Disc Level Research Articles

Risk factors for residual back pain following percutaneous vertebral augmentation: the importance of paraspinal muscle fatty degeneration

PurposeResidual back pain (RBP) after percutaneous vertebral augmentation (PVA) still exists considerable, and it even affects daily life due to moderate or severe back pain. A variety of risk factors have been previously identified for developing residual back pain. However, there are conflicting reports regarding the association between sarcopenia and residual back pain. As such, the aim of this study was to investigate whether paraspinal muscle fatty degeneration is a predictor of residual back pain.MethodsWe retrospectively reviewed the medical records of patients with single-segment OVCF who underwent PVA from January 2016 to January 2022. Patients were divided into RBP group (86 patients) and control group (790 patients) according to whether the visual analog scale (VAS) score ≥ 4. The clinical and radiological data were analyzed. Paraspinal musculature fatty degeneration was measured using the Goutallier classification system (GCS) at the L4 − 5 intervertebral disc level. Univariate and multivariate logistic regression analyses were performed to identify risk factors.ResultsThe results of multivariate logistical regression analysis revealed that posterior fascia injury (odds ratio (OR) = 5.23; 95% confidence interval (CI) 3.12–5.50; P < 0.001), as regards paraspinal muscle fatty degeneration, including Goutallier grading (OR = 12.23; 95% CI 7.81–23.41; P < 0.001), fCSA (OR = 3.06; 95% CI 1.63–6.84; P = 0.002), fCSA/CSA (%) (OR = 14.38; 95% CI 8.80–26.29; P < 0.001), and facet joint violation (OR = 8.54; 95% CI 6.35–15.71; P < 0.001) were identified as independent risk factors for RBP.ConclusionsPosterior fascia injury, paraspinal muscle fatty degeneration, and facet joint violation were identified as independent risk factors for RBP, with paraspinal muscle fatty degeneration playing an important role.

Lumbar Sympathetic Chain Tract and Mobility of Oblique Lumbar Interbody Fusion Approach: A Cadaveric Study

To assess lumbar sympathetic chain (LSC) relation to the surgical corridor for oblique lumbar approach and the ability to mobilize the LSC. Forty-three cadavers were included. Left-sided anterior retroperitoneal approach was performed in a supine position. Distance between the great vessels and psoas muscle (oblique corridor) and distance between great vessels and LSC at L2/3, L3/4, and L4/5 disc levels were measured. Mobilization of LSC at each disc level was done either close to or away from the psoas muscle and each mobilization distance was measured. The presence rates of LSC in oblique corridor were 19.5%, 43%, and 75.7% at L2/3, L3/4, and L4/5 levels, respectively. At L2/3 disc level, mean distance between psoas muscle and LSC and its mobility were 0.61±1.31 mm, and 2.72±1.24 mm, respectively. At L3/4 disc level, mean distance between psoas muscle and LSC and its mobility were 1.72±2.53 mm, and 3.11±1.02 mm, respectively. At L4/5 disc level, mean distance between psoas muscle and LSC and its mobility were 2.94±3.52 mm, and 2.53±1.03 mm, respectively. The mean width of corridor of L2/3, L3/4, and L4/5 were 10.73±5.82, 12.63±5.02, and 15.43±6.31 mm, respectively. The LSC tract usually lies in the oblique corridor in L4/5 but keeps decreasing in prevalence when approaching L3/4 and L2/3 levels. It can be mobilized a few millimeters close to or away from the psoas muscle. Care should be taken to prevent LSC injury, particularly when the LSC needs to be retracted along with the psoas muscle.

Cage subsidence-Amultifactorial matter!

