Electrodiagnostic findings in amyotrophic lateral sclerosis: Variation with region of onset and utility of thoracic paraspinal muscle examination.

INTRODUCTION/AIMS: Limited data exist regarding variation of electrodiagnostic (EDX) findings in amyotrophic lateral sclerosis (ALS) patients with different onset regions and specificity of thoracic paraspinal muscle (TPSP) examination for confirming a diagnosis of ALS. We aimed to demonstrate the variation of EDX features and characterize the utility of TPSP muscle examination in the electrodiagnosis of ALS. METHODS: This is a retrospective study of a large cohort of ALS patients who had a comprehensive EDX evaluation. RESULTS: The study included 448 patients; all fulfilled the Gold Coast criteria for ALS. The average age at the time of EDX study was 64 years, and 41.1% were women. The onset region was identified as follows: bulbar (N = 149), cervical (N = 127), lumbosacral (N = 162), and other (N = 10). In contrast to limb onset, bulbar-onset patients more frequently demonstrated a pattern of normal or near normal needle electromyography (EMG) (p < .0001) and less frequently had abnormalities on EMG of TPSP (p = .002). Clinical or EDX diagnosis of sensory polyneuropathy was present in 12.6% patients, more frequently in the lumbosacral onset subgroup (p < .03). EMG showed active denervation in 9.6% and chronic denervation in 59% of craniobulbar muscles examined, without observed difference among different onset regions. TPSP showed higher frequencies of active and chronic denervation in ALS than a group of patients with non-ALS neuromuscular disorders. DISCUSSION: EDX features may differ among ALS patients of different onset regions. TPSP EMG is highly useful in differentiating ALS from non-ALS neuromuscular disorders while the yield of craniobulbar muscles, especially for active denervation, is low.

Inter-software and inter-threshold reliability of quantitative paraspinal muscle segmentation.

PURPOSE: Changes in the cross-sectional area (CSA) and functional cross-sectional area (FCSA) of the lumbar multifidus (MF) and erector spinae muscles (ES) are factors that can contribute to low back pain. For the assessment of muscle CSA and composition there are various software and threshold methods used for tissue segmentation in quantitative analysis. However, there is currently no gold standard for software as well as muscle segmentation. This study aims to analyze the measurement error between different image processing software and different threshold methods for muscle segmentation. METHODS: Magnetic resonance images (MRI) of 60 patients were evaluated. Muscle CSA and FCSA measurements were acquired from axial T2-weighted MRI of the MF and ES at L4/L5 and L5/S1. CSA, FCSA, and FCSA/CSA ratio were measured independently by two observers. The MRI images were measured using two different software programs (ImageJ and Amira) and with two threshold methods (Circle/Overlap method) for each software to evaluate FCSA and FCSA/CSA ratio. RESULTS: Inter-software comparisons revealed high inter-rater reliability. However, poor inter-rater reliability were obtained with different threshold methods. CSA, FCSA, and FCSA/CSA showed excellent inter-software agreement of 0.75-0.99 regardless of the threshold segmentation method. The inter-rater reliability between the two observers ranged between 0.75 and 0.99. Comparison of the two segmentation methods revealed agreement between 0.19 and 0.84. FCSA and FCSA/CSA measured via the Overlap method were significantly higher than those measured via the Circle method (P < 0.01). CONCLUSION: The present study showed a high degree of reliability with very good agreement between the two software programs. However, study results based on different threshold methods should not be directly compared.

Association between lumbar intervertebral vacuum phenomenon severity and posterior paraspinal muscle atrophy in patients undergoing spine surgery.

PURPOSE: Intervertebral vacuum phenomenon (IVP) and paraspinal muscular atrophy are age-related changes in the lumbar spine. The relationship between both parameters has not been investigated. We aimed to analyze the correlation between IVP and paraspinal muscular atrophy in addition to describing the lumbar vacuum severity (LVS) scale, a new parameter to estimate lumbar degeneration. METHODS: We analyzed patients undergoing spine surgery between 2014 and 2016. IVP severity was assessed utilizing CT scans. The combination of vacuum severity on each lumbar level was used to define the LVS scale, which was classified into mild, moderate and severe. MRIs were used to evaluate paraspinal muscular fatty infiltration of the multifidus and erector spinae. The association of fatty infiltration with the severity of IVP at each lumbar level was assessed with a univariable and multivariable ordinal regression model. RESULTS: Two hundred and sixty-seven patients were included in our study (128 females and 139 males) with a mean age of 62.6 years (55.1-71.2). Multivariate analysis adjusted for age, BMI and sex showed positive correlations between LVS-scale severity and fatty infiltration in the multifidus and erector spinae, whereas no correlation was observed in the psoas muscle. CONCLUSION: IVP severity is positively correlated with paraspinal muscular fatty infiltration. This correlation was stronger for the multifidus than the erector spinae. No correlations were observed in the psoas muscle. The lumbar vacuum severity scale was significantly correlated with advanced disc degeneration with vacuum phenomenon.

