Quantification of Multifidus Atrophy and Fatty Infiltration Following a Minimally Invasive Microdiscectomy

A comparison of interferential current efficacy in elderly intervertebral disc degeneration patients with or without sarcopenia: a retrospective study

BACKGROUND

Intervertebral disc degeneration and sarcopenia are both age-related diseases without effective treatments. Their comorbidities may worsen the prognosis, and further studies on interaction and therapy are needed. The purpose of the study was to investigate the prevalence of sarcopenia in intervertebral disc degeneration, and to compare the characteristics of intervertebral disc degeneration with and without sarcopenia and effects of interferential current.

METHODS

One hundred twenty disc degeneration patients were included from 2021 to 2022 in a single institute. Medical records, examination results and radiological reports were reviewed. Patients with sarcopenia were screened and grouped according to Asian Working Group for Sarcopenia 2019. VAS, ODI, SARC-F, SMI, gait speed (GS), grip strength, disc Pfirrmann grading, standard cross-sectional area (SCSA), degree of fatty infiltration (DFF), and nerve conduction velocity (NCV) were assessed before and after treatment.

RESULTS

The prevalence of sarcopenia in intervertebral disc degeneration was 28.3%. The difference of VAS, ODI, disc Pfirrmann grading, SCSA, DFF and NCV between two groups were significant before intervention (P < 0.05), SCSA and DFF were related to the degree of disc degeneration. The improvement of SMI, GS, grip strength, VAS, SARC-F and ODI in intervertebral disc degeneration with sarcopenia group was significant after intervention, as well as SMI, GS, grip strength, VAS and ODI in those without sarcopenia (P < 0.05). The improvement of grip strength, GS, ODI and SARC-F in intervertebral disc degeneration with sarcopenia group were greater than the one without sarcopenia (P < 0.05), whereas there was no significance in improvement degree of other indicators between the two groups (P > 0.05).

CONCLUSION

The prevalence of sarcopenia was high in intervertebral disc degeneration, and paravertebral muscles degeneration correlated with the degree of disc degeneration. Compared to those without sarcopenia, intervertebral disc degeneration patients with sarcopenia have more severe pain, poorer mobility and neurological function. Interferential current is effective in intervertebral disc degeneration patients and sarcopenia patients.

[Minimally invasive removal of dumbbell shaped schwannomas with transforaminal lumbar fusion: a retrospective study with a minimum 3-year follow-up]

Currently, there are no standards in surgical treatment of dumbbell-shaped tumors of lumbo-foraminal region.

OBJECTIVE

To evaluate the effectiveness and long-term results of minimally invasive resection of dumbbell-shaped lumbar schwannomas Eden type 2 and 3 combined with transforaminal lumbar interbody fusion and transpedicular stabilization.

MATERIAL AND METHODS

A retrospective study included 13 patients (8 men and 5 women) with lumbar dumbbell tumors Eden type 2 and 3 who underwent minimally invasive facetectomy through posterolateral anatomical corridor, microsurgical tumor resection and MI TLIF. We analyzed intraoperative parameters, neurological functions (ASIA scale), clinical characteristics (ODI, SF-36), and complications. Resection quality and area of the multifidus muscle were assessed according to MRI data. All patients were followed-up throughout at least 3-year.

RESULTS

Surgery time was 147 min, blood loss - 118 ml, hospital-stay - 7 days. Clinical parameters significantly improved in the follow-up period: ODI score decreased from 72 to 12 (p=0.004), SF-36 PCS increased from 26.24 to 48.51 (p=0.006) and MCS score increased from 29.13 to 53.68 (p=0.002). According to MRI data, no tumor recurrences and severe muscle atrophy (>30%) were observed after 3 years in all cases. Superficial wound infection occurred in 1 (7.7%) case. There were normal neurological functions (ASIA type E) in all patients.

CONCLUSION

Minimally invasive facetectomy through posterolateral approach with MI TLIF technology can be used for safe and effective resection of dumbbell-shaped schwannomas Eden type 2 and 3.

Paraspinal muscles atrophy on both sides and at multiple levels after unilateral lumbar partial discectomy

To identify the changes in cross-sectional areas (CSAs) and fatty infiltration of both sides of the paravertebral muscles and their associations with prognostic factors in patients who underwent unilateral lumbar discectomy. We retrospectively reviewed 27 patients who underwent magnetic resonance imaging before and after 1- or 2-level lumbar discectomy. The CSAs and functional cross-sectional areas of the paraspinal muscles were bilaterally measured from L1 to L2 to L5 to S1 based on T2-weighted axial images. These parameters were compared pre-and postoperatively. CSAs and functional cross-sectional areas decreased also in non-operative, non-surgical levels, not only in operated levels after discectomy. In the correlation analysis, the CSA of psoas major muscle at L1 to L2 was significantly decreased in patients with lower preoperative lordosis (r = 0.598, P = .040). The postoperative CSA of psoas major muscle at L4 to L5 was lower in those with the higher Pfirrmann grade (r = -0.590, P = .002); however, the CSA of quadratus lumborum muscle at L1 to L2 showed the opposite result (r = 0.526, P = .036). Similar results were also observed in the partial correlation adjusted for age and postoperative duration. Patients who underwent discectomy experienced overall paraspinal muscle atrophy in the lumbar region, including surgical and non-surgical sites. Such atrophic changes emphasized the need for core strengthening and lumbar rehabilitation from the early period after partial discectomy.