Retrospective cohort study OBJECTIVE: Wider cages are associated with improved decompression and reduced subsidence, but variation in cage physical properties limits consistent outcome analysis after thoracolumbar interbody fusion. This study investigated cage subsidence and its relationship to lateral and posterior approaches with afocus on the hypothesis that the larger surface area of lateral cages results in lower subsidence rates. This study retrospectively reviewed 194patients who underwent interbody fusion between 2016 and 2019 with aprimary outcome of cage subsidence. Secondary outcomes were cage distribution (patients, approaches, expandability), cage dimensions, t‑scores, length of hospital stay, blood loss, surgical time, and pelvic incidence-lumbar lordosis (PI-LL) mismatch. Medical records were reviewed for 194patients receiving 387 cages at 379 disc levels. Subsidence was identified in 35.1% of lateral cages, 40.9% of posterior cages, and 36.3% of all cages. Lower surface area (p = 0.008) and cage expandability were associated with subsidence risk. Lower anteroposterior cage length proved to be asignificant factor in the subsidence of posteriorly placed cages (p = 0.007). Osteopenic and osteoporotic patients experienced cage subsidence 36.8% of the time compared to 3.5% of patients with normal t‑scores (p = 0.001). Cage subsidence correlated with postoperative deterioration of the PI-LL mismatch (p = 0.03). Patients receiving fusion augmentation with bone morphogenic protein experienced higher fusion rates (p < 0.01). Cage subsidence is acommon complication that can significantly impact operative outcomes following thoracolumbar interbody fusion. Low t‑scores, smaller surface area, cage expandability, and lower cage length in posterior approaches contribute significantly to cage subsidence.

676 Anatomic Assessment of L1-S1 Neural Foraminal Dimensions Using Computed Tomography

INTRODUCTION: While radiographic parameters for diagnosis of central lumbar canal stenosis are well known, parameters for diagnosis of neural foraminal stenosis are less well defined. Previous research has used magnetic resonance imaging (MRI) to describe neural foraminal dimensions. However, the blooming artifact on MRI may distort these measurements. There is limited research using computed tomography (CT) to investigate normal neuroforamina dimensions. METHODS: We evaluated CT imaging of 55 female and 55 male subjects between 18 and 35 years of age. Those with history of degenerative disc disease, spondylolisthesis, fracture, neoplasm, trauma, existing spinal hardware, CT imaging performed due to back pain, or previous spinal surgery were excluded from review. Three independent reviewers were trained by a board-certified neuroradiologist to measure L1-S1 neural foraminal dimensions bilaterally. Intraclass correlation coefficient (ICC) two-way mixed model on absolute agreement was used to analyze interrater reliability. Pearson’s correlation was used to evaluate associations among variables. Differences between sexes were analyzed using independent sample t-tests. Measurement differences between disc levels and left- and right-sided measurements were analyzed using paired sample t-tests and one-way analysis of variance. RESULTS: Mean subject age, height, weight, and BMI were 27.16 years, 1.71 m, 88.1 kg, and 29.63 kg/m2, respectively. No moderate or strong correlations were found between measurements and age, height, weight, or BMI for all levels L1-S1. No sex differences were found for measurements at all levels L1-S1. CONCLUSIONS: This study describes CT-based L1-S1 neural foraminal dimensions in patients without pathology affecting the neuroforamina. Dimensions were not strongly influenced by demographic or anthropometric factors.

Evaluation of Lumbar Spine Morphology in Magnetic Resonance Images Using Cobb's Method

Lumbar lordosis represents one of the most prevalent postural disorders; it is classified as significant lumbar curving in the vertebral column's sagittal plane. The study's aims were to investigate lumbar spine morphology in Sudanese patients using Cobb's approach, as well as magnetic resonance imaging sagittal T2-weighted images. It was carried out between August 2015 and August 2016 in Khartoum Sudan's Advanced Diagnostic Center and Baraha Medical City hospital, with 140 patients (55 male and 85 female patients). The controlled cases involved in this study consisted of 40 patients (10 male and 30 female patients), ranging in age from 13 to 90 years. The results revealed substantial variation between the population having normal health and disc herniated patients in the Cobb angle (P = .000) and intervertebral disc space of L3 (P = .011), but no substantial improvement (P &gt; .05) between individuals with abnormal values and control individuals in the lumbosacral angle, L1-L5 body vertebrae, and L1, L2, L4, and L5 intervertebral disc levels. In addition, there was a notable change among the LS and Cobb angles in the patients with abnormal values (P = .045), but not in the control individuals (P = .691). We discovered a straight linear correlation among the Cobb angle and vertebral body L5-L2 in patients with bulged disc at various levels, as well as the Cobb angle and the L5-L2 intervertebral disc spaces also exhibit an indirect linear connection. It is concluded that magnetic resonance imaging is good for diagnosing disease associated with soft tissues, particularly the spinal discs that are frequently affected and cause low back problems.

