no LSTV.

CONCLUSIONS

Patients with low back pain had a higher incidence of sacralization with corresponding disc degeneration, facet tropism ,and end plate changes. In patients with radicular pain, lumbarization was associated only with facet tropism. These findings may aid clinicians in prognostication and patient counseling.

A simple method for the selection of valid spinopelvic parameters and lumbar lordosis in patients with transitional lumbosacral vertebrae

PURPOSE

Transitional lumbosacral vertebrae (TLSV) are a congenital anomaly of the lumbosacral region that is characterized by the presence of a vertebra with morphological properties of both the lumbar and sacral vertebrae, with a prevalence of up to 36% in asymptomatic patients and 20% in adolescent idiopathic scoliosis patients. In patients with TLSV, because of these morphological changes and the different numbers of lumbar vertebrae, there are two optional reference sacral endplates that can be selected intently or inadvertently to measure the spinopelvic parameters: upper and lower endplates. The spinopelvic parameters measured using the upper and lower endplates are significantly different from each other as well as from the normative values. Therefore, the selection of a reference endplate changes the spinopelvic parameters, lumbar lordosis (LL), and surgical goals, which can result in surgical over- or under-correction. Because there is no consensus on the selection of sacral endplate among these patients, it is unclear as to which of these parameters should be used in diagnosis or surgical planning. The present study describes a standardization method for measuring the spinopelvic parameters and LL in patients with TLSV.

METHODS

Upper and lower endplate spinopelvic parameters (i.e., pelvic incidence [PI], sacral slope [SS], and pelvic tilt) and LL of 108 patients with TLSV were measured by computed tomography. In addition, these parameters were measured for randomly selected subjects without TLSV. The PI value in the TLSV group, which was closer to the mean PI value of the control group, was accepted as valid and then used to create an optimum PI (OPI) group. Finally, the spinopelvic parameters and LL of the OPI and control groups were compared.

RESULTS

Except for SS, all spinopelvic parameters and LL were comparable between the OPI and control groups. In the OPI group, 60% of the patients showed valid upper endplate parameters, and 40% showed valid lower endplate parameters. No difference was noted in the frequency of valid upper or lower endplates between the sacralization and lumbarization groups. Both the OPI and control groups showed nearly comparable correlations between their individual spinopelvic parameters and LL, except for PI and LL in the former.

CONCLUSIONS

Because PI is unique for every individual, the endplate whose PI value is closer to the normative value should be selected as the reference sacral endplate in patients with TLSV.

The influence of lumbosacral transitional vertebrae on lumbar lordosis and the angle of pelvic incidence

Pelvic incidence and lumbar lordosis have only normative values for spines comprising five lumbar and five sacral vertebrae. However, it is unclear how pelvic incidence and lumbar lordosis are affected by the common segmentation anomalies at the lumbo-sacral border leading to lumbosacral transitional vertebrae, including lumbarisations and sacralisations. In lumbosacral transitional vertebrae it is not trivial to identify the correct vertebral endplates to measure pelvic incidence and lumbar lordosis because ontogenetically the first sacral vertebra represents the first non-mobile sacral segment in lumbarisations, but the second segment in sacralisations. We therefore assessed pelvic incidence and lumbar lordosis with respect to both of these vertebral endplates. The type of segmentation anomaly was differentiated using spinal counts, spatial relationship with the iliac crest and morphological features. We found significant differences in pelvic incidence and lumbar lordosis between lumbarisations, sacralisations and the control group. The pelvic incidence in the sacralised group was mostly below the range of the lubarisation group and the control group when measured the traditional way at the first non-mobile segment (30.2°). However, the ranges of the sacralisation and lubarisation groups were completely encompassed by the control group when measured at the ontogenetically true first sacral vertebra. The mean pelvic incidence of the sacraliation group thus increased from 30.2° to 58.6°, and the mean pelvic incidence of the total sample increased from 45.6° to 51.2°, making it statistically indistinguishable from the control sample, whose pelvic incidence was 50.2°. Our results demonstrate that it is crucial to differentiate sacralisations from lumbarisation in order to assess the reference vertebra for pelvic incidence measurement. Due to their significant impact on spino-pelvic parameters, lumbosacral transitional vertebrae should be evaluated separately when examining pelvic incidence and lumbar lordosis.

Lumbar spine segmentation in MR images: a dataset and a public benchmark

This paper presents a large publicly available multi-center lumbar spine magnetic resonance imaging (MRI) dataset with reference segmentations of vertebrae, intervertebral discs (IVDs), and spinal canal. The dataset includes 447 sagittal T1 and T2 MRI series from 218 patients with a history of low back pain and was collected from four different hospitals. An iterative data annotation approach was used by training a segmentation algorithm on a small part of the dataset, enabling semi-automatic segmentation of the remaining images. The algorithm provided an initial segmentation, which was subsequently reviewed, manually corrected, and added to the training data. We provide reference performance values for this baseline algorithm and nnU-Net, which performed comparably. Performance values were computed on a sequestered set of 39 studies with 97 series, which were additionally used to set up a continuous segmentation challenge that allows for a fair comparison of different segmentation algorithms. This study may encourage wider collaboration in the field of spine segmentation and improve the diagnostic value of lumbar spine MRI.

