Lumbar Paraspinal Muscles Research Articles

Use of two-point and six-point Dixon MRI for fat fraction analysis in the lumbar vertebral bodies and paraspinal muscles in healthy dogs: comparison with magnetic resonance spectroscopy.

Fatty degeneration of the vertebral bodies and paravertebral muscles is associated with the presence, severity, and prognosis of spinal disease such as intervertebral disc degeneration. Therefore, the fat fraction (FF) of the vertebral bodies and paraspinal muscles has been considered a potential biomarker for assessing the pathophysiology, progression, and treatment response of spinal disease. Magnetic resonance spectroscopy (MRS) is considered the reference standard for fat quantification; however, it has limitations of a long acquisition time and is technically demanding. Chemical shift-encoding water-fat imaging, called the Dixon method, has recently been applied for rapid fat quantification with high spatial resolution. However, the Dixon method has not been validated in veterinary medicine, and we hypothesized that the Dixon method would provide a comparable assessment of the FF to MRS but would be faster and easier to implement in dogs. In this prospective study, we assessed the FF of the lumbar vertebral bodies and paravertebral muscles from the first to sixth lumbar vertebrae using MRS, the two-point Dixon method (LAVA-FLEX), and the six-point Dixon method (IDEAL-IQ) and compared these techniques. The FFs of vertebral bodies and paravertebral muscles derived from LAVA-FLEX and IDEAL-IQ showed significant correlations and agreement with those obtained with MRS. In particular, the FFs obtained with IDEAL-IQ showed higher correlations and better agreement with those obtained with MRS than those derived by LAVA-FLEX. Both Dixon methods showed excellent intra- and interobserver reproducibility for FF analysis of the vertebral bodies and paraspinal muscles. However, the test-retest repeatability of vertebral body and paraspinal muscle FF analysis was low for all three sequences, especially for the paraspinal muscles. The results of this study showed that LAVA-FLEX and IDEAL-IQ have high reproducibility and that their findings were highly correlated with the FFs of the lumber vertebral bodies and paraspinal muscles determined by MRS in dogs. The FF analysis could be performed much more easily and quickly using LAVA-FLEX and IDEAL-IQ than using MRS. In conclusion, LAVA-FLEX and IDEAL-IQ can be used as routine procedures in spinal magnetic resonance imaging in dogs for FF analysis of the vertebral bodies and paraspinal muscles.

Association between Paraspinal Muscle Parameters and single-segment Degenerative Lumbar Spondylolisthesis: A Retrospective, cross-sectional Cohort Study.

A retrospective, cross-sectional cohort study. This study aims to investigate the association between paraspinal muscle parameters and single-segment degenerative lumbar spondylolisthesis (DLS). The relationship between lumbar paraspinal muscles morphology and single-segment DLS remains unclear. A retrospective review was conducted on 115 patients with L4/5 single-segment DLS and 105 subjects without DLS. Two independent investigators assessed the relative cross-sectional area and fat infiltration rate of the multifidus, erector spinae, and psoas major at L3/4, L4/5, and L5/S1 levels, comparing these measurements between the two groups. Additionally, binary logistic regression analysis was performed with DLS as the dependent variable to analyze the relative cross-sectional area and fat infiltration rate of different paraspinal muscles. Within the DLS group, the correlation between paraspinal muscle characteristics and the anteroposterior diameter of the spinal canal was examined. The fat infiltration rate of multifidus, erector spinae, and psoas major were higher in the DLS group than in the control group, while the relative cross-sectional area of multifidus and psoas major were lower in the DLS group. Binary logistic regression analysis revealed a significant correlation between fat infiltration rate of multifidus and psoas major and DLS. The relative cross-sectional area of multifidus and erector spinae was significantly smaller below the affected segment in the DLS group compared to the control group. A significant positive correlation was observed between the relative cross-sectional area of multifidus and erector spinae and the anteroposterior diameter of the spinal canal. There is a close association between paraspinal muscle degeneration and single-segment DLS, with increased relative cross-sectional area of the multifidus and psoas major possibly being risk factors for single-segment DLS. The restoration or enhancement of paraspinal muscle function could potentially serve as a pivotal target for the prevention and treatment of single-segment DLS. III.

Muscle reoxygenation is slower after higher cycling intensity, and is faster and more reliable in locomotor than in accessory muscle sites.

Wearable near-infrared spectroscopy (NIRS) can be used during dynamic exercise to reflect the balance of muscle oxygen delivery and uptake. This study describes the behaviour and reliability of postexercise reoxygenation with NIRS as a function of exercise intensity at four muscle sites during an incremental cycling test. We discuss physiological components of faster and slower reoxygenation kinetics in the context of sport science and clinical applications. We hypothesised that reoxygenation would be slower at higher intensity, and that locomotor muscles would be faster than accessory muscles. We quantified test-retest reliability and agreement for each site. Twenty-one trained cyclists performed two trials of an incremental cycling protocol with 5-min work stages and 1-min rest between stages. NIRS was recorded from the locomotor vastus lateralis and rectus femoris muscles, and accessory lumbar paraspinal and lateral deltoid muscles. Reoxygenation time course was analysed as the half-recovery time (HRT) from the end of work to half of the peak reoxygenation amplitude during rest. Coefficient of variability (CV) between participants, standard error of the measurement (SEM) within participants, and intraclass correlation coefficient (ICC) for test-retest reliability were evaluated at 50%, 75%, and 100% peak workloads. A linear mixed-effects model was used to compare differences between workloads and muscle sites. HRT was slower with increasing workload in the VL, RF, and PS, but not DL. VL had the fastest reoxygenation (lowest HRT) across muscle sites at all workloads (HRT = 8, 12, 17s at 50%, 75%, 100% workload, respectively). VL also had the greatest reliability and agreement. HRT was sequentially slower between muscle sites in the order of VL < RF < PS < DL, and reliability was lower than for the VL. This study highlights the potential for using wearable NIRS on multiple muscle sites during exercise. Reoxygenation kinetics differ between local muscle sites with increasing intensity. Moderate-to-good reliability in the VL support its increasing use in sport science and clinical applications. Lower reliability in other muscle sites suggest they are not appropriate to be used alone, but may add information when combined to better reflect systemic intensity and fatigue during exercise at different intensities.