ISSLS PRIZE in Clinical Science 2023: comparison of degenerative MRI features of the intervertebral disc between those with and without chronic low back pain. An exploratory study of two large female populations using automated annotation

ObjectivesThe relationship of degeneration to symptoms has been questioned. MRI detects apparently similar disc degeneration and degenerative changes in subjects both with and without back pain. We aimed to overcome these problems by re-annotating MRIs from asymptomatic and symptomatics groups onto the same grading system.MethodsWe analysed disc degeneration in pre-existing large MRI datasets. Their MRIs were all originally annotated on different scales. We re-annotated all MRIs independent of their initial grading system, using a verified, rapid automated MRI annotation system (SpineNet) which reported degeneration on the Pfirrmann (1–5) scale, and other degenerative features (herniation, endplate defects, marrow signs, spinal stenosis) as binary present/absent. We compared prevalence of degenerative features between symptomatics and asymptomatics.ResultsPfirrmann degeneration grades in relation to age and spinal level were very similar for the two independent groups of symptomatics over all ages and spinal levels. Severe degenerative changes were significantly more prevalent in discs of symptomatics than asymptomatics in the caudal but not the rostral lumbar discs in subjects < 60 years. We found high co-existence of degenerative features in both populations. Degeneration was minimal in around 30% of symptomatics < 50 years.ConclusionsWe confirmed age and disc level are significant in determining imaging differences between asymptomatic and symptomatic populations and should not be ignored. Automated analysis, by rapidly combining and comparing data from existing groups with MRIs and information on LBP, provides a way in which epidemiological and ‘big data’ analysis could be advanced without the expense of collecting new groups.Level of evidence IDiagnostic: individual cross-sectional studies with consistently applied reference standard and blinding.

Position of lumbar plexus nerves in the psoas major: Application to transpsoas approaches to the lumbar spine.

Far lateral interbody fusion is a minimally invasive operating technique. However, the incidence of postoperative neurological complications is high, and some scholars question its safety. This study describes the neuroanatomical features and spatial orientation within the psoas major. Ten embalmed male cadavers were selected and the left psoas major was dissected. Subsequently, the area between the anterior and the posterior edges of the vertebral body was divided into three equal zones. The nerves' distribution, number, and spatial orientation of the L1/2 to L4/5 intervertebral discs were examined. A caliper was used to measure the diameter of the nerve. The safety zone of the L1/2 intervertebral disc level is located in zone I and II, the relative safe zones of the L2/3 and L4/5 intervertebral discs are located in zone II, and the safety zone of the L3/4 intervertebral disc level is located in the caudal side of zone II. The genitofemoral nerve exits the psoas major in a co-trunk or two-branch pattern, and its exit point was distributed between the L3 and L4 vertebral bodies, mainly at the L3/4 intervertebral disc level. The sympathetic ganglia in the psoas major appeared only in zone I at the L2/3 intervertebral disc level. This is a systematic anatomical study that describes the nerves of the psoas major. Spine surgeons can use this study-which consists of important clinical implications-for preoperative planning, and thus, reduce the risk of nerve injury during surgery.

Characteristics of the paravertebral muscle in adult degenerative scoliosis with PI-LL match or mismatch and risk factors for PI-LL mismatch.

