Changes In Paraspinal Muscles Research Articles

Clinical outcome and multifidus muscle changes of transforaminal lumbar interbody fusion

Background: Minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) has shown to have smaller skin incision, decreased muscular dissection, and less retraction of the thecal sac, compared to conventional open approach. However, its effects on long term functional outcome and degenerative changes of paraspinal muscles are still obscure. Materials and Methods: We studied 81 patients treated by one team of surgeons at a single institution. In the two level spinal fusion, 18 patients underwent conventional TLIF (C TLIF) and 20 patients underwent MIS TLIF. In three level spinal fusion, 23 patients were treated with C TLIF and 20 patients were treated with MIS TLIF. Clinical outcomes included mean operative times, volume of blood loss, percentage of early ambulation, visual analog scale (VAS), and oswestry disability index (ODI) were analyzed. The change of multifidus muscle was calculated from magnetic resonance imaging (MRI) taken before and 6-month after the operation. Results: Lesser blood loss was noted in the MIS TLIF group compared to the conventional group in two- or three-level circumferential spinal fusion. Early ambulation (within 3 days after operation) was found in the MIS TLIF groups. Analysis of VAS scores at leg area showed no significant differences in improvement between each group at 18 month follow up. The postoperative ODI score was significantly less in the MIS TLIF groups than in the C TLIF groups after 6 month follow up. In three segment spinal fusion, MIS TLIF minimized multifidus muscle atrophy, when compared with C TLIF. Conclusion: MIS TLIF in three level lumbar fusion not only has a better functional recovery but also ameliorates the degenerative change of multifidus muscle.

Radiological Assessment of Postoperative Paraspinal Muscle Changes After Lumbar Interbody Fusion With or Without Minimally Invasive Techniques.

Retrospective cohort study. Percutaneous pedicle screws (PPS) have the advantage of being able to better preserve the paraspinal muscles when compared with a traditional open approach. However, the nature of changes in postoperative paraspinal muscle after damage by lumbar fusion surgery has remained largely unknown. It is clinically important to clarify and compare changes in paraspinal muscles after the various surgeries. (1) To determine postoperative changes of muscle density and cross-sectional area using computed tomography (CT), and (2) to compare paraspinal muscle changes after posterior lumbar interbody fusion (PLIF) with traditional open approaches and minimally invasive lateral lumbar interbody fusions (LLIF) with PPS. We included data from 39 consecutive female patients who underwent open PLIF and 23 consecutive patients who underwent single-staged treatment with LLIF followed by posterior PPS fixation at a single level (L4-5). All patients underwent preoperative, 6 months postoperative, and 1-year postoperative CT imaging. Measurements of the cross-sectional area (CSA) and muscle densities of paraspinal muscles were obtained using regions of interest defined by manual tracing. We did not find any decrease of CSA in any paraspinal muscles. We did find a decrease of muscle density in the multifidus at 1 year after surgery in patients in the PILF group, but not in those in LLIF/PPS group. One year after surgery, a significant postoperative decrease of muscle density of the multifidi was observed only in patients who underwent open PLIF, but not in those who underwent LLIF/PPS.

Lumbar intervertebral disc degeneration, end-plates and paraspinal muscle changes in children and adolescents with low-back pain.

The prevalence of low-back pain (LBP) in adolescents ranges from 7 to 72%. We aimed to define the radiologic characteristics of the lumbar spine in children and adolescents with LBP with/without leg pain. Two hundred and fourteen children and adolescents, who were born between 2001 and 2009 and had lumbar spine MRI for LBP with/without leg pain, were evaluated in terms of intervertebral disc degeneration (IVDD), end-plates and paraspinal muscle changes on lumbar spine MRIs. Severe IVDD was detected at all lumbar levels except for L2-L3. Modic changes were present in 4.2% of the patients. Modic changes were more common in patients with severe IVDD than in those with mild-to-moderate IVDD. Severe IVDD was significantly associated with Modic changes at the corresponding L1-L2 and L3-L4 disc levels. Girls had significantly more fatty infiltration in the paraspinal muscles when compared to boys. The risk of having severe IVDD concomitant with Modic changes was high [odds ratio (OR), 8.6]. The OR was 20.7 for predicting the presence of severe IVDD at any level if Modic changes presented particularly at the L3-L4 level. The ORs of Modic changes presented at any lumbar level at the background of fat-infiltrated multifidus at L3-L4 and L4-L5 levels were 8.3 and 9.1, respectively. Fatty infiltration in the paraspinal muscles and IVDD were closely associated with Modic changes in children and adolescents with LBP. Lumbar IVDD in children and adolescents could be the result of a mechanical pathology.