Radiofrequency Neurotomy Does Not Cause Fatty Degeneration of the Lumbar Paraspinal Musculature in Patients with Chronic Lumbar Pain-A Retrospective 3D-Computer-Assisted MRI Analysis Using iSix Software

OBJECTIVE

The present study aimed (1) to analyze the relative paraspinal autochthonous intramuscular fat volume before and after radiofrequency neurotomy (RFN) and (2) to compare it to the contralateral non-treated side.

DESIGN

Retrospective cohort study.

SETTING

Inselspital, University Hospital Bern, University of Bern.

SUBJECTS

Twenty patients (59.60 ± 8.49 years; 55% female) with chronic low back pain, treated with RFN (L2/3-L5/S1) due to symptomatic facet joint syndrome (FCS) between 2008 and 2017 were included.

METHODS

All patients received a magnetic resonance imaging (MRI) of the lumbar spine before and at a minimum of 6 months after RFN. The absolute (cm3) and relative (%) paraspinal muscle and fat volume was analyzed three-dimensionally on standard T2-MRI sequences using a newly developed software (iSix, Osiris plugin). Both sides were examined and allocated as treated or non-treated side.

RESULTS

A total of 31 treated and 9 non-treated sides (Level L2/3-L5/S1) were examined. There were no differences in the relative paraspinal intramuscular fat volume before and at a median of 1.4 [0.9 - 2.6] years after RFN (P = .726). We found no differences in the relative fat volume between the treated and non-treated side before (P = .481) and after (P = .578) RFN.

CONCLUSIONS

Our study shows that there are no differences in the paraspinal muscle/fat distribution after RFN. RFN of the medial branches for FCS does not seem to cause fatty degeneration of the lumbar paraspinal muscles as a sign of iatrogenic muscle denervation.

Is preoperative fat infiltration in lumbar spine muscles associated with worse clinical outcomes after lumbar interbody fusion?

PURPOSE

Lumbar musculature has a fundamental role in spine stability and spinal balance. Muscle atrophy and fat infiltration play an important role in pain pathophysiology. Accordingly, the preoperative condition of lumbar muscles may influence clinical outcomes after surgical treatment. In this context, the aim of this study was to evaluate the association between preoperative lumbar paravertebral muscle fat infiltration and clinical outcomes after lumbar interbody fusion.

METHODS

A retrospective study of patients with lumbar pathology submitted to lumbar transforaminal (TLIF) or posterior interbody fusion (PLIF) was performed, with a minimum of two years of follow-up. Preoperative lumbar magnetic resonance imaging (MRI) images were classified for fat infiltration in lumbar multifidus muscle and correlated with clinical outcomes.

RESULTS

Seventy-five patients were included: 24 submitted to PLIF and 51 to TLIF. Most patients underwent surgery for spondylolisthesis (67%). Higher degrees of fat infiltration were associated with more advanced age (54.8 vs. 49.1 years old, p = 0.04) and more leg pain after surgery (p = 0.04). No statistically significant differences in other clinical outcomes such as Oswestry Disability Index, visual analogue scale for back and leg pain, self-reported back pain relief, return to work and overall satisfaction were found between different groups of fat infiltration. The improvement in leg pain was associated with improvement in self-reported lumbar pain (p < 0.001).

CONCLUSION

Age and preoperative degree of fat infiltration may be important to predict improvement in leg pain after lumbar interbody fusion. The absence of solid literature on this topic and universal assessment methodologies reinforce the need for further studies.

Is preoperative fat infiltration in lumbar spine muscles associated with worse clinical outcomes after lumbar interbody fusion?

PURPOSE

Lumbar musculature has a fundamental role in spine stability and spinal balance. Muscle atrophy and fat infiltration play an important role in pain pathophysiology. Accordingly, the preoperative condition of lumbar muscles may influence clinical outcomes after surgical treatment. In this context, the aim of this study was to evaluate the association between preoperative lumbar paravertebral muscle fat infiltration and clinical outcomes after lumbar interbody fusion.

METHODS

A retrospective study of patients with lumbar pathology submitted to lumbar transforaminal (TLIF) or posterior interbody fusion (PLIF) was performed, with a minimum of two years of follow-up. Preoperative lumbar magnetic resonance imaging (MRI) images were classified for fat infiltration in lumbar multifidus muscle and correlated with clinical outcomes.