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.

Influences of lumbo-sacral transitional vertebrae for anterior lumbar interbody fusion

Lumbo-sacral transitional vertebrae (LSTV) are frequent congenital variances of the spine and are associated with increased spinal degeneration. Nevertheless, there is a lack of data whether bony alterations associated with LSTV result in reduced segmental restoration of lordosis when performing ALIF. 58 patients with monosegmental stand-alone ALIF in the spinal segment between the 24th and 25th vertebra (L5/S1)/(L5/L6) where included. Of these, 17 patients had LSTV and were matched to a control population by age and sex. Pelvic incidence, pelvic tilt, sagittal vertical axis, lumbar lordosis, segmental lordosis, disc height and depth were compared. LSTV-patients had a significantly reduced segmental lordosis L4/5 (p = 0.028) and L5/S1/(L5/L6) (p = 0.041) preoperatively. ALIF resulted in a significant increase in segmental lordosis L5/S1 (p < 0.001). Postoperatively, the preoperatively reduced segmental lordosis was no longer significantly different in segments L4/5 (p = 0.349) and L5/S1/(L5/6) (p = 0.576). ALIF is associated with a significant increase in segmental lordosis in the treated segment even in patients with LSTV. Therefore, ALIF is a sufficient intervention for restoring the segmental lordosis in these patients as well.

The effect of lumbosacral transitional vertebra on lumbar spine degeneration and spondylolisthesis among patients with low back pain

AIM

To examine the impact of lumbosacral transitional vertebra (LSTV) on lumbar spine degeneration, disc protrusion, and spondylolisthesis among patients with low back pain.

METHODS

The records of the patients who had undergone anterioposterior lumbar radiographs and lumbar magnetic resonance imaging (MRI) for low back pain between November 2014 and September 2021 were extracted retrospectively and assessed for eligibility. Of the remaining patients, those with LSTV were assigned as "case group." Age- and sex-matched patients without LSTV were assigned as "control group." On digitalized lumbar MRIs, Modic degeneration (type I-III) and Pfirrman's disc degeneration (grade I-V) immediately cephalad to the transitional level were evaluated; intervertebral disc height (mm), disc protrusion (mm), and percentage of vertebral slippage (%) were measured.

RESULTS

Of the 501 patients with low back pain, 128 ineligible patients were excluded; 113 patients with LSTV and 117 age- and sex-matched controls were included in the study. LSTV group revealed decreased intervertebral disc height, increased vertebral endplate degeneration, and slippage, as well as increased disc degeneration and protrusion when compared with controls (p < 0.001). Patients with type III LSTV had greater disc protrusion and higher percentage of slippage compared to those with type I LSTV (p = 0.008 and p = 0.009, respectively). Vertebral endplate degeneration, disc height, and disc degeneration did not differ across categories of LSTV type.

CONCLUSION

Lumbosacral transitional vertebra malformation is related to decreased intervertebral disc height, increased disc degeneration, vertebral endplate degeneration, disc protrusion, and slippage above the level of transition. Patients with type III LSTV revealed the highest percentage of slippage and disc protrusion.

Effect of sacralization on the success of lumbar transforaminal epidural steroid injection treatment: prospective clinical trial

OBJECTIVE

The aim of this study was to invastigate the effect of the sacralization on the results of transforaminal epidural steroid injection for radicular low back pain.

MATERIALS AND METHODS

The study included 64 patients diagnosed with radicular low back pain due to unilateral and single-level lumbar disk herniation. Patients were divided into 2 groups: patients with sacralization (Group S) and patients without lumbosacral transitional vertebrae (Group A). Injection was applied to the relevant level. Patients were evaluated with Numeric Rating Scale and Modified Oswestry Disability Index before, at week 3 and month 3 after the procedure. Sacralization presence was determined by MRI. Sacralization was categorized by anteroposterior lumbar radiography using Castellvi classification. Treatment success was considered as ≥ 50% reduction in NRS scores.

RESULTS

Numeric Rating Scale and Modified Oswestry Disability Index scores decreased in both groups on both week 3 and month 3 (p < 0.05). Pain scores of Group S (median value 5 (3-6)) were significantly higher than Group A ((median value 3 (0-5)) in the third month follow-up (p = 0.026), but no significant difference was observed at other time points. There was no significant difference in Modified Oswestry Disability Index scores between the groups at all follow-ups (p > 0.05). Treatment success in the third month was 44.8% in Group S and 65.6% in Group A.

CONCLUSION

Transforaminal epidural steroid injection is an effective and safe method for radicular low back pain. Sacralization presence should be evaluated before treatment considering that it may be a risk factor reducing treatment success.