The quality of bone and paraspinal muscle in the fragility osteoporotic vertebral compression fracture: a comprehensive comparison between different indicators.

PURPOSE: To evaluate the value of five indicators in predicting OVCF through a retrospective case-control study, and explore the internal correlation of different indicators. METHOD: We retrospectively enrolled patients over 50 years of age who had been subjected to surgery for fragility OVCF at China Japan Friendship Hospital from January 2021 to September 2023. Demographic characteristics, T-score based on dual-energy X-ray absorptiometry (DXA), CT-based Hounsfield unit (HU) value, vertebral bone quality (VBQ) score based on magnetic resonance imaging (MRI), relative cross-sectional area (rCSA) and the rate of fat infiltration (FI) of paraspinal muscle were collected. A 1:1 age- and sex-matched, fracture-free control group was established from patients admitted to our hospital for lumbar spinal stenosis or lumbar disk herniation. RESULTS: A total of 78 patients with lumbar fragility OVCF were included. All the five indicators were significantly correlated with the occurrence of OVCFs. Logistic regression analysis showed that average HU value and VBQ score were significantly correlated with OVCF. The area under the curve (AUC) of VBQ score was the largest (0.89). There was a significantly positive correlation between average T-score, average HU value and average total rCSA. VBQ score was significantly positive correlated with FI. CONCLUSION: VBQ score and HU value has good value in predicting of fragility OVCF. In addition to bone mineral density, we should pay more attention to bone quality, including the fatty signal intensity in bone and the FI in paraspinal muscle.

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

OBJECTIVE: Increasing 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). METHODS: A 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. RESULTS: Among 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). CONCLUSION: In 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.

Mo-fi-disc scoring system: Towards understanding the radiological tools to better delineate the disease process and enhancing our solutions for low back pain in artificial intelligence era.

BACKGROUND: 'Mo-fi-disc' is a new scoring system that quantifies degeneration of the lumbar spine and predicts the intensity of low back pain (LBP). However, its association with LBP-related disability is unknown. In the present study, we aimed to analyze whether 'Mo-fi-disc' scoring system could predict LBP-related disability and distinguish patients with LBP from asymptomatic subjects, while the spine medicine marching towards the era of artificial intelligence (AI). METHODS: This is a cross-sectional analysis of a prospectively collected database. We included age-, gender-, and BMI-matched 132 subjects (patients: 66, asymptomatic subjects: 66). Modic changes (Mo), fatty infiltration in the paraspinal muscles (fi), and intervertebral disc degeneration (disc) were evaluated using 'Mo-fi-disc' scoring system on lumbar spine magnetic resonance imaging. Pain and disability were evaluated with visual analogue scale (VAS) and Oswestry disability index (ODI), respectively. RESULTS: A Mo-fi-disc score of 5.5 was the most appropriate cut-off value. Mo-fi-disc scoring system had an OR of 1.79 in distinguishing patients with LBP from asymptomatic subjects. One point increment in VAS and ODI had ORs of 1.82 and 1.13 for predicting higher Mo-fi-disc scores. CONCLUSION: 'Mo-fi-disc' scoring system is a useful tool depicting intensity of LBP and LBP-related disability. The cut off value of Mo-fi-disc score is 5.5 to distinguish patients with LBP from asymptomatic subjects. This scoring system, with progressive improvement of its faults, could help clinicians to select appropriate patients for conservative and surgical management in the very near future, in AI-based spine medicine. IRB APPROVAL NO: ATADEK 2019-12/4.

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.

The sarcopenia index measured using the lumbar paraspinal muscle is associated with prognosis in endometrial cancer.

