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.

A rare cause of low back pain in adolescence - Bertolotti syndrome: A case report

Background

Bertolotti syndrome (BS) is defined as a congenital anomaly of the spine that includes sacralization of the lowest lumbar vertebra or lumbarization of the first sacral vertebra (i.e., lumbosacral transitional vertebra- LSTV) and the pain associated with this condition. The incidence of BS in adolescence is rare; we found only three such case reports of patients under the age of 18 in the literature, here will add a fourth.

Case Description

A 17-year-old female presented with a 2-month history of low back pain exacerbated by physical activity. Her neurological examination was normal, except for pain elicited when applying pressure over the sacroiliac joints bilaterally, and over the spinous process of the L5 vertebra. The computed tomography scan documented BS: (i.e., LSTV - Castellvi classification: Type IIa on the left side). She was successfully treated with nonsteroidal anti-inflammatory drugs (NSAIDs) alone.

Conclusion

Here, we report a 17-year-old female who was symptomatic from BS and was successfully treated with NSAIDs.

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.

Clinical assessment and management of Bertolotti Syndrome: a review of the literature

Bertolotti Syndrome is a diagnosis given to patients experiencing pain caused by the presence of a lumbosacral transitional vertebra (LSTV), which is characterized by enlargement of the L5 transverse process(es), with potential pseudoarticulation or fusion with the sacrum. The Castellvi classification system is commonly utilized to grade LSTVs based on the degree of contact between the L5 transverse process(es) and the sacrum. LSTVs present a diagnostic dilemma to the treating clinician, as they may remain unidentified on plain x-rays and even advanced imaging; additionally, even if the malformation is identified, patients with a LSTV may be asymptomatic or have nonspecific symptoms, such as low back pain with or without radicular symptoms. With low back pain being extremely prevalent in the general population; it can be difficult to implicate the LSTV as the source of this pain. Care should be taken however, to exclude Bertolotti Syndrome in patients under 30 years old presenting with persisting low back pain given its congenital origin. If a LSTV is identified, typically with acquisition of a MRI or CT scan of the lumbosacral spine, and there is an absence of a more compelling or obvious source for the patient's symptoms, a conservative, step-wise management plan is recommended. This may include assessing for improvement in symptoms with injections prior to proceeding with surgical intervention. Additional concerns arise from the biomechanical alterations that a LSTV induces in adjacent spinal levels, predisposing this patient population to a more rapid-onset of adjacent segment disease, raising the question as to the most appropriate surgery (resection of LSTV pseudoarticulation with or without fusion). Postoperative outcome data for patients undergoing surgical treatment is limited in the literature with promising, but variable, results. More large-scale, controlled studies must be performed to gain further insight into the ideal work-up and management of this pathology.

Re-examining the Spectrum of Lumbosacral Transitional Dysmorphisms: Quantifying Joint Asymmetries and Evaluating the Anatomy of Screw Fixation Corridors

Objective

Although a wide range of sacral dysmorphisms has been documented with lumbosacral transitional vertebrae (LSTV) variations, quantitative characterization of the upper segment morphology and articular anatomy across the array of lumbosacral transitions are hardly found in the literature. This study presents LSTV anomalies as a series of sequential morphological changes (the LSTV spectrum) and quantitatively compares 6 LSTV subtypes with normative sacral dimensions including the anatomy at the upper sacral segments used for percutaneous sacroiliac screw insertion.

Methods

Seven linear dimensions were measured from LSTV subtypes and normal sacral variants from dried adult sacral specimens. The auricular, superior articular and facet surface areas were quantified. Obliquity and thickness of osseous corridors used for sacroiliac screw fixation were measured. Data were statistically compared within and between LSTV subtypes and the normal variants.

Results

LSTVs presented a wide range of morphometric differences in comparison to the normal bones. Grouping LSTV according to auricular surface positions (high, normal, and low) demonstrated significant between-group differences in the obliquity and thickness at the S1 and S2 segmental corridors.

Conclusion

Frequent occurrence of LSTV in the general population may require evaluation of anatomical parameters in these variations for safe sacroiliac instrumentation around this region.

Bertolotti's syndrome in low-backache population: Classification and imaging findings

Objective:

Lumbosacral transition vertebrae (LSTVs) are associated with alterations in biomechanics and anatomy of spinal and paraspinal structures, which have important implications on surgical approaches and techniques. LSTVs are often inaccurately detected and classified on standard anteroposterior radiographs and magnetic resonance imaging. The use of whole-spine images as well as geometric relationships between the sacrum and lumbar vertebra increases accuracy. The diagnosis of symptomatic LSTV is considered with appropriate patient history and imaging studies. This study aimed to classify the anatomical variations in LSTV and determine, by plain radiography, if there exists a relationship between sacralization and low backache (LBP).

Materials and Methods:

Five hundred lumbosacral radiographs of LBP patients were examined after obtaining prior consent from the patient and approval from the “institutional ethics committee.” Data collection consisted of the patient's age at the time of imaging gender and number of lumbar vertebral bodies. Dysplastic transverse processes were classified according to the Castellvi radiographic classification system. The incidence of sacralization in patients and the control groups was reported, and the anomaly was compared according to the groups.

Results:

Of these patient groups, 134 were classified as positive for sacralization, which resulted in an incidence of 26.8%. The most common anatomical variant was Castellvi Type IA (7.6%). There were no statistically significant differences between men and women who had anomaly (P = 0.9256). Higher incidences of Type IB and Type IIB were found in men, but those results were not statistically significant (P = 0.133 and P = 0.581, respectively) when compared with the female group. Daily frequency and intensity of LBP were assessed in patients using visual analog scale (VAS) scores. The patients with LBP and no malformation reported an average pain level on the VAS for pain of 2.2 versus 5.2 in patients with LBP and a transitional vertebra, respectively.

Conclusion:

Based on our data, we conclude that lumbosacral transitional segments are a common cause in the low-backache population. However, no relationship was found between age and genders in this study. However, in comparison with the nonspecific low-backache group, the VAS scores were significantly higher and the pain duration was significantly longer in the LSTV group.

Pars inter-articularis and laminar morphology of the terminal lumbar vertebra in lumbosacral transitional variations

Background:

Lumbo-sacral transitional variations are common in the general population. Structural inadequacies of the terminal lumbar vertebral pars interarticularis (PI) and lamina have often been implicated as important factors for lumbo-sacral instability.

Aims:

Quantifying dimensions of PI and laminae in terminal lumbar vertebrae associated with lumbosacral transitions and compare them with their normal counterparts.

Materials and Methods:

Fourth lumbar vertebrae in spines involved with complete sacralization of the fifth lumbar (L5) vertebrae and L5 vertebrae associated with lumbosacral accessory articulation were measured for the height, width and thickness of the PI and the laminae on both sides and compared to normal vertebrae.

Results:

Dimensions in sacralization associated terminal vertebrae were smaller than the normal. The height of the PI and the widths of laminae were observed to be significantly smaller in terminal lumbar segment in sacralized specimen. Lumbo-sacral accessory articulations demonstrated smaller overall dimensions of several parameters. Lamiane in the last lumbar segment associated with lumbo-sacral transitions demonstrate smaller dimensions compared to the normal ones. Sacralization results in maximum diminution of these parameters.

Conclusions:

Smaller PI may predispose spondylolysis and spondylolisthesis at lumbo-sacral junctions associated with transitional variations, and warrant special attention to avoid iatrogenic injuries.