RESULTS

Seventy-five patients were included: 24 submitted to PLIF and 51 to TLIF. Most patients underwent surgery for spondylolisthesis (67%). Higher degrees of fat infiltration were associated with more advanced age (54.8 vs. 49.1 years old, p = 0.04) and more leg pain after surgery (p = 0.04). No statistically significant differences in other clinical outcomes such as Oswestry Disability Index, visual analogue scale for back and leg pain, self-reported back pain relief, return to work and overall satisfaction were found between different groups of fat infiltration. The improvement in leg pain was associated with improvement in self-reported lumbar pain (p < 0.001).

CONCLUSION

Age and preoperative degree of fat infiltration may be important to predict improvement in leg pain after lumbar interbody fusion. The absence of solid literature on this topic and universal assessment methodologies reinforce the need for further studies.

A Comparative Study of a New Retractor‐Assisted WILTSE TLIF, MIS‐TLIF, and Traditional PLIF for Treatment of Single‐Level Lumbar Degenerative Diseases

Objectives

To compare the clinical efficacy of a new retractor‐assisted Wiltse transforaminal lumbar interbody fusion (TLIF), minimally invasive TLIF (MIS‐TLIF), and traditional posterior lumbar interbody fusion (PLIF) in treating single‐level lumbar degenerative diseases.

Methods

A retrospective study was conducted by analyzing the clinical and imaging data of consecutive patients with single‐level lumbar degenerative diseases who underwent the new retractor‐assisted Wiltse TLIF, MIS‐TLIF, or traditional PLIF. This study enrolled 87 concurrent patients between June 2016 and December 2019 (Wiltse TLIF 29 cases; MIS‐TLIF 28 cases; PLIF 30 cases). The three groups were compared for perioperative indicators (including intraoperative blood loss, postoperative drainage volume, operation time, intraoperative fluoroscopy time, bedridden time), creatine kinase (CK), visual analog score (VAS), Oswestry disability index (ODI), Japanese Orthopaedic Association (JOA) score, intervertebral fusion rate, muscle atrophy, and fatty infiltration (including ratio of multifidus atrophy and ratio of lean‐to‐total cross‐sectional area [CSA]).

Results

Intraoperative blood loss (F = 62.628, p < 0.001), postoperative drainage volume (F = 72.048, p < 0.001), and bedridden time (χ² = 62.289, p < 0.001) were significantly lower in the MIS‐TLIF and Wiltse groups than in the PLIF group. The operative and intraoperative radiation times of the MIS‐TLIF group were significantly longer than those of the Wiltse and PLIF groups. The CK concentration in the Wiltse and MIS‐TLIF groups were significantly lower than those in the PLIF group 1 day (F = 9.331, p < 0.001) and 3 days after surgery (F = 15.967, p < 0.001). The PLIF group's back pain VAS score was higher than those of the Wiltse and MIS‐TLIF groups. The PLIF group had a higher ODI 6 months (F = 3.282, p = 0.042) and 12 months (F = 5.316, p = 0.007) after surgery and a lower JOA score than the Wiltse and MIS‐TLIF groups 6 months (F = 3.234, p = 0.044) and 12 months (F = 3.874, p = 0.025) after surgery. The ratio of multifidus atrophy in the PLIF group (41.70 ± 8.84%) was significantly higher than those of the Wiltse group (24.13 ± 6.82%) and the MIS‐TLIF group (22.35 ± 5.03%). The ratio of lean‐to‐total CSA in the PLIF group was lower than those of the Wiltse and MIS‐TLIF groups after surgery (F = 8.852, p < 0.001). MIS‐TLIF group showed longer operation time (169.11 ± 29.38 min) and intraoperative fluoroscopy time (87.61 ± 3.13 s) than the Wiltse group.

Conclusion

Wiltse TLIF assisted by the new retractor is a more convenient and minimally invasive surgical method than the traditional PLIF and MIS‐TLIF methods, which are linked to a long learning curve and long operation and fluoroscopy time.

Clinical utility and reproducibility of surface electromyography in individuals with chronic low back pain: a protocol for a systematic review and meta-analysis

INTRODUCTION

Chronic low back pain (CLBP) is one of the most common disorders presenting in primary healthcare. Kinematic studies of low lumbar pelvic mobility allied with surface electromyography (sEMG) may assist in the assessment and management of CLBP. However, the applicability in the use of sEMG in the clinical setting remains uncertain. In this protocol, we aim to review the clinical utility and reproducibility of the sEMG component of these kinematic studies in patients with CLBP.