OBJECTIVE: The number of type-II endometrial cancer patients has been increasing and the prognosis is not favorable. We aim to investigate whether sarcopenia index in any of several different muscles could serve as a novel biomarker of prognosis in patients with type-II endometrial cancer. METHODS: We retrospectively investigated a total of 194 patients at four hospitals. Ninety patients were treated as derivation set and the other 104 patients as validation set. Using preoperative computed tomography images, we measured the horizontal cross-sectional area at the third lumbar spine level: the (i) psoas major, (ii) iliac and (iii) paraspinal muscle. The clinical information including recurrence-free survival and overall survival were retrospectively collected. These results were validated with external data sets of three hospitals. RESULTS: The median values of the sarcopenia index (cm2/m2) ± standard deviation with the first data of 90 patients using the psoas, iliac and paraspinal muscle were 3.4 ± 1.0, 1.7 ± 0.6 and 12.6 ± 3.2, respectively. In univariate analyses, the sarcopenia indexes measured using the psoas or paraspinal muscle were associated with recurrence-free survival and overall survival. On the other hand, in multivariate analyses, only the sarcopenia index using paraspinal muscle was significantly related to recurrence-free survival (hazard ratio = 3.78, 95% confidence intervals = 1.29-5.97, P = 0.009) and overall survival (hazard ratio = 3.13, 95% confidence interval = 1.18-8.26, P = 0.022). Paraspinal sarcopenia index was also related to overall survival (hazard ratio = 3.74, 95% confidence interval = 1.31-10.72, P = 0.014) even in patients with advanced stage. Serum albumin was significantly correlated with the sarcopenia index (P = 0.012). Within the analysis of the validation set, sarcopenia index using paraspinal muscle was related to recurrence-free survival (hazard ratio = 2.06, P = 0.045) in multivariate analysis and recurrence-free survival (P = 0.009) in patients with advanced stage. CONCLUSIONS: The sarcopenia index using the paraspinal muscle, not psoas, could be a suitable index to predict recurrence-free survival and overall survival in patients with type-II endometrial cancer even in advanced stage.

Comparison of paraspinal muscle composition measurements using IDEAL fat-water and T2-weighted MR images.

PURPOSE: The purpose of this study was to evaluate the agreement between paraspinal muscle composition measurements obtained from fat-water images using % fat-signal fraction (%FSF) in comparison to those obtained from T2-weighted magnetic resonance images (MRI) using a thresholding method. METHODS: A sample of 35 subjects (19 females, 16 males; 40.26 ± 11.3 years old) was selected from a cohort of patients with chronic low back pain (LBP). Axial T2-weighted and IDEAL (Lava-Flex, 2 echo sequence) fat and water MR images were obtained using a 3.0 Tesla GE scanner. Multifidus, erector spinae, and psoas major muscle composition measurements were acquired bilaterally at L4-L5 and L5-S1 using both imaging sequences and related measurement methods. All measurements were obtained by the same rater, with a minimum of 7 days between each method. Intra-class correlation coefficients (ICCs) were calculated to assess intra-rater reliability. Pearson Correlation and Bland-Altman 95% limits of agreement were used to assess the agreement between both measurement methods. RESULTS: The intra-rater reliability was excellent for all measurements with ICCs varying between 0.851 and 0.997. Strong positive correlations indicating a strong relationship between composition measurements were obtained from fat-water and T2-weighted images for bilateral multifidus and erector spinae muscles at both spinal levels and the right psoas major muscle at L4-L5, with correlation coefficient r ranging between 0.67 and 0.92. Bland-Altman plots for bilateral multifidus and erector spinae muscles at both levels revealed excellent agreement between the two methods, however, systematic differences between both methods were evident for psoas major fat measurements. CONCLUSION: Our findings suggest that utilizing fat-water and T2-weighted MR images are comparable for quantifying multifidus and erector spinae muscle composition but not of the psoas major. While this suggests that both methods could be used interchangeably for the multifidus and erector spinae, further evaluation is required to expand and confirm our findings to other spinal levels.

Percentiles for paraspinal muscle parameters at the L3 vertebra level in patients undergoing lumbar computed tomography scanning.