Fiber Type-Specific Morphological and Cellular Changes of Paraspinal Muscles in Patients with Severe Adolescent Idiopathic Scoliosis.

BackgroundParaspinal muscle (PSM) has been suggested to have a role in adolescent idiopathic scoliosis (AIS). Few studies have investigated the fiber type-specific changes of PSM in detail.Material/MethodsBilateral multifidus muscles were harvested from the apical vertebra level (T7–T10) of 12 AIS patients and 6 control individuals. Immunohistological staining was performed to evaluate the muscle fiber type composition, fiber type-specific cross-sectional area (CSA), myonuclei density, and the total and activated satellite cell (SC) density. The correlations between these characteristics and curve initiation/severity were analyzed.ResultsIn comparison with the PSM in convexity and the control group, PSM in concavity showed a significant reduction of CSA (concavity, 2601.1±574.1 μm2; convexity, 3732.1±545.1 μm2; control, 3426.5±248.4 μm2), myonuclei density (concavity, 2.0±0.3 myonuclei/fiber; convexity, 2.5±0.4 myonuclei/fiber; control, 2.2±0.2 myonuclei/fiber), and activated SC density (concavity, 0.7±0.4 cells/100 fibers; convexity, 1.5±0.7 cells/100 fibers; control, 1.2±0.3 cells/100 fibers) for fiber type I. The Cobb angle was positively correlated with the bilateral ratio of CSA (convexity/concavity) for both fiber types. The apical vertebral translation was positively correlated with bilateral difference of myonuclei density (type I), total SC density (types I and II), and activated SC density (type I).ConclusionsThe fiber type-specific pathological changes on the concave side seemed to be more severe. Some fiber type-specific characteristics (CSA, myonuclei density, total/activated SC density) were closely associated with curve severity. More attention should be paid to PSM physiotherapy treatment on the concave side.

Reciprocal relationship between multifidus and psoas at L4-L5 level in women with low back pain

Background Low back pain (LBP) may originate from different sources such as intervertebral disc degeneration (IVDD), end-plate and paraspinal muscle changes. Our aim is to explore the relevance of paraspinal muscles’ fat-infiltration in women with LBP and its association with IVDD and Modic changes. Methods Consecutive female patients presenting with chronic LBP to the outpatient clinics were included. Patients were evaluated in terms of IVDD, vertebral end-plate changes, and fatty infiltration in the paraspinal muscles at all lumbar levels on lumbar spine magnetic resonance imaging (MRI). Visual Analogue Scale (VAS) scores were recorded using our prospectively collected database. Results Patients with higher VAS scores were significantly more likely to have more fatty infiltration in the multifidus and less fatty infiltration in the psoas at L4-L5 level when compared to those with lower VAS scores (69.1 vs. 31.8%, p = 0.003). To predict LBP, fatty infiltration in the multifidus and psoas had odds ratio (OR) of 4 ( p = 0.010), and 0.3 ( p = 0.013), respectively; whereas disc degeneration had an OR of 0.5 ( p = 0.028). Conclusion This is the first clinical cross-sectional study suggested that women with chronic low back pain could have less fat-infiltrated psoas to compensate more fat-infiltrated multifidus at L4-L5 disc level.

Magnetic Resonance Imaging-Based Morphological Change of Paraspinal Muscles in Girls With Adolescent Idiopathic Scoliosis.

