Aims. The presence of facet tropism has been correlated with an elevated susceptibility to lumbar disc pathology. Our objective was to evaluate the impact of facet tropism on chronic lumbosacral discogenic pain through the analysis of clinical data and finite element modelling (FEM). Methods. Retrospective analysis was conducted on clinical data, with a specific focus on the spinal units displaying facet tropism, utilizing FEM analysis for motion simulation. We studied 318 intervertebral levels in 156 patients who had undergone provocation discography. Significant predictors of clinical findings were identified by univariate and multivariate analyses. Loading conditions were applied in FEM simulations to mimic biomechanical effects on intervertebral discs, focusing on maximal displacement and intradiscal pressures, gauged through alterations in disc morphology and physical stress. Results. A total of 144 discs were categorized as ‘positive’ and 174 discs as ‘negative’ by the results of provocation discography. The presence of defined facet tropism (OR 3.451, 95% CI 1.944 to 6.126) and higher Adams classification (OR 2.172, 95% CI 1.523 to 3.097) were important predictive parameters for discography-‘positive’ discs. FEM simulations showcased uneven stress distribution and significant disc displacement in tropism-affected discs, where loading exacerbated stress on facets with greater angles. During varied positions, notably increased stress and displacement were observed in discs with tropism compared to those with normal facet structure. Conclusion. Our findings indicate that facet tropism can contribute to disc herniation and changes in intradiscal pressure, potentially exacerbating disc degeneration due to altered force distribution and increased mechanical stress. Cite this article: Bone Joint Res 2024;13(9):452–461

The management of discogenic pain continues to be controversial. The results for operative and non-operative management are variable. This study aims to look at the results of interbody fusion versus dynamic stabilisation in patients with discogenic pain. Diagnosis was made by use of MRI and provocative discography. All patients had pre-operative Visual Analogue Scores and Oswestry Disability Index scores. Patients were then assessed in the post-operative period at 6 months, 1 year and 2 years. Case matched series with 19 patients in each group with a mean follow-up of 24 months. In comparison of both techniques there were no statistically significant differences but the dynamic stabilisation group had improved outcomes with both measures. The results did raise some further issues, as several patients in each group were either worse or had no significant improvement following surgery. In conclusion this paper raises concerns regarding the use of surgery for patients with discogenic pain. If surgery is however considered, dynamic stabilisation is a valid alternative to interbody fusion

To assess the effectiveness of dynamic stabilisation as a treatment for discogenic pain compared to standard treatment of interbody fusion. All patients were referred for a 2 year back-pain management programme. Patients with continued pain following conservative treatment underwent discography & MRI. Patients with painful degenerate discs on the above investigations were selected. Patients underwent interbody fusion (PLIF/TLIF) or dynamic stabilisation. Mean follow-up was 24 months with a minimum follow-up of 12 months. All patients had pre-operative ODI and VAS scores. Patients were then sent further questionnaires at 6 month intervals. The mean improvement in ODI following dynamic stabilisation was 20% (-20% → 56%), the mean improvement in the pain score was 2.4 (0→8). The mean improvement in ODI following interbody fusion was 11% (-14%→48%), the mean improvement in the pain score was 2.6 (-4→9). 10 patients in the dynamic stabilisation group had a greater than 20% improvement in ODI, 7 patients in the interbody fusion group had similar results. The above results demonstrate that dynamic stabilisation is at least as effective at treating discogenic pain as interbody fusion. The results however do question the validity of either interbody fusion (PLIF/TLIF) or dynamic stabilisation in the management of discogenic pain

Objective. To assess the effectiveness of dynamic stabilisation as a treatment for discogenic pain compared to standard treatment of interbody fusion. Study Design & Subjects. All patients were referred for a 2 year back-pain management programme. Patients with continued pain following conservative treatment underwent discography & MRI. Patients with painful degenerate discs on the above investigations were selected. Patients underwent interbody fusion (PLIF/TLIF) or dynamic stabilisation. Mean follow-up was 24 months with a minimum follow-up of 12 months. Outcome Measures. All patients had pre-operative ODI and VAS scores. Patients were then sent further questionnaires at 6 month intervals. Results. The mean improvement in ODI following dynamic stabilisation was 20% (-20% → 56%), the mean improvement in the pain score was 2.4 (0→8). The mean improvement in ODI following interbody fusion was 11% (-14%→48%), the mean improvement in the pain score was 2.6 (-4→9). 10 patients in the dynamic stabilisation group had a greater than 20% improvement in ODI, 7 patients in the interbody fusion group had similar results. Conclusion. The above results demonstrate that dynamic stabilisation is at least as effective at treating discogenic pain as interbody fusion. The results however do question the validity of either interbody fusion (PLIF/TLIF) or dynamic stabilisation in the management of discogenic pain

