Intervertebral disc degeneration (IDD) affects more than 80% of the population all over the world. Current strategies for the treatment of IDD are based on conservative or surgical procedures with the aim of relieving pain. Mesenchymal stem cell (MSC) transplantation has emerged as a promising therapy in recent decades, but studies showed that the particularly hostile microenvironment in the intervertebral disc (IVD) can compromise cells survival rate. The use of exosomes, extracellular vesicles released by various cell types, possess considerable economic advantages including low immunogenicity and toxicity. Exosomes allow intercellular communication by conveying functional proteins, RNA, miRNA and lipids between cells. The purpose of this study is to assess the therapeutic effects of exosomes derived from Wharton Jelly mesenchymal stromal cells (WJ-MSC) on human nucleuspulposus cells (hNPC) in an in vitro 3D culture model. Exosomes (exos) were isolated by tangential flow filtration of WJ-MSC conditioned media and characterized by: quantification with BCA test; morphological observation with TEM, surface marker expression by WB and size evaluation by NTA. Confocal microscopy has been used to identify exosomes marked with PKH26 and monitor fusion and/or incorporation in hNPC. hNPC were isolated from waste surgical material from patients undergoing discectomy (n = 5), expanded, encapsulated in alginate beads and treated with: culture medium (control group); WJ-MSC exos (WJ-exos) at different concentrations (10 μg/ml, 50 μg/ml and 100 μg/ml). They were then analysed for: cell proliferation (Trypan Blu); viability (Live/Dead Assay); quantification of nitrites (Griess) and glycosaminoglycans, GAG (DMBB). The hNPC in alginate beads treated for 7 days were included in paraffin and histologically analysed to determine the presence of extracellular matrix (ECM) components. Finally, the expression levels of catabolic and anabolic genes were evaluated through real-time polymerase chain reaction (qPCR). All concentrations of WJ-exos under exam were capable to induce a significant increase in cell proliferation after 10 and 14 days of treatment (p < 0.01 and p < 0.001, respectively). Live/Dead assay showed a decrease in cell death at 50 μg/ml of WJ-exos (p < 0.05). While cellular oxidative stress indicator, nitrite production, was reduced in a dose-dependent way and statistically significant only with 100 μg/ml of WJ-exos (p < 0.05). WJ-exos at 10 and 100 μg/ml induced a significant increase in GAG content (p < 0.05; p < 0.01, respectively) confirmed by Alcian Blu staining. Exos derived from WJ-MSC modulated gene expression levels by increasing expression of ACAN and SOX-9 genes and reducing significantly of IL-6, MMP-1, MMP-13 and ADAMTS-5 levels (p < 0.05; p < 0.01) compared to the control group. Our results supported the potential use of exosomes from WJ-MSC for the treatment of IDD. Exosomes improved hNPC growth, attenuated ECM degradation and reduced oxidative stress and inflammation. This study offers a new scenario in IVD regeneration, promoting the potential use of extracellular vesicles as an alternative strategy to cell therapy