A cross-sectional study. To investigate and compare any morphological differences in paraspinal muscles (PSM) between adolescent idiopathic scoliosis (AIS) patients (with severe or non-severe curves) and healthy controls. Several studies have reported abnormalities in biochemical, electromyographic activity, and histological changes of PSM in AIS. However, these studies only had qualitative data and without comparison with controls. Changes of muscle mass and mean density at the lumbar region have been described for scoliotic spines. All these findings suggested that imbalance of PSM in AIS could be a contributing factor to the development of severe scoliotic curve. T2-weighted MR images with multi-planar reconstruction were acquired in 41 Chinese AIS girls with a primary right-sided thoracic curve and 23 age-matched controls. In AIS, measurements of PSM were taken on both concavity and convexity of scoliosis starting from two vertebrae above and two below the apex. Morphological assessments of the multifidus (MF) and erector spinae (ES) muscles on both sides were made including signal intensity (SI) and fat deposition using manual tracing and thresholding technique, respectively. Same parameters were measured in controls at matched vertebrae. One-way analysis of variance (ANOVA) and Pearson correlation tests were used for statistical analysis. Abnormalities were found at concavity of muscles between AIS and controls. Significantly higher SI and fatty components was observed in AIS at MF muscles on concavity than controls (P-value <0.001). Additionally, SI at MF muscles was significantly correlated with Cobb angle. Increased SI and fatty components are asymmetrically present in PSM at apex in AIS. Our results showed higher intensity in PSM at concavity in AIS when compared with controls. There was a significant linear correlation between abnormal muscle signal and scoliotic curve. Above features are suggestive of altered muscle composition in concave PSM, possibly due to prolonged compression and reduced muscle activity of PSM caused by the spinal deformity. 4.

Histochemical and histological changes of paraspinal muscles in patients with thoracic and lumbar spine fractures treated with open and minimally invasive stabilisation.

Histological and histochemical analyses of muscle samples were used to determine the intensity of paraspinal muscle injury during open (OPEN) and minimally invasive (MIS) procedures due to spinal trauma. A randomised prospective study design was chosen. According to our hypothesis, OPEN procedures will lead to more intensive microscopic changes than MIS. Muscle samples were collected during the primary surgery - fracture surgery (FRS) from the left and during material extraction (EXS) from the right side. Complete samples were acquired from 17 OPEN and 18 MIS subjects. We compared them histochemically and histologically; muscle fibre typing and statistical analysis were performed. We statistically confirmed that the increase in fibrosis in the OPEN EXS sample was significantly higher than in the MIS EXS sample, with p< 0.05 (p= 0.000322453). Fibre types in MIS did not differ almost at all in both samples; the changes were statistically insignificant.In OPEN samples, the number of type I fibres differed significantly. In EXS, it was significantly lower (46.23%) than in FRS (60.63%), at a statistically significant level, p< 0.05 (p= 0.0234375000) especially with the increase of the type IIA fibres, less in IIB fibres. These microscopic findings provide a statistically significant confirmation that OPEN procedures in spinal fracture lead, in most cases, to significant changes in the structure of the corset muscle at the fracture site and surgical access point than MIS procedures.

Muscle Injury Associated Elevated Oxidative Stress and Abnormal Myogenesis in Patients with Idiopathic Scoliosis.

Idiopathic scoliosis (IS) is a disease with unknown etiology characterized by spinal rotation asymmetry. Reports describing the histochemical and pathological analyses of IS patients have shown that necrosis, fibrosis and fatty involution occurred on the apex paraspinal muscles. However, research on the changes in the paraspinal muscles of IS patients compared with those in matched controls is rare; thus, the basic mechanism of how paraspinal muscles are injured in IS patients is still unclear. In this study, we investigated the morphological changes of paraspinal muscles in the control group and IS patients, and the possible mechanisms were examined in vivo and in vitro. Increased myofiber necrosis was found on both sides of the apex paraspinal muscles of IS patients compared with those of the control group, and the number of TUNEL-positive apoptotic cells was also increased. Apoptosis signaling pathways, including pro-apoptosis proteins such as cleaved-caspase 3 and cytochrome c, were markedly upregulated, whereas the anti-apoptotic Bcl-2/Bax was significantly downregulated in IS patients compared with the control group. Moreover, PGC-1α and SOD1 were upregulated in accordance with the increased ROS production in IS patients. The distribution of myofiber types, as well as the mRNA levels of type IIa myofiber marker MYH2 and the important myogenesis regulator MYOG were remarkably changed in IS patients. In addition, C2C12 or human skeletal muscle mesenchymal progenitor cells treated with antimycin A in glucose-free and serum-free culture medium, which can activate oxidative stress and induce apoptosis, showed similar patterns of the changed distribution of myofiber types and downregulation of MYH2 and MYOG. Altogether, our study suggested that the extents of severe muscle injury and accumulated oxidative stress were increased in IS patients compared with the control group, and the abnormal myogenesis was also observed in IS patients. Since elevated oxidative stress can lead to apoptosis and the dysregulation of myogenesis in muscle cells, it may be associated with the pathological changes observed in IS patients and contribute to the development and progression of IS.