Pelvic incidence (PI) minus the lumbar lordosis (LL) angle (PI-LL) correlates with function and disability. It is associated with paravertebral muscle (PVM) degeneration and is a valuable tool for surgical planning of adult degenerative scoliosis (ADS). This study aims to explore the characteristics of PVM in ADS with PI-LL match or mismatch and to identify the risk factors for PI-LL mismatch. A total of 67 patients with ADS were divided into PI-LL match and mismatch groups. The visual analog scale (VAS), symptom duration, and Oswestry disability index (ODI) were used to assess patients' clinical symptoms and quality of life. The percentage of fat infiltration area (FIA%) of the multifidus muscle at the L1-S1 disc level was measured by using MRI with Image-J software. Sagittal vertical axis, LL, pelvic tilt (PT), PI, sacral slope, and the asymmetric and average degeneration degree of the multifidus were recorded. Logistic regression analysis was done to identify the risk factors for PI-LL mismatch. In the PI-LL match and mismatch groups, the average FIA% of the multifidus on the convex side was less than that on the concave side (P < 0.05). There was no statistical difference of asymmetric degeneration degree of the multifidus between the two groups (P > 0.05). In the PI-LL mismatch group, the average degeneration degree of the multifidus, VAS, symptom duration, and ODI were significantly higher than that in the PI-LL match group, respectively (32.22 ± 6.98 vs. 26.28 ± 6.23 (%), 4.33 ± 1.60 vs. 3.52 ± 1.46, 10.81 ± 4.83 vs. 6.58 ± 4.23 (month), 21.06 ± 12.58 vs. 12.97 ± 6.49, P < 0.05). The average degeneration degree of the multifidus muscle was positively correlated with the VAS, symptom duration, and ODI, respectively (r = 0.515, 0.614, and 0.548, P < 0.05). Sagittal plane balance, LL, PT, and the average degeneration degree of the multifidus were the risk factors for PI-LL mismatch (OR: 15.447, 95% CI: 1.274-187.269; OR: 0.001, 95% CI: 0.000-0.099; OR: 107.540, 95% CI: 5.195-2,225.975; OR: 52.531, 95% CI: 1.797-1,535.551, P < 0.05). The PVM on the concave side was larger than that on the convex side in ADS irrespective of whether PI-LL matched or not. PI-LL mismatch could aggravate this abnormal change, which is an important cause of pain and disability in ADS. Sagittal plane imbalance, decreased LL, higher PT, and larger average degeneration degree of the multifidus were independent risk factors for PI-LL mismatch.

Refining the OJ 287 2022 impact flare arrival epoch

ABSTRACT The bright blazar OJ 287 routinely parades high brightness bremsstrahlung flares, which are explained as being a result of a secondary supermassive black hole (SMBH) impacting the accretion disc of a more massive primary SMBH in a binary system. The accretion disc is not rigid but rather bends in a calculable way due to the tidal influence of the secondary. Next, we refer to this phenomenon as a variable disc level. We begin by showing that these flares occur at times predicted by a simple analytical formula, based on general relativity inspired modified Kepler equation, which explains impact flares since 1888. The 2022 impact flare, namely flare number 26, is rather peculiar as it breaks the typical pattern of two impact flares per 12-yr cycle. This is the third bremsstrahlung flare of the current cycle that follows the already observed 2015 and 2019 impact flares from OJ 287. It turns out that the arrival epoch of flare number 26 is sensitive to the level of primary SMBH’s accretion disc relative to its mean level in our model. We incorporate these tidally induced changes in the level of the accretion disc to infer that the thermal flare should have occurred during 2022 July–August, when it was not possible to observe it from the Earth. Thereafter, we explore possible observational evidence for certain pre-flare activity by employing spectral and polarimetric data from our campaigns in 2004/05 and 2021/22. We point out theoretical and observational implications of two observed mini-flares during 2022 January–February.

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.

Do lumbar intervertebral disc parameters in patients with chronic low back pain differ quantitatively from healthy individuals? A comparative study

Objectives: Studies in the past were not able to find any definitive correlation between disc parameters and LBP. The objectives of the current study were to evaluate the association of the lumbar disc parameters with LBP and to find the quantitative differences between the discs in LBP patients and healthy individuals. Methodology: Fifty patients with chronic LBP (group A) and 25 healthy individuals (group B) were subjected to magnetic resonance imaging of lumbar spine. Disc parameters of orientation and size were estimated. Results: There was a statistically significant difference in disc angle at L1-L2 ( p = 0.01), L2-L3 ( p = 0.05), and L3-L4 ( p = 0.001), and skin angle at L2-L3 ( p = 0.03) and L4-L5 ( p = 0.05) level. Length and cross-sectional area (CSA) of anterior intervertebral height, posterior intervertebral height, intervertebral disc, anterior disc material, posterior disc material; and volume of anterior disc material and volume of posterior disc material were statistically significantly more at various disc levels in group A. Antero-posterior dural sac length and CSA of the sac were statistically significantly smaller at L4-L5 and L5-S1 levels. There was a significant association between average disc height and dural sac area at L1-L2 ( p-value = 0.0393) and L5-S1 ( p-value = 0.0022) and CSA of the disc and dural sac area at L5-S1 ( p-value = 0.049) in group A. Conclusions: There was a significant difference in the lumbar disc orientation and dimensions between LBP patients and healthy individuals. Larger disc parameters (height, volume, CSA, and length) and altered orientation may affect the biomechanics of the spine, thus predisposing to LBP.