METHODS AND ANALYSIS

This protocol was informed by the Preferred Reporting Items for Systematic review and Meta-Analysis Protocols (PRISMA-P) and results will be reported in line with the PRISMA. Searches will be conducted on PubMed, Scopus, Web of Science, Embase, CINAHL and Google Scholar databases, along with a comprehensive review of grey literature. Two reviewers will conduct the searches and independently screen them, according to title and abstract. Two independent reviewers will then assess the full-text versions of those selected articles and assess the risk of bias using the defined protocol inclusion criteria. The risk of bias within the studies included will be assessed via the Quality Assessment of Diagnostic Accuracy Studies tool, V.2 and the Grading of Recommendations Assessment, Development and Evaluation guidelines will be used to assess certainty of evidence for recommendations based on the risk of bias findings. Meta-analysis will be conducted where appropriate on groups of studies with low heterogeneity. In instances of higher heterogeneity, meta-synthesis will instead be completed, comparing results in terms of increased or decreased clinical utility and/or reproducibility of sEMG.

ETHICS AND DISSEMINATION

Ethics approval was not required for this research. It is anticipated that the results will influence the use, interpretation and further development of sEMG in management and assessment of these patients.

PROSPERO REGISTRATION NUMBER

CRD42021273936.

Magnetic Resonance Imaging Documentation of Approach Trauma With Lumbar Endoscopic Interlaminar, Translaminar, Compared to Open Microsurgical Discectomy

BACKGROUND

Endoscopic spine surgery is associated with less approach trauma than conventional open translaminar surgery. However, objective evidence to corroborate this empiric observation is scarce. Preservation of the anatomic attachment and sensory function of multifidus muscles have been stipulated to be critical to maintaining the normal function of the lumbar spinal motion segment. The authors were interested in comparing the postoperative approach trauma between traditional open translaminar microsurgical and interlaminar endoscopic discectomy.

METHODS

The approach trauma to the paraspinal muscles due to interlaminar or open microsurgical discectomy was evaluated on T2-weighted axial magnetic resonance imaging (MRI) images of 39 consecutive patients who underwent lumbar disc surgery. Postoperative MRI images taken at 4 days and within 1 year after surgery were analyzed. Eleven patients underwent conventional open translaminar microdiscectomy surgery. Endoscopic discectomy was performed on 17 patients via the interlaminar and on another 11 patients via the transforaminal approach. The immediate surgical approach trauma was estimated as the defect zone by measuring the normalized relative cross-sectional area (rCSA) of muscle disruption in the surgical corridor 4 days postoperatively. The long-term effect of surgical approach trauma was assessed by measuring the area of the paraspinal muscles that had been replaced by fatty tissue 1 year postoperatively.

RESULTS

The rCSA data showed diminished approach trauma with a smaller surgical defect zone in the interlaminar endoscopy group (17.6%) was smaller than in the microsurgical group 4 days postoperatively (41.2%). At 1 year postoperatively, the mean fatty replacement of the paraspinal muscles was 23.6% after microsurgery and 2.1% after the interlaminar endoscopy. Muscle recovery was substantially reduced in the interlaminar endoscopic group, with the muscle zone reducing from 20.3% to 2.1% when analyzed 1 year postoperatively. In the microsurgery group, the muscle damage by atrophy increased from 41.2% to 62.9% at 1 year postoperatively (P < 0.001). Fatty replacement of the multifidus muscle was seen on the ipsilateral and contralateral approach side. There was a negligible change in the muscle zone with the transforaminal approach.

CONCLUSIONS

Tissue trauma was significantly reduced with endoscopic surgery techniques compared with the traditional translaminar microdiscectomy approach. There was a minor postoperative tissue trauma and hardly any long-term replacement of the multifidus and paraspinal muscles by fatty tissue 1 year postoperatively with the endoscopic technique. The transforaminal approach has the least effect on the paraspinal muscles of the surgical motion segment. Further study is needed to investigate whether these findings translate into decreased postoperative instability or low back pain following endoscopic discectomy surgery.

CLINICAL RELEVANCE

MRI analysis of multifidus atrophy following various lumbar translaminar and transforaminal decompression techniques.

LEVEL OF EVIDENCE: 3

[Results of minimally invasive lumbar fusion in professional athletes: a single-center retrospective study]

Professional athletes have a high basic level of physical fitness and significant motivation for returning to previous rhythm of functional activity within the shortest period after trauma without deterioration of baseline level of sportsmanship. Despite the well-presented results of lumbar spine fusion in general population, these data among professional athletes are not well understood.

OBJECTIVE

To analyze the results of minimally invasive lumbar fusion in professional athletes.

MATERIAL AND METHODS

A retrospective study included 27 athletes (19 men and 8 women) aged 29 (26; 34) years after minimally invasive lumbar spine decompression and fusion via anterior, lateral and posterior approaches. Total lumbar lordosis, degenerative changes in adjacent segment, area of multifidus muscle, perioperative complications and timing of sports rehabilitation were analyzed within 3-5 (mean 4) years after surgery.