Comparative study of the paraspinal muscles after OVF between the insufficient union and sufficient union using MRI

BackgroundIdentification of poor prognostic factors for OVF is important but has not yet been clearly established. Despite paraspinal muscles could play an important role in the etiology of OVF, what influence time-dependent changes in paraspinal muscles have after OVF, and the impact on conservative treatments for patients who have an OVF remain largely unknown. The purposes of this study were to (1) evaluate time-dependent changes of the paraspinal musculature using MRI after injury in patients with osteoporotic vertebral fractures (OVFs), and (2) compare paraspinal muscles between conservatively treated patients with OVF who have successful union and those failed to conservative treatment.MethodsA total of 115 consecutive patients who had sustained a recent OVF injury in the thoracolumbar region were assessed for eligibility using medical records and all required data were available from 90 patients who had been followed up for at least 6 months. Patients who needed to undergo surgery and patients who were diagnosed as having insufficient union after 6 months of follow-up were assigned to a group with insufficient union. Lumbar trunk parameters, relative cross-sectional area (rCSA) and proportion of fat infiltration (FI%) were calculated from MRI. To evaluate the time-dependent changes in the paraspinal muscle in patients after OVF injury, correlations between the timing of MRI and rCSA, FI% were determined. To clarify the impact of paraspinal muscles on the outcome of conservative treatments of patients with OVF, we compared rCSA between the groups.ResultsSixty-five patients were assigned to a group with insufficient union and 25 patients were assigned to a group with successful union. FI% of the multifidus and erector spinae in the group with insufficient union were significantly greater than in the group with union. The timing of MRI in relation to initial injury was significantly correlated with FI% of the multifidus and erector spinae. rCSA of the erector spinae was significantly larger in the group with successful union than in the group with insufficient union.ConclusionsThese findings indicated a time-dependent increase of fatty degeneration of the multifidus and erector muscles, but no change in the rCSA and larger rCSAs of spinal erectors may play a role in successful union in patients with OVF.

A Clinical Study on Axial Symptoms and Imaging Changes in Paraspinal Muscles after Cervical Posterior Open-door Laminoplasty.

This research aimed to gain a better understanding of the relationship between cervical posterior open-door laminoplasty on axial symptoms, the net cross-sectional area of paraspinal muscles, and the degree of pimelosis. A retrospective study was conducted on a consecutive series of 37 patients who had underwent cervical posterior open-door laminoplasty + lateral mass fixation and bone graft fusion between January 2015 and July 2015. All patients received postoperative examinations at 6 months and 18 months after the operation. For each follow-up visit, the VAS Rating Scale and ODI Function Index Questionnaire were filled out. Meanwhile, a C-Spine X-ray and MRI of the patients were taken. In the measurements taken with ImageJ 1.51 K Software, the cervical vertebra MRI T2-weighted image cross-section for each segment was measured separately, mainly including the mean T2 signal value of the contour area and the net area of the paraspinal muscles. Differences between VAS and ODI (%) at three different time points were of statistical significance (p < 0.01). Pairwise comparisons of the results showed that VAS and ODI (%) at different times were clearly different (p < 0.01). Differences in the mean T2 signal value and net area at different times were of statistical significance (p < 0.01). Pairwise comparisons of the results indicated that the mean T2 signal value and net area at different times were clearly different (p < 0.01). The corresponding analytical results for VAS, ODI (%), and the mean of the T2 signal value and net area demonstrated that VAS6 months after surgery was positively correlated to the net area of C3/4 and C4/5 (r = 0.352, p < 0.05; r = 0.338, p < 0.05). The analogous analytical results for the mean T2 signal value and net area were of no statistical significance (p > 0.05). We believe that axial symptoms after cervical spine surgery does not affect the recovery of neurological function. There is a process of acute or subacute enlargement of paraspinal muscles on segments C3/4 and C4/5 after the operation, while the results of the follow-up visits show that there is a gradual process of atrophy in local posterior muscles, which may be related to axial symptoms. The degree of pimelosis of the neck paraspinal muscles may have no relationship with axial symptoms.