BACKGROUND: Computed tomography (CT) is the gold standard for analyzing muscle parameters. PURPOSE: To clarify sex-specific paraspinal muscle area (PMA), paraspinal muscle index (PMI), and muscle fat infiltration (MFI) percentiles. MATERIAL AND METHODS: This was a cross-sectional study of 760 individuals (45% men; age range = 20-92 years; mean age = 53.4 ± 21.1 years) with a body mass index (BMI) in the range of 16.4-38.1 kg/m2. CT scans were retrospectively used to establish PMA, PMI, and MFI at L3 level using a deep-learning (DL) tool. Sex-specific distributions for these parameters were assessed based on associations between age/BMI and individual muscle parameters, after which age- and BMI-specific percentile estimates were determined. The 5th percentile was regarded as the cutoff for PMA/PMI, and the 95th percentile was regarded as the cutoff for MFI. RESULTS: Sex-specific PMA, PMI, and MFI cutoffs in the paraspinal muscles group were 52.9 cm2, 15.0 cm2/m2, and 33.3%, respectively, in men, and 33.2 cm2, 9.5 cm2/m2, and 41.2% in women. Age was moderately negatively correlated with PMA and was strongly negatively correlated with PMI, but age was strongly positively correlated with MFI. BMI was moderately positively correlated with PMA/PMI in men and strongly positively correlated in women; BMI was weakly positively correlated with MFI, thus enabling the establishment of age- and BMI-specific cutoff percentiles. CONCLUSION: Sex-specific PMA, PMI, and MFI percentiles and age- and BMI-specific cutoff values for these parameters were successfully established for an outpatient population.

Deep learning for automatic segmentation of paraspinal muscle on computed tomography.

BACKGROUND: Muscle quantification is an essential step in sarcopenia evaluation. PURPOSE: To develop and evaluate an automated machine learning (ML) algorithm for segmenting the paraspinous muscles on either abdominal or lumbar (L) computed tomography (CT) scans. MATERIAL AND METHODS: A novel deep neural network algorithm for automated segmentation of paraspinous muscle was developed, CT scans of 504 consecutive patients conducted between January 2019 and February 2020 were assembled. The muscle was manually segmented at L3 vertebra level by three radiologists as ground truth, divided into training and testing subgroups. Muscle cross-sectional area (CSA) was recorded. Dice similarity coefficients (DSCs) and CSA errors were calculated to evaluate system performance. The degree of muscle fat infiltration (MFI) recording by percentage value was the fat area within the region of interest divided by the muscle area. An analysis of the factors influencing the performance of the V-net-based segmentation system was also implemented. RESULTS: The mean DSCs for paraspinous muscles were high for both the training (0.963, 0.970, 0.941, and 0.968, respectively) and testing (0.950, 0.960, 0.929, and 0.961, respectively) datasets, while the CSA errors were low for both training (1.9%, 1.6%, 3.1%, and 1.3%, respectively) and testing (3.4%, 3.0%, 4.6%, and 1.9%, respectively) datasets. MFI and muscle area index (MI) were major factors affecting DSCs of the posterior paraspinous and paraspinous muscle groups. CONCLUSION: The ML algorithm for the measurement of paraspinous muscles was compared favorably to manual ground truth measurements.

Abdominal aortic calcification is independently associated with increased atrophy and fatty infiltration of the lumbar paraspinal muscles: a retrospective cross-sectional study.

BACKGROUND: Aortic abdominal calcification (AAC) is associated with spine-related conditions, such as lower back pain and reduced bone mineral density. Similar to peripheral vascular disease, AAC possibly reduces blood flow to the lumbar posterior paraspinal muscles (PPM) which may lead to atrophy and increased fatty infiltration. METHODS: Imaging of patients with lower back pain was analyzed. AAC was assessed on lateral lumbar radiographs according to the Kauppila classification. The cross-sectional area of the PPM was measured on a T2-weighted axial MRI sequence and the functional cross-sectional area (fCSA) and fatty infiltration (FI) were calculated with custom software. The association of AAC and FI as well as AAC and fCSA was assessed by multivariable linear regression, adjusted for age, sex, body mass index (BMI), diabetes, and smoking. RESULTS: Two hundred and thirty patients (47.8% female) with a median age of 60 years (IQR 48-68) were analyzed. In patients, without AAC the median FI of the PPM was 33.3% (IQR 29.1-37.6%), compared to 44.6% (IQR 38.5-54.3%) in patients with AAC (p < 0.001). In the multivariable linear regression, both fCSA and FI of the PPM were significantly and independently associated with the degree of AAC (p = 0.037 and p = 0.015, respectively). CONCLUSIONS: This is the first study to demonstrate a significant and independent association between AAC and PPM morphology. The results of this study improve our understanding of the interaction between AAC and spinal musculature, with AAC being a reason for atrophy of the PPM.