Clinical and Radiological Characteristics of Cervical Spondylotic Myelopathy in Young Adults: A Retrospective Case Series of Patients under Age 30.

Background and Objectives: Cervical spondylotic myelopathy (CSM) is a degenerative disease and occurs more frequently with age. In fact, the development of non-herniated CSM under age 30 is uncommon. Therefore, a retrospective case series was designed to clarify clinical and radiological characteristics of young adult patients with CSM under age 30. Materials and Methods: A total of seven patients, all men, with non-herniated, degenerative CSM under age 30 were retrieved from the medical records of 2598 hospitalized CSM patients (0.27%). Patient demographics and backgrounds were assessed. The sagittal alignment, congenital canal stenosis, dynamic canal stenosis, and vertebral slips in the cervical spine were radiographically evaluated. The presence of degenerative discs, intramedullary high-signal intensity lesions, and sagittal spinal cord compression on T2-weighted magnetic resonance images (MRIs) and axial spinal cord deformity on T1-weighted MRIs was identified. Results: All patients (100.0%) had relatively high daily sports activities and/or jobs requiring frequent neck extension. Cervical spine radiographs revealed the sagittal alignment as the "reverse-sigmoid" type in 57.1% of patients and "straight" type in 28.6%. All patients (100.0%) presented congenital cervical stenosis with the canal diameter ≤12 mm and/or Torg-Pavlov ratio <0.80. Furthermore, all patients (100.0%) developed dynamic stenosis with the canal diameter ≤12 mm and/or posterior vertebral slip ≥2 mm at the neurologically responsible segment in full-extension position. In MRI examination, all discs at the neurologically responsible level (100.0%) were degenerative. Intramedullary abnormal intensity lesions were detected in 85.7% of patients, which were all at the neurologically responsible disc level. Conclusions: Patients with non-herniated, degenerative CSM under age 30 are rare but more common in men with mild sagittal "reverse-sigmoid" or "straight" deformity and congenital canal stenosis. Relatively high daily activities, accumulating neck stress, can cause an early development of intervertebral disc degeneration and dynamic canal stenosis, leading to CSM in young adults.

Establishment and validation of reference values for abdominal skeletal muscle compartments in children

Sarcopenia, resulting from skeletal muscle loss, is a serious concern in children, for whom nutrition and physical activity are essential for growth. In sarcopenia research, the skeletal muscle mass is often obtained from computed tomography (CT) cross-sectional images in both adults and children; however, the method of evaluating skeletal muscle using CT, especially the area range to be measured, has not yet been validated in children. The aim of this study is to establish reference values for three compartments of the abdominal skeletal muscle area (aSMA) obtained from cross-sectional CT images, and to validate the differences among them by assessing correlations with physical development. We conducted a single-centre, retrospective, cross-sectional study and included patients aged 1-17 years who underwent abdominal CT at Chiba University Hospital from 2007 to 2020. Patients with chronic diseases such as malignant tumours and inflammatory bowel disease were excluded from the analysis. aSMA was obtained from CT cross-sections at the lumbar L3-L4 intervertebral disc level by dividing it into three compartments: the psoas muscle area (PMA), paraspinal muscle area (PSMA), and total skeletal muscle area (TSMA). Quartile regression curves by sex and muscle compartment were generated using non-crossover and nonparametric regression quantile estimation. The correlation between each compartment of aSMA with height and weight was assessed using Spearman's rank correlation coefficient. We analysed the abdominal CT images of 593 children (male: n=335, female: n=258) and generated curves predictive for the 5th, 25th, 50th, 75th, and 95th percentiles for each compartment of aSMA by sex. In patients aged 13 years and older, boys had significantly larger aSMA areas than girls in all three compartments. Among the three compartments, PSMA had the strongest correlation coefficient with height and weight for both boys and girls. We generated quantile regression curves for three aSMA compartments obtained from cross-sectional CT images and established reference values in children. PSMA values were most strongly correlated with height and weight among the three aSMA compartments.

