Herniated Nucleus Pulposus Research Articles

Fibrin sealants in lumbar annuloplasty after endoscopic discectomy as a method to prevent recurrent lumbar disc herniation

Fibrin sealant as a promising agent for providing scaffold and efficient hemostasis is widely accepted in several specialties. However, the outcome of Fibrin sealants in lumbar annuloplasty after endoscopic discectomy has not been evaluated in patients with disc herniation. The goal of this study was to evaluate the efficacy, response, and probability of future recurrence rates in herniated nucleus pulposus (HNP) with the use of fibrin sealant in conjunction with endoscopic disc surgery. A total of 35 patients (28 men, 7women) were evaluated, including 18 patients who underwent endoscopic discectomy alone and 17 patients that received fibrin sealant at the site of annulus tear and endoscopic discectomy. All patients were followed through both clinical and imaging methods for an average of 10.5 months. Primary outcome measure was defined as lumbar decompression approved by imaging and symptom alleviation after endoscopic spinal discectomy with Visual Analogue Scale (VAS) score ≤ 4 (cut-off point). Median size of annular tearing was significantly lower in the endoscopic discectomy group (median, 3) (minimum, 2; maximum, 5); however, the corresponding factor in the endoscopic discectomy plus fibrin sealant group was significantly larger (median, 6) (minimum, 5; maximum, 10), with P <0.001. Only one patient in the endoscopic discectomy group had an HNP recurrence during follow-up compared to two patients in the endoscopic discectomy plus fibrin sealant group. Due to the temporary effects of fibrin sealant in preventing disc herniation and the observed recurrence rate in both the case and control groups, the results of this study suggest a role of fibrin sealants combined with endoscopic discectomy to prevent early HNP recurrence rate.

Fibrin sealants in lumbar annuloplasty after endoscopic discectomy as a method to prevent recurrent lumbar disc herniation.

Fibrin sealant as a promising agent for providing scaffold and efficient hemostasis is widely accepted in several specialties. However, the outcome of Fibrin sealants in lumbar annuloplasty after endoscopic discectomy has not been evaluated in patients with disc herniation. The goal of this study was to evaluate the efficacy, response, and probability of future recurrence rates in herniated nucleus pulposus (HNP) with the use of fibrin sealant in conjunction with endoscopic disc surgery. A total of 35 patients (28 men, 7women) were evaluated, including 18 patients who underwent endoscopic discectomy alone and 17 patients that received fibrin sealant at the site of annulus tear and endoscopic discectomy. All patients were followed through both clinical and imaging methods for an average of 10.5 months. Primary outcome measure was defined as lumbar decompression approved by imaging and symptom alleviation after endoscopic spinal discectomy with Visual Analogue Scale (VAS) score ≤ 4 (cut-off point). Median size of annular tearing was significantly lower in the endoscopic discectomy group (median, 3) (minimum, 2; maximum, 5); however, the corresponding factor in the endoscopic discectomy plus fibrin sealant group was significantly larger (median, 6) (minimum, 5; maximum, 10), with P <0.001. Only one patient in the endoscopic discectomy group had an HNP recurrence during follow-up compared to two patients in the endoscopic discectomy plus fibrin sealant group. Due to the temporary effects of fibrin sealant in preventing disc herniation and the observed recurrence rate in both the case and control groups, the results of this study suggest a role of fibrin sealants combined with endoscopic discectomy to prevent early HNP recurrence rate.

The transcription factors regulating intervertebral disc development.

Damage to the intervertebral discs (IVDs) occurs due to aging or excessive mechanical stress, causing a series of IVD‐related degenerative diseases, such as spinal disc herniation and spondylosis. These IVD‐related diseases are difficult to cure, partially because the regeneration ability of IVDs is not sufficient. As a novel strategy for treatment of IVD‐related diseases, mesenchymal stem cell transplantation to the damaged discs has been reported in animal studies. To further develop and improve this approach, it is necessary to gain a better understanding of the molecular network regulating IVD development by critical transcription factors. Recent findings reveal that during IVD development, nucleus pulposus and annuls fibrosus differentiation is coordinated by a series of transcription factors, such as Mkx, Pax1, 9, Shh, Foxa1, 2, T‐Brachyury, and Sox5, 6, 9. The combination of mesenchymal stem cell transplantation with the regulation of these molecules may provide a novel strategy for treatment of degenerative disc diseases.