Approach-related anatomical differences in patients with lumbo-sacral transitional vertebrae undergoing lumbar fusion surgery at level L4/5

INTRODUCTION

Lumbo-sacral transitional vertebrae (LSTV) are accompanied by changes in soft tissue anatomy. The aim of our retrospective study was to evaluate the effects of LSTV as well as the number of free lumbar vertebrae on surgical approaches of ALIF, OLIF and LLIF at level L4/5.

MATERIAL AND METHODS

We assessed the CTs of 819 patients. Of these, 53 had LSTV from which 11 had six (6LV) and 9 four free lumbar vertebrae (4LV). We matched them for sex and age to a control group.

RESULTS

Patients with LSTV had a higher iliac crest and vena cava bifurcation, a greater distance between the common iliac veins and an anterior translation of the psoas muscle at level L4/5. In contrast, patients with 6LV had a lower iliac crest and aortic bifurcation, no differences in vena cava bifurcation and distance between the iliac veins compared to the control group.

CONCLUSIONS

For patients with LSTV and five or four free lumbar vertebrae, the LLIF approach at L4/5 may be hindered due to a high riding iliac crest as well as anterior shift of the psoas muscle. Whereas less mobilization and retraction of the iliac veins may reduce the risk of vascular injury at this segment by ALIF and OLIF. For patients with 6LV, a lower relative height of the iliac crest facilitates lateral approach during LLIF. For ALIF and OLIF, a stronger vessel retraction due to the deeper-seated vascular bifurcation is necessary during ALIF and is therefore potentially at higher risk for vascular injury.

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 Vertebral Anomalies Among Healthy Volunteers and Patients with Hip Pathology: Association with Spinopelvic Characteristics

A lumbosacral transitional vertebra (LSTV) has been reported to be prevalent among patients with hip dysplasia. The aims of this study were to determine the (1) prevalence of an LSTV in young patients presenting with hip pain and a group of asymptomatic volunteers, (2) effect of an LSTV on spinopelvic characteristics, and (3) presence of low back pain among patients with an LSTV.

Methods

This cross-sectional study included 102 patients with hip pathology and 51 asymptomatic volunteers (mean age, 33.9 ± 7.3 years; mean body mass index, 26.0 ± 5.0 kg/m2; 57.5% female). Participants underwent radiographic assessment of the lumbar spine and pelvis in standing and deep-seated positions. LSTV occurrence was classified according to the Castellvi system. Spinopelvic characteristics included lumbar lordosis (including segmental lumbar angles), pelvic tilt, and hip flexion (pelvic-femoral angle). Differences between standing and deep-seated values were calculated. Low back pain was assessed using the Oswestry Disability Index.

Results

The prevalence of LSTV type ≥II was 8.5%, with no difference between patients and volunteers (p = 0.386). Individuals with an LSTV had a greater standing L1-L5 angle (mean, 51.6° ± 11.7° versus 38.9° ± 9.3°; p < 0.001). The overall spinal flexion (change in L1-S1 angle between the standing and deep-seated positions) in individuals with an LSTV was similar to that in individuals without an LSTV; restricted L5-S1 mobility was compensated for at L1-L2 (10.2° ± 5.8° in those with versus 8.4° ± 4.1° in those without an LSTV; p = 0.070). No significant difference in the presence of low back pain was found (p = 0.250).

Conclusions

An LSTV was found in 8.5% of young adults, with no difference between patients with hip pathology and controls. Individuals with an LSTV have greater standing lumbar lordosis, with altered mechanics at the cephalad adjacent level, which may predispose these individuals to degenerative changes at this level.

Level of Evidence

Prognostic Level II. See Instructions for Authors for a complete description of levels of evidence.

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 Influence on Acetabular Orientation and Pelvic Tilt

Lumbosacral transitional vertebrae (LSTV) are common congenital variances with a prevalence found in the population up to 35.6%. The literature demonstrates an influence of LSTV on bony pelvic anatomy. The influence on the anatomical acetabular orientation, which is important for cup positioning in total hip arthroplasty, has not yet been described for patients with LSTV. A total of 53 patients with LSTV were identified from a CT Database including 819 subjects. Fifty patients with LSTV could be included and were matched for age and sex against a control group. We examined the influence of LSTV, classified according to Castellvi, on acetabular orientation and pelvic tilt in the supine position. Functional acetabular anteversion and inclination, assessed against the table plane, were compared against anatomical acetabular anteversion and inclination, assessed against the anterior pelvic plane. The anatomical acetabular inclination correlated with the pelvic tilt (r = 0.363, p < 0.001). The anatomical acetabular inclination was significantly larger than the functional acetabular inclination in the supine position (p < 0.001). Castellvi grading of LSTV correlated negatively with pelvic tilt (ρ = −0.387, p = 0.006). Castellvi grading correlated significantly with functional acetabular anteversion (ρ = 0.324, p = 0.022) and anatomical acetabular anteversion (ρ = 0.306, p = 0.022). A higher Castellvi grading was accompanied by a reduced pelvic tilt in the supine position. The functional acetabular anteversion and anatomical acetabular anteversion increased in parallel to the higher Castellvi grading. Therefore, LSTV and Castellvi grading might be assessed on pre-operative X-rays prior to hip arthroplasty and surgeons might consider adjusting cup positioning accordingly.