RESULTS

We found an increase of total lumbar lordosis from 35.2° to 44.1° (p=0.02), no significant muscle atrophy (<30%) and degeneration of adjacent segment (p>0.05). There were 5 perioperative complications (18.5%). Mean period of sports rehabilitation was 14 (9; 17) weeks. One (3.7%) patient did not return to his previous sports career.

CONCLUSION

Minimally invasive short-segment lumbar interbody fusion in professional athletes is characterized by low risk of fixation element failure, no significant degeneration of adjacent level and postoperative muscle atrophy. This procedure ensures early rehabilitation and returning to sports.

Efficacy of percutaneous endoscopic lumbar discectomy for pediatric lumbar disc herniation and degeneration on magnetic resonance imaging: case series and literature review

Objective

Pediatric lumbar disc herniation (LDH), although uncommon, causes significant pain, discomfort, and sometimes disability. We examined the efficacy of percutaneous endoscopic lumbar discectomy (PELD) for pediatric LDH and the degree of lumbar disc degeneration at 1 year after PELD.

Methods

We retrospectively reviewed the data of pediatric patients with LDH who underwent PELD from December 2007 to July 2018. The patients’ symptoms, physical examination findings, clinical images, visual analog scale (VAS) scores, Oswestry Disability Index (ODI), and perioperative results (blood loss, length of hospital stay, and complications) were obtained from the medical records. Lumbar disc degeneration was graded using the modified Pfirrmann grading system at the 1-year postoperative magnetic resonance imaging (MRI) examination.

Results

Six boys and four girls who underwent PELD were evaluated. The patients’ mean age was 15.6 years (range, 13–17 years). The mean VAS score for low back pain, mean VAS score for lower limb pain, and mean ODI preoperatively and 1 year postoperatively were 6.2 and 0.3, 6.9 and 0.5, and 20 and 0.1, respectively. MRI showed significant disc degeneration after PELD.

Conclusions

Treating pediatric LDH with PELD is safe and effective. It relieves pain and reduces disability. However, lumbar disc degeneration still occurs.

Inconsistent descriptions of lumbar multifidus morphology: A scoping review

Background

Lumbar multifidus (LM) is regarded as the major stabilizing muscle of the spine. The effects of exercise therapy in low back pain (LBP) are attributed to this muscle. A current literature review is warranted, however, given the complexity of LM morphology and the inconsistency of anatomical descriptions in the literature.

Methods

Scoping review of studies on LM morphology including major anatomy atlases. All relevant studies were searched in PubMed (Medline) and EMBASE until June 2019. Anatomy atlases were retrieved from multiple university libraries and online. All studies and atlases were screened for the following LM parameters: location, imaging methods, spine levels, muscle trajectory, muscle thickness, cross-sectional area, and diameter. The quality of the studies and atlases was also assessed using a five-item evaluation system.

Results

In all, 303 studies and 19 anatomy atlases were included in this review. In most studies, LM morphology was determined by MRI, ultrasound imaging, or drawings – particularly for levels L4–S1. In 153 studies, LM is described as a superficial muscle only, in 72 studies as a deep muscle only, and in 35 studies as both superficial and deep. Anatomy atlases predominantly depict LM as a deep muscle covered by the erector spinae and thoracolumbar fascia. About 42% of the studies had high quality scores, with 39% having moderate scores and 19% having low scores. The quality of figures in anatomy atlases was ranked as high in one atlas, moderate in 15 atlases, and low in 3 atlases.

Discussion

Anatomical studies of LM exhibit inconsistent findings, describing its location as superficial (50%), deep (25%), or both (12%). This is in sharp contrast to anatomy atlases, which depict LM predominantly as deep muscle. Within the limitations of the self-developed quality-assessment tool, high-quality scores were identified in a majority of studies (42%), but in only one anatomy atlas.

Conclusions

We identified a lack of standardization in the depiction and description of LM morphology. This could affect the precise understanding of its role in background and therapy in LBP patients. Standardization of research methodology on LM morphology is recommended. Anatomy atlases should be updated on LM morphology.

Minimal Clinically Important Difference in Patient-Reported Outcome Measures with the Transforaminal Endoscopic Decompression for Lateral Recess and Foraminal Stenosis

Background

Patient-reported outcome measures (PROMs) have become widely used to better measure patients' judgment of treatment benefits from surgical spine care. The concept of determining the minimal clinically important differences (MCIDs) of PROMs is aimed at assessing the benefits of lumbar spine care that are meaningful to the patient. The goal of this study was to validate the utility of MCIDs of the visual analog score (VAS) and Oswestry Disability Index (ODI) in patients with sciatica-type low back and leg pain due to lateral recess and foraminal stenosis who were treated with directly visualized transforaminal outpatient endoscopic decompression.