Prevalence of Risk Factors for Hospital-Acquired Venous Thromboembolism in Neurosurgery and Orthopedic Spine Surgery Patients.

Hospital-acquired venous thromboembolisms (HA-VTE) are a significant source of morbidity and mortality in spine surgery patients. The purpose of this study was to review HA-VTE rates at our institution and evaluate the prevalence of known risk factors in patients who developed HA-VTE among both neurosurgical and orthopedic spine surgeries. Retrospective chart reviews were conducted of all spine surgery patients from January 1, 2013, to July 31, 2017, to evaluate rates of HA-VTE and prevalence of known HA-VTE risk factors among these patients. Univariate and multivariate logistic regression analysis for categorical variables and independent Student t test for continuous variables were utilized with significance set at P < .05. The overall HA-VTE rate was 0.94% (0.61% orthopedic, 1.87% neurosurgery). Patients with VTEs had higher rates of thoracic procedure (P = .002), posterior approach (P = .001), diagnosis of fracture (P = .013) or flatback syndrome (P = .028), neurosurgery division (P < .001), and diagnosis-related group (DRG) of noncervical malignancy (P = .001). Patients with VTEs had lower rates of cervical procedure (P < .001), diagnosis of herniated nucleus pulposus (P = .006) and degenerative disc disease (P = .001), and DRG of cervical spine fusion (P < .001). In the patients who sustained VTE, the neurosurgical patients had higher rates of active cancer (22.86% vs 0%, P = .004) and age >60 (80% vs 50%, P < .001), and orthopedic patients had higher estimated blood loss (EBL) (2436 ml vs 1176 mL, P = .006) and rates of anterior-posterior surgery (22.58% vs 0%, P = .003). Neurosurgery department, diagnosis of fracture, and DRG of noncervical malignancy were found to be significant independent risks for developing HA-VTE. Cervical procedures were independently associated with significantly lower risk. Postoperative anticoagulation initiated sooner in neurosurgery patients (postoperative day 1.26 vs 3.19, P < .001). The overall HA-VTE rate at our institution was 0.94% (0.61% orthopedic, 1.87% neurosurgery). In patients who sustained VTE, neurosurgical patients had higher rates of active cancer and age >60 years, and orthopedic patients had higher EBL and rates of anterior-posterior surgery. This highlights the different patient populations between the 2 departments and the need for individualized thromboprophylaxis regimens. 4.

Should Initial Management for Lumbar Herniated Nucleus Pulposus Resulting in a Dense Nerve Palsy Be Surgical.

Should Initial Management for Lumbar Herniated Nucleus Pulposus Resulting in a Dense Nerve Palsy Be Surgical.

Which is the most affected muscle in lumbar back pain – multifidus or erector spinae?

IntroductionThe purpose of this study is to evaluate the relationship between lumbar back pain, lumbar disc herniation, and erector spinae and multifidus muscle lipomatous degeneration.Material and methodsAfter receiving approval from the clinical studies Ethics Committee, magnetic resonance imaging (MRI) studies of patients who had physical examination in orthopaedic, neurology, neurosurgery, physical medicine and rehabilitation clinics were evaluated. Their pre-diagnoses were ‘herniated nucleus pulposus’ or ‘lumbar disc herniation’ or ‘back pain’ and their age range was between 18 and 64 years. Patients who had vertebral fracture, spondylitis-spondylodiscitis, tumours, structural anomalies such as spondylolisthesis, scoliosis and vertebral segmentation anomalies and previous surgery in the lumbar area were excluded. There were 205 patients in the case group who had lumbar disc herniation between L1-S1 level and there were 187 patients in the control group who had no lumbar disc herniation. In the study, patient age, sex, herniation level and erector spinae and multifidus muscle lipomatous degeneration were compared. Muscle lipomatous degeneration were evaluated with a visual scale.ResultsThere were 105 men and 100 women in the case group and 88 men and 99 women in the control group. In the case group, lumbar disc herniation was detected mostly at L4-5 and L5-S1 levels. There was no significant difference between case and control groups with regard to erector spinae and multifidus muscle lipomatous degeneration. In the case group, lipomatous degeneration of the erector spinae was higher compared to that of the multifidus muscle.ConclusionsPatients with low back pain may have fatty degeneration in erector spina and multifidus muscles with or without LDH, but LDH accelerates this process rather than being a result of it. In patients with LDH, fatty degeneration in the erector spina is more pronounced than in multifidus, and the erector spina is more affected by the LDH process.

