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.

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.

Quantitative Evaluation of the Lumbar Multifidus Muscle by Shear Wave Dispersion in Healthy Adults: A Preliminary Study.

OBJECTIVES: To investigate the application value of shear wave dispersion (SWD) in healthy adults with the lumbar multifidus muscle (LMM), to determine the range of normal reference values, and to analyze the influences of factors on the parameter. METHODS: Ninety-five healthy volunteers participated in the study, from whom 2-dimensional, shear wave elastography (SWE), and SWD images of the bilateral LMM were acquired in three positions (prone, standing, and anterior flexion). Subcutaneous fat thickness (SFH), SWE velocity, and SWD slope were measured accordingly for analyses. RESULTS: The mean SWD slope of the bilateral LMM in the prone position was as follows: left: 14.8 ± 3.1 (m/second)/kHz (female) and 13.0 ± 2.5 (m/second)/kHz (male); right: 14.8 ± 3.7 (m/second)/kHz (female) and 14.2 ± 3.4 (m/second)/kHz (male). In the prone position, there was a weak negative correlation between the bilateral LMM SWD slope of activity level 2 and level 1 (ß = -1.5 (2 versus 1, left), -1.9 (2 versus 1, right), all P < .05), and between the left SWD slope of activity level 3 and level 1 (ß = -2.3 [3 versus 1, left], P < .05). The correlation between SWE velocity and SWD slope value changed with the position: there was a weak positive correlation in the prone position (r = 0.3 [left], 0.37 [right], both P < .05), and a moderate positive correlation in the standing and anterior flexed positions (r = 0.49-0.74, both P < .001). SFH was moderately negatively correlated with bilateral SWD slope values in the anterior flexion (left: r = -0.4, P = .01; right: r = -0.7, P < .01). CONCLUSIONS: SWD imaging can be used as an adjunct tool to aid in the assessment of viscosity in LMM. Further, activity level, and position are influencing factors that should be considered in clinical practice.

Fatty infiltration of the erector spinae at the upper lumbar spine could be a landmark for low back pain.

PURPOSE: Intervertebral disc degeneration (IVDD), Modic changes, and fatty infiltration in the paraspinal muscles are possible causes of low back pain (LBP). Multifidus has been the most commonly blamed paraspinal muscle in the etiology of LBP. However, it contributes to 20% of the extensor moment on the lumbar spine. In the present study, we aimed to identify whether patients with LBP and asymptomatic subjects differed in terms of intervertebral discs, end-plates, and fatty infiltration in their paraspinal muscles. METHODS: Consecutive women and men, who visited the spine outpatient clinics with chronic LBP and had lumbar spine MRI for their LBP without leg pain were included. Asymptomatic subjects without LBP/leg pain for the last year were recruited. Modic changes, IVDD, and fatty infiltration in the paraspinal muscles were evaluated on lumbar spine magnetic resonance imagings of the patients with LBP and age-, gender- and BMI-matched asymptomatic controls. RESULTS: Low back pain was closely associated with fatty infiltration in the paraspinal muscles at all lumbar levels whereas it had association with severe IVDD and Modic changes at lower lumbar levels. Multifidus at the lower lumbar levels was the fattiest paraspinal muscle in both asymptomatic subjects and patients with LBP. Patients with LBP had severe fatty infiltration in the erector spinae at the upper lumbar levels. CONCLUSION: Severe IVDD and Modic changes were more common at lower lumbar levels in patients with LBP. Both asymptomatic subjects and those with LBP had fatty multifidus at lower lumbar levels, whereas those with LBP had fatty infiltration in the erector spinae at upper lumbar levels. We suggest that fatty infiltration could have started in the multifidus. The erector spinae had greater contribution to the lumbar extension compared to the multifidus. Thus, LBP could develop when the quality of the erector spinae at the upper lumbar levels impairs due to fatty infiltration.

Thoracolumbar Fascia and Lumbar Muscle Stiffness in Athletes with A History of Hamstring Injury.