The Immediate Effects of a Standardized Kettlebell Swing Protocol on Lumbar Paraspinal Muscle Function: A Randomized Controlled Trial.

Hanney, WJ, Perez, A, Collado, G, Palmer, AC, Wilson, AT, Richardson, RM, and Kolber, MJ. J Strength Cond Res XX(X): 000-000, 2024-Kettlebell swings (KBSs) are commonly used to target the lumbar erector spinae and lower body musculature. This exercise exhibits distinct loading properties that requires cyclical contraction of the trunk extensors and posterior chain, potentially explaining its novel influence on muscle contractility. Tensiomyography (TMG) is a reliable, noninvasive, passive technique that may be used to examine muscular fatigue produced by exercises such as KBSs. The purpose of this randomized control trial was to determine the extent of muscle fatigue in the lumbar erector spinae musculature following the performance of a previously published high-intensity interval KBS protocol. Forty-one adults between the ages of 18 and 45 years were recruited. Inclusion criteria included subjects with no recent history of low back pain and clearance by the physical activity readiness questionnaire. Subjects were randomly allocated to either a KBS group (n = 21) or a control group (CON; n = 20) who only performed the unloaded warm-up. Subjects were assessed at baseline, postintervention, and 24-hours postintervention for bilateral erector spinae fatigue, measured by 5 TMG parameters (Dm, Tc, Tr, Td, and Ts). The results were evaluated through a 2 × 3 (group × time) repeated-measures analysis of variance. The level of significance was set at p ≤ 0.05. There was no significant difference in lumbar erector spinae fatigue, measured by the 5 TMG parameters (p ≥ 0.079), following the interval KBS protocol in comparison with the CON group at 3 assessment periods. A high-intensity interval KBS protocol failed to produce significant differences in erector spinae fatigue compared with the control group that did not perform a KBS. These findings warrant further investigation into muscle fatigue produced with higher intensity protocols and possibly suggest, depending on the programming goals, the need for an alternate KBS training parameters.

Assessment of lumbar paraspinal muscle morphology using mDixon Quant magnetic resonance imaging (MRI): a cross-sectional study in healthy subjects.

Lumbar paraspinal muscles (LPM) are a part of the deep spinal stabilisation system and play an important role in stabilising the lumbar spine and trunk. Inadequate function of these muscles is thought to be an essential aetiological factor in low back pain, and several neuromuscular diseases are characterised by dysfunction of LPM. The main aims of our study were to develop a methodology for LPM assessment using advanced magnetic resonance imaging (MRI) methods, including a manual segmentation process, to confirm the measurement reliability, to evaluate the LPM morphological parameters [fat fraction (FF), total muscle volume (TMV) and functional muscle volume (FMV)] in a healthy population, to study the influence of physiological factors on muscle morphology, and to build equations to predict LPM morphological parameters in a healthy population. This prospective cross-sectional observational comparative single-centre study was conducted at the University Hospital in Brno, enrolling healthy volunteers from April 2021 to March 2023. MRI of the lumbar spine and LPM (erector spinae muscle and multifidus muscle) were performed using a 6-point Dixon gradient echo sequence. The segmentation of the LPM and the control muscle (psoas muscle) was done manually to obtain FF and TMV in a range from Th12/L1 to L5/S1. Intra-rater and inter-rater reliability were evaluated. Linear regression models were constructed to assess the effect of physiological factors on muscle FF, TMV and FMV. We enrolled 90 healthy volunteers (median age 38 years, 45 men). The creation of segmentation masks and the assessment of FF and TMV proved reliable (Dice coefficient 84% to 99%, intraclass correlation coefficient ≥0.97). The univariable models showed that FF of LPM was influenced the most by age (39.6% to 44.8% of variability, P<0.001); TMV and FMV by subject weight (34.9% to 67.6% of variability, P<0.001) and sex (24.7% to 64.1% of variability, P<0.001). Multivariable linear regression models for FF of LPM included age, body mass index and sex, with R-squared values ranging from 45.4% to 51.1%. Models for volumes of LPM included weight, age and sex, with R-squared values ranged from 37.4% to 76.8%. Equations were developed to calculate predicted FF, TMV and FMV for each muscle. A reliable methodology has been developed to assess the morphological parameters (biomarkers) of the LPM. The morphological parameters of the LPM are significantly influenced by physiological factors. Equations were constructed to calculate the predicted FF, TMV and FMV of individual muscles in relation to anthropometric parameters, age, and sex. This study, which presented LPM assessment methodology and predicted values of LPM morphological parameters in a healthy population, could improve our understanding of diseases involving LPM (low back pain and some neuromuscular diseases).