MODIFIED OSWESTRY DISABILITY INDEX (ODI) IN ASSESSING MAGNETIC RESONANCE IMAGING FINDINGS IN LUMBAR DEGENERATIVE DISEASES

INTRODUCTION: Lumbar degenerative disease is one of the common causes for low back pain may cause debilitation. Mild degenerative changes of spine are physiological and should be considered pathological only if these abnormalities are causing symptoms and clinical signs. Many structural components of spine are responsible for low backache of degenerative etiology including the intervertebral disc, vertebral periosteum, facet joints and spinal ligaments. The most frequent and common location of these changes is lumbar spine due to heavy mechanical stress. The aim of AIM: this study is to establish a relationship between the MRI changes in established lumbar degenerative disease and the severity of self-assessed modied Oswestry Disability Index in patients. MATERIALS &amp; METHODS: Study included 120 consenting patients of all age groups irrespective of sex, having low back pain who were referred for MRI lumbar spine. Standard spine protocol sequences like T1- weighted image T2-weighted image Fluid-sensitive sequence, such as STIR or fat suppressed T2-weighted image Gradient-echo image Post gadolinium T1- weighted image were performed and the ndings were correlated with Modied Oswestry Disability Index(ODI). Disc degenerative changes is common RESULTS: among 40 – 60 years age group. Females are more commonly affected than males. Central is the most type of disc bulge. L5-S1 is the most common level to be affected by disc bulge. Annulus ssure/ tear is most common in L4-L5 intervertebral disc level. Type I degenerative end plate changes are most common in L5-S1 intervertebral disc level. Whereas typeII degenerative end plate changes are most common in L4-L5 intervertebral disc level. Facetal Arthropathy changes are common in L4- L5 levels both in grade I and II. Spinal canal stenosis is common in L4-L5 levels both in grade I and II. Oswestry disability score is higher in patients with severe spinal canal stenosis. So, there is signicant correlation between spinal canal narrowing and Oswestry disability index is seen. So ODI score acts as an invaluable tool for assessing patients' functional disability. MRI is better for the CONCLUSION: identication and grading the severity of lumbar degenerative disease. Oswestry disability index is a better tool for assessing patients' functional disability.

Facet Joint Orientation/Tropism Could Be Associated with Fatty Infiltration in the Lumbar Paraspinal Muscles

Facet joint orientation (FJO) and facet joint tropism (FJT) are associated with intervertebral disc degeneration and paraspinal muscle atrophy. However, none of the previous studies has evaluated the association of FJO/FJT with fatty infiltration in the multifidus, erector spinae, and psoas muscles at all lumbar levels. In the present study, we aimed to analyze whether FJO and FJT were associated with fatty infiltration in the paraspinal muscles at any lumbar level. Paraspinal muscles and FJO/FJT were evaluated from L1-L2 to L5-S1 intervertebral disc levels on T2-weighted axial lumbar spine magnetic resonance imaging. Facet joints were more sagittally and coronally oriented at the upper and lower lumbar levels, respectively. FJT was more obvious at lower lumbar levels. The FJT/FJO ratio was higher at upper lumbar levels. Patients with sagittally oriented facet joints at the L3-L4 and L4-L5 levels had fattier erector spinae and psoas muscles at the L4-L5 level. Patients with increased FJT at upper lumbar levels had fattier erector spinae and multifidus at lower lumbar levels. Patients with increased FJT at the L4-L5 level had less fatty infiltration in the erector spinae and psoas at the L2-L3 and L5-S1 levels, respectively. Sagittally oriented facet joints at lower lumbar levels could be associated with fattier erector spinae and psoas muscles at lower lumbar levels. The erector spinae at upper lumbar levels and psoas at lower lumbar levels might have become more active to compensate the FJT-induced instability at lower lumbar levels.

Anterior Column Realignment Using an Anterior-To-Psoas Approach: A Radiographic-Anatomic Feasibility Study at L1-L5.