Evaluation of lumbar paraspinal muscles degeneration and fatty infiltration in dynamic sagittal imbalance based on magnetic resonance imaging.

PURPOSE: To explore degeneration and fatty infiltration (FI) of lumbar paraspinal muscles in patients with dynamic sagittal imbalance (DSI) and the relationship between lumbar paraspinal muscles degeneration, fatty infiltration and severity of the disease. METHODS: We recruited 41 DSI patients and selected 22 lumbar spinal stenosis (LSS) patients without osphyalgia as controls. All patients received magnetic resonance imaging (MRI) scan and DSI patients also received pre-walk and post-walk X-rays. DSI patients were divided into 2 subgroups according to their symptom improvement after conservative treatment. We calculated rmCSA and FI of the lumbar paraspinal muscles. The rmCSA and FI between DSI and control and between DSI subgroups were compared by t test. The regression analysis was used to explore the risk factors influencing disease severity. Receiver operating characteristic (ROC) curves and area under curves (AUCs) were used to evaluate the severity of the disease. RESULTS: In comparison of rmCSA and FI between DSI and control, there are significant differences of most muscles. In comparison of rmCSA between two subgroups, there are significant differences of most muscles, while in comparison of FI, only muscles in L4 segment have significant different. In logistic regression analysis, total rmCSA and total FI are risk factors influencing disease severity. ROC curves shows that total rmCSA and total FI both achieve an AUC greater than 0.7. CONCLUSION: Compared with control, DSI patients have degeneration and fatty infiltration of the lumbar paraspinal muscles. The degeneration and fatty infiltration are risk factors influencing disease severity. The total rmCSA and total FI can be used as an indicator to determine whether a patient has severe DSI.

Significance of paraspinal muscle quality in risk between single and multiple osteoporotic vertebral fractures.

PURPOSE: To compare paraspinal muscle quality between patients with single and multiple osteoporotic vertebral fractures (OVFs) and evaluate the role of the paraspinal muscles in OVFs. METHODS: A total of 262 consecutive patients with OVFs were retrospectively analyzed in two groups: those with single OVF (n = 173) and those with multiple OVFs (n = 89). The cross-sectional area (CSA) and fatty degeneration of the paraspinal muscles were calculated from axial T2-weighted magnetic resonance imaging at the level of the L4 upper endplate by manual tracing in ImageJ software. Pearson's correlation analysis was performed to analyze correlations of paraspinal muscle quality to multiple OVFs. RESULTS: FD in all the paraspinal muscles was significantly higher in the multiple OVF group than the single OVF group (all p < 0.005). The functional CSA (fCSA) of the paraspinal muscles was significantly lower in the multiple OVF group than the single OVF group (all Ps < 0.001), except for the erector spine (p = 0.304). The Pearson's correlation analysis showed significant positive inter-correlations for the fCSAs of all the paraspinal muscles and the occurrence of multiple OVFs. CONCLUSIONS: The pure muscle volumes of the multifidus, psoas major, and quadratus lumborum were lower in patients with multiple OVFs than in those with a single OVF. Furthermore, the inter-correlation among all the paraspinal muscles indicate that the muscle-bone crosstalk profoundly existed in vertebral fracture cascade. Therefore, special attention to paraspinal muscle quality is needed to prevent progression to multiple OVFs.

Characteristics of paraspinal muscle degeneration in patients with adult degenerative scoliosis.

INTRODUCTION: Adult degenerative scoliosis (ADS) is a 3D deformity that greatly affects the quality of life of patients and is closely related to the quality of paraspinal muscles (PSMs), but the specific degenerative characteristics have not been described. METHODS: This study included ADS patients who were first diagnosed in our hospital from 2018 to 2022. Muscle volume (MV) and fat infiltration (FI) of PSM were measured by 3D reconstruction, and spinal parameters were assessed by X-ray. The values of convex side (CV) and concave side (CC) were compared. RESULTS: Fifty patients were enrolled with a mean age of 64.1 ± 5.8 years old. There were significant differences in MV, FI, and Cobb angle between male and female groups. The MV of MF and PS on the CC was significantly larger than that on the CV. In the apex and the segments above the apex, the FI of the MF on the CC is greater than the CV, and in the CV of the segment below the apex, the FI of the MF is greater than the CC. Besides, there was a significant positive correlation between the FI and Cobb angle in the MF of the CC-CV. CONCLUSION: There were significant differences in the MV and FI of PSM on both sides of the spine in ADS patients. It was determined that the PSM of ADS showed different degrees of degeneration in different levels of the lumbar spine and were positively correlated with Cobb angle.