Introduction: Recent cadaveric studies have identified neovascularisation and neoneuralisation as probable mechanisms in the causation of discogenic pain. Calcium pyrophosphate deposits have been observed in discs in several studies. Their significance in the causation of discogenic pain is unclear. Direct correlation between the pain site and histological features can be verified by aware state endoscopic visualisation. Aim and Objectives: The study aims to examine and correlate the presence of neovascularisation, crystalline pyrophosphate deposits in the disc, and discogenic pain by spinal probing and discography under endoscopic visualisation. Material and Methods: Tissue removed from intervertebral discs of 224 patients during surgery was examined directly, and polarised microscopy was used to identify the presence of calcium pyrophosphate and neovascularisation. Their presence was correlated to diagnostic provocative findings of spinal probing and discography and intradiscal distortion during aware state endoscopy. Results: Calcium Pyrophosphate: Twenty out of 224 patients (9%) demonstrated calcium pyrophosphate in the discs. Fourteen had pain reproduced on probing or discography. Thirteen out of 20 patients (65%) had either an annular collection or leak at the index level. 6 had an extradiscal cause of pain. One hundred percent of the patients with annular collections or leaks had pain on spinal probing or discography. Sixteen patients with pyrophosphate deposits did not have neovascularisation. Neovascularisation: Thirty seven out of 224 patients (16.5%) showed neovascularisation in the disc. Four discs had crystalline pyrophosphate deposits. Thirty three out of 37 (90%) had pain on probing and/or discography. Out of four patients who had no pain on probing or discography, two had demonstrated tears during previous discographic procedures which were treated with laser annealing. These patients had disc bulges and compressive radiculopathy. Conclusion: The presence of pyrophosphate in the disc without a tear or leak does not directly render them tender to provocation. The presence of pyrophosphate is not correlated to neovascularisation. Annular tears or leaks are not directly correlated to the presence of pyrophosphates. There is a high correlation between pain provocation and neovascularisation

Anterior lumbar interbody fusion (ALIF) is an accepted surgical treatment for disabling discogenic pain. Additional posterior fixation has been advocated. This is a prospective clinic al study evaluating a stand-alone anterior fusion cage with an integrated titanium plate and four divergent locking screws. Patients who had failed conservative management for lumbar discogenic pain were recruited into the study. All underwent diagnostic discography. Surgery was performed through an anterior retro-peritoneal approach. The fusion cage was packed with autogenous bone graft. Outcome measures included: Visual Analogue Scores (VAS), Oswestry Disability Index (ODI) and SF-36 data. Fine-cut CT was performed at one and two years post-operatively. Fusion was defined as continuous bony trabeculae joining the vertebral bodies. Fifty levels were operated on in 39 patients with a mean age of 40.8 years (22–55). The mean operative time was less than 120 minutes, and mean blood loss less than 100 mls. Radiographic fusion at one year was 78% and 100% at two years. Two year mean VAS sc ores for back pain improved from 7.0 to 3.7 (p< 0.01) and for leg pain from 6.1 to 3.1 (p< 0.01). The mean ODI scores decreased from 50.7 to 31.7 (p< 0.01), and SF-36 (PCS) scores increased from 28.4 to 37.5 (p< 0.01). There were no major complications and no patients have required supplementary posterior fixation. This technique is safe and is as effective as 360° fusion in achieving fusion in the management of discogenic back pain over one and two levels. This technique has the advantage of avoiding the morbidity associated with additional posterior fixation

Objectives: To examine and correlate the presence of neovascularisation, crystalline pyrophosphate deposits and other hisotological features in the disc and discogenic pain established by spinal probing and discography under aware state endoscopic visualisation. Design: Tissue removed from intervertebral discs of 224 patients during surgery were examined by direct and polarised microscopy to identify the presence of calcium pyrophosphate and neovascularisation. Material and Methods: Histology was correlated to the diagnostic provocative findings of spinal probing and discography, discal palpation during aware state endoscopy. Results:Calcium Pyrophosphate: 20/224 (9%) patients demonstrated calcium pyrophosphate in the discs. Fourteen had pain reproduced on probing or discography; 13/20 (65%) of patients had either an annular collection or leak at the index level; 6/20 had an extradiscal cause of pain. Neovascularisation: Thirty-seven out of 224 (16.5%) patients showed neovascularisation in the disc; four discs had crystalline pyrophosphate deposits; 33/37 (90%) had pain on probing and/or discography. Conclusion: The presence of pyrophosphate in a disc without a tear or leak is not associated with annular tenderness. The presence of pyrophosphates in radial tears or leaks is associated with annular tenderness. Annular tears or leaks are not directly correlated to the presence of pyrophosphates. There is a high correlation between pain provocation and neovascularisation