Introduction:. Exercise has showed to reduce pain and improve function in patients with discogenic low back pain (LBP). Although there is currently no biologic evidence that the intervertebral disc (IVD) can respond to physical exercise in humans, a recent study has shown that chronic running exercise is associated with increased IVD hydration and hypertrophy1. Irisin, a myokine released upon muscle contraction, has demonstrated to yield anabolic effects on different cell types, including chondrocytes2. This study aimed to investigate the effect of irisin on human nucleus pulposus cells (hNPCs). Our hypothesis is that irisin may improve hNPCs metabolism and proliferation. METHODS:. The hNPCs, isolated from discectomy surgical waste material (n = 5), were expanded and encapsulated in alginate beads. The hNPCs were treated with: i) only growth medium (control); ii) medium with recombinant irisin (r-IR) at different concentrations (5, 10 and 25 ng / mL); iii) medium with Interleukin-1β (IL1β); iv) medium with IL1β for 24 h and then with IL1β and r-IR; v) medium with r-IR for 24 h and then with r-IR and IL1 β. We evaluated proliferation (trypan blue and PicoGreen), metabolic activity (MTT), nitrite concentration (Griess), and expression levels of catabolic and anabolic genes via real-time polymerase chain reaction (qPCR). Each analysis was performed in triplicate for each donor and each experiment was performed three times. Data were expressed as mean ± S.D. One-way ANOVA was used for the groups under exam. RESULTS:. Irisin increased hNPCs proliferation (p < 0.001), metabolic activity at 10 ng/mL (p < 0.05), and GAG content at concentration of 10 ng/mL and 25 ng/mL (p < 0.01; p < 0.001, respectively). The production of nitrites, used as an indicator of cellular oxidative stress, was significantly decreased (p < 0.01). Gene expression levels compared to the control group increased for COL2A1 (p < 0.01), ACAN (p < 0.05), TIMP-1 and −3 (p < 0.01), while a decrease in mRNA levels of MMP-13 (p < 0.05) and IL1β (p < 0.001) was noticed. r-IR pretreatment of hNPCs cultured in pro-inflammatory conditions resulted in a rescue of metabolic activity (p < 0.001), as well as a decrease of IL-1β (p < 0.05) levels. Similarly, incubation of hNPCs with IL-1β and subsequent exposure to r-IR led to an increment of hNPC metabolic activity (p < 0.001), COL2A1 gene expression (p < 0.05) and a reduction of IL-1β (p < 0.05) and ADAMTS-5 gene levels (p < 0.01). CONCLUSIONS:. The present study suggested that irisin may stimulate hNPCs proliferation, metabolic activity, and anabolism by reducing the expression of IL-1β and catabolic enzymes while promoting the synthesis of extracellular matrix components. Furthermore, this myokine was able to blunt the catabolic effect of in vitro inflammation. Our results indicate that irisin may be one of the mediators by which physical exercise and muscle tissues modulate IVD metabolism, thus suggesting the existence of a biological cross-talk mechanism between the muscle and the IVD

Background. Recently, some studies have focused attention on the possibility that anaerobic pathogens of low virulence could constitute an etiological factor in disc herniation. There have been isolated such strains, predominantly Propionibacterium acne, between 7 and 53% of patients undergoing surgery for disc pathology. According to these studies, patients with anaerobic infections of the disc are more likely to develop Modic changes in the adjacent vertebrae. The aim of this work was to test this hypothesis by growing in specific media the disc material extracted in a series of lumbar discectomy and relating this factor with the presence of pre-intervention Modic changes. Methods. A total of 22 consecutive patients undergoing primary unisegmental discectomy for lumbar disc herniation (77.2% male, mean age 40.1 ± 9.1 years) were included. All patients were immunocompetent and none had previously received an epidural steroid injection prior surgery. MRI study confirmed the disc herniation. Following strict antiseptic protocols, the extracted disc material was sent for slow-growth anaerobic enriched culture (>10 days). Results. In total, anaerobic cultures were positive in 7 cases (31.8%) all men. In 5 of these cases, the symptoms developed with an acute onset. The isolated germs were always unique: Propionibacterium acne (3), Streptococcus parasanguinis (1), Actinomyces naeslundii (1), Actinomyces meyeri (1) and methicillin sensitive Staphylococcus epidermidis. Only two (28.6%) of these 7 patients had Modic changes on MRI prior surgery (one type I, one type 2). None of the patients with negative cultures had Modic changes. Conclusions. These findings support the theory that anaerobic infections of low virulence and slow growth may contribute to the pathogenesis of herniated discs. However, these cases do not necessarily develop type 1 Modic changes as previously speculated. Level of evidence. Level IV

Lumbar disc herniation represents by far the most prevalent pathology, causing pain and sciatica and constitutes an important cause of disability and one of the most cost-intensive health problems. The aetiology is very complex. In recent years, it has been suggested in twin and family studies that genetic risk factors contribute to the development of LDH. Our purpose is to analyse genetic susceptibility to symptomatic LDH in Spanish surgical patients treated with different surgical techniques. Single-nucleotide polymorphisms (SNPs) in VDR, GDF5, Col1A1, THBS2 and CHST were genotyped in a case-control study with 50 symptomatic LDH in Spanish surgical patients and 50 Spanish health controls. All patients provided signed informed consent. Sampling was carried out with a puncture of the pad of a finger using a sterile, single-use lancet. SNPs were determined by real-time polymerase chain reaction (PCR) using specific, unique probes with the analysis of the melting temperature of hybrids. The X2 test compared genotypes between groups. Multivariate logistic regression analysed the significance of many covariates and the incidence of LDH. We found significant differences in age, gender and smoking status between the two groups. There were significant differences in the CC (rs2228570) genotype in VDR in patients with LDH (p<0.05). There were significant differences in the GT (rs1800012) genotype in Col1A1 in patients with LDH (p=0.001). In Col1A1, T allele was more frequent in the case group than in the control group (p<0.001). Regarding surgical techniques, of the 50 patients included in the cases group, 25 were treated with open microdiscectomy and 25 received endoscopic discectomy. Outcomes were assessed at 12 months using VAS, and NASS instrument. Postoperative pain and pain medication were significantly reduced in the endoscopic group. Patient satisfaction is greater in the endoscopic group, with shorter hospital stays and earlier return to normal activity. GT genotype in Col1A1 was more frecuent in the endoscopic group compared to the microdiscectomy group (p=0.002). CC genotype in VDR and GT genotype in Col1A1 are associated with symptomatic LDH susceptibility in Spanish surgical patients. GT genotype in Col1A1 is associated with symptomatic LDH treated with full-endoscopic discectomy