Effect of aquatic exercise versus standard care on paraspinal and gluteal muscles morphology in individuals with chronic low back pain: a randomized controlled trial protocol.

BACKGROUND: Low back pain (LBP) is one of the most disabling diseases and a major health issue. Despite the evidence of a link between paraspinal and gluteal muscle dysfunction and LBP, it is unknown whether aquatic exercises can lead to improvements in paraspinal and gluteal muscle morphology and function, and whether improvements in overall muscle health are associated with improvements in patients' outcomes. The unique properties of water allow a water-based exercise program to be tailored to the needs of those suffering from LBP. This study uses magnetic resonance imaging (MRI) to investigate the effect of an aquatic exercise program versus standard exercise on 1) paraspinal and gluteal muscle size, quality and strength and 2) pain, disability, and psychological factors (pain related fear, depression, anxiety, sleep quality) in chronic LBP. METHODS: This study will include 34 participants with chronic non-specific LBP and moderate to severe disability, aged between 18 and 65, who will be randomly assigned (1:1) to the aquatic exercise group or land-based standard care exercise group. Both groups will receive 20 supervised sessions, twice per week over 10 weeks. MRIs will be obtained along the lumbosacral spine (L1-L5) and pelvis at the start and end of the intervention to assess the effect of each exercise intervention on paraspinal and gluteal muscle size and quality. Pre- to post-intervention changes in all outcomes between each group will be assessed, and the association between the changes in back muscle quality and clinical outcomes will be examined. Between-subjects repeated measure analysis of variance will be used to examine the changes in paraspinal muscle morphology over the different time points. Linear mixed models will be used to assess whether baseline scores can modify the response to the exercise therapy treatment. DISCUSSION: This study will determine if water-based exercises targeting the lower back and gluteal muscles can lead to important changes in muscle quality and function, and their possible relation with patients' pain and functional improvements. Our findings will have strong clinical implications and provide preliminary data to design a community program to better support individuals with chronic LBP. TRIAL REGISTRATION: NCT05823857, registered prospectively on April 27th, 2023.

Effect of Muscularity and Fatty Infiltration of Paraspinal Muscles on Outcome of Lumbar Interbody Fusion.

BACKGROUND: Lumbar paraspinal muscles play an important role in maintaining global spinal alignment and are associated with lower back pain; however, only a few studies on the effect of the paraspinal muscles on the surgical outcome exist. Therefore, this study aimed to analyze the association of preoperative muscularity and fatty infiltration (FI) of paraspinal muscles with the outcome of lumbar interbody fusion. METHODS: Postoperative clinical and radiographic outcomes were analyzed in 206 patients who underwent surgery for a degenerative lumbar disease. The preoperative diagnosis was spinal stenosis or low-grade spondylolisthesis, and the surgery performed was posterior lumbar interbody fusion or minimally invasive transforaminal lumbar interbody fusion. Indications for surgery were a complaint of severe radiating pain that did not improve with conservative treatment and neurological symptoms accompanied by lower extremity motor weakness. Patients with fractures, infections, tumors, or a history of lumbar surgery were excluded from this study. Clinical outcome measures included functional status, measured using the Oswestry disability index (ODI) and visual analog scale (VAS) score for lower back and leg pain. Other radiographic parameters included measures of spinal alignment, including lumbar lordosis, pelvic tilt, sacral slope, pelvic incidence, C7 sagittal vertical axis, and pelvic incidence-lumbar lordosis mismatch. Lumbar muscularity (LM) and FI were measured preoperatively using a lumbar magnetic resonance image (MRI). RESULTS: The high LM group showed more significant improvement in VAS score for lower back pain than the low LM group. In contrast, the VAS score for leg pain demonstrated no statistical significance. The high LM group showed more significant improvement in ODI postoperatively than the medium group. The severe FI group showed more significant improvement in ODI postoperatively, whereas the less severe FI group showed more significant improvement in the sagittal balance postoperatively. CONCLUSION: Patients with high LM and mild FI ratio observed on preoperative MRI demonstrated more favorable clinical and radiographic outcomes after lumbar interbody fusion. Therefore, preoperative paraspinal muscle condition should be considered when planning lumbar interbody fusion.