Generation Change of Practice in Spinal Surgery: Can Endoscopic Spine Surgery Expand its Indications to Fill in the Role of Conventional Open Spine Surgery in Most of Degenerative Spinal Diseases and Disc Herniations: A Study of 616 Spinal Cases 3 Years.

A paucity of literature on the effect of spinal endoscopic surgery replacing a large percentage of open and microscopic minimally invasive surgery on outcomes in patients. Evaluation of the effect of endoscopic practice expansion in degenerative spinal conditions and disc herniations on patients' outcome as we shifted from first-generation endoscopic discectomy to second-generation decompression and finally third generation of endoscopic spinal fusion practice. Retrospective cohort study on surgical treatment of degenerative spinal conditions for 616 spinal cases. Basic demographics, preoperative, postoperative 1 week, 6 months, and final follow-up of patients' clinical outcomes in terms of pain score, Oswestry disability index, and MacNab's criteria for pain score were evaluated. 75%, 91%, and 97% of the surgeries with complications rate of 8.2%, 9%, and 3.4% were found in Generation 1, 2, and 3 of endoscopic surgery, respectively. Compared to preoperative scores, each generation VAS and ODI scores all statistically significantly improved. In the final follow-up, compared to preoperative state, the mean VAS improvement was 4.75 ± 1.7, 5.49 ± 1.66, and 5.37 ± 1.70, mean ODI improvement was 45.99 ± 11.8, 48.93 ± 11.2, and 48.43 ± 11.41, and MacNab's criteria showed a trend of upward improvement of 87.3%, 96.0%, and 98.7% cases, which showed good-to-excellent outcome, in Generation 1, 2, and 3, respectively. Generation change of increasing percentage of endoscopic surgeries and expansion of endoscopic spinal indications over open surgeries in degenerative spinal conditions and disc herniations are possible as a surgeon gets more experience with endoscopic spine surgery producing a good clinical outcome.

The Immune Privilege of the Intervertebral Disc: Implications for Intervertebral Disc Degeneration Treatment.

The intervertebral disc (IVD) is the largest avascular organ of the body. It is composed of three parts: the nucleus pulposus (NP), the annulus fibrosus (AF) and the cartilaginous endplate (CEP). The central NP is surrounded by the AF and sandwiched by the two CEPs ever since its formation. This unique structure isolates the NP from the immune system of the host. Additionally, molecular factors expressed in IVD have been shown inhibitive effect on immune cells and cytokines infiltration. Therefore, the IVD has been identified as an immune privilege organ. The steady state of immune privilege is fundamental to the homeostasis of the IVD. The AF and the CEP, along with the immunosuppressive molecular factors are defined as the blood-NP barrier (BNB), which establishes a strong barrier to isolate the NP from the host immune system. When the BNB is damaged, the auto-immune response of the NP occurs with various downstream cascade reactions. This effect plays an important role in the whole process of IVD degeneration and related complications, such as herniation, sciatica and spontaneous herniated NP regression. Taken together, an enhanced understanding of the immune privilege of the IVD could provide new targets for the treatment of symptomatic IVD disease. However, the underlying mechanism above is still not fully clarified. Accordingly, the current study will extensively review and discuss studies regarding the immune privilege of the IVD.

Comparison of 1-year results of single transforaminal epidural steroid injection among patients with different spinal pathologies-related radicular pain.