Intramuscular Adipose Tissue in the Lumbar Paraspinal Muscles Does Not Correlate With Low Back Pain in Medical Students

Objective: The objective of the study is to identify any intergroup differences or statistically significant correlations between paraspinal intramuscular adipose tissue (IntraMAT) deposition and variables such as low back pain, gender, self-reported activity level, body mass index (BMI), age, and academic class-year, as measured by sonographic intensity analysis. This study is specific to a cohort of first- and second-year medical students. Materials and Methods: The right lumbar paraspinal muscles, at the level of the fifth lumbar vertebrae, were investigated with sonography among a cohort of medical students. Image pixels, within the selected region of interest, were segregated by pixel intensity and analyzed for IntraMAT content. Participants reported on additional study variables by responding to a survey. The cohort responses were analyzed to seek correlations between those variables and IntraMAT. Results: The female participants were found to have more IntraMAT ( P &lt; .001). Most participants reported low back pain. There were no significant correlations between IntraMAT and reported low back pain, academic class year, or BMI. Moderate exercise increased IntraMAT deposition, and each year of increasing age decreased IntraMAT ( P &lt; .05). Second-year students experienced more self-reported low back pain than first-year students. Conclusion: A cohort of medical students who were reportedly sedentary had more low back pain than their peers. Back pain was more prevalent in second-year students, irrespective of age, suggesting that ill effects of a sedentary lifestyle may be cumulative. The validity of the sonographic pixel intensity analysis performed was supported by the highly significant increase in IntraMAT observed in female participants. The relationship between low back pain, exercise, BMI, and IntraMAT was uncertain based on available evidence and the results of this study.

Vertebral bone quality score was associated with paraspinal muscles fat infiltration, but not modic classification in patients with chronic low back pain: a prospective cross-sectional study

BackgroundThe lumbar vertebra and paraspinal muscles play an important role in maintaining the stability of the lumbar spine. Therefore, the aim of this study was to investigate the relationship between paraspinal muscles fat infiltration and vertebral body related changes [vertebral bone quality (VBQ) score and Modic changes (MCs)] in patients with chronic low back pain (CLBP).MethodsPatients with CLBP were prospectively collected in four hospitals and all patients underwent 3.0T magnetic resonance scanning. Basic clinical information was collected, including age, sex, course of disease (COD), and body mass index (BMI). MCs were divided into 3 types based on their signal intensity on T1 and T2-weighted imaging. VBQ was obtained by midsagittal T1-weighted imaging (T1WI) and calculated using the formula: SIL1−4/SICSF. The Proton density fat fraction (PDFF) values and cross-sectional area (CSA) of paraspinal muscles were measured on the fat fraction map from the iterative decomposition of water and fat with the echo asymmetry and least-squares estimation quantitation (IDEAL-IQ) sequences and in/out phase images at the central level of the L4/5 and L5/S1 discs.ResultsThis study included 476 patients with CLBP, including 189 males and 287 females. 69% had no Modic changes and 31% had Modic changes. There was no difference in CSA and PDFF for multifidus(MF) and erector spinae (ES) at both levels between Modic type I and type II, all P values>0.05. Spearman correlation analysis showed that VBQ was weakly negatively correlated with paraspinal muscles CSA (all r values < 0.3 and all p values < 0.05), moderately positive correlation with PDFF of MF at L4/5 level (r values = 0.304, p values<0.001) and weakly positively correlated with PDFF of other muscles (all r values<0.3 and all p values<0.001). Multivariate linear regression analysis showed that age (β = 0.141, p < 0.001), gender (β = 4.285, p < 0.001) and VBQ (β = 1.310, p = 0.001) were related to the total PDFF of muscles. For MCs, binary logistic regression showed that the odds ratio values of age, BMI and COD were 1.092, 1.082 and 1.004, respectively (all p values ＜ 0.05).ConclusionsPDFF of paraspinal muscles was not associated with Modic classification. In addition to age and gender, PDFF of paraspinal muscles is also affected by VBQ. Age and BMI are considered risk factors for the MCs in CLBP patients.

Relation Between Abnormal Spontaneous Brain Activity and Altered Neuromuscular Activation of Lumbar Paraspinal Muscles in Chronic Low Back Pain

ObjectiveTo investigate the neural mechanism underlying functional reorganization and motor coordination strategies in patients with chronic low back pain (cLBP). DesignA case-control study based on data collected during routine clinical practice. SettingThis study was conducted at a university hospital. ParticipantsFifteen patients with cLBP and 15 healthy controls. InterventionsNot applicable. Main Outcome MeasuresWhole brain blood oxygen level-dependent signals were measured using functional magnetic resonance imaging and amplitude of low-frequency fluctuation (ALFF) method to identify pain-induced changes in regional spontaneous brain activity. A novel approach based on the surface electromyogram (EMG) system and fine-wire electrodes was used to record EMG signals in the deep multifidus, superficial multifidus, and erector spinae. ResultsIn cLBP, compared with healthy groups, ALFF was higher in the medial prefrontal, primary somatosensory, primary motor, and inferior temporal cortices, whereas it was lower in the cerebellum and anterior cingulate and posterior cingulate cortices. Furthermore, the decrease in the average EMG activity of the 3 lumbar muscles in the cLBP group was positively correlated with the ALFF values of the primary somatosensory cortex, motor cortex, precuneus, and middle temporal cortex but significantly negatively correlated with the ALFF values of the medial prefrontal and inferior temporal cortices. Interestingly, the correlation between the functional activity in the cerebellum and the EMG activity varied in the lumbar muscles. ConclusionsThese findings suggest a functional association between changes in spontaneous brain activity and altered voluntary neuromuscular activation patterns of the lumbar paraspinal muscles, providing new insights into the mechanisms underlying pain chronicity as well as important implications for developing novel therapeutic targets of cLBP.