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.

Influence of lumbosacral transitional vertebrae on spinopelvic parameters using biplanar slot scanning full body stereoradiography-analysis of 291 healthy volunteers

BACKGROUND

Proper identification of lumbosacral transitional vertebrae (LSTV) is important to characterize the relationship between the transitional segment and adjacent levels. Classical classification schemes are inaccurate with respect to the whole spine. We propose a precise vertebral numbering method and investigated the relationship between LSTV and whole-body sagittal alignment.

METHODS

A total of 291 healthy adult volunteers with no history of spinal disease were evaluated with biplanar slot scanning full body stereoradiography to determine the prevalence of LSTV. Vertebrae were counted from the first cervical vertebra using both coronal and sagittal plane images. We then investigated the influence of LSTV on whole-body sagittal alignment in 279 participants. Whole-body key parameters descriptive statistics were compared among groups according to the number of vertebrae (L4, L5, and L6). Statistical analysis was performed between normal and LSTV cases using the Steel-Dwass analysis.

RESULTS

Of the 291 subjects, 14 (4.8%) had 23 vertebrae and 16 (5.5%) had 25 vertebrae. Eleven (3.8%) had Th11, 3 (1.0%) had L4, and 1 (0.3%) had Th11 + L6, 16 (5.5%) had L6. Compared with the normal group, the sacral base in relation to the pelvis was higher in the L4 group and lower in the L6 group. The C2-C7 angle and lumbar lordosis (LL) were increased in both the L4 and L6 groups. All remaining parameters were decreased in the L4 group and increased in the L6 group. The relationship between LL and PI was similar in the normal and LSTV groups, despite the difference in the sacral base location.

CONCLUSIONS

We propose a precise method for numbering the vertebrae using coronal and sagittal full body images. The spinopelvic parameters of the LSTV population significantly differed from those in the normal spine population due to differences in the sacral base location.

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.

Associations between Patient Report of Pain and Intervertebral Foramina Changes Visible on Axial-Loaded Lumbar Magnetic Resonance Imaging

The intervertebral foramen may influence spinal nerve roots and, therefore, be related to the corresponding dermatomal pain. In vivo evaluation of the intervertebral foramen–dermatome relationship is essential for understanding low back pain (LBP) pathophysiology. The study aimed to correlate the lumbar MRI unloaded-loaded foraminal area changes with dermatomal pain in the patient’s pain drawings. Dynamic changes of the dermatomal pain distribution related to the intervertebral foramen area changes between quantitative conventional supine MRI (unloaded MRI) and axial-loading MRI (alMRI) were analyzed. The MRI axial-loading intervertebral foramen area changes were observed, and the most significant effect of reducing the foraminal area (−6.9%) was reported at levels of L2–L3. The incidence of pain in the dermatomes increases linearly with the spine level, from 15.6% at L1 to 63.3% at L5 on the right and from 18.9% at L1 to 76.7% at L5 on the left. No statistically significant effect of changes in the intervertebral foramen area on the odds of pain along the respective dermatomes was confirmed. Changes in the foraminal area were observed between the unloaded and loaded phases, but differences in area changes between foramen assigned to painful dermatomes and foramen assigned to non-painful dermatomes were not significant.

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.

Clinical decision-making for spinal manipulation for persistent spinal pain following lumbar surgery: a protocol for a systematic review and meta-analysis of individual participant data

INTRODUCTION

There are limited available research and guidance regarding the use of spinal manipulative therapy (SMT) in patients with low back-related symptoms following lumbar spine surgery, a condition called persistent spinal pain syndrome type 2 (PSPS-2). This publication outlines a review protocol to identify and synthesise individual participant data (IPD) to examine associations between patient, clinical and surgical variables and SMT application in adults with PSPS-2.

METHODS AND ANALYSIS

PubMed, OVID, Web of Science, Scopus, PEDro, Index to Chiropractic Literature and KoreaMed will be searched from inception to 1 January 2022 without language restrictions. Case reports, series, observational studies and cases from grey literature of adults receiving SMT for PSPS-2 will be included. Two investigators will independently screen citations, abstracts and full-text articles. A risk-of-bias assessment will be performed in duplicate to rate cases according to exposure and outcome ascertainment and data completeness. Data extraction will be performed in duplicate and missing IPD will be requested from corresponding authors. Multiple binary logistic regression will be used to identify independent predictors of the use of lumbar-SMT, lumbar-manual-thrust SMT and SMT within 1-year postsurgery. Patient, clinical and surgical variables will be summarised using descriptive statistics, while SMT-related outcomes (lumbar-SMT, lumbar-manual-thrust SMT and 1-year surgery-to-SMT interval) will be described using adjusted ORs with 95% CIs.

ETHICS AND DISSEMINATION

This study was deemed not human subjects research by the University Hospitals' institutional review board. The results of this review will be disseminated at conferences and/or published in a peer-reviewed journal.