Cross-sectional radioanatomic study. To determine the feasibility of performing an anterior column realignment (ACR) using an anterior-to-psoas (ATP) approach at L1-L5. Axial magnetic resonance images (MRI) of the L1-L5 disc levels obtained at a single institution were obtained and analyzed. The feasibility of performing an ACR was assessed using a combination of the size of the left oblique corridor (OC), the psoas morphology using the modified Moro classification, and the anterior disc edge to great vessel distance. Three hundred MRI studies obtained from 300 patients were included. All patients had a measurable left OC at the L1-L4 levels. Twenty patients (6.7%) had no measurable OC at the L4-L5 level. According to the modified Moro's classification, a high-rising psoas was seen in 4 patients (1.3%) at the L3-L4 level and 57 patients (19.0%) at the L4-L5 level. An ALL release was considered high risk due to no measurable space between the anterior disc edge and the great vessels in 54 patients (18.0%) at the L1-L2 level, 39 patients (13.0%) at the L2-L3 level, 119 patients (39.7%) at the L3-L4 level, and 226 patients (75.3%) at the L4-L5 level. ACR using an ATP approach is the most radioanatomically feasible at L2-L3. The L4-L5 level has the highest risk with regards to both the ATP approach and the ALL release for an ACR due to high rates of unmeasurable left OC and space between the anterior disc edge and the great vessels.

Patent blue versus methylene blue and indigo carmine as a better dye for chromodiscography: in vitro staining efficacy and cytotoxicity study using bovine coccygeal intervertebral discs

BACKGROUND CONTEXTChromodiscography is an integral part of full-endoscopic discectomy (FED), comprising ordinary discography with radiopacity produced by contrast medium and intradiscal stain for visualizing annular defects in the endoscopic field. Nevertheless, concerns remain about the cytotoxicity of the stains used. The study of their staining efficacy is also lacking. PURPOSETo evaluate the feasibility of methylene blue, patent blue, and indigo carmine for intradiscal injection, investigate the effectiveness of each dye, and define critical concentration with adequate staining efficacy and tolerable cytotoxicity for use in chromodiscography during FED. STUDY DESIGNAn experimental in vitro study. METHODSDye stock solutions were prepared from powder. The stock was diluted with culture medium or balanced saline and used for cytotoxicity or intervertebral disc staining assays, respectively. Bovine tails were obtained from the local slaughterhouse and functional spine units of intervertebral discs were acquired by transverse incision at the disc level. Each disc was punctured over the posterolateral aspect using a surgical knife to simulate an annular defect. The intradiscal injection was performed with each dye at different concentrations using a 22G needle from the contralateral aspect of the punctured site. Staining efficacy was quantified using ImageJ software. Primary cells of bovine tails were cultivated in each dye at different concentrations. Cytotoxicity was assessed 24 hours after stain exposure using the CCK-8 toxicity assay. RESULTSStaining efficacy and cytotoxicity were proportional to the concentration of tested dyes. Lower limits of concentration producing significant staining efficacy of indigo carmine, methylene blue, and patent blue were 0.25 mg/mL, 0.25 mg/mL, and 0.05 mg/mL, respectively. Compared with controls, concentrations showing significant toxicity for indigo carmine, methylene blue, and patient blue were 1 mg/mL, 0.5 mg/mL, and 2.5 mg/mL, respectively. CONCLUSIONSPatent blue can serve as a more suitable tissue stain than either indigo carmine or methylene blue due to the widest range of tradeoff concentration within 0.05 to 2.5 mg/mL. CLINICAL SIGNIFICANCEPatent blue with the characteristic of good staining efficacy and lower cytotoxicity may be a promising option for chromodiscography during FED.

Correlation of psoas major muscle morphology with function and clinical symptoms in patients with symptomatic multilevel lumbar spinal stenosis

