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

Transitional, fused and/or supernumerary vertebrae in the lumbosacrocaudal region of the spine - A reality in many domestic mammals

The aim of this study was to identify the presence of transitional lumbosacral and sacrocaudal vertebrae in domestic mammals, to realise a comparative analysis of the localisation and conformation of this abnormal condition. The research included the following species: cattle - 29 specimens, sheep - 32 specimens, horse - 31 specimens, pig - 26 specimens, rabbit - 33 specimens, dog - 89 specimens and cat - 57 specimens. The spine of the animals was analysed post-mortem or radiologically. The investigations revealed the presence of transitional vertebrae as follows: in cattle - 3 cases (8.7%), all being about the lumbarisation of the first sacral vertebra (S1); in sheep - 3 cases (9.37%), two lumbarisation cases of S1 and one caudalisation of S4 (the last sacral vertebra); in horses - 4 cases (12.9%), all about the sacralisation of Cd1 (first caudal vertebra); in pigs - 3 cases (11.53%), two lumbarisation cases of S1 and one sacralisation of Cd1; in rabbits - 3 cases (9.09%), a lumbar supernumerary vertebra (L8) and two cases of caudalisation of S4; in dogs - 4 cases (4.49%), a lumbar supernumerary vertebra (L8) and 3 cases of sacralisation of the last lumbar vertebra (L7 or L8); in cats - 3 cases (5.26%), two sacralisation cases of the last lumbar vertebra and one case of caudalisation of the last sacral vertebra (S3). A strong lumbarisation process was observed in ruminants (especially in cattle), then in pigs, the sacralisation being prevalent in carnivores. The sacrocaudal transitional vertebra was predominant in horses. No evident influence of the sex and age of the animals was observed.

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.

Redefining the Treatment of Lumbosacral Transitional Vertebrae for Bertolotti Syndrome: Long-Term Outcomes Utilizing the Jenkins Classification to Determine Treatment

OBJECTIVE

Using the Jenkins classification, we propose a strategy of shaving down hypertrophic bone, unilateral fusion, or bilateral fusion procedures to achieve pain reduction and improve quality of life for patients with Bertolotti syndrome.

METHODS

We reviewed 103 patients from 2012 through 2021 who had surgically treated Bertolotti syndrome. We identified 56 patients with Bertolotti syndrome and at least 6 months of follow-up. Patients with iliac contact preoperatively were presumed to be more likely to have hip pain that could respond to surgical treatment, and those patients were tracked for those outcomes as well.

RESULTS

Type 1 patients (n = 13) underwent resection. Eleven (85%) had improvement, 7 (54%) had good outcome, 1 (7%) had subsequent surgery, 1 (7%) was suggested additional surgery, and 2 (14%) were lost to follow-up. In Type 2 patients (n = 36), 18 underwent decompressions and 18 underwent fusions as a first line. Of the 18 patients treated with resection an interim analysis saw 10 (55%) with failure and needing subsequent procedures. With subsequent procedure, 14 (78%) saw improvement. For fusion surgical patients, 16 (88%) saw some improvement and 13 (72%) had a good outcome. In Type 4 patients (n = 7), 6 (86%) did well with unilateral fusion, with durable benefit at 2 years. In patients who had hip pain preoperatively (n = 27), 21 (78%) had improvement of hip pain postoperatively.

CONCLUSIONS

The Jenkins classification system provides a strategy for patients with Bertolotti syndrome who fail conservative therapy. Patients with Type 1 anatomy respond well to resection procedures. Patients with Type 2 and Type 4 anatomy respond well to fusion procedures. These patients respond well in regard to hip pain.

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

Background

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

Methods

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

Results

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

Conclusion

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

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.

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

OBJECTIVE

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSION

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