Importance of the lumbar paraspinal muscles on the maintenance of global sagittal alignment after lumbar pedicle subtraction osteotomy.

There are limited data about the influence of the lumbar paraspinal muscles on the maintenance of sagittal alignment after pedicle subtraction osteotomy (PSO) and the risk factors for sagittal realignment failure. The authors aimed to investigate the influence of preoperative lumbar paraspinal muscle quality on the postoperative maintenance of sagittal alignment after lumbar PSO. Patients who underwent lumbar PSO with preoperative lumbar MRI and pre- and postoperative whole-spine radiography in the standing position were included. Spinopelvic measurements included pelvic incidence, sacral slope, pelvic tilt, L1-S1 lordosis, T4-12 thoracic kyphosis, spinosacral angle, C7-S1 sagittal vertical axis (SVA), T1 pelvic angle, and mismatch between pelvic incidence and L1-S1 lordosis. Validated custom software was used to calculate the percent fat infiltration (FI) of the psoas major, as well as the erector spinae and multifidus (MF). A multivariable linear mixed model was applied to further examine the association between MF FI and the postoperative progression of SVA over time, accounting for repeated measures over time that were adjusted for age, sex, BMI, and length of follow-up. Seventy-seven patients were recruited. The authors' results demonstrated significant correlations between MF FI and the maintenance of corrected sagittal alignment after PSO. After adjustment for the aforementioned parameters, the model showed that the MF FI was significantly associated with the postoperative progression of positive SVA over time. A 1% increase from the preoperatively assessed total MF FI was correlated with an increase of 0.92 mm in SVA postoperatively (95% CI 0.42-1.41, p < 0.0001). This study included a large patient cohort with midterm follow-up after PSO and emphasized the importance of the lumbar paraspinal muscles in the maintenance of sagittal alignment correction. Surgeons should assess the quality of the MF preoperatively in patients undergoing PSO to identify patients with severe FI, as they may be at higher risk for sagittal decompensation.

Relationship between facet joint osteoarthritis and lumbar paraspinal muscle atrophy: a cross-sectional study.

The paraspinal muscles play an essential role in the stabilization of the lumbar spine. Lumbar paraspinal muscle atrophy has been linked to chronic back pain and degenerative processes within the spinal motion segment. However, the relationship between the different paraspinal muscle groups and facet joint osteoarthritis (FJOA) has not been fully explored. In this cross-sectional study, the authors analyzed adult patients who underwent lumbar spinal surgery between December 2014 and March 2023 for degenerative spinal conditions and had preoperative MRI and CT scans. The fatty infiltration (FI) and functional cross-sectional area (fCSA) of the psoas, erector spinae, and multifidus muscles were assessed on axial T2-weighted MR images at the level of the upper endplate of L4 based on established studies and calculated using custom-made software. Intervertebral disc degeneration at each lumbar level was evaluated using the Pfirrmann grading system. The grades from each level were summed to report the cumulative lumbar Pfirrmann grade. Weishaupt classification (0-3) was used to assess FJOA at all lumbar levels (L1 to S1) on preoperative CT scans. The total lumbar FJOA score was determined by adding the Weishaupt grades of both sides at all 5 levels. Correlation and linear regression analyses were conducted to assess the relationship between FJOA and paraspinal muscle parameters. A total of 225 patients (49.7% female) with a median age of 61 (IQR 54-70) years and a median BMI of 28.3 (IQR 25.1-33.1) kg/m2 were included. After adjustment for age, sex, BMI, and the cumulative lumbar Pfirrmann grade, only multifidus muscle fCSA (estimate -4.69, 95% CI -6.91 to -2.46; p < 0.001) and FI (estimate 0.64, 95% CI 0.33-0.94; p < 0.001) were independently predicted by the total FJOA score. A similar relation was seen with individual Weishaupt grades of each lumbar level after controlling for age, sex, BMI, and the Pfirrmann grade of the corresponding level. Atrophy of the multifidus muscle is significantly associated with FJOA in the lumbar spine. The absence of such correlation for the erector spinae and psoas muscles highlights the unique link between multifidus muscle quality and the degeneration of the spinal motion segment. Further research is necessary to establish the causal link and the clinical implications of these findings.

Does Paraspinal Muscle Mass Predict Lumbar Lordosis before and after Decompression for Degenerative Spinal Stenosis?