ObjectiveThis study was performed to quantify the morphological characteristics of the psoas major muscle in patients with symptomatic multilevel degenerative lumbar spinal stenosis (SMLSS) and assess the correlations of these morphological characteristics with function and clinical symptoms.MethodsOne hundred fourteen patients diagnosed with SMLSS (≥ 3 segments) were included. The patients’ presenting symptoms were assessed with the Oswestry Disability Index (ODI), and visual analogue scale (VAS) scores were recorded. The morphology of the psoas major was evaluated at the L3/4 intervertebral disc level in three ways: by measuring (i) the psoas muscle mass index (PMI); (ii) the mean muscle attenuation (Hounsfield units, HU); and (iii) the morphologic change of the psoas major (mean ratios of the short axis to the long axis of the bilateral psoas major).ResultsMen had a higher PMI than women (p = 0.001). Patients with severe disability had a significantly lower PMI (p = 0.002) and muscle attenuation (p = 0.001). The PMI and muscle attenuation were significantly higher in the patients with no or mild back pain (both p < 0.001). In the univariable and multivariable analyses, a greater HU value was associated with a higher functional status as assessed by the ODI (p = 0.002), and a higher PMI was associated with less severe back pain as measured by the VAS score (p < 0.001).ConclusionThis study showed that muscle attenuation of psoas major positively correlated with the functional status and PMI negatively correlated with low back pain severity in patients diagnosed with SMLSS. Future prospective studies are needed to evaluate whether improvement in such muscle parameters through physiotherapy programs can alleviate the clinical symptoms and improve the functional status of patients with SMLSS.

The association between vertebral endplate defects, subchondral bone marrow changes, and lumbar intervertebral disc degeneration: a retrospective, 3-year longitudinal study.

To investigate the influence of vertebral endplate defects and subchondral bone marrow changes on the development of lumbar intervertebral disc degeneration (DD). Patients > 18 y/o without any history of lumbar fusion who had repeat lumbar magnetic resonance imaging scans primarily for low back pain (LBP) performed at a minimum of 3years apart at a single institution, and no spinal surgery in between scans were included. Total endplate score (TEPS), Modic changes (MC), and Pfirrmann grading (PFG) per lumbar disc level were assessed. DD was defined as PFG ≥ 4. Three hundred and fifty-three patients (54.4% female) were included in the final analysis, comprising 1765 lumbar intervertebral discs. The patient population was 85.6% Caucasian with a median age of 60.1years and a body mass index (BMI) of 25.8kg/m2. A cutoff score of 5 was identified for the TEPS above which both the prevalence of DD and the odds of developing DD increased. The probability of developing DD did not differ significantly between lumbar disc levels (P = 0.419). In the multivariable analysis with adjustments for age, sex, race, body mass index (BMI), MC, TEPS cutoff > 5, and spinal level, only age (OR = 1.020; P = 0.002) was found to be an independent risk factor for developing intervertebral DD. Our results suggest that TEPS does not unequivocally predict intervertebral DD in patients with LBP, since higher degrees of endplate defects might also develop secondarily to DD, and MC tend to occur late in the cascade of degeneration.

Role of diffusion kurtosis imaging in evaluating microstructural changes in spinal cord of patients with cervical spondylosis.

Analytical cross-sectional study. To study the role of diffusion kurtosis imaging (DKI) in evaluating microstructural changes in patients with cervical spondylosis. Cervical spondylosis is a common progressive degenerative disorder of the spine. Conventional magnetic resonance imaging (MRI) can only detect the changes in the spinal cord once there are visual signal changes; hence, it underestimates the extent of the injury. Newer imaging techniques like Diffusion Tensor and Kurtosis Imaging can evaluate the microstructural changes in cervical spinal cord before the obvious signal changes appear. Conventional MRI, diffusion tensor imaging (DTI), and DKI scans were performed for 90 cervical spondylosis patients on 1.5-T MR Siemens Magnetom aera after obtaining informed consent. Eight patients were excluded due to poor image quality. Fractional anisotropy (FA) colour maps and diffusion kurtosis (DK) maps corresponding to spinal cord cross sections at C2-C3 intervertebral disc level (control) and at the most stenotic levels were obtained. Modified Japanese Orthopaedic Association (mJOA) scoring was used for clinical assessment of the spinal cord function. The changes in DTI and DKI parameters and their correlation with mJOA scores were analysed by SPSS 23 software. In our study, mean FA and mean kurtosis (MK) values at the stenotic level (0.54, 1.02) were significantly lower than values at the non-stenotic segment (0.70, 1.27). The mean diffusivity (MD) value at the stenotic segment (1.25) was significantly higher than in the non-stenotic segment (1.09). We also observed a strong positive correlation between mJOA score and FA and MK values and a negative correlation between mJOA score and MD values, suggesting a correlation of FA, MK, and MD with the clinical severity of the disease. Addition of DTI and DKI sequences helps in early identification of the disease without any additional cost incurred by the patient.