This study aims to investigate the effectiveness of transforaminal epidural steroid injection (TFESI) in patients with lumbar radicular pain or radiculopathy caused by different spinal pathologies. One hundred and seventy seven patients who underwent single transforaminal epidural steroid injection were included in the study group and divided into 3 subgroups (central spinal stenosis + lateral recess stenosis, foraminal stenosis, lumbar disc herniation) according to existing spinal pathology. Patients' visuel analogue scale (VAS) measures and Oswestry Disability Index (ODI) scores were recorded and the patients who give favourable response to treatment were called respondents and who were not called as non-respondents. Subgroups were compared statistically at the end of 12 months. Sixty patients (33.9%) were considered as respondents and 117 patients (66.1%) were non-respondents in the entire study group. Patients with foraminal stenosis included the vast majority of the respondents and showed better results of pain relief as opposed to patients of other groups at the end of 12 months (P < 0.001). TFESI was an effective treatment modality for pain relief and functional improvement in patients with foraminal stenosis. However, it could not produce the same results in patients with central spinal stenosis and lumbar disc herniations.

Long non-coding RNA zinc finger antisense 1 expression associates with increased disease risk, elevated disease severity and higher inflammatory cytokines levels in patients with lumbar disc degeneration.

This study aimed to investigate the correlation of long noncoding RNA zinc finger antisense 1 (lncRNA ZFAS1) expression with disease risk, disease severity and inflammatory cytokines levels in lumbar disc degeneration (LDD) patients.83 LDD patients underwent surgery and 28 traumatized, non-LDD patients underwent lumbar disc surgery (controls) were consecutively enrolled in this case-control study. Lumbar disc tissue was obtained during surgery and herniated nucleus pulposus (HNP) was isolated to detect lncRNA ZFAS1 expression and inflammatory cytokines mRNA levels by RT-qPCR, and determine protein levels of inflammatory cytokines by western blot.HNP lncRNA ZFAS1 expression in LDD patients was up-regulated compared with controls (P < .001), and receiver operating characteristic (ROC) curve showed lncRNA ZFAS1 expression disclosed a good predictive value for LDD risk with area under curve (AUC) 0.753 (95% CI 0.646–0.859). And after adjustment by age, gender and body mass index (BMI), lncRNA ZFAS1 (P = .017) remained to be an independent predictive factor for higher LDD risk. In addition, lncRNA ZFAS1 expression was positively associated with Modified Pfirrmann Grade (P = .015). As to inflammatory cytokines, lncRNA ZFAS1 expression was observed to be positively correlated with TNF-α (P = .002), IL-1β (P = .007) and IL-6 (P = .015) mRNAs expressions while reversely associated with IL-10 mRNA level (P = .014); and lncRNA ZFAS1 expression was also positively correlated with protein levels of TNF-α (P = .038) and IL-6 (P = .027) while reversely associated with IL-10 protein expression (P = .039).lncRNA ZFAS1 expression associates with increased risk, elevated disease severity and higher inflammatory cytokines levels in LDD patients.

Development of Prediction Model for the Prognosis of Sick Leave Due to Low Back Pain.

The aim of this study was to develop a prediction model for the prognosis of sick leave due to low back pain (LBP). This is a cohort study with 103 employees sick-listed due to non-specific LBP and spinal disc herniation. A prediction model was developed based on questionnaire data and registered sick leave data with follow up of 180 days. At follow up 31 (30.1%) employees were still sick-listed due to LBP. Forward selection procedure resulted in a model with: catastrophizing, musculoskeletal work load, and disability. The explained variance was 27.3%, calibration was adequate and discrimination was fair with area under the ROC-curve (AUC) = 0.761 (interquartile range [IQR]: 0.755-0.770). The prediction model of this study can adequately predict LBP sick leave after 180 days and could be used for employees sick listed due LBP.

Indicação do Uso do Cateter de St. Reed no Tratamento da Dor Lombar Crônica

Introdução: A dor lombar crônica é uma patologia de alta morbidade, sendo associada à limitação das atividades básicas diárias e aumento do estresse psicológico. Há diversas linhas de tratamento que podem ser propostas, variando de fármacos até procedimento cirúrgico. Para os casos refratários, uma alternativa é a aplicação de esteroides com o cateter St. Reed. Objetivos: Descrever as indicações do uso do cateter de St. Reed para o tratamento da dor lombar crônica. Métodos: Foi realizada busca de artigos nas bases de dados PubMed (9) e UptoDate (2) através das palavras-chave: “low back pain”, “chronic pain” e “treatment failure”. Resultados: A dor lombar causada por hérnia de núcleo pulposo e estenose espinhal sem resposta ao tratamento conservador, tem como opção a aplicação de corticoide via cateter St. Reed. As vantagens são: falta de necessidade de anestesia geral, rápida recuperação e curto período de internação. As contraindicações são infecções no local, gravidez e doença mental. Estudos apontam que a aplicação alivia os sintomas, além de ser tratamento com baixos riscos de complicações e resolutividade em casos refratários. Conclusão: o uso deste cateter é uma opção para casos refratários de hérnia de disco com radiculopatia, dor discogênica e estenose espinhal.