The purpose of this study was to examine the differences in thoracolumbar fascia (TLF) and lumbar muscle modulus in individuals with and without hamstring injury using shear wave elastography (SWE). Thirteen male soccer players without a previous hamstring injury and eleven players with a history of hamstring injury performed passive and active (submaximal) knee flexion efforts from 0°, 45° and 90° angle of knee flexion as well as an active prone trunk extension test. The elastic modulus of the TLF, the erector spinae (ES) and the multifidus (MF) was measured using ultrasound SWE simultaneously with the surface electromyography (EMG) signal of the ES and MF. The TLF SWE modulus was significantly (p < 0.05) higher in the injured group (range: 29.86 ± 8.58 to 66.57 ± 11.71 kPa) than in the uninjured group (range: 17.47 ± 9.37 to 47.03 ± 16.04 kPa). The ES and MF modulus ranged from 14.97 ± 4.10 to 66.57 ± 11.71 kPa in the injured group and it was significantly (p < .05) greater compared to the uninjured group (range: 11.65 ± 5.99 to 40.49 ± 12.35 kPa). TLF modulus was greater than ES and MF modulus (p < 0.05). Active modulus was greater during the prone trunk extension test compared to the knee flexion tests and it was greater in the knee flexion test at 0° than at 90° (p < 0.05). The muscle EMG was greater in the injured compared to the uninjured group in the passive tests only (p < 0.05). SWE modulus of the TLF and ES and MF was greater in soccer players with previous hamstring injury than uninjured players. Further research could establish whether exercises that target the paraspinal muscles and the lumbar fascia can assist in preventing individuals with a history of hamstring injury from sustaining a new injury.

CORRELATION OF SPINOPELVIC PARAMETERS WITH DISABILITY STATUS IN PATIENTS WITH DEGENERATIVE LUMBAR DISEASES.

Lumbar degenerative disease usually manifests in spine clinics. This study examines the spino-pelvic characteristics of lumbar degenerative disease patients as well as the clinical ramifications in the Indian population which help in early identification of sagittal spine anomalies. Purpose - to study the spinopelvic parameters and correlate them with disability status in patients with degenerative lumbar diseases. This cross-sectional observational study focused on patients aged 40 to 60, diagnosed with degenerative lumbar spine diseases, seen at the Orthopedics Outpatient Department. Thorough history, clinical examination, and disability assessment were conducted using the modified Oswestery Disability Questionnaire (ODI). Radiological evaluation included measuring spinopelvic parameters-Pelvic Incidence (PI), Pelvic Tilt (PT), Sacral Slope (SS), and Lumbar Lordosis (LL)-correlated with disability. Disability status was determined through the Oswestry Low Back Pain Disability (ODI) Questionnaire. Among the study population, the difference in mean of Pelvic Tilt, Sacral slope, Lumbar lordosis, Pelvic incidence across disability status was not statistically significant. BMI and sacral slope showed positive correlation to sacral slope and negative correlation to Pelvic Tilt, Lumbar Lordosis, ODI. This study concluded there was no association between spinopelvic characteristics and level of disability in degenerative lumbar disease. Early detection of spinopelvic changes can aid in early intervention, slow down disease progression, and lessen impairment brought on by degenerative disc diseases.

Iatrogenic lumbosacral infiltration with petroleum (hydrodesulfurized heavy) with secondary intrathecal distribution-a case report.

Petroleum is commonly used as a solvent, and primary intrathecal administration or secondary diffusion and subsequent clinical management has not been reported. We report the case of a male patient with intrathecal petroleum diffusion following accidental lumbar infiltration. After the onset of secondary myeloencephalopathy with coma and tetraparesis, continuous cranio-lumbar irrigation using an external ventricular and a lumbar drain was established. Cranial imaging revealed distinct supra- and infratentorial alterations. The patient improved slowly and was referred to rehabilitation. Intrathecal petroleum leads to myeloencephalopathy and continuous cranio-lumbar irrigation might be a safe treatment option.

Inter-Examiner Disagreement for Assessing Cervical Multifidus Ultrasound Metrics Is Associated with Body Composition Features.

Ultrasound imaging (US) is a biosensing technique that is widely used in several healthcare disciplines (including physiotherapy) for assessing multiple muscle metrics, such as muscle morphology and quality. Since all biosensors need to be tested in order to demonstrate their reliability, accuracy, sensitivity, and specificity, identifying factors that affect their diagnostic accuracy is essential. Since previous studies analyzed the impact of sociodemographic but not body composition characteristics in US errors, this study aimed to assess whether body composition metrics are associated with ultrasound measurement errors. B-mode images of the lumbar multifidus muscle at the L5 level were acquired and analyzed in 47 healthy volunteers by two examiners (one experienced and one novice). The cross-sectional area, muscle perimeter, and mean echo intensity were calculated bilaterally. A correlation analysis and a multivariate linear regression model were used for assessing the inter-examiner differences with respect to body composition metrics. The results demonstrated good-to-excellent reliability estimates for the cross-sectional area, muscle perimeter, aspect ratio, roundness, circularity, and mean brightness metrics (all ICC > 0.85). However, solidity showed unacceptable reliability (ICC < 0.7). Age, height, total lean mass, trunk lean mass, and water volume were associated with inter-examiner disagreement on mean echo intensity. Cross-sectional area, perimeter, and roundness measurement errors were associated with lean mass and water volume.