Relationships between vitamin D and paraspinal muscle: human data and experimental rat model analysis

Background ContextVitamin D deficiency (VDD) has been closely linked with skeletal muscle atrophy in many studies, but to date no study has focused on the paraspinal muscle. PurposeTo verify paraspinal muscle changes according to serum vitamin D level. Study DesignA cross-sectional study of patients who visited our hospital and an in vivo animal study. MethodsWe measured serum vitamin D concentration in 91 elderly women and stratified them according to their vitamin D status in three groups, control, vitamin D insufficiency, and VDD, and obtained magnetic resonance imaging data of the lumbar spine and evaluated the quality and quantity of the paraspinal muscles. Additionally, we designed experimental rat models for VDD and VDD replacement. Then, we analyzed the microcomputed tomography data and histologic data of paraspinal muscles, and the histologic data and reverse transcription-quantitative polymerase chain reaction data of intramyonuclear vitamin D receptor (VDR) in paraspinal muscle through comparison with control rats (n=25, each group). This work was supported by a Biomedical Research Institute grant ($40,000), Kyungpook National University Hospital (2014). ResultsIn the human studies, a significant decrease was noted in the overall paraspinal muscularity (p<.05) and increase in fatty infiltration in the VDD group as compared with the other groups (p<.05). In the rat experiment, a decrease was noted in paraspinal muscle fiber size and VDR concentration and VDR gene expression level, and total muscle volume of the VDD rats as compared with the control rats (p<.05). Vitamin D replacement after VDD could partially restore the muscle volume, muscle fiber size, and intramyonuclear VDR concentration levels (p<.05) of the paraspinal muscles. ConclusionsVDD induces paraspinal muscle atrophy and decreases the intramyonuclear VDR concentration and VDR gene expression level in these muscles. Vitamin D replacement contributes to the recovery from atrophy and restoration of intramyonuclear VDR concentration in VDD status.

Fatty Degeneration of the Paraspinal Muscle in Patients With Degenerative Lumbar Kyphosis: A New Evaluation Method of Quantitative Digital Analysis Using MRI and CT Scan.

A comparative case-control study. The aim of this study was to quantify the degree of paraspinal muscle changes in degenerative lumbar kyphosis (DLK) patients using magnetic resonance imaging and computed tomography scanning. Although the pathophysiology of DLK is not completely understood, extensive degeneration and weakness of the lumbar extensor muscles are thought to underlie the condition in most patients. However, there is no ideal method to quantify the degree of fat infiltration and atrophy of the paraspinal muscles in patients with DLK. The study group comprised 20 patients with DLK and 20 healthy volunteers. The cross-sectional areas of the psoas, erector spinae (ES), multifidus (MF), quadratus lumborum, and vertebral body were measured. The ratio between the cross-sectional area of the muscle and the vertebral body was used to evaluate lumbar muscularity. The degree of fatty change was evaluated by measuring the ratio between the mean signal intensity of the muscle and that of the subcutaneous fat within regions of interest. Muscularity in the MF and ES was not significantly different between the DLK and control groups at L1, L2, or L3, but was significantly different at L4 (ES, P=0.001; MF, P=0.001) and L5 (ES, P=0.001; MF, P=0.015). The mean signal intensities of the ES and MF were higher in the DLK group than in the control group at all levels. The degree of fatty change in the ES and MF was significantly higher in the DLK group than in the control group (P<0.05). Quantitative analysis using magnetic resonance imaging and computed tomography scanning showed differences in paraspinal muscle volume and fatty degeneration between patients with DLK and healthy volunteers. This evaluation method may be useful for measuring the extent of paraspinal muscle degeneration.

Electrophysiological and histological changes of paraspinal muscles in adolescent idiopathic scoliosis.

The pathogenesis of adolescent idiopathic scoliosis (AIS) remains poorly understood. To date, potentially involved local changes in the deep paraspinal muscles still remain unknown. Needle electromyography (EMG) and muscle biopsy of paraspinal muscles at convexity and concavity of the AIS main thoracic curve were performed in 25 subjects. In this group, EMG was performed in 16 AIS subjects (12 females, 12-27years), muscle biopsy in 18 AIS subjects (15 females, 11-31years) compared to 10 non-scoliotic controls (6 females, 12-55years). Samples of muscle tissue were removed during corrective surgery and were examined histologically, enzyme histochemically and immunohistochemically. Both methods of EMG and muscle biopsy were performed in 9 subjects (7 women, 12-27years). Right curve convexity was found in 24 AIS subjects. Amplitudes of motor unit action potentials (MUPs) were significantly increased on the AIS curve convexity versus concavity. Turns, duration and phases of MUPs were without any significant changes. In all 18 subjects, the histological examination revealed muscle fiber redistribution with numerical predominance of type I on the curve convexity which strongly correlated with the progression of the Cobb angle. Our findings demonstrate significant changes of muscle fiber redistribution in the paraspinal muscles of AIS with increased proportion of type I on the convexity corresponding to a significantly higher amplitude of MUPs on the same side. A possible explanation of this alteration is a secondary adaptation due to chronic high load demand.