Introduction. This study sought to determine whether the functional outcome of two common spinal operations could be improved by a programme of post-operative rehabilitation and/or an educational booklet each compared with usual care. Methods. This was a multi-centre, factorial, randomised controlled trial on the post operative management of spinal surgery patients, with randomisation stratified by surgeon and operative procedure. The study compared the effectiveness of a rehabilitation programme and an education booklet for the postoperative management of patients undergoing discectomy or lateral nerve root decompression surgery, each compared with “usual care” using a 2 × 2 factorial design, randomising patient to four groups; rehabilitation-only, booklet-only, rehabilitation-plus-booklet, and usual care only. The primary outcome measure was the Oswestry Disability Index (ODI) at 12 months, with secondary outcomes including visual analogue scale measures of back and leg pain. An economic analysis was also performed. Results. 338 patients were recruited into the study with outcomes preformed pre-operatively, and postoperatively at 6 weeks, 3, 6, 9 and 12 months post-operatively. At the one year review the effect of rehabilitation on ODI was −2.7 (95% CI −6.8 to 1.5) and the effect of booklet was 2.7 (95% CI −1.5 to 6.9). There were no significant differences in costs or outcomes associated with either intervention and neither intervention was cost-effective. Discussion. This study found that neither intervention had a significant impact on long term outcome or cost. There was some evidence to suggest that the impact of the interventions was different between patients undergoing discectomy and those having spinal decompression. Conflicts of Interest. None. Source of Funding. Arthritis Research UK. Previously presented at International Society for the Study of the Lumbar Spine 2011

With an ageing population and increasing pressures on all orthopaedic services, it is vital that we are able to develop efficient and acceptable means to streamline the patient journey. Our department uses telephone review appointments for selected patients to reduce the need for additional visits to the outpatient clinic. The aim of this study was to assess the efficacy of this approach, and to determine whether it was acceptable to patients. We identified all patients who had received a first-time telephone review appointment within a four month period. Using a short structured telephone questionnaire they were asked about their experiences of the process, whether they had subsequently required a clinic visit, and whether they would have preferred to be seen in person in the clinic. 50 of the 55 (91%) patients were successfully contacted, and all gave consent to participate. Reasons for follow-up included post-operative discectomy and lumbar decompression, post-nerve root injection, and MRI results. All patients (100%) were satisfied with the telephone consultation. Only 8 (16%) would have preferred a clinic appointment with 5 of these subsequently visiting the clinic. 32 (64%) of the patients did not require a further clinic appointment for the same problem. 32 (64%) of patients stated that they were very satisfied with the overall follow-up process with the remaining 18 (36%) being satisfied. Our study has shown that using telephone review follow-up for selected patients is effective at reducing the number of clinic visits, and is acceptable to patients