Retrospective Cohort Study. The purpose of this study was to determine if muscle mass and quality of the lumbar paraspinal muscles was associated with improvements in lumbar lordosis and other sagittal parameters after isolated posterior lumbar decompression surgery for lumbar spinal stenosis. Over time, either due to degenerative changes or other spinal conditions, individuals may develop sagittal imbalance. In patients with lumbar spinal stenosis, sagittal imbalance can further exacerbate symptoms of pain and radiculopathy. Sarcopenia of paraspinal muscles has been implicated in previous spine research as a variable with influence on surgical outcomes. Sagittal parameters were measured on preoperative and postoperative lateral lumbar radiographs and included lumbar lordosis (LL), sacral slope (SS), and pelvic tilt (PT). Preoperative MRI images were evaluated at the base of the L4 vertebral body to assess muscles mass of the psoas muscle and paravertebral muscles (PVM) and Goutallier grade of the PVM. Patients were divided into 3 muscle size groups based on PVM normalized for body size (PVM/BMI): Group A (smallest), Group B, and Group C (largest). Patients in Group C had greater LL preoperatively (51.5° vs. 47.9° vs. 43.2, P=0.005) and postoperatively (52.2° vs. 48.9° vs. 45.7°, P=0.043). There was no significant difference in the ∆LL values between groups (P>0.05). Patients in Group C had larger SS preoperatively (35.2° vs. 32.1° vs. 30.0°, P=0.010) and postoperatively (36.1° vs. 33.0° vs. 31.7°, P=0.030). Regression analysis showed that PVM/BMI was a significant predictor of LL preoperatively (P=0.039) and postoperatively (P=0.031), as well as SS preoperatively (P=0.001) and postoperatively (P<0.001). Muscle mass of the paravertebral muscles significantly impacts lumbar lordosis and sacral slope in patients with lumbar spinal stenosis before and after posterior lumbar decompression. These findings highlight a need to address risk factors for poor muscle quality in patients with sagittal imbalance.

Relationship between paraspinal muscle properties and bone mineral density based on QCT in patients with lumbar disc herniation

ObjectiveIncreasing research suggests that paraspinal muscle fat infiltration may be a potential biological marker for the assessment of osteoporosis. Our aim was to investigate the relationship between lumbar paraspinal muscle properties on MRI and volumetric bone mineral density (vBMD) based on QCT in patients with lumbar disc herniation (LDH).MethodsA total of 383 patients (aged 24–76 years, 193 females) with clinically and radiologically diagnosed LDH were enrolled in this retrospective study. The muscle cross-sectional area (CSA) and the proton density fat fraction (PDFF) were measured for the multifidus (MF), erector spinae (ES) and psoas major (PS) at the central level of L3/4, L4/5 and L5/S1 on lumbar MRI. QCT was used to measure the vBMD of two vertebral bodies at L1 and L2 levels. Patients were divided into three groups based on their vBMD values: normal bone density group (> 120 mg/cm3), osteopenia group (80 to 120 mg/cm3) and osteoporosis group (< 80 mg/cm3). The differences in paraspinal muscle properties among three vBMD groups were tested by one-way ANOVA with post hoc analysis. The relationships between paraspinal muscle properties and vBMD were analyzed using Pearson correlation coefficients. Furthermore, the association between vBMD and paraspinal muscle properties was further evaluated using multiple linear regression analysis, with age and sex also included as predictors.ResultsAmong the 383 LDH patients, 191 had normal bone density, 129 had osteopenia and 63 had osteoporosis. In LDH patients, compared to normal and osteopenia group, paraspinal muscle PDFF was significantly greater in osteoporosis group, while paraspinal muscle CSA was lower (p < 0.001). After adjusting for age and sex, it was found that MF PDFF and PS CSA were found to be independent factors influencing vBMD (p < 0.05).ConclusionIn patients with LDH, paraspinal muscle properties measured by IDEAL-IQ sequence and lumbar MR scan were found to be related to vBMD. There was a correlation between the degree of paraspinal muscle PDFF and decreasing vBMD, as well as a decrease paraspinal muscle CSA with decreasing vBMD. These findings suggest that clinical management should consider offering tailored treatment options for patients with LDH based on these associations.

Georg Schmorl Prize of the German Spine Society (DWG) 2023: the influence of sarcopenia and paraspinal muscle composition on patient-reported outcomes: a prospective investigation of lumbar spinal fusion patients with 12-month follow-up.

This study aimed to investigate the impact of sarcopenia and lumbar paraspinal muscle composition (PMC) on patient-reported outcomes (PROs) after lumbar fusion surgery with 12-month follow-up (12M-FU). A prospective investigation of patients undergoing elective lumbar fusion was conducted. Preoperative MRI-based evaluation of the cross-sectional area (CSA), the functional CSA (fCSA), and the fat infiltration(FI) of the posterior paraspinal muscles (PPM) and the psoas muscle at level L3 was performed. Sarcopenia was defined by the psoas muscle index (PMI) at L3 (CSAPsoas [cm2]/(patients' height [m])2). PROs included Oswestry Disability Index (ODI), 12-item Short Form Healthy Survey with Physical (PCS-12) and Mental Component Scores (MCS-12) and Numerical Rating Scale back and leg (NRS-L) pain before surgery and 12months postoperatively. Univariate and multivariable regression determined associations among sarcopenia, PMC and PROs. 135 patients (52.6% female, 62.1years, BMI 29.1kg/m2) were analyzed. The univariate analysis demonstrated that a higher FI (PPM) was associated with worse ODI outcomes at 12M-FU in males. Sarcopenia (PMI) and higher FI (PPM) were associated with worse ODI and MCS-12 at 12M-FU in females. Sarcopenia and higher FI of the PPM are associated with worse PCS-12 and more leg pain in females. In the multivariable analysis, a higher preoperative FI of the PPM (β = 0.442; p = 0.012) and lower FI of the psoas (β = -0.439; p = 0.029) were associated with a worse ODI at 12M-FU after adjusting for covariates. Preoperative FI of the psoas and the PPM are associated with worse ODI outcomes one year after lumbar fusion. Sarcopenia is associated with worse ODI, PCS-12 and NRS-L in females, but not males. Considering sex differences, PMI and FI of the PPM might be used to counsel patients on their expectations for health-related quality of life after lumbar fusion.