ID 113 – Neurophysiology and biopsy of paraspinal muscles in idiopathic scoliosis

Objective The pathogenesis of idiopathic scoliosis (IS) remains poorly understood. Local changes in deep paraspinal muscles and/or dysfunction of spinal inhibitory circuits are not fully elucidated. We compared the morphological and functional changes of paraspinal muscles on both sides of the scoliosis curve. Methods Before corrective surgery we performed EMG and muscle biopsy of paraspinal muscles at convexity and concavity of scoliotic curve in 10 subjects with IS (8 women, 11–29years). Cutaneous silent period (CSP) induced by noxious digit II stimulation in thenar muscles was recorded in IS patients and in healthy volunteers. Results Right curve convexity had 8 subjects. All of them presented changes in muscle fiber distribution with numerical predominance of type I on the curve convexity. Seven subjects have increased MUP amplitude on this side (range 10–62%). CSP did not significantly differ between concavity and convexity but shortening of CSP duration was observed in more pronounced scoliotic curve. Conclusion Our findings demonstrate a significant asymmetry in fiber type distribution corresponding with an altered function in paraspinal muscles with predominance on convexity of scoliotic curve. Spinal inhibitory reflex is preserved; however, it could be modulated in more progressive IS. Supported by Grants PRVOUK P34, IGA-NT 13693.

Postoperative posterior lumbar muscle changes and their relationship to segmental motion preservation or restriction: a randomized prospective study.

To date, it remains unclear whether the preservation of segmental motion by total disc replacement (TDR) or motion restriction by stand-alone anterior lumbar interbody fusion (ALIF) have an influence on postoperative degeneration of the posterior paraspinal muscles or the associated clinical results. Therefore, the purpose of the present prospective randomized study was to evaluate the clinical parameters and 3D quantitative radiological changes in the paraspinal muscles of the lumbar spine in surgically treated segments and superior adjacent segments after ALIF and TDR. A total of 50 patients with chronic low-back pain caused by single-level intervertebral disc degeneration (Pfirrmann Grade ≥ III) and/or osteochondrosis (Modic Type ≤ 2) without symptomatic facet joint degeneration (Fujiwara Grade ≤ 2, infiltration test) of the segments L4-5 or L5-S1 were randomly assigned to 2 treatment groups. Twenty-five patients were treated with a stand-alone ALIF and the remaining 25 patients underwent TDR. For ALIF and TDR, a retroperitoneal approach was used. At 1 week and at 12 months after surgery, CT was used to analyze paraspinal lumbar muscle tissue volume and relative fat content. Residual muscle tissue volume at 12 months and change in the relative fat content were compared between the groups. In addition, clinical parameters (visual analog scale [VAS] for low-back pain and Oswestry Disability Index [ODI] Questionnaire Version 2 for function) were compared. Compared with 1 week after surgery, the radiological analysis at 12 months revealed a small decrease in the posterior muscle volume (the mean decrease was < 2.5%), along with a small increase in the relative fat content (the mean increase was < 1.9%), in both groups at the index and superior adjacent segments. At the adjacent segment, the ALIF group presented significantly less muscle tissue volume atrophy and a smaller increase in fat content compared with the TDR group. At final follow-up, the clinical parameters related to pain and function were significantly improved in both groups compared with 1 week postsurgery, but there were no differences between the groups. Motion restriction via stand-alone ALIF and motion preservation via TDR both present small changes in the posterior lumbar paraspinal muscles with regard to volume atrophy or fatty degeneration at the index and superior adjacent segments. Therefore, although the clinical outcome was not affected by the observed muscular changes, the authors concluded that the expected negative influence of motion restriction on the posterior muscles compared with motion preservation does not occur on a clinically relevant level.

Quantitative MRI and X-ray analysis of disc degeneration and paraspinal muscle changes in degenerative spondylolisthesis.