Summary. Cytokines produced within the degenerate disc induce expression of neurotrophic factors and pain related peptides which could be important in nerve ingrowth and pain sensitisation leading to low back pain. The intervertebral disc (IVD) is considered the largest aneural and avascular structure within the human body, yet during degeneration vascularisation of the IVD is seen to be accompanied by nociceptive nerves. Low back pain is a highly debilitating condition affecting around 80% of the population, 40% of which are attributed to IVD degeneration. Discogenic pain was largely thought to be a result of irritation and compression of the nerve root, yet recent data suggests that pain may be attributed to the sensitisation of sensory nerves by the synthesis of pain related peptides, calcitonin gene related peptide (CGRP) and substance P. It is known that cytokines and chemokines produced by nucleus pulposus cells elicit various effects including the production of matrix degrading enzymes, and decreased matrix molecules. Here, we investigate the hypothesis that cytokines regulate both neurotrophic factor and pain related peptide synthesis within nucleus pulposus and nerve cells which may elicit algesic effects. Real-Time PCR was performed to investigate gene expression of the neurotrophic factors NGF, BDNF, NT3 and their receptors Trk A, B and C along with Substance P and CGRP on directly extracted RNA from human NP cells and NP cells cultured in alginate for 2 weeks prior to treatment for 48hours with IL-1, IL-6 or TNFα at 0–100ng/mL. Similarly SH-SY5Y neuroblastoma cells were differentiated in retinoic acid for 7 days prior to stimulation with IL-1, IL-6 or TNFα at 0ng/mL and 10ng/mL for 48hours. Immunohistochemistry was used to localise neurotrophic factor receptors Trk A, B and C in both degenerate discs and neuronal cells. NGF expression was present in normal and degenerate disc samples, however only degenerate discs expressed the high affinity receptor TrkA. Similarly Trk B was present in 22% of normal samples increasing to 100% expression within degenerate disc samples. All cytokines increased expression of NGF in NP cells (P≤0.05). TNFα also increased BDNF significantly, whereas no significant affects were seen in NT3 expression in NP cells. Trk B expression was significantly increased by IL-1 and TNFα treatment of NP cells. Conversely Trk C was down regulated by IL-6. Substance P was significantly increased by IL-1 and TNFα treatments whilst IL-6 and TNFα increased CGRP expression in NP cells. In SH-SY5Y cells, IL-1 significantly increased BDNF whilst IL-6 and TNFα failed to induce significant differences in neurotrophic factors. All cytokines increased Trk expression in the nerve cell line; however this failed to reach significance. Immunohistochemistry confirmed the presence of Trk receptors within the neuronal cell line. Here we have demonstrated that a number of cytokines known to be up regulated during disc degeneration and disc prolapse, induce expression of various neurotrophic factors, their receptors and pain related peptides within human NP cells, as well as SH-SY5Y cells. This data suggests that the presence and production of cytokines within the degenerate disc may be responsible for nerve ingrowth and sensitisation of nerves which may result in discogenic pain

Persistent back pain in the presence of an intact posterior fusion is commonly seen and is often regarded as being psychogenic in origin. This paper discusses five patients, all of whom were chronically disabled by such pain; all five had a confirmed posterior and/or lateral fusion. In each case lateral discography identified the disc within the fused segment as the source of symptoms and pain relief was obtained with an anterior interbody fusion. This source of pain should be considered as a possibility in similar cases of failed back surgery.

Purpose: The purpose of this prospective study is to evaluate the benefits of this treatment for discogenic back pain. Method: Thirty-four patients with chronic discogenic back pain underwent this therapy. All the patients had a failed trial of conservative treatment. Patients with a positive provocative discogram were selected for intra-discal electrothermal therapy (IDET). The outcome is assessed using a SF 36 questionnaire filled in pre-procedure and then at three, six, twelve and eighteen months and two years post-operatively. Results: The mean age group of the patients was 37 years (range 15–58 years). All the patients had a minimum follow up of 12 months (range 6–2 years). Out of the 34 patients 5(14%) had no improvement and had to undergo an interbody fusion following IDET. No patient developed any neurological complications. At a minimum of one year follow-up 56% patients had improvement in physical function scores and 52% had improvement in pain scores as per the SF 36. Conclusion: Thus IDET appears to be an effective procedure in the short-term relief of discogenic back pain in patients who otherwise might be candidates for fusion

The afferent pathways of discogenic low-back pain have not been fully investigated. We hypothesised that this pain was transmitted mainly by sympathetic afferent fibres in the L2 nerve root, and in 33 patients we used selective local anaesthesia of this nerve. Low-back pain disappeared or significantly decreased in all patients after the injection. Needle insertion provoked pain which radiated to the low back in 23 patients and the area of skin hypoalgesia produced included the area of pre-existing pain in all but one. None of the nine patients with related sciatica had relief of that component of their symptoms. Our findings show that the main afferent pathways of pain from the lower intervertebral discs are through the L2 spinal nerve root, presumably via sympathetic afferents from the sinuvertebral nerves. Discogenic low-back pain should be regarded as a visceral pain in respect of its neural pathways. Infiltration of the L2 nerve is a useful diagnostic test and also has some therapeutic value