Methods

The retrospective study population consisted of 406 patients on whom PROMs were obtained preoperatively, and again postoperatively at final follow-up. Employing an anchor-based approach with a patient satisfaction index based on the modified Macnab criteria, a receiver operating characteristics (ROC) and area under the curve (AUC) analysis was performed using IBM SPSS 25.0 to define the optimal MCID in VAS and ODI with the transforaminal endoscopy using the top-left-corner criteria and the Youden index. Improvements in walking endurance were recorded as an additional parameter of patient functioning and correlated with PROMs to test for statistical significance.

Results

The patients' average age was 41.08 years, ranging from 30 to 84 years. The mean follow-up was 33.59 months, ranging from 24 to 85 months, with a standard deviation of 12.79. The MCIDs for VAS and ODI were 2.5 to 3.5 and 15 to 16.5, respectively. Patients were dichotomized as improved (377/406; 92.9%) if they reported excellent (224/406; 55.2%), good (112/406; 27.6%), and fair (41/406; 10.1%) Macnab outcomes. Patients were dichotomized as failed if they reported poor (29/406; 7.1%) Macnab outcomes. Preoperatively, only 32.5% (132/406) of patients had unlimited walking endurance compared to 77.6% (315/406) of patients postoperatively. The ROC and AUC analysis showed better accuracy with the single-integer VAS score (0.926) than with the 10-item ODI score (0.751).

Conclusions

Transforaminal outpatient endoscopic decompression for symptomatic foraminal and lateral recess stenosis is an effective surgical treatment to alleviate sciatica-type and back symptoms in 92.9% of patients. Of the PROMs analyzed, the VAS provided a more meaningful and accurate reflection of patients' interpretation of outcome with the transforaminal endoscopic spinal decompression procedure than ODI. Understanding which patient expectations drive these MCIDs may aid in replacing open surgeries for sciatica-type low back and leg pain currently preferred by traditional spine surgeons with a personalized early-staged transforaminal endoscopic hybrid decompressive/ablative procedures favored by the authors. These may prove more cost effective by focusing on significant pain generators validated with a diagnostic interventional workup instead of employing image-based indication criteria for surgery.

Paraspinal muscle changes after single-level posterior lumbar fusion: volumetric analyses and literature review

Background

Posterior lumbar fusion is a widely accepted surgical technique; however, it has been related to the possibility of paraspinal muscle atrophy after surgery. We investigated 1-year postoperative changes in paraspinal muscle volume using a simple formula applicable to magnetic resonance imaging (MRI) or computed tomography (CT) images.

Methods

Patients with degenerative lumbar spinal stenosis who underwent posterior interbody fusion (PLIF) at the L4/5 level in the period from May 2010 to June 2017 were enrolled in this study. Radiologic parameters were measured using MRI or CT images which were taken before surgery and at 1 year after surgery. The volume of the paraspinal muscles was calculated using a simple formula which was derived from the formula for calculating the volume of truncated elliptic cones.

Results

A total of 40 patients were included; 24 were analyzed using MRI and 16 were analyzed using CT. The mean age of the patients was 59.6 ± 12.1 years and 32 (80.5%) were female. When comparing the preoperative and 1-year-postoperative images, multifidus muscle (MF) reduction was consistently observed in the MRI and CT groups, right and left (p = 0.003, p < 0.001, p = 0.005 and p < 0.001, respectively). In the erector spinae (ES) group, decrease in muscle volume was observed in the right-sided muscles of the CT group (p < 0.001), but no significant change was observed in the MRI group. The psoas muscle showed no significant change after 1 year. Conversely, regression analysis showed a negative correlation between MF muscle volume loss and age in the MRI group (right and left, p = 0.002 and p = 0.015, respectively), that is, the younger the age, the greater loss of muscle mass.

Conclusion

After the posterior lumbar fusion, the volume of the MF muscles was markedly decreased, and the degree of decrease was apparent in the MRI. The volume of the ES muscles, which are located relatively laterally, also tended to decrease at 1 year after surgery.

Paraspinal muscle atrophy after posterior lumbar surgery with and without pedicle screw fixation with the classic technique

OBJECTIVES

Lumbar spine surgery causes a muscular injury during its approach that could worsen long-term postoperative functional results. This study aims to analyze the postoperative paraspinal atrophy associated with two types of intervention.

MATERIAL AND METHODS

Clinical records and lumbar magnetic resonance imaging were collected from a group of 41 patients, 20 underwent laminectomy with lumbar fixation due to lumbar spinal stenosis (fixation group) and another group of 21 underwent hemilaminectomy without fixation due to lumbar disc disease (non-fixation group). In which muscle atrophy was analyzed quantitatively.

RESULTS

We found a negative correlation between age and preoperative muscle, which was higher in those who underwent lumbar fixation (rho = -0.64 p = .002). We also found a positive correlation between preoperative muscle and postoperative atrophy (rho = 0.32 p = .041). In the age, sex and fixation adjusted multivariate linear regression model (R² = 0.31), laminectomy with fixation is attributed to 5.3% atrophy (IC95 1.4-9.5%, p = .017); preoperative musculature > 70% is attributed to atrophy of 13.8% (95% CI 5.5%-22%, p = .002). Age did not correlate with postoperative atrophy.