Ultrasound evidence of altered lumbar fascia in patients with low back pain.

Different hypotheses have been proposed about the role of lumbar connective tissue in low back pain (LBP). However, none of the previous studies have examined the change in the elastic behavior of lumbar fascia in patients with LBP. The present study aimed to evaluate the changes in the elastic behavior of lumbar fascia in patients with chronic non-specific LBP based on ultrasound imaging. The sonographic strain imaging assessed the thoracolumbar fascia (TLF) of 131 human subjects (68 LBP and 63 non-LBP). Assessments were done at L2-L3 and L4-L5 levels bilaterally. The points were located 2 cm lateral to the midpoint of the interspinous ligament. There were no significant differences in age, sex, and BMI between LBP and healthy individuals. There is a strong inverse relationship between pain severity (r = -0.76, n = 68, p = 0.004) and the TLF elastic modulus coefficient. No significant relationship were observed between age (r = 0.053, n = 68, p = 0.600), BMI (r = -0.45, n = 68, p = 0.092), and gender (r = -0.09, n = 68, p = 0.231) with the TLF elasticity coefficient. The LBP group had a 25%-30% lower TLF elastic modulus coefficient than healthy individuals. The present study is the first to evaluate the elastic coefficient of TLF using the ultrasound imaging method. The study results showed that the TLF elastic coefficient in patients with LBP was reduced compared to healthy individuals and directly related to LBP severity.

Reliability of lumbar multifidus ultrasound assessment during the active straight leg raise test.

BACKGROUND: Previous evidence showed altered lumbar multifidus (LM) activation in populations with chronic nonspecific low back pain (LBP). We aimed to investigate the test-retest and inter-examiner reliability of ultrasound imaging (US) for assessing LM thickness at rest and activation during the active straight leg raise test (ASLR) and the association between thickness changes with clinical outcomes. METHODS: Fifty-two patients with LBP and two examiners (one experienced and one novice) participated in this study. A total of 18 B-mode images at L4-L5 or L5-S1 level (both sides, 3 at rest and 6 during ASLR) were collected. For assessing test-retest reliability, the experienced examiner repeated the procedure after 7 days. Intraclass correlation coefficients (ICC), standard error of measurements (SEM) and minimal detectable changes (MDC) were calculated. RESULTS: Inter-examiner agreement was good to excellent (ICC3,2 = 0.71-0.92) and test-retest reliability was excellent (ICC3,1 = 0.91-0.98). Mean average of multiple measurements improved the agreement. Greater LM thickness at rest (p < .05) and greater thickness change after 3 s (p < .01) and 10 s (homolateral side, p < .01; contralateral side, p < .05) were associated with less pain intensity. CONCLUSIONS: US is a reliable method to assess the LM thickness at rest and contracted during the ASLR in patients with LBP. The measurement at 3 s after maintaining ASLR, as well as the use of the mean of three measurements, has been shown to be the most reliable method for measuring LM muscle thickness during ASLR.

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.

Increased vertebral body area, disc and facet joint degeneration throughout the lumbar spine in patients with lumbosacral transitional vertebrae.