PROSPERO REGISTRATION NUMBER

CRD42021250039.

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.

Approach to Radiculopathy

Low back pain and neck pain, often with associated radiculopathy, are two of the most common reasons for referral to the outpatient neurology clinic. A thorough clinical evaluation remains paramount in establishing an accurate diagnosis and subsequently an appropriate treatment plan. In this article, we review anatomic considerations for spondylotic radiculopathy; outline the clinical approach for the evaluation of these patients, including discussion of electrodiagnostic and imaging modalities; and address treatment options based on a stratified treatment approach.

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.

Pediatric Back Pain Associated with Bertolotti Syndrome: A Report of 3 Cases with Varying Treatment Strategies

CASE

Three pediatric patients with back pain associated with Bertolotti syndrome are presented. After failing conservative management, 1 patient underwent mega-apophysis resection, another underwent resection with decompression, and the final underwent posterior fusion. All patients had complete resolution of back pain and returned to full activity at final follow-up.

CONCLUSION

Lumbosacral transitional vertebrae are congenital anomalies spanning a spectrum from partial/complete L5 sacralization to partial/complete S1 lumbarization with varying clinical presentations. Identification of variable anatomy and symptoms guides surgical management. We present 3 cases with differing surgical techniques including pseudoarticulation resection, arthrodesis of the involved levels, and neuroforaminal decompression.

The association of lumbosacral transitional vertebral anomalies with acetabular dysplasia in adult patients with hip-spine syndrome : a cross-sectional evaluation of a prospective hip registry cohort

AIMS

Some patients presenting with hip pain and instability and underlying acetabular dysplasia (AD) do not experience resolution of symptoms after surgical management. Hip-spine syndrome is a possible underlying cause. We hypothesized that there is a higher frequency of radiological spine anomalies in patients with AD. We also assessed the relationship between radiological severity of AD and frequency of spine anomalies.

METHODS

In a retrospective analysis of registry data, 122 hips in 122 patients who presented with hip pain and and a final diagnosis of AD were studied. Two observers analyzed hip and spine variables using standard radiographs to assess AD. The frequency of lumbosacral transitional vertebra (LSTV), along with associated Castellvi grade, pars interarticularis defect, and spinal morphological measurements were recorded and correlated with radiological severity of AD.

RESULTS

Out of 122 patients, 110 (90.2%) were female and 12 (9.8%) were male. We analyzed the radiographs of 122 hips (59 (48.4%) symptomatic left hips, and 63 (51.6%) symptomatic right hips). Average age at time of presentation was 34.2 years (SD 11.2). Frequency of LSTV was high (39% to 43%), compared to historic records from the general population, with Castellvi type 3b being the most common (60% to 63%). Patients with AD have increased L4 and L5 interpedicular distance compared to published values. Frequency of pars interarticularis defect was 4%. Intraclass correlation coefficient for hip and spine variables assessed ranged from good (0.60 to 0.75) to excellent (0.75 to 1.00). Severity of AD did not demonstrate significant correlation with frequency of radiological spine anomalies.

CONCLUSION

Patients with AD have increased frequency of spinal anomalies seen on standard hip radiographs. However, there exists no correlation between radiological severity of AD and frequency of spine anomalies. In managing AD patients, clinicians should also assess spinal anomalies that are easily found on standard hip radiographs. Cite this article: Bone Joint J 2021;103-B(8):1351-1357.

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.

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

Objective

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

Methods

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

Results

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

Conclusions

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

Current Applications and Selected Technical Details of Dual-Energy X-Ray Absorptiometry

The application of dual-energy X-ray absorptiometry (DXA) examinations in the assessment of bone mineral density (BMD) in the lumbar spine, hip, and forearm is the basic diagnostic method for recognition of osteoporosis. The constant development of DXA technique is due to the aging of societies and the increasing importance of osteoporosis as a public health problem. In order to assess the degree of bone demineralization in patients with hyperparathyroidism, forearm DXA examination is recommended. The vertebral fracture assessment (VFA) of the thoracic and lumbar spine, performed by a highly-skilled technician, is an interesting alternative to the X-ray examination. The DXA total body examination can be useful in the evaluation of fat redistribution among patients after bariatric surgery, in patients infected with HIV and receiving antiretroviral therapy, and in patients with metabolic diseases and suspected to have sarcopenia. The assessment of visceral adipose tissue (VAT) and detection of abdominal aortic calcifications may be useful in the prediction of cardiovascular events. The positive effect of anti-resorptive therapy may affect some parameters of DXA hip structure analysis (HSA). Long-term anti-resorptive therapy, especially with the use of bisphosphonates, may result in changes in the DXA image, which may herald atypical femur fractures (AFF). Reduction of the periprosthetic BMD in the DXA measurements can be used to estimate the likelihood of loosening the prosthesis and periprosthetic fractures. The present review aims to present current applications and selected technical details of DXA.

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.