CONCLUSIONS

Paraspinal muscle atrophy after lumbar spinal surgery is greater if an extensive approach is performed such as complete laminectomy with bilateral facetectomy and transpedicular fixation. A greater previous musculature regardless of age, sex and type of surgery also predicts greater postoperative atrophy.

Analysis of intra and extramyocellular lipids in the multifidus muscle in patients with chronic low back pain using MR spectroscopy

OBJECTIVE

To analyse the intra- (IMCL) and extramyocellular lipids (EMCL) concentration in the multifidus muscle (Mm) using MR spectroscopy (MRS) in patients with low back pain (LBP), and to evaluate the correlation between those lipid concentrations and age, obesity, atrophy of the Mm and LBP intensity.

METHODS

60 LBP patients underwent routine diagnostic MRI of the lumbar spine before undergoing imaging for the study. Body mass index, as an indicator of obesity and visual analogue scale, as an indicator of LBP were also measured. Proton MRS was acquired with a single-voxel point-resolved spectroscopy sequence. Furthermore, the MRS volume of interest for measuring the IMCL and EMCL concentration at L4/5 for the right Mm was determined, and we measured the cross-sectional area of Mm as an indicator of muscle atrophy.

RESULTS

Age showed correlation with EMCL concentration (r = 0.314, p = 0.008). The body mass index showed correlation with EMCL concentration (r = 0.358, p = 0.005). The cross-sectional area of Mm showed correlation with EMCL concentration (r = -0.543, p < 0.001). Moreover, the LBP visual analogue scale showed correlation with IMCL concentration (r = 0.367, p = 0.004).

CONCLUSION

There were correlations between age, obesity, muscle atrophy, and EMCL concentration in Mm. IMCL concentration in Mm showed a correlation with LBP intensity. This may suggest that IMCL concentration could become an effective objective indicator of chronic LBP intensity. Advances in knowledge: We investigated the characteristics of fat content in Mm with LBP patients. This study was demonstrated the association of the IMCL and EMCL concentration in Mm with various patient parameters.

[Minimally invasive dorsal decompression-stabilization surgery in patients with overweight and obesity]

Spinal surgery in patients with overweight and obesity is associated with an increased risk of perioperative complications. Minimally invasive (MIS-TLIF) and traditional (O-TLIF) techniques of rigid stabilization are extensively used, but the advantages and disadvantages of MIS-TLIF in patients with an elevated body mass index (BMI) remain controversial.

AIM

The study aim was to assess the efficacy of a new low-invasive rigid fixation technique and traditional open spinal fusion in surgical treatment of degenerative lumbar spine diseases in patients with overweight and obesity.

MATERIAL AND METHODS

The study included 73 patients (49 males and 24 females, aged 53 (42; 65) years) with a BMI of more than 25 kg/m². Two study groups were allocated: group I (MIS-TLIF, n=32) included patients operated on using an original technique of spinal canal reconstruction, interbody spinal fusion, and combined transpedicular stabilization; group II (O-TLIF, n=41) included patients who underwent single-level rigid stabilization through the median approach. The mean follow-up period was 34 months in group I and 40 months in group II. Comparative analysis assessed clinical parameters, intraoperative indicators, postoperative period specificity, instrumental data, and complications.

RESULTS

Compared to the O-TLIF group, the MIS-TLIF group was characterized by a shorter time of surgery, X-ray exposure, activation, and hospital stay as well as by a smaller amount of blood loss. A comparative analysis of the pain severity (visual analogue scale) and performance status (ODI) in the follow-up period revealed significantly better results in group I, which was associated with smaller intraoperative injury to soft tissues. The total rate of postoperative complications was 9% in group I and 17% in group II (p=0.01). In this case, the interbody bone block formed in the long-term postoperative period in 88% of group I patients and in 83% of group II patients (p=0.15). According to the instrumental data, there was statistically significant greater muscular atrophy in the group after O-TLIF (p<0.001).

CONCLUSION

The original technique of minimally invasive rigid stabilization is safe and highly effective in surgical treatment of degenerative lumbar spine diseases in patients with overweight and obesity. MIS-TLIF has a number of significant advantages over O-TLIF in the dynamics of clinical parameters and a low number of perioperative complications, which is confirmed by smaller injury to paravertebral tissues and a better performance status in the long-term postoperative period.

Correlation between intervertebral disc degeneration, paraspinal muscle atrophy, and lumbar facet joints degeneration in patients with lumbar disc herniation

Background

To assess the correlation between lumbar disc degeneration (LDD), multifidus muscle atrophy (LMA), and facet joints degeneration in patients with L4-L5 lumbar disc herniation (LDH).