Correlation between posterior paraspinal muscle atrophy and lumbar intervertebral disc degeneration in patients with chronic low back pain.

BACKGROUND: Although enormous studies have been devoted to solving the problem of intervertebral disc degeneration/herniation, little attention is paid to the effect of paraspinal muscles on it. We aimed to investigate the correlation between paraspinal muscle atrophy and lumbar disc degeneration to recognize paraspinal muscle atrophy and its importance to the spine. PATIENTS AND METHODS: A total of 107 patients were enrolled in the study (65 females, 42 males; age 50.87 ± 15.391 years old). Cross-sectional area, functional cross-sectional area, and fatty infiltration of the posterior paraspinal muscles were measured at the level of L4/5, and the degree of facet joint degeneration was evaluated at the levels of L3/4, L4/5, and L5/S1 by MRI. After controlling the confounding factors by multiple linear regression, the correlations among paraspinal muscle atrophy, disc degeneration, and facet joint degeneration were analyzed. Meanwhile, Pearson/Spearson rank analysis was used to analyze the correlation between clinical symptoms (VAS and ODI) and paraspinal muscle atrophy. RESULTS: There was a strong correlation between paraspinal muscle atrophy and disc degeneration after controlling the confounding factors (p < 0.05, R > 0.5). There was a weak correlation between paraspinal muscle atrophy and facet joint degeneration (p < 0.05, R < 0.5). There was a significant correlation between facet joint degeneration and intervertebral disc degeneration (p < 0.05, R > 0.7). The fatty infiltration of paraspinal muscle was weakly correlated with ODI (p < 0.05, R < 0.3), but VAS was not. CONCLUSIONS: The degree of paraspinal muscle atrophy increased with lumbar disc degeneration and facet joint degeneration and fatty infiltration of multifidus was more susceptible to weight.

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

PURPOSE: Residual 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. METHODS: We 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. RESULTS: The 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. CONCLUSIONS: Posterior 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.

The association between lumbar paraspinal muscle functional cross-sectional area on MRI and regional volumetric bone mineral density measured by quantitative computed tomography.

Osteosarcopenia is a common condition among elderly and postmenopausal female patients. Site-specific bone mineral density is more predictive of bone-related complications. Few studies have investigated muscle-bone associations. Our results demonstrated that in women, significant positive associations between paraspinal muscles FCSA and vBMD exist at different lumbosacral levels. These regional differences should be considered when interpreting bone-muscle associations in the lumbar spine. INTRODUCTION: There is increasing evidence between bone and muscle volume associations. Previous studies have demonstrated comorbidity between osteoporosis and sarcopenia. Recent studies showed that sarcopenic subjects had a fourfold higher risk of concomitant osteoporosis compared to non-sarcopenic individuals. Although site-specific bone mineral density (BMD) assessments were reported to be more predictive of bone-related complications after spinal fusions than BMD assessments in general, there are few studies that have investigated level-specific bone-muscle interactions. The aim of this study is to investigate the associations between muscle functional cross-sectional area (FCSA) on magnetic resonance imaging (MRI) and site-specific quantitative computed tomography (QCT) volumetric bone mineral density (vBMD) in the lumbosacral region among spine surgery patients. METHODS: We retrospectively reviewed a prospective institutional database of posterior lumbar fusion patients. Patients with available MRI undergoing posterior lumbar fusion were included. Muscle measurements and FCSA were conducted and calculated utilizing a manual segmentation and custom-written program at the superior endplate of the L3-L5 vertebrae level. vBMD measurements were performed and calculated utilizing a QCT pro software at L1-L2 levels and bilateral sacral ala. We stratified by sex for all analyses. RESULTS: A total of 105 patients (mean age 61.5 years and 52.4% females) were included. We found that female patients had statistically significant lower muscle FCSA than male patients. After adjusting for age and body mass index (BMI), there were statistically significant positive associations between L1-L2 and S1 vBMD with L3 psoas FCSA as well as sacral ala vBMD with L3 posterior paraspinal and L5 psoas FCSA. These associations were not found in males. CONCLUSIONS: Our results demonstrated that in women, significant positive associations between the psoas and posterior paraspinal muscle FCSA and vBMD exist in different lumbosacral levels, which are independent of age and BMI. These regional differences should be considered when interpreting bone and muscle associations in the lumbar spine.