Effects of age and sex on the distribution and symmetry of lumbar spinal and neural foraminal stenosis: a natural language processing analysis of 43,255 lumbar MRI reports

Purpose

The purpose of this study is to investigate relationship of patient age and sex to patterns of degenerative spinal stenosis on lumbar MRI (LMRI), rated as moderate or greater by a spine radiologist, using natural language processing (NLP) tools.

Methods

In this retrospective, IRB-approved study, LMRI reports acquired from 2007 to 2017 at a single institution were parsed with a rules-based natural language processing (NLP) algorithm for free-text descriptors of spinal canal stenosis (SCS) and neural foraminal stenosis (NFS) at each of six spinal levels (T12-S1) and categorized according to a 6-point grading scale. Demographic differences in the anatomic distribution of moderate (grade 3) or greater SCS and NFS were calculated by sex, and age and within-group differences for NFS symmetry (left vs. right) were calculated as odds ratios.

Results

Forty-three thousand two hundred fifty-five LMRI reports (34,947 unique patients, mean age = 54.7; sex = 54.9% women) interpreted by 152 radiologists were studied. Prevalence of significant SCS and NFS increased caudally from T12-L1 to L4-5 though less at L5-S1. NFS was asymmetrically more prevalent on the left at L2-L3 and L5-S1 (p < 0.001). SCS and NFS were more prevalent in men and SCS increased with age at all levels, but the effect size of age was largest at T12-L3. Younger patients (< 50 years) had relatively higher NFS prevalence at L5-S1.

Conclusion

NLP can identify patterns of lumbar spine degeneration through analysis of a large corpus of radiologist interpretations. Demographic differences in stenosis prevalence shed light on the natural history and pathogenesis of LSDD.

Changes of Fixed Anatomical Spinopelvic Parameter in Patients with Lumbosacral Transitional Vertebrae: A Matched Pair Analysis

Functional spinopelvic parameters are crucial for describing spinal alignment (SA), but this is susceptible to variation. Anatomically fixed pelvic shape is defined by the parameters pelvic radius (PR), pelvic incidence (PI), and sacral table angle (STA). In patients with lumbosacral transitional vertebrae (LSTV), the spinopelvic alignment may be altered by changes of these parameters and influences of SA. There have been no reports studying the relation between LSTV, four (4 LV) and six (6 LV) lumbar vertebrae, and fixed anatomical spinopelvic parameters. A retrospective analysis of 819 abdomen–pelvis CT scans was performed, identifying 53 patients with LSTV. In a matched-pair analysis, we analyzed the influence of LSTV and the subgroups 4 LV (n = 9) and 6 LV (n = 11) on PR, PI, and STA. LSTV were classified according to Castellvi classification. In patients with 6 LV, measurement points at the superior endplates of S1 and S2 were compared. The prevalence of LSTV was 6.5% (53/819), 6 LV was 1.3% (11/819), and 4 LV was 1.1% (9/819) in our study population. PI significantly increased (p < 0.001), STA significantly decreased (p < 0.001), and PR (p = 0.051) did not differ significantly in the LSTV group (n = 53). Similar findings were observed in the 4 LV subgroup, with an increase in PI (p < 0.021), decrease in STA (p < 0.011), and no significant difference in PR (p < 0.678). The same results were obtained in the 6 LV subgroup at measuring point S2 (true S1) PI (p = 0.010), STA (p = 0.004), and PR (p = 0.859), but not at measuring point S1 (true L6). Patients with LSTV, 4 LV, and 6 LV showed significant differences in PI and STA compared to the matched control group. PR showed no significant differences. The altered spinopelvic anatomy in LSTV patients need to be reflected in preoperative planning rebalancing the sagittal SA.

Evaluation of a multiview architecture for automatic vertebral labeling of palliative radiotherapy simulation CT images

PURPOSE

The purpose of this work was to evaluate the performance of X-Net, a multiview deep learning architecture, to automatically label vertebral levels (S2-C1) in palliative radiotherapy simulation CT scans.

METHODS

For each patient CT scan, our automated approach 1) segmented spinal canal using a convolutional-neural network (CNN), 2) formed sagittal and coronal intensity projection pairs, 3) labeled vertebral levels with X-Net, and 4) detected irregular intervertebral spacing using an analytic methodology. The spinal canal CNN was trained via fivefold cross validation using 1,966 simulation CT scans and evaluated on 330 CT scans. After labeling vertebral levels (S2-C1) in 897 palliative radiotherapy simulation CT scans, a volume of interest surrounding the spinal canal in each patient's CT scan was converted into sagittal and coronal intensity projection image pairs. Then, intensity projection image pairs were augmented and used to train X-Net to automatically label vertebral levels using fivefold cross validation (n = 803). Prior to testing upon the final test set (n = 94), CT scans of patients with anatomical abnormalities, surgical implants, or other atypical features from the final test set were placed in an outlier group (n = 20), whereas those without these features were placed in a normative group (n = 74). The performance of X-Net, X-Net Ensemble, and another leading vertebral labeling architecture (Btrfly Net) was evaluated on both groups using identification rate, localization error, and other metrics. The performance of our approach was also evaluated on the MICCAI 2014 test dataset (n = 60). Finally, a method to detect irregular intervertebral spacing was created based on the rate of change in spacing between predicted vertebral body locations and was also evaluated using the final test set. Receiver operating characteristic analysis was used to investigate the performance of the method to detect irregular intervertebral spacing.