The intervertebral disc degeneration changes and paraspinal muscles changes are believed to be risk factors for lumbar degenerative spondylolisthesis (LDS). But there is limited quantitative information about this progression. This study is to reveal their changes the in the progression of LDS. Data were gathered from 149 middle-aged degenerative spondylolisthesis patients and same amount of age- and sex-matched control group with both lumber spine MRI and X-ray. Narrowed disc space were measured in percent as anterior inferior disc height (DHIA)/anterior superior disc height (DHSA), inferior disc height (DHI)/superior disc height (DHS), and posterior inferior disc height (DHIP)/posterior superior disc height (DHSP). Signal intensity ratio of multifidus muscle (RM) and erector spinae (RES) to psoas muscle, muscle atrophy ratio of lean CSA (LCSA) to gross CSA (GCSA) of paraspinal muscles were calculated. In the case group the most common slipped vertebra was L4 (75.84%). Disc height (DHIA/DHSA, DHI/DHS) and multifidus muscle atrophy ratio (M-LCSA/M-GCSA) tended to be lower than those in the control group, whereas the disc degeneration degree and T2 signal intensity ratio (RM,RES) of the paraspinal muscles and erector spinae muscle atrophy ratio were higher than control group. The difference between the two groups was statistically significant (P< 0.05). Using multivariate logistic regression analysis, it was confirmed that ES-LCSA/ES-GCSA, especially RM are independent predisposing factors to lumbar spondylolisthesis (OR > 1, P< 0.05) while DHIA/DHSA, M-LCSA/M-GCSA are independent protective factors (OR < 1, P< 0.05). Decreased anterior disc height and multifidus muscle atrophy are found in the LDS patients and thy could be the cause of LDS. The presence of erector spinae hypertrophy could be a compensatory mechanism to compensate for the instability.

Paraspinal Muscle Morphology and Composition

The purposes of this study were to define the natural progression of age-related changes of the lumbar paraspinal muscles during adulthood and to investigate the influence of lifestyle and individual factors (e.g., physical activity levels at work and leisure, body mass index, and low back pain [LBP]). This population-based longitudinal study included a sample of 99 adult male twins. Data were collected through a structured interview, physical examination, and magnetic resonance imaging. Measurements of the lumbar multifidus and erector spinae muscles were obtained from T2-weighted axial images at L3-L4 and L5-S1 at baseline and 15-yr follow-up. Muscle cross-sectional area (CSA), functional CSA (FCSA) (fat-free mass), and FCSA/CSA (composition) as well as CSA and FCSA asymmetry and FCSA/CSA side-to-side differences were measured. Subjects' mean ± SD age was 47.3 ± 7.4 yr at baseline and 62.3 ± 8.0 yr at follow-up. During the 15-yr period, both muscles exhibited a decrease in CSA and FCSA and an increase in fatty infiltration and side-to-side differences in size and composition at both spinal levels. Both muscles displayed greater changes at L5-S1 than L3-L4. Age and BMI were found to be significantly associated with the degree of paraspinal muscle changes over time. However, there was no association between the change in paraspinal muscle size, composition, or asymmetry with the level of physical demands at work or leisure or LBP history. The present longitudinal study suggests that over adulthood, the multifidus and erector spinae undergo similar morphological changes. Moreover, our findings suggest that the long-term progression of lumbar paraspinal muscle changes evaluated through magnetic resonance imaging are not associated with the range of physical demand levels as were typical of Finnish men or LBP history.

Image changes of paraspinal muscles and clinical correlations in patients with unilateral lumbar spinal stenosis

This is a retrospective study. To compare the morphometric parameters of the psoas major and lumbar multifidus muscles in lumbar spinal stenosis (LSS) patients exhibiting different functional performance. LSS refers to symptoms related to size reduction of the lumbar spinal canal; however, the degree of stenosis is poorly related to symptom severity and functional impairments. Morphometric changes in the paraspinal muscles have been correlated with chronic lower back pain in previous studies. However, correlations between the functional performance of LSS patients and the morphometric changes in paraspinal muscles have seldom been reported. Sixty-six LSS patients without mechanical back pain or segmental instability were enrolled in the study. A review of their medical records and MRI images was performed. Morphometric parameters, including the fatty infiltration (FI) of the lumbar multifidus muscle as well as the relative cross-sectional area (RCSA) of the psoas major and lumbar multifidus muscles, were measured. Subjects were divided into high and low functional performance groups according to their Japanese Orthopedic Association (JOA) scores. The male LSS patients exhibited a larger psoas RCSA than the female patients, whereas the older patients exhibited a smaller psoas RCSA and higher multifidus FI than the younger patients. LSS patients in the high functional performance group exhibited a significantly larger psoas RCSA and lower multifidus FI. The psoas RCSA and multifidus FI can be used as predictive factors for functional performance in LSS patients.