Study Design: A retrospective study of the clinical outcome of patients with lumbar discogenic pain with Modic changes on MRI prior to intradiscal steroid injection. Objectives: To determine whether the clinical outcome of patients with discogenic back pain who underwent intradiscal steroid injection could be predicted from MRI Modic changes. Methods: The pre-operative scans were studied by two senior spinal surgeons. The lumbar vertebral end-plate changes were then classified according to the method described by Modic. The intra- and inter-observer ratings were satisfactory. Subjects: 40 patients with discogenic back pain were recruited in this study. The mean age was 43.6 years (23 to 72 years). The male to female ratio was 1 to 1. Outcome Measures: The clinical outcomes at six months post-intradiscal steroid injection were correlated with the Modic changes. The clinical outcomes were assessed using visual analogue scores for back pain as well as Oswestry disability index (ODI). At least a 2-point improvement in visual analogue score and a 20-point improvement in ODI were required to indicate significant symptomatic relief. Results: We found that in those patients without Modic changes there was improvement of the low back pain in 9% (1/11). In those with Modic I changes there were significant relief in 64% (9/14), moderate relief in 29% (4/14) and no relief in 7% (1/14). In those with Modic II changes there were significant relief in 27% (4/15), moderate relief in 27% (4/15) and no relief in 47% (7/15). There were no cases with Modic III changes. Conclusions: Previous studies on intradiscal steroid injections have shown variable results. Two prospective double-blind clinical trials, using intradiscal steroids, identified no significant benefit or improvement in the clinical outcome. Our results however suggest that patients with Modic I changes on MRI are most likely to benefit from intradiscal steroid injection in the short term

Purpose of Study. To review the medium-term results of the Dynesys stabilisation system used in 113 consecutive patients with discogenic back pain. Methods and Results. 113 consecutive patients with discogenic back pain were treated with Dynesys as the sole intervention. Inclusion criteria included mri proven disc degeneration and an improvement in symptoms following an injection into the disc with local anaesthetic and steroid (spinal disc probing). Patients were followed up for a minimum of 5 years, with outcome measures including SF-36, Oswestry disability index (ODI) and visual pain analogue scores (VPAS). Additional factors reviewed included previous spinal operations, complications, loosening and revision rates with subsequent outcomes. Mean pre-operative ODI was 49.5, SF-36 was 37.6 and VPAS back pain was 60.9. At one year post operatively, these scores were 36.9, 49.4 and 39.8, at five years follow up, the scores were 33.3, 51.8 and 40.1 respectively. We note wide variations in our results. Several significant factors appear to contribute to the outcome of surgery. These include undergoing surgery before the age of 43, no more than 2-level disc degeneration, leg pain less than VPAS 4, and no previous spinal surgery. 19 patients had screw loosening evident on plain film x-rays (4 requiring removal), and 2 patients had screw breakages. 19 patients had implant removal for failure and 2 patients went on to have a fusion procedure. Discussion. Dynesys has a role in the treatment of discogenic back pain. Patient selection is important to outcome and we have identified several pre-operative factors that increase the likelihood of success. The effects are present at 1 year postoperatively and are maintained for at least 5 years. There is a significant screw loosening rate and our series had a 17% revision rate

Introduction: Surgical management of discogenic low back pain has in the past been limited to spinal fusion. Recently disc arthroplasty has become available. The rationale for disc arthroplasty is that it may avoid the long term consequences of adjacent segment degeneration. Avoidance of long term consequences is of no value unless the short term outcome is at least equivalent between fusion and arthroplasty.

Methods: A series of patients with chronic low back pain with concordant lumbar discography and a negative control discogram were surgically treated. Prospective data was collected preoperatively and at regular intervals during the post-operative period for a historical series of combined anterior and posterior lumbar fusion (n =24), a series of SB Charité (DePuy Spine) disc replacements (n =23), and recently, a series of Maverick (Medtronic Sofamor Danek) artificial disc replacements (n =9). Self assessed outcome measures of visual analog pain score (VAS), Low Back Outcome Score (LBOS) and SF12 general health data was obtained at intervals after the surgery. This paper presents the results of the consecutive series that have a minimum of 3 months follow-up.

Results: The data for the two groups of arthroplasty was combined and compared to the fusion group. The mean age for the fusion group was 37.6 years and the mean age for the arthroplasty group was 38.6 years. There were 5 compensation cases (20.8 %) in the fusion group and 5 