RESULTS

The spinal canal architecture yielded centroid coordinates spanning S2-C1 with submillimeter accuracy (mean ± standard deviation, 0.399 ± 0.299 mm; n = 330 patients) and was robust in the localization of spinal canal centroid to surgical implants and widespread metastases. Cross-validation testing of X-Net for vertebral labeling revealed that the deep learning model performance (F1 score, precision, and sensitivity) improved with CT scan length. The X-Net, X-Net Ensemble, and Btrfly Net mean identification rates and localization errors were 92.4% and 2.3 mm, 94.2% and 2.2 mm, and 90.5% and 3.4 mm, respectively, in the final test set and 96.7% and 2.2 mm, 96.9% and 2.0 mm, and 94.8% and 3.3 mm, respectively, within the normative group of the final test set. The X-Net Ensemble yielded the highest percentage of patients (94%) having all vertebral bodies identified correctly in the final test set when the three most inferior and superior vertebral bodies were excluded from the CT scan. The method used to detect labeling failures had 67% sensitivity and 95% specificity when combined with the X-Net Ensemble and flagged five of six patients with atypical vertebral counts (additional thoracic (T13), additional lumbar (L6) or only four lumbar vertebrae). Mean identification rate on the MICCAI 2014 dataset using an X-Net Ensemble was increased from 86.8% to 91.3% through the use of transfer learning and obtained state-of-the-art results for various regions of the spine.

CONCLUSIONS

We trained X-Net, our unique convolutional neural network, to automatically label vertebral levels from S2 to C1 on palliative radiotherapy CT images and found that an ensemble of X-Net models had high vertebral body identification rate (94.2%) and small localization errors (2.2 ± 1.8 mm). In addition, our transfer learning approach achieved state-of-the-art results on a well-known benchmark dataset with high identification rate (91.3%) and low localization error (3.3 mm ± 2.7 mm). When we pre-screened radiotherapy CT images for the presence of hardware, surgical implants, or other anatomic abnormalities prior to the use of X-Net, it labeled the spine correctly in more than 97% of patients and 94% of patients when scans were not prescreened. Automatically generated labels are robust to widespread vertebral metastases and surgical implants and our method to detect labeling failures based on neighborhood intervertebral spacing can reliably identify patients with an additional lumbar or thoracic vertebral body.

Sacroiliac joint syndrome after lumbosacral fusion

INTRODUCTION

One-third of low back pain cases are due to the sacroiliac (SI) joint. The incidence increases after lumbosacral fusion. A positive Fortin Finger Test points to the SI joint being the origin of the pain; however, clinical examination and imaging are not specific and minimally contributory. The gold standard is a test injection of local anesthetic. More than 70% reduction in pain after this injection confirms the SI joint is the cause of the pain. The aim of this study was to evaluate the decrease in pain on a Numerical Rating Scale (NRS) after intra-articular injection into the SI joint. We hypothesised that intra-articular SI injection will significantly reduce SI pain after lumbosacral fusion.

METHODS

All patients with pain (NRS>7/10) suspected of being caused by SI joint syndrome 1 year after lumbosacral fusion with positive Fortin test were included. Patients with lumbar or hip pathologies or inflammatory disease of the SI joint were excluded. Each patient underwent a 2D-guided injection of local anesthetic into the SI joint. If this failed, a second 2D-guided injection was done; if this also failed, a third 3D-guided injection was done. Reduction of pain on the NRS by>70% in the first 2 days after the injection confirmed the diagnosis. Whether the injection was intra-articular or not, it was recorded. Ninety-four patients with a mean age of 57 years were included, of which 70% were women.

RESULTS

Of the 94 patients, 85 had less pain (90%) after one of the three injections. The mean NRS was 8.6/10 (7-10) before the injection and 1.7/10 after the injection (0-3) (p=0.0001). Of the 146 2D-guided injections, 41% were effective and 61% were intra-articular. Of the 34 3D-guided injections, 73% were effective and 100% were intra-articular.

DISCUSSION

This study found a significant decrease in SI joint-related pain after intra-articular injection into the SI joint in patients who still had pain after lumbosacral fusion. If this injection is non-contributive when CT-guided under local anesthesia, it can be repeated under general anesthesia with 3D O-arm guidance. This diagnostic strategy allowed us to confirm that pain originates in the SI joint after lumbosacral fusion in 9 of 10 patients.

CONCLUSION

If the first two CT-guided SI joint injections fail, 3D surgical navigation is an alternative means of doing the injection that helps to significantly reduce SI joint-related pain after lumbosacral fusion.

LEVEL OF EVIDENCE

IV, retrospective study.

Segmented lordotic angles to assess lumbosacral transitional vertebra on EOS

PURPOSE

To test the vertical posterior vertebral angles (VPVA) of the most caudal lumbar segments measured on EOS to identify and classify the lumbosacral transitional vertebra (LSTV).