OBJECTIVES: Lumbosacral transitional vertebrae (LSTV), developmental spinal canal stenosis, lumbar disc and facet joint degeneration are all common lumbar spine conditions. This study explores the relationship between these entities. METHODS: Five hundred and five patients (254 females, 251 males), mean age 57 ± 13 years, who underwent abdominopelvic CT examinations were studied. Vertebral body cross-sectional area (CSA), spinal canal CSA, width and depth were measured from L1 to L5. The presence of LSTV was documented and the severity of disc/facet joint degeneration graded. RESULTS: LSTV was present in 155 (31%) of 505 patients, being twice as common in males than in females. After controlling for age, height and weight, vertebral body CSAs from L1 to L5 in male LSTV patients were, on average, 9.8% larger than those in male non-LSTV patients (p < 0.0001 for all) while vertebral body areas at L3 and L4 were 4.5% larger in female LSTV patients than in non-LSTV female patients. Disc degeneration from L2/3 to L5/S1 and facet joint degeneration from L2/3 to L4/5 were more severe in LSTV patients. LSTV Castellvi Type II patients appear to be most prone to disc and facet degeneration. CONCLUSIONS: LSTV patients, and particularly male patients, have an increased vertebral body CSA compared to non-LSTV patients throughout the lumbar spine. LSTV patients also have more severe disc and facet joint degeneration. The increase in vertebral body area may be contributing to the increased lumbar and facet joint degeneration seen in LSTV patients. KEY POINTS: • LSTV patients have increased vertebral body cross-sectional area throughout their lumbar spine compared to non-LSTV patients. This vertebral body area increase was more pronounced in male patients and also apparent in younger patients with LSTV. • LSTV patients have increased disc and facet joint degeneration affecting most of the lumbar spine than non-LSTV patients. • Increased vertebral body area may contribute to the increased lumbar disc and facet joint degeneration seen in LSTV patients.

Subcutaneous fat index: a reliable tool for lumbar spine studies.

OBJECTIVES: Obesity has been proposed as a risk factor for low back pain (LBP), and the body mass index (BMI) has been used for obesity; however, a more reliable tool is required to assess obesity-related health issues. A recent study depicted the subcutaneous fat tissue thickness (SFTT) at the L1-L2 level as superior to BMI in predicting LBP and spine degeneration. However, the study failed to answer the following questions: (1) What was the cutoff value for the SFTT to predict LBP and spine degeneration? (2) Could this new index be adjusted according to gender? (3) Could this new index predict fatty infiltration in the paraspinal muscles, severe intervertebral disk degeneration (IVDD), and Modic changes in the lumbar spine? Therefore, the current study aimed to answer these questions by developing and validating a new anthropometric index-the subcutaneous fat index (SFI). METHODS: This study retrospectively reviewed the magnetic resonance imaging database of patients with LBP and compared them with asymptomatic volunteers. RESULTS: Appropriate cutoff values for females and males were 8.45 mm and 9.4 mm, respectively. Females and males with the SFI of > 8.45 mm and > 9.4 mm, respectively, had significantly higher rates of spine degeneration. CONCLUSION: The SFI reliably distinguished patients with LBP from the asymptomatic subjects and could reliably distinguish patients with severe IVDD/Modic changes at the lower lumbar levels and those with moderate-to-severe fat-infiltrated paraspinal muscles at all lumbar levels with reliable cutoff values for males and females. KEY POINTS: • The subcutaneous fat tissue thickness at L1-L2 level (subcutaneous fat index [SFI]) was superior to BMI in predicting LBP and spine degeneration. However, a reliable cutoff value has not been previously defined. • The subcutaneous fat index had reliable cutoff values of 8.45 mm and 9.4 mm for females and males, respectively. • Females with an SFI of > 8.45 mm and males with > 9.4 mm had significantly higher rates of severe IVDD, Modic changes, and fatty infiltration in their paraspinal muscles.

Individuals With Impaired Lumbopelvic Control Demonstrate Lumbar Multifidus Muscle Activation Deficit Using Ultrasound Imaging in Conjunction With Electrical Stimulation: A Cross-sectional Study.

OBJECTIVE: To determine lumbar multifidus (LM) muscle activation deficits in individuals with impaired lumbopelvic control (iLPC) based on musculoskeletal ultrasound in conjunction with electrical stimulation approach and the correlation between back extension force and LM activation. DESIGN: A cross-sectional study design. SETTING: A university laboratory. PARTICIPANTS: Fifty participants (25 iLPC and 25 no low back pain [NoLBP]) were recruited from the university physical therapy clinic and surrounding areas. MAIN OUTCOME MEASURES: The musculoskeletal ultrasound was used to measure LM thickness at rest, maximum voluntary isometric contraction (MVIC), and electrical stimulation combined with MVIC, and a handheld dynamometer was used to record force during MVIC and electrical stimulation combined with MVIC. These data were used to derive LM activation (LMACT) and percentage force generation (ForceGEN). RESULTS: The iLPC group had significantly lower LMACT (17%) than the NoLBP group (P<.05). No significant difference was seen in ForceGEN between the NoLBP and iLPC groups (P>.05). No significant correlation was seen between LMACT and ForceGEN (P>.05). CONCLUSIONS: The findings support the utility of our protocol to determine LM activation deficits. The lower LM activation in iLPC group suggests that individuals with iLPC were unable to fully recruit the motor units available in LM. Force generation measurements may not be an appropriate approach to determine such deficits in LM.