급성 요통환자와 만성 요통환자에서 척추주변근육의 정량적 분석

본 연구는 MRI를 사용하여 급성 및 만성 요통환자들의 척추주변근육에 나타나는 변화를 정량적으로 측정 및 분석하고 이를 토대로 요통에 대한 진단 및 치료에 임상적 기초자료를 제공하고자 2012년 8월부터 2013년 1월까지 내원한 환자로 요통이 발생한지 12주 이내의 급성요통환자 20명과 요통이 발생한지 12주 이상 경과된 만성 요통 환자 20명을 대상자로 선정하여 MRI를 촬영한 후 측정하여 비교하였다. 왼쪽과 오른쪽의 지방변성율에서는 척추세움근과 뭇갈래근에서 유의한 차이가 있었고(p<.001), 전체 집단 간 지방변성율 비교에서도 급성요통군과 만성요통군간의 큰허리근, 척추세움근, 뭇갈래근에서 유의한 차이가 있었다(p<.001). 사후검정에서는 급성요통군과 만성요통군에서 각각 다열근과 척추세움근의 지방변성율이 가장 높은 것으로 나타났다. 만성 요통군에서 다열근과 척추기립근의 심한 지방율의 변성은 척추의 안정성을 유지하는 근육의 근력 약화로 나타나는데 본 연구결과를 토대로 급성 만성요통환자들의 재활운동과정에 있어서 뭇갈래근, 급성 요통군은 뭇갈래근과 큰허리근에 더 주의를 기울이고 재활운동 선정 과정에서 중요한 자료와 근거를 제시 할 수 있으라고 사료된다. This study was conducted to measure and analyze the changes in paraspinal muscles of acute and chronic low back pain patients using MRI, and to provide clinical basic data for diagnosis and treatment for low back pain. For this purpose, 20 patients with acute low back pain frome August 2012 to January 2013 which occurred within 12 weeks, and 20 patients with chronic low back pain that progressed over 12 weeks, were chosen as subjects, and their MRI measurements were compared with one another. As a result, in relation to in the fatty degeneration ratio of the left spine and right spine, there were significant differences in erector spinae and multifidus(p<.001), and in relation to the Fat Infiltration ratio between all the groups, there were significant differences in psoas major, erector spinae and multifidus between the acute low back pain patient group and the chronic low back pain patient group(p<.001). In the post-hoc test, multifidus and erector spinae in the acute low back pain group and chronic low back pain group showed the highest Fat Infiltration ratio. The serious Fat Infiltration of multifidus and erector spinae in the chronic low back pain group led to weakened strength of muscles that stabilize the spine. In conclusion, it is considered that this study would present important data and basis in making acute and chronic low back pain patients pay more attention to multifidus and psoas major during rehabilitation exercise, and selecting a rehabilitation exercise program.

Changes of Paraspinal Muscles in Postmenopausal Osteoporotic Spinal Compression Fractures: Magnetic Resonance Imaging Study

BackgroundTo investigate the changes of cross sectional area (CSA) in paraspinal muscles upon magnetic resonance imaging (MRI) and bone mineral density (BMD) in postmenopausal osteoporotic spinal compression fractures.MethodsWe reviewed 81 postmenopausal women with osteoporosis, who had underwent MRI examination. The patients were divided into 51 patients who had osteoporotic spinal compression fractures (group I), and 30 patients who without fractures (group II). Group I were subdivided into IA and IB, based on whether they were younger (IA) of older (IB) than 70 years of age. We additionally measured body mass index and BMD. The CSA of multifidus, erector spinae, paraspinal muscles, psoas major (PT), and intervertebral (IV) discs were measured. The degree of fatty atrophy was estimated using three grades.ResultsThe BMD and T-score of group I were significantly lower than those of group II. The CSA of erector spinae, paraspinal muscles, and PT in the group I was significantly smaller than that of group II. The CSA of paraspinal muscles in group IB were significantly smaller than those of group IA. The CSA of erector spinae, mutifidus, and PT in group IB were smaller than those of group IA, but the difference was not statistically significant. Group 1 exhibited greater fat infiltration in the paraspinal muscle than group II.ConclusionsPostmenopausal osteoporotic spinal compression fracture is associated with profound changes of the lumbar paraspinal muscle, reduction of CSA, increased CSA of IV disc, and increased intramuscular fat infiltration.