Size Matters: Which Adolescent Patients Are Most Likely to Require Surgical Decompression for Lumbar Disk Herniations?

Lumbar herniated nucleus pulposis (HNP) occurs infrequently in the pediatric/adolescent population. A minority of patients with radicular symptoms fail to improve with conservative management and require discectomy. The authors hypothesize that children who ultimately require surgical intervention have an underlying lumbar stenosis predisposing them to continued symptoms. Pediatric patients with a lumbar HNP on advanced imaging were retrospectively identified at a tertiary pediatric orthopaedic institution. Patients with spondylolisthesis, fractures, previous spine surgery, or structural thoracolumbar scoliosis were excluded. On sagittal magnetic resonance imagings, measurements were taken of the L4 and L5 vertebral body diameters (VBD) and canal diameters (CD) by 2 independent reviewers. Statistical analysis was performed using 2 sample T tests followed by logistic regression analysis. This was utilized to identify significant associations between CD and need for surgical decompression. A total of 76 patients (37 males/39 females) were identified with a lumbar HNP from 2001 to 2016. Eleven patients underwent discectomy. Sixty-five patients were managed conservatively. Age at magnetic resonance imaging was not different between groups (15.1±1.7 vs. 14.9±2.2 y, P=0.82). VBD at L4 and L5 were not different between groups (P=0.2 and 0.36, respectively). The reviewers had fair to good (0.584-0.854) interrater reliability correlation coefficients. CD was decreased in the surgically treated cohort at L4 (11.6±1.6 vs. 14.2±2.1 mm, P=0.0002) and at L5 (10.1±1.3 vs. 14.2±2.2 mm, P<0.00001). The ratio of CD:VBD was lower in the surgically treated group at L4 (0.36±0.06 vs. 0.46±0.08, P=0.0002) and L5 (0.31±0.68 vs. 0.45±0.08, P<0.00001). Patients with a L4 CD<12.6 mm were 18.8× more likely to require surgical decompression. 100% of patients with a L5 CD<12.36 mm ultimately underwent surgical decompression. Adolescent patients with congenital lumbar stenosis that develop a lumbar HNP are significantly more likely to require surgical decompression to relieve persistent radicular symptoms. A L4 CD<12.6 mm and a L5 CD<12.36 mm were highly correlated with the need for decompression. Level III-prognostic study.

Clinical outcomes of lumbar diseases specific test in patients who undergo endoscopy-assisted tubular surgery with lumbar herniated nucleus pulposus: an analysis using the Japanese Orthopaedic Association Back Pain Evaluation Questionnaire (JOABPEQ)

PurposeThis study was to evaluate clinical outcomes using a patient-oriented test that scores health-related quality of life (HRQOL) for patients after minimally invasive surgery using microendoscopic discectomy (MED) for lumbar disc hernia. Few studies regarding MED in terms of disease-specific quality of life measures using Japanese Orthopaedic Association Back Pain Evaluation Questionnaire (JOABPEQ) have been published.MethodsRetrospective analysis of the surgical and clinical outcomes with regard to reducing pain and improving the functional status for 31 patients who underwent MED for lumbar disc hernia was conducted. These patients were evaluated at 3-year follow-up. The evaluations were based on a visual analogue scale (VAS), the Japanese Orthopaedic Association (JOA) scoring system, and the JOABPEQ, which is an objective, patient-oriented test that assesses HRQOL in patients with lumbar disorders.ResultsA low rate of improvement was seen only in mental health until 1 year, the low rate of improvement in mental health and was independently correlated with body mass index (BMI), pre-operative scores on the Brief Scale for Psychiatric problems in Orthopaedic Patients (BS-POP), and scores on the BS-POP at 12 months post-operatively.ConclusionsAll categories of VAS, JOA scores, and all domains of JOABPEQ were significantly higher over 3 years than those obtained pre-operatively. But only mental health domain showed mild improvement until 1 year. Moreover, BMI showed a negative correlation with improvements in the mental health domain post-operatively. As patients may be mentally exhausted from lumbar disc herniation, pre-operative mental health may be improved by surgical treatment.