Spinopelvic measurements of sagittal balance with deep learning: systematic review and critical evaluation.

PURPOSE: To summarize and critically evaluate the existing studies for spinopelvic measurements of sagittal balance that are based on deep learning (DL). METHODS: Three databases (PubMed, WoS and Scopus) were queried for records using keywords related to DL and measurement of sagittal balance. After screening the resulting 529 records that were augmented with specific web search, 34 studies published between 2017 and 2022 were included in the final review, and evaluated from the perspective of the observed sagittal spinopelvic parameters, properties of spine image datasets, applied DL methodology and resulting measurement performance. RESULTS: Studies reported DL measurement of up to 18 different spinopelvic parameters, but the actual number depended on the image field of view. Image datasets were composed of lateral lumbar spine and whole spine X-rays, biplanar whole spine X-rays and lumbar spine magnetic resonance cross sections, and were increasing in size or enriched by augmentation techniques. Spinopelvic parameter measurement was approached either by landmark detection or structure segmentation, and U-Net was the most frequently applied DL architecture. The latest DL methods achieved excellent performance in terms of mean absolute error against reference manual measurements (~ 2° or ~ 1 mm). CONCLUSION: Although the application of relatively complex DL architectures resulted in an improved measurement accuracy of sagittal spinopelvic parameters, future methods should focus on multi-institution and multi-observer analyses as well as uncertainty estimation and error handling implementations for integration into the clinical workflow. Further advances will enhance the predictive analytics of DL methods for spinopelvic parameter measurement. LEVEL OF EVIDENCE I: Diagnostic: individual cross-sectional studies with the consistently applied reference standard and blinding.

An externally validated deep learning model for the accurate segmentation of the lumbar paravertebral muscles.

PURPOSE: Imaging studies about the relevance of muscles in spinal disorders, and sarcopenia in general, require the segmentation of the muscles in the images which is very labour-intensive if performed manually and poses a practical limit to the number of investigated subjects. This study aimed at developing a deep learning-based tool able to fully automatically perform an accurate segmentation of the lumbar muscles in axial MRI scans, and at validating the new tool on an external dataset. METHODS: A set of 60 axial MRI images of the lumbar spine was retrospectively collected from a clinical database. Psoas major, quadratus lumborum, erector spinae, and multifidus were manually segmented in all available slices. The dataset was used to train and validate a deep neural network able to segment muscles automatically. Subsequently, the network was externally validated on images purposely acquired from 22 healthy volunteers. RESULTS: The median Jaccard index for the individual muscles calculated for the 22 subjects of the external validation set ranged between 0.862 and 0.935, demonstrating a generally excellent performance of the network, although occasional failures were noted. Cross-sectional area and fat fraction of the muscles were in agreement with published data. CONCLUSIONS: The externally validated deep neural network was able to perform the segmentation of the paravertebral muscles in an accurate and fully automated manner, although it is not without limitations. The model is therefore a suitable research tool to perform large-scale studies in the field of spinal disorders and sarcopenia, overcoming the limitations of non-automated methods.

Mapping of lumbar multifidus stiffness Quantification in ankylosing spondylitis with shear-wave elastography.