Methods

Sixty patients with L4-L5 LDH diagnosed by a 1.5 T MRI scanner were enrolled in the study group and another 60 patients with non-specific back pain were enrolled in the control group. LDD, LMA, and facet joints degeneration were examined and analyzed independently by two independent orthopedic surgeons using T2-weighted images. Wilcoxon test was used for analyzing the difference of LDD and facet joints degeneration between L3-L4 and L5-S1 and difference of LMA between the herniated and control groups. Correlation analysis of the three degeneration grades at the same level was determined by Spearman rank correlation test.

Results

In the herniated group, most LMA at L3-L4 level was grade 1 (42, 70.0%); grade 2 (33, 55.0%) at L4-L5 level; and grade 3 (27, 45.0%) at L5-S1 level. LMA and LDD grading were significantly different between L3-L4 and L5-S1 levels (P < 0.05). In the herniation group, the Spearman value for LDD and LMA grading were 0.352 (P < 0.01) at L3-L4 and 0.036 (P > 0.05) at the L5-S1 level. The differences in LMA between the herniated and control groups at the three levels were significant (P < 0.05).

Conclusions

Disc degeneration and multifidus muscles atrophy were positively correlated at the L3-L4 disc level. A lumbar extension muscle strengthening program could be helpful in preventing muscle atrophy and lumbar spinal degeneration.

Magnetic resonance spectroscopic analysis of multifidus muscles lipid content and association with spinopelvic malalignment in chronic low back pain

OBJECTIVE

To analyze intramyocellular lipids (IMCLs) and extramyocellular lipids (EMCLs) of the multifidus muscle (Mm) using MR spectroscopy in chronic low back pain (CLBP) and control groups and to identify correlations with spinopelvic alignment.

METHODS

40 patients (16 males, 24 females; mean age, 62.9 ± 1.9 years) whose visual analogue scale scores were >30 mm for CLBP were included. Furthermore, 40 control participants matched with the CLBP group subjects by sample size, gender and age (17 males, 23 females; mean age, 65.0 ± 1.2 years) were included. We compared the body mass index, physical workload, leisure time physical activity level, spinopelvic parameters, and IMCLs and EMCLs of the Mm between the groups. We also evaluated possible correlations of spinopelvic parameters with IMCLs and EMCLs of the Mm in the groups.

RESULTS

There were no statistically significant differences in body mass index, physical workload, exercise intensity level, spinopelvic parameters and EMCLs between the groups. The IMCLs were significantly higher in the CLBP group than in the control group (p < 0.01). In the CLBP group, there was a significantly negative correlation between IMCLs and lumbar lordosis (r = -0.64, p < 0.01) and a significantly positive correlation between IMCLs and sagittal vertical axis (r = 0.43, p < 0.01).

CONCLUSION

The measurement of IMCLs might be a characteristic finding of CLBP as well as a precursor to spinal deformity. Advances in knowledge: IMCLs of the Mm may be a useful prognostic marker in rehabilitation strategies for patients with CLBP.

Evaluation of intramyocellular and extramyocellular lipids in the paraspinal muscle in patients with chronic low back pain using MR spectroscopy: preliminary results

OBJECTIVE:

To analyze the intramyocellular lipids (IMCL) and extramyocellular lipids (EMCL) in the psoas muscle (Pm) and multifidus muscle (Mm) using MR spectroscopy (MRS) in patients with chronic low back pain (CLBP) and asymptomatic volunteers.

METHODS:

This prospective study had institutional review board approval, and written informed consent was obtained from all individual participants. 20 patients with CLBP (mean age, 49.8 ± 12.5 years; age range, 28-66 years) with low back pain (LBP) duration of ≥3 months and asymptomatic volunteers (mean age, 44.0 ± 12.8 years; age range, 28-65 years) underwent MRS for the quantification of IMCL and EMCL of the right Pm and Mm in a volume of interest at the intervertebral level of L4 through L5. We compared patients with CLBP and asymptomatic volunteers for age and body mass index (BMI), IMCL and EMCL of Pm and Mm. The Mann-Whitney U-test was used for significant difference testing, with p-value <0.05 indicating statistical significance.

RESULTS:

No statistically significant differences were observed in the age and BMI of patients with CLBP and asymptomatic volunteers. There was no statistically significant difference in the EMCL and IMCL in Pm between the two groups. EMCL in Mm was not statistically significantly different; the IMCL of patients with CLBP was significantly higher than that of asymptomatic volunteers (p < 0.05).

CONCLUSION:

MRS demonstrates that IMCL in the Mm of patients with CLBP is significantly higher than that of asymptomatic volunteers. The increase of IMCL in the Mm may be a characteristic finding in CLBP.

ADVANCES IN KNOWLEDGE:

We investigated the detail of the fat content in the paraspinal muscles in patients CLBP and asymptomatic volunteers. The increase of fat content in the Mm of patients with LBP on previous studies was demonstrated to be the increase of IMCL.