Preoperative MRI predictors of health-related quality of life improvement after microscopic lumbar discectomy

BACKGROUNDLumbar herniated nucleus pulposus (HNP) is a common spinal pathology often treated by microscopic lumbar discectomy (MLD), though prior reports have not demonstrated which preoperative MRI factors may contribute to significant clinical improvement after MLD. PURPOSETo analyze the MRI characteristics in patients with HNP that predict meaningful clinical improvement in health-related quality of life scores (HRQoL) after MLD. STUDY DESIGN/SETTINGRetrospective clinical and radiological study of patients undergoing MLD for HNP at a single institution over a 2-year period. PATIENT SAMPLEEighty-eight patients receiving MLD treatment for HNP. OUTCOME MEASURESCephalocaudal Canal Migration; Canal & HNP Anterior-Posterior (AP) Lengths and Ratio; Canal & HNP Axial Areas and Ratio; Hemi-Canal & Hemi-HNP Axial Areas and Ratio; Disc appearance (black, gray, or mixed); Baseline (BL); and 3-month (3M) postoperative HRQoL scores. METHODSPatients >18 years old who received MLD for HNP with BL and 3M HRQoL scores of PROMIS (Physical Function, Pain Interference, and Pain Intensity), ODI, VAS Back, and VAS Leg scores were included. HNP and spinal canal measurements of cephalocaudal migration, AP length, area, hemi-area, and disc appearance were performed using T2 axial and sagittal MRI. HNP measurements were divided by corresponding canal measurements to calculate AP, Area, and Hemi-Area ratios. Using known minimal clinically important differences (MCID) for each ΔHRQoL score, patients were separated into two groups based on whether they reached MCID (MCID+) or did not reach MCID (MCID–). The MCID for PROMIS pain intensity was calculated using a decision tree. A linear regression illustrated correlations between PROMIS vs ODI and VAS Back/Leg scores. Independent t-tests and chi-squared tests were utilized to investigate significant differences in HNP measurements between the MCID+ and MCID– groups. RESULTSThere were 88 MLD patients included in the study (Age=44.6±14.9, 38.6% female). PROMIS pain interference and pain intensity were strongly correlated with ODI and VAS Back/Leg (R≥0.505), and physical function correlated with ODI and VAS Back/Leg (R=−0.349) (all p<.01). The strongest MRI predictors of meeting HRQoL MCID were gray disc appearance, HNP area (>116.6 mm2), and Hemi-Area Ratio (>51.8%). MCID+ patients were 2.7 times more likely to have a gray HNP MRI signal than a mixed or black HNP MRI signal in five out of six HRQoL score comparisons (p<.025). MCID+ patients had larger HNP areas than MCID– patients had in five out of six HRQoL score comparisons (116.6 mm2±46.4 vs 90.0 mm2±43.2, p<.04). MCID+ patients had a greater Hemi-Area Ratio than MCID– patients had in four out of six HRQoL score comparisons (51.8%±14.7 vs 43.9%±14.9, p<.05). CONCLUSIONSPatients who met MCID after MLD had larger HNP areas and larger Hemi-HNP Areas than those who did not meet MCID. These patients were also 2.7× more likely to have a gray MRI signal than a mixed or black MRI signal. When accounting for HNP area relative to canal area, patients who met MCID had greater Hemi-HNP canal occupation than patients who did not meet MCID. The results of this study suggest that preoperative MRI parameters can be useful in predicting patient-reported improvement after MLD.

Current techniques of endoscopic decompression in spine surgery.