BACKGROUND: Lower back pain and stiffness are the typical symptoms of ankylosing spondylitis (AS). In this study, muscle mass was assessed by muscle density, mechanical elasticity, and area. We investigated the characteristics of lumbar paraspinal-muscle (PSM) mass using muscle ultrasound shear-wave elastography (SWE), as well as the validity of this method for identifying patients with AS. METHODS: We recruited a representative cohort of 30 AS patients, and 27 healthy volunteers who were age- and sex-matched to the patient study group, investigated the Young's modulus (YM), cross-sectional area (CSA) and thickness of lumbar multifidus (LM) muscle using SWE. This study did not need to be randomized. Data were collected at the department of ultrasonography of Guangdong Provincial Hospital of Chinese Medicine. We analyzed the data using SPSS version 18.0 (IBM Corp, Armonk, NY, USA). Normal distribution was evaluated by the Shapiro-Wilk test and Q-Q plots. Demographic and baseline data will be analyzed with standard descriptive statistics. Data will be presented as the mean ± standard deviation (SD). Non-normally distributed data are presented as medians with interquartile ranges (IQR). RESULTS: Young's modulus (YM) of SWE in AS patients was significantly higher than that in volunteers. Percentage change in lumbar multifidus (LM) muscle cross-sectional area (CSA) and thickness were significantly lower in AS patients than in healthy volunteers on the left side of the body. Correlation analysis showed a positive correlation between percentage change in CSA and thickness in both volunteers and AS patients. In AS patients, YM was negatively correlated with percentage change of CSA and thickness on the right side, while increased disease duration in AS was associated with increased YM on the left. CONCLUSION: AS patients showed reductions in LM muscle mass and function as the disease progressed, SWE could reflect these changes well. TRIAL REGISTRATION: Chinese Clinical Trial Registry, ChiCTR2000031476. Registered 02/04/2020. http://www.chictr.org.cn/index.aspx .

A guide for standardized interpretation of lumbar multifidus ultrasonography; an observational study.

BACKGROUND: Inconsistent descriptions of Lumbar multifidus (LM) morphology were previously identified, especially in research applying ultrasonography (US), hampering its clinical applicability with regard to diagnosis and therapy. The aim of this study is to determine the LM-sonoanatomy by comparing high-resolution reconstructions from a 3-D digital spine compared to standard LM-ultrasonography. METHODS: An observational study was carried out. From three deeply frozen human tissue blocks of the lumbosacral spine, a large series of consecutive photographs at 78 µm interval were acquired and reformatted into 3-D blocks. This enabled the reconstruction of (semi-)oblique cross-sections that could match US-images obtained from a healthy volunteer. Transverse and oblique short-axis views were compared from the most caudal insertion of LM to L1. RESULTS: Based on the anatomical reconstructions, we could distinguish the LM from the adjacent erector spinae (ES) in the standard US imaging of the lower spine. At the lumbosacral junction, LM is the only dorsal muscle facing the surface. From L5 upwards, the ES progresses from lateral to medial. A clear distinction between deep and superficial LM could not be discerned. We were only able to identify five separate bands between every lumbar spinous processes and the dorsal part of the sacrum in the caudal anatomical cross-sections, but not in the standard US images. CONCLUSION: The detailed cross-sectional LM-sonoanatomy and reconstructions facilitate the interpretations of standard LM US-imaging, the position of the separate LM-bands, the details of deep interspinal muscles, and demarcation of the LM versus the ES. Guidelines for electrode positioning in EMG studies should be refined to establish reliable and verifiable findings. For clinical practice, this study can serve as a guide for a better characterisation of LM compared to ES and for a more reliable placement of US-probe in biofeedback.

Seated Position Does Not Change Lumbar Dimensions Compared With Lateral Position.

OBJECTIVE: The infant lumbar puncture (LP) can be a technically challenging procedure. Understanding the anatomical lumbar dimensions may optimize LP conditions. Data from preterm neonates, older children, and adults indicate measurements of the lumbar spine in the seated LP position may be superior when compared with the lateral position. We use point-of-care ultrasound (US) to determine if the seated position, when compared with the lateral decubitus position, significantly affected the lumbar dimensions of infants 12 months or younger presenting to the pediatric emergency department. METHODS: We conducted a prospective observational study of a convenience sample of patients 12 months or younger. We used US to obtain 3 still images oriented longitudinally in the midline over the L3 to L4 interspace in the lateral decubitus and seated positions. A US fellowship-trained emergency physician, blinded to patient position, measured interspinous space, subarachnoid space width, and spinal canal depth. We then compared the means of all 3 dimensions in the lateral and seated positions. RESULTS: From 50 subjects, 49 subjects provided 46 evaluable sets of images for each measure. Interspinous space, spinal canal depth, and subarachnoid space width did not differ significantly between positions. Mean differences did not exceed 0.02 cm for any of the measured dimensions. We report no significant differences in the 3 lumbar dimensions at the seated position when compared with the lateral decubitus position. CONCLUSIONS: For infants younger than 12 months, sonographic measurements of lumbar dimensions did not differ between the positions commonly used for LP.

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.