Relation of bone mineral density with fat infiltration of paraspinal muscles: The Goutallier classification

ObjectivesMuscle and bone tissue are interrelated throughout their developmental processes via paracrine and endocrine pathways. Osteosarcopenia has emerged with the growing data proving the high rate of simultaneous occurrence of sarcopenia and osteoporosis. We aimed to evaluate the relationship between osteoporosis, and muscle quality by grading the fatty infiltration in paraspinal muscles according to the Goutallier classification in magnetic resonance imaging (MRI). MethodsData of postmenopausal patients who underwent MRI for low back pain were analyzed retrospectively. Lumbar spine and femoral neck bone mineral density (BMD) were measured by using dual energy X-ray absorptiometry (DXA). Grade of paraspinal muscle fatty infiltration for each level of lumbar vertebrae including L1-L2, L2-L3, L3-L4, was evaluated separately according to Goutallier classification system. ResultsA total of 91 postmenopausal women were included in the study. The mean age of the study population was 60.5 ± 11. Lumbar vertebrae L1-L4 total T-scores and BMD g/cm2 were lower in patients with higher grades of Goutallier classification (P = 0.031 and P = 0.023, respectively). The distribution of the severity of fatty degeneration was significantly higher in the osteoporosis/osteopenia group at all 3 disc levels. No significant correlation was observed between femoral neck BMD and paraspinal muscle fat infiltration. ConclusionsThere is a strong relationship between osteoporosis of the lumbar spine and paraspinal muscle quality, which can be considered as a reflection of osteosarcopenia. The Goutailler classification can be an effective and easy method in the evaluation of muscle quality with MRI.

Influence of paraspinal muscle degeneration and postoperative Roussouly classification restoration on mechanical complications in female patients with degenerative scoliosis after surgery

Objective: To investigate the impact of lumbar paraspinal muscle degeneration and postoperative failure to restore ideal Roussouly classification on the occurrence of mechanical complications (MC) following long-segment spinal correction surgery in female patients with degenerative scoliosis (DS). Methods: The clinical data of 72 female DS patients who underwent long-segment spinal correction surgery in Gulou Hospital from June 2017 to November 2021 were retrospectively analyzed. According to whether restoring the ideal Roussouly classification after surgery, the patients were divided into R group(recovery group) (n=51) and N group(non-recovery group) (n=21). According to whether mechanical complications occurred after operation within two years, the patients were divided into MC (mechanical complications)group (n=24) and NMC(non-mechanical complications) group (n=48). The RM group (n=14) experienced mechanical complications in the R group, while the RN group (n=37) did not. The NM group (n=10) experienced mechanical complications in the N group, while the NN group (n=11) did not.Radiographic assessment included Sagittal parameters of spine and pelvis, standardized cross-sectional area (SCSA) and fat infiltration rate (FI%) of paraspinal muscle at each lumbar disc level. Results: The age of DS patients in this study was (61.4±6.2) years.The incidence of MC was 33.33%(n=24)in all patients. The incidence of MC was 27.45%(n=14)in group R and 47.62%(n=10) in group N. The correction amount of pelvic tilt angle (PT) (-11.62°±10.06° vs -7.04°±8.45°, P=0.046) and T1 pelvic angle(TPA)(-12.88°±11.23° vs -7.31°±9.55°, P=0.031)during surgery were significantly higher in MC group compared to the NMC group. In group R, the FI% of paraspinal muscles in each lumbar segment of patients with postoperative MC was higher than that in patients without MC (P<0.05). In the R and N groups, there was no significant difference inthe SCSA of the lumbar paravertebral muscles between patients with postoperative MC and those without MC at each level (all P>0.05). Multivariate logistic regression analysis showed that the average FI% of lumbar PSM was correlated with the occurrence of MC after spinal fusion in DS patients.The average FI% of lumbar PSM≥22.63% was a risk factors for MC after spinal fusion (P=0.010,OR=1.088, 95%CI:1.020-1.160). Conclusions: Female DS patients with higher degree of preoperative paraspinal muscle degeneration have a higher incidence of postoperative mechanical complications. For these patients,.there is still a higher risk of mechanical complications after surgery even if the ideal Roussouly classification is restored after surgery.

Paraspinal Muscle Changes in Individuals with and without Chronic Low Back Pain over a 4-Month Period: A Longitudinal MRI Study.