Endoscopic spine surgery has become a practical, minimally invasive technique for decompression in patients with spinal disc herniation or stenosis. This review aimed to summarize the current techniques of endoscopic decompression technique in spine surgery and to discuss the benefits, limitations, and future perspectives of this minimally invasive technique. Endoscopic spine decompression surgery can be categorized according to the endoscopic property: percutaneous endoscopic (full-endoscopic), microendoscopic, and biportal endoscopic. It can also be classified based on the approach: transforaminal, interlaminar, anterior, posterior, and caudal approaches. Theoretically, each technique can be applied in the lumbar, cervical, and thoracic spine. The various endoscopic spine surgery techniques should be appropriately conducted according to the disease entities, level, and zone of pathologies. Although the current level of evidence is relatively low and the relevance of the technique is controversial, recent clinical results and the critical concept are promising. Development in optics, instruments, and approach will improve its safety and reduce technical complexity. In the meantime, high-quality clinical studies, including randomized trials and meta-analyses, are due for publication. Eventually, endoscopic spine surgery is expected to become the golden standard for spinal surgery.

Minimally invasive lumbar decompression in an ambulatory surgery center.

There is limited data regarding clinical and surgical outcomes of minimally invasive lumbar decompression (MIS LD) as an outpatient procedure. In this context, our purpose is to evaluate a single surgeon's experience with performing MIS LD in the outpatient versus inpatient setting and determining if there are differences in surgical and clinical outcomes. Patients undergoing primary, one- to three-level MIS LD were retrospectively reviewed and stratified by surgical setting: ambulatory surgical center (ASC) versus hospital. The cohorts were compared with respect to demographics, perioperative characteristics, complications, postoperative pain and narcotics consumption, and improvements in patient-reported outcomes. Five hundred and nine patients were included: 332 patients underwent surgery at an ASC and 177 patients underwent surgery at a hospital. The ASC patients were younger, more likely to be male, and carry Workers' Compensation insurance. The hospital patients were older, more likely to be diabetic, and had a greater comorbidity burden. Patients undergoing MIS LD in an ASC were less likely to have multi-level procedures and more likely to have decompression with discectomy compared to patients in the hospital cohort. There were two cases of superficial wound infection in the ASC cohort and a single case of a pulmonary embolus in the hospital cohort. Additionally, a total of 28 patients had recurrent herniated nucleus pulposus in the ASC cohort compared to 12 patients in the hospital cohort. There was one case of residual stenosis in the ASC cohort compared to eight cases in the hospital cohort. Both cohorts demonstrated similar preoperative ODI, VAS back pain, and VAS leg pain scores through 12-month follow-up. MIS LD is a safe and effective procedure in an ASC, however, appropriate patient selection and postoperative protocols are imperative in minimizing complications and optimizing safety and efficacy in the outpatient setting.

Integrating transcriptome-wide study and mRNA expression profiles yields novel insights into the biological mechanism of chondropathies

BackgroundChondropathies are a group of cartilage diseases, which share some common pathogenetic features. The etiology of chondropathies is still largely obscure now.MethodsA transcriptome-wide association study (TWAS) was performed using the UK Biobank genome-wide association study (GWAS) data of chondropathies (including 1314 chondropathy patients and 450,950 controls) with gene expression references of muscle skeleton (MS) and peripheral blood (YBL). The candidate genes identified by TWAS were further compared with three gene expression profiles of osteoarthritis (OA), cartilage tumor (CT), and spinal disc herniation (SDH), to confirm the functional relevance between the chondropathies and the candidate genes identified by TWAS. Functional mapping and annotation (FUMA) was used for the gene ontology enrichment analyses. Immunohistochemistry (IHC) was conducted to validate the accuracy of integrative analysis results.ResultsIntegrating TWAS and mRNA expression profiles detected 84 candidate genes for knee OA, such as DDX20 (PTWAS YBL = 1.79 × 10− 3, fold change (FC) = 2.69), 10 candidate genes for CT, such as SRGN (PTWAS YBL = 1.46 × 10− 3, FC = 3.36), and 4 candidate genes for SDH, such as SUPV3L1 (PTWAS YBL = 3.59 × 10− 3, FC = 3.22). Gene set enrichment analysis detected 73 GO terms for knee OA, 3 GO terms for CT, and 1 GO term for SDH, such as mitochondrial protein complex (P = 7.31 × 10− 5) for knee OA, cytokine for CT (P = 1.13 × 10− 4), and ion binding for SDH (P = 3.55 × 10− 4). IHC confirmed that the protein expression level of DDX20 was significantly different between knee OA cartilage and healthy control cartilage (P = 0.0358).ConclusionsMultiple candidate genes and GO terms were detected for chondropathies. Our findings may provide a novel insight in the molecular mechanisms of chondropathies.