METHODS

We reviewed the EOS examinations of 906 patients to measure the VPVA at the most caudal lumbar segment (cVPVA) and at the immediately proximal segment (pVPVA), with dVPVA being the result of their difference. Mann-Whitney, Chi-square, and ROC curve statistics were used.

RESULTS

172/906 patients (19%) had LSTV (112 females, mean age: 43 ± 21 years), and 89/172 had type I LSTV (52%), 42/172 type II (24%), 33/172 type III (19%), and 8/172 type IV (5%). The cVPVA and dVPVA in non-articulated patients were significantly higher than those of patients with LSTV, patients with only accessory articulations, and patients with only bony fusion (all p < .001). The cVPVA and dVPVA in L5 sacralization were significantly higher than in S1 lumbarization (p < .001). The following optimal cutoff was found: cVPVA of 28.2° (AUC = 0.797) and dVPVA of 11.1° (AUC = 0.782) to identify LSTV; cVPVA of 28.2° (AUC = 0.665) and dVPVA of 8° (AUC = 0.718) to identify type II LSTV; cVPVA of 25.5° (AUC = 0.797) and dVPVA of - 7.5° (AUC = 0.831) to identify type III-IV LSTV; cVPVA of 20.4° (AUC = 0.693) and dVPVA of - 1.8° (AUC = 0.665) to differentiate type II from III-IV LSTV; cVPVA of 17.9° (AUC = 0.741) and dVPVA of - 4.5° (AUC = 0.774) to differentiate L5 sacralization from S1 lumbarization.

CONCLUSION

The cVPVA and dVPVA measured on EOS showed good diagnostic performance to identify LSTV, to correctly classify it, and to differentiate L5 sacralization from S1 lumbarization.

Anatomical Variations That Can Lead to Spine Surgery at the Wrong Level: Part III Lumbosacral Spine

Spine surgery at the wrong level is an undesirable event and unique pitfall in spine surgery. It is detrimental to the relationship between the patient and the surgeon and typically results in profound medical and legal consequences. It falls under the wrong-site surgery sentinel events reporting system. This error is most frequently observed in lumbosacral spine. Several risk factors are implicated; however, anatomical variations of the lumbosacral spine are a major risk factor. The aim of this article was to provide a detailed description of these high-risk anatomical variations, including transitional vertebrae, lumbar ribs, butterfly vertebrae, hemivertebra, block/fused vertebrae, and spinal dysraphism. A literature review was performed in the database PubMed to obtain all relative English-only articles concerning these anatomical variations and their implication in the development of lumbosacral spine surgery at the wrong level. We also described patient characteristics that can lead to lumbosacral surgery at the wrong level such as tumors, infection, previous lumbosacral surgery, obesity, and osteoporosis. Certain techniques to prevent such incorrect surgery were explained. Lumbosacral spine anatomical variations are surgically significant. Awareness of their existence may provide better pre-operative planning and surgical intervention, leading to avoidance of incorrect-level surgery and potentially better clinical outcomes. In addition, collaboration with radiologists and careful examination of patient’s anatomy and characteristics should be exercised, especially in difficult cases.

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.

Sacral Dysmorphism and Lumbosacral Transitional Vertebrae (LSTV) Review

Background

Anatomic variation in the relationship between the lumbar spine and sacrum was first described in the literature nearly a century ago and continues to play an important role in spine deformity, low back pain (LBP), and pelvic trauma. This review will focus on the clinical and surgical implications of abnormal lumbosacral anatomy in the context of sacroiliac joint (SIJ) disease, spine deformity, and pelvic trauma.

Methods

A PubMed search using the keywords "lumbosacral transitional vertebrae," "LSTV," "transitional lumbosacral vertebrae," "TLSV," and "sacral dysmorphism" was performed. The articles presented here were evaluated by the authors.

Clinical Significance

The prevalence of LSTV varies widely in the literature from 3.9-% to 35.6% in the spine literature, and sacral dysmorphism is described in upwards of 50% of the population in the trauma literature. The relationship between LSTV and LBP is well established. While there is no agreed-on etiology, the source of pain is multifactorial and may be related to abnormal biomechanics and alignment, disc degeneration, and arthritic changes.

Surgical Implications

Understanding abnormal lumbosacral anatomy is crucial for preoperative planning of SIJ fusion, spine deformity, and pelvic trauma surgery. LSTV can alter spinopelvic parameters crucial in planning spine deformity correction. Traditional safe zones for sacroiliac screw placement do not apply in the first sacral segment in sacral dysmorphism and risk iatrogenic nerve injury.

Conclusions

LSTV and sacral dysmorphism are common anatomic variants found in the general population. Abnormal lumbosacral anatomy plays a significant role in clinical evaluation of LBP and surgical planning in SIJ fusion, spine deformity, and pelvic trauma. Further studies evaluating the influence of abnormal lumbosacral anatomy on LBP and surgical technique would help guide treatment for these patients.

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.