Background and Objectives: Previous research has shown associations between atrophy and fatty infiltration of the lumbar paraspinal musculature and low back pain (LBP). However, few studies have examined longitudinal changes in healthy controls and individuals with LBP without intervention. We aimed to investigate the natural variations in lumbar paraspinal musculature morphology and composition in this population over a 4-month period. Materials and Methods: Healthy controls and individuals with LBP were age- and sex-matched and completed several self-administered questionnaires. MRIs of L1-L5 were taken at baseline, 2 months, and 4 months to investigate cross-sectional area (CSA), along with DIXON fat and water images. A total of 29 participants had clear images for at least one level for all three time points. Means and standard deviations were calculated for the participant demographics. A two-way repeated measures ANOVA was performed to investigate CSA, fat signal fraction, and CSA asymmetry. Results: A total of 27 images at L3/L4, 28 images at L4/L5, and 15 images at L5/S1 were included in the final analysis. There were significant main effects of group for psoas CSA at the L3/L4 level (p = 0.02) and erector spinae (ES) CSA % asymmetry at the L3/L4 level (p < 0.001). There was a significant main effect of time for lumbar multifidus (LM) CSA % asymmetry at L4/L5 level (p = 0.03). Conclusions: This study provides insights into LM, ES, and psoas morphology in both healthy controls and affected individuals over a 4-month period without any intervention. Our findings suggest that psoas CSA at higher lumbar levels and CSA % asymmetry in general may be a better indicator of pathology and the development of pathology over time. Evaluating natural variations in paraspinal musculature over longer time frames may provide information on subtle changes in healthy controls and affected individuals and their potential role in chronic LBP.

Association patterns between lumbar paraspinal muscles and sagittal malalignment in preoperative patients undergoing lumbar three-column osteotomy.

We aim to investigate the associations between lumbar paraspinal muscles and sagittal malalignment in patients undergoing lumbar three-column osteotomy. Patients undergoing three-column osteotomy between 2016 and 2021 with preoperative lumbar magnetic resonance imaging (MRI) and whole spine radiographs in the standing position were included. Muscle measurements were obtained using a validated custom software for segmentation and muscle evaluation to calculate the functional cross-sectional area (fCSA) and percent fat infiltration (FI) of the m. psoas major (PM) as well as the m. erector spinae (ES) and m. multifidus (MM). Spinopelvic measurements included pelvic incidence (PI), sacral slope (SS), pelvic tilt (PT), L1-S1 lordosis (LL), T4-12 thoracic kyphosis (TK), spino-sacral angle (SSA), C7-S1 sagittal vertical axis (SVA), T1 pelvic angle (TPA) and PI-LL mismatch (PI-LL). Statistics were performed using multivariable linear regressions adjusted for age, sex, and body mass index (BMI). A total of 77 patients (n = 40 female, median age 64years, median BMI 27.9kg/m2) were analyzed. After adjusting for age, sex and BMI, regression analyses demonstrated that a greater fCSA of the ES was significantly associated with greater SS and SSA. Moreover, our results showed a significant correlation between a greater FI of the ES and a greater kyphosis of TK. This study included a large patient cohort with sagittal alignment undergoing three-column osteotomy and is the first to demonstrate significant associations between the lumbar paraspinal muscle parameters and global sagittal alignment. Our findings emphasize the importance of the lumbar paraspinal muscles in sagittal malalignment.

Investigating the associations between lumbar paraspinal muscle health and age, BMI, sex, physical activity, and back pain using an automated computer-vision model: a UK Biobank study

Background contextThe role of lumbar paraspinal muscle health in back pain (BP) is not straightforward. Challenges in this field have included the lack of tools and large, heterogenous datasets to interrogate the association between muscle health and BP. Computer-vision models have been transformative in this space, enabling the automated quantification of muscle health and the processing of large datasets. PurposeTo investigate the associations between lumbar paraspinal muscle health and age, sex, BMI, physical activity, and BP in a large, heterogenous dataset using an automated computer-vision model. DesignCross-sectional study. Patient sampleParticipants from the UK Biobank with abdominal Dixon fat-water MRI (N=9,564) were included (41.8% women, mean [SD] age: 63.5 [7.6] years, BMI: 26.4 [4.1] kg/m2) of whom 6,953 reported no pain, 930 acute BP, and 1,681 chronic BP. Outcome measuresIntramuscular fat (IMF) and average cross-sectional area (aCSA) were automatically derived using a computer-vision model for the left and right lumbar multifidus (LM), erector spinae (ES), and psoas major (PM) from the L1 to L5 vertebral levels. MethodsTwo-tailed partial Pearson correlations were generated for each muscle to assess the relationships between the muscle measures (IMF and aCSA) and age (controlling for BMI, sex, and physical activity), BMI (controlling for age, sex, and physical activity), and physical activity (controlling for age, sex, and BMI). One-way ANCOVA was used to identify sex differences in IMF and aCSA for each muscle while controlling for age, BMI, and physical activity. Similarly, one-way ANCOVA was used to identify between-group differences (no pain, acute BP, and chronic BP) for each muscle and along the superior-inferior expanse of the lumbar spine while controlling for age, BMI, sex, and physical activity (α=0.05). ResultsFemales had higher IMF (LM mean difference [MD]=11.1%, ES MD=10.2%, PM MD=0.3%, p<.001) and lower aCSA (LM MD=47.6 mm2, ES MD=350.0 mm2, PM MD=321.5 mm2, p<.001) for all muscles. Higher age was associated with higher IMF and lower aCSA for all muscles (r≥0.232, p<.001) except for LM and aCSA (r≤0.013, p≥.267). Higher BMI was associated with higher IMF and aCSA for all muscles (r≥0.174, p<.001). Higher physical activity was associated with lower IMF and higher aCSA for all muscles (r≥0.036, p≤.002) except for LM and aCSA (r≤0.010, p≥.405). People with chronic BP had higher IMF and lower aCSA than people with no pain (IMF MD≤1.6%, aCSA MD≤27.4 mm2, p<.001) and higher IMF compared to acute BP (IMF MD≤1.1%, p≤.044). The differences between people with BP and people with no pain were not spatially localized to the inferior lumbar levels but broadly distributed across the lumbar spine. ConclusionsParaspinal muscle health is associated with age, BMI, sex, and physical activity with the exception of the association between LM aCSA and age and physical activity. People with BP (chronic>acute) have higher IMF and lower aCSA than people reporting no pain. The differences were not localized but broadly distributed across the lumbar spine. When interpreting measures of paraspinal muscle health in the research or clinical setting, the associations with age, BMI, sex, and physical activity should be considered.

Predictors of achieving minimal clinically important difference in functional status for elderly patients with degenerative lumbar spinal stenosis undergoing lumbar decompression and fusion surgery

ObjectiveTo identify the predictors for the achievement of minimal clinically important difference (MCID) in functional status among elderly patients with degenerative lumbar spinal stenosis (DLSS) undergoing lumbar decompression and fusion surgery.MethodsPatients who underwent lumbar surgery for DLSS and had a minimum of 1-year follow-up were included. The MCID achievement threshold for the Oswestry Disability Index (ODI) was set at 12.8. General patient information and the morphology of lumbar paraspinal muscles were evaluated using comparative analysis to identify influencing factors. Multiple regression models were employed to identify predictors associated with MCID achievement. A receiver operating characteristic (ROC) curve analysis was conducted to determine the optimal cut-off values for predicting functional recovery.ResultsA total of 126 patients (46 males, 80 females; mean age 73.0 ± 5.9 years) were included. The overall rate of MCID achievement was 74.6%. Patients who achieved MCID had significantly higher psoas major muscle attenuation (43.55 vs. 39.23, p < 0.001) and preoperative ODI (51.5 vs. 41.6, p < 0.001). Logistic regression showed that elevated psoas major muscle attenuation (p = 0.001) and high preoperative ODI scores (p = 0.001) were independent MCID predictors. The optimal cut-off values for predicting MCID achievement were found to be 40.46 Hounsfield Units for psoas major muscle attenuation and 48.14% for preoperative ODI.ConclusionPreoperative psoas major muscle attenuation and preoperative ODI were reliable predictors of achieving MCID in geriatric patients undergoing lumbar decompression and fusion surgery. These findings offer valuable insights for predicting surgical outcomes and guiding clinical decision-making in elderly patients.

The Goutallier Classification System: How Does Paravertebral Adipose Degeneration Change in Patients With Symptomatic Lumbar Spinal Stenosis?

Retrospective, observational study. To determine the relationship between the Goutallier classification system (GS) and anthropometric, clinical, and radiologic features in 168 patients with lumbar spinal stenosis (LSS). There is no agreement on a classification system that is both reliable and easy to use for describing the severity of fatty degeneration in the paravertebral muscles of the lower back in patients with symptomatic LSS. This study aimed to determine the statistical relationship between the GS and anthropometric, clinical, and radiologic factors in 168 patients with LSS. This study was conducted on 168 patients with LSS scheduled for elective decompressive surgery. A control group of 110 healthy individuals was enrolled. The study assessed paralumbar musculature fatty infiltration using GS on preoperative magnetic resonance imaging. The authors evaluated the statistical association between patient age, body mass index (BMI), preoperative Oswestry disability index (ODI) questionnaire, and cross-sectional areas (CSAs) of the dural sac and lumbar paraspinal muscles. Multivariate analysis was performed to adjust for confounding. This study enrolled 168 patients with symptomatic LSS (95 men, 73 women); mean±SD age: 67.81±9.38 (range: 32.78-92.34) years; BMI: 28.29±3.36 (19.95-38.10) kg/m 2 . The control group was comprised of 110 healthy patients (61 men and 49 women). Age, sex, BMI, and erector spinae (ES)-CSA were not significantly different between the two groups. The authors found a direct relationship between GS grade and age and an inverse relationship between GS grade and dural sac-, multifidus lumbaris (LM)-, ES-, and psoas muscle (PM)-CSAs. Univariate analyses showed the variables statistically related to a higher GS grade included patient age ( P <0.001), ODI ( P =0.136), dural sac-CSA ( P =0.011), LM-CSA ( P < 0.001), ES-CSA ( P <0.001), and PM-CSA ( P <0.001). Multivariate least squares analysis showed the GS grade to be influenced by patient age ( P =0.01), LM-CSA ( P =0.002), ES-CSA ( P =0.002), and PM-CSA ( P =0.003). GS shows great potential as a tool for evaluating fat infiltration in the paralumbar muscles. This measure does not correlate with the ODI and BMI but is related to all radiologic parameters and patient age. Further prospective studies are required to establish a link between preoperative and postoperative outcomes in the setting of paraspinal fat infiltration.