54. Preoperative MRI predictors of health related quality of life improvement after microscopic lumbar discectomy

54. Preoperative MRI predictors of health related quality of life improvement after microscopic lumbar discectomy

P12. Comparisons of patterns of upregulation of inflammatory cytokines in herniated nucleus pulposus, disc and nerve root lavagates and in the serum of patients with acute sciatica secondary to lumbar disc herniation undergoing surgery

BACKGROUND CONTEXT The pathogenesis of acute sciatica secondary to lumbosacral spine nucleus pulposus extrusion (AS/NPE) is mediated through an acute inflammatory response. Thus, AS/NPE patients are of particular interest in the study of the complex interaction of cytokines that regulate the severity of inflammation. Marked upregulation of TNFα and some interleukins (IL) has been demonstrated in the serum of AS/LPE patients. TNFα and IL-1β also activate extracellular matrix metalloproteinases and therefore also play an important role in enhancing the degradation/resorption of acute herniated disc tissue. IL-8 is known to be a major initiator of the acute inflammatory response by specifically activating neutrophils and RANTES (Regulation on Activation Normal T Cell Expressed and Secreted) is an inflammatory cytokine that has been correlated to intensity of disc-related pain. To date, research studies correlating patient clinical parameters to elevated cytokine levels have relied upon measurements in serum or percutaneously-obtained disc lavagate and/or nerve root lavagate. Whether or not these methods of measuring cytokine levels, particularly in serum, provide an accurate representation of the true levels and patterns of the up-regulated cytokine response in extruded disc in vivo, has yet to be determined. PURPOSE To compare the patterns of up-regulation of key inflammatory cytokines in extruded disc tissue with that identified in the serum, disc lavagate (DL) and nerve root lavagate (NRL) in patients with AS/NPE undergoing surgery. STUDY DESIGN/SETTING ELISA cytokine immunoassay. PATIENT SAMPLE Inclusion: AS/HNP of less than 16 weeks duration undergoing laminectomy discectomy surgery; spinal nerve root motor score of >3/5; McCulloch score of 5/5 Exclusion: Red flag condition; prior lumbar surgery, other active inflammatory diseases. OUTCOME MEASURES TNFα, IL-1β, 2, 6, 8, 9, 10 and RANTES patterns of upregulation and concentrations (pg/ml) in herniated nucleus pulposus (HNP), DL, NRL and in serum. METHODS At the time of surgery, 5cc saline lavagates of the spinal nerve root (NRL) and at the site of the annular disruption (DL), the extruded disc tissue removed surgically and a venous blood sample, were obtained for study. Blood samples were centrifuged in a standardized manner and the serum collected. The serum and HNP, DL, NRT samples (placed in physiological buffer with protease inhibitors) were stored at -80°C. The concentrations of TNFα, IL-2, 6, 8, 10 and RANTES in all serum and tissue samples were determined using ELISA immunoassay. Research ethics approval was obtained. RESULTS Twenty-four patients had laminectomy discectomy surgery carried out by eight different spine surgeons. In extruded disc tissue, 22/24 (92%) of the patients studied,cytokine concentrations showed a consistent pattern of upregulation with highest concentrations of RANTES (>500 pg/ml), mid-range concentrations of TNFα, IL-1β,IL-6 and IL-8 (100-200 pg/ml) and lower concentrations of IL-2, 9, 10 ( CONCLUSIONS In patients with acute sciatica secondary to lumbar disc herniation, serum and intraoperative disc lavagate cytokine content patterns of upregulation were similar to those identified in extruded disc tissue.The cytokine concentrations in nerve root lavagate samples showed significant variation and correlations with clinical parameters in patients with AS/NPE should be interpreted with caution. Funded by a research grant from the National Institutes of Health, Bethesda USA. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.