Summary Statement. To test regenerative therapies for the intervertebral disc it is necessary to create a cavity in the nucleus polposus mantaining the annulus fibrosus intact. The transpedicular mechanical nucleotomy represents the best method for this purpose. Introduction. New cells/hydrogel based treatments for intervertebral disc (IVD) regeneration need to be tested on animal models before clinical translation. Ovine IVD represents a good model but doesn't allow the injection of a significant volume into intact IVD. The objective of the study was to compare different methods to create a cavity into ovine nucleus pulposus (NP) by enzymatic digestion (E), mechanical discectomy (M) and a combination of both (E+M), as a model to study IVD regeneration strategies with intact anulus fibrosus (AF). Methods. Ovine lumbar functional spinal units (FSU) were used. The transpedicular approach via the endplate route (2mm tunnel) was performed to access the NP with AF intact. FSUs were treated through M (Arthroscopic shaver), E (Trypsin/Collagenase) and E+M. The cavity was macro- and micro-scopically evaluated. The degradation of GAG (gel chromatography) around the cavity (inner AF) was assessed. The cavity volume was quantified through µCT after injection of Agarose gel/Contrast agent. Results. The cavity has been successfully created using all methods. The M group showed high reproducibility, low GAG degradation and no endplate thinning compared to other groups. The histology analysis demonstrated NP matrix degradation in E groups while the proteoglycan content was still homogenous in the M. The percentage of the cavity volume normalised to the total IVD volume was 5.2% ± 1.6 in E, 5% ±1.4 in E+M and 4, 2% ± 0.1in M. Discussion. M represents the best method to create a reproducible and less destructive cavity in the NP. Indeed, E-based methods perform better in terms of cavity volume but the GAG of the surrounding tissue may be affected. While a lesion of the end-plate might lead to further IVD degeneration, this approach is minimal invasive (2mm) and can be easily sealed using bone cylinder, cements or scaffolds. The biomechanical characterization and in vivo evaluation are on going

Background. The majority of studies assessing minimal clinical important difference in outcome do so for management of chronic low back pain. Those that identify MCID following spinal surgical intervention fail to differentiate between the different pathologies and treatments or use variable methods and anchors in the calculation. Aim. To identify the MCID in scores across the most common spinal surgical procedures using standardised methods of calculation. Method. Prospective longitudinal study following elective lumbar spinal surgery. All patients had a complete set of spinal outcome assessments (ODI and VAS) and self perceived rating of the global and Mcnab criteria. MCID was calculated as defined by Hagg et al. Results. 244 patients of average age 53 years were followed up for 62 months post surgery. The MCID across the range of spinal surgeries was a 10 point change in ODI and 28 points for the VAS. A MCID following lumbar decompression surgery was a 3 point change in ODI and 29 points for VAS; 24 points in ODI and 37 points in the VAS for a discectomy, and 13 points in ODI and 23 point change in VAS for revision surgery. This value also varied depending on the anchor and method used for calculation. Conclusion. The MCID in score varies between different spinal procedures, method of calculation and the external anchor used. Standardised methods of calculating MCID in outcome measures should be used to allow comparative research and assessment. Generalisation of MCID in scores across a range of spinal procedures should be strongly discouraged. Conflicts of Interest. None. Source of Funding. None. This abstract has not been previously published in whole or substantial part nor has it been presented previously at a national meeting

Posterior fixation of intervertebral discs is used to treat, and occasionally diagnose, discogenic pain since it is thought that it will reduce the internal loading of the discs in vitro. We measured the internal loading of ten intervertebral discs using stress profilometry under simulated physiological loads and then after posterior fixation. Partial discectomies were performed to simulate advanced disc degeneration and the sequence repeated. Posterior fixation had very little effect on the magnitude of the loads acting on the disc and none when disc degeneration was simulated. It did, however, reduce bulging of the anterior annulus under combined bending and compression (p < 0.03). Recent experiments in vivo have shown that discogenic pain is associated with abnormal bulging of the annulus which suggests that the clinical benefit of fixation may be due to this

Objectives

Interleukin 18 (IL-18) is a regulatory cytokine that degrades the disc matrix. Bone morphogenetic protein-2 (BMP-2) stimulates synthesis of the disc extracellular matrix. However, the combined effects of BMP-2 and IL-18 on human intervertebral disc degeneration have not previously been reported. The aim of this study was to investigate the effects of the anabolic cytokine BMP-2 and the catabolic cytokine IL-18 on human nucleus pulposus (NP) and annulus fibrosus (AF) cells and, therefore, to identify potential therapeutic and clinical benefits of recombinant human (rh)BMP-2 in intervertebral disc degeneration.

In a study on ten fresh human cadavers we examined the change in the height of the intervertebral disc space, the angle of lordosis and the geometry of the facet joints after insertion of intervertebral total disc replacements. SB III Charité prostheses were inserted at L3-4, L4-5, and L5-S1. The changes studied were measured using computer navigation sofware applied to CT scans before and after instrumentation.

After disc replacement the mean lumbar disc height was doubled (p < 0.001). The mean angle of lordosis and the facet joint space increased by a statistically significant extent (p < 0.005 and p = 0.006, respectively). By contrast, the mean facet joint overlap was significantly reduced (p < 0.001). Our study indicates that the increase in the intervertebral disc height after disc replacement changes the geometry at the facet joints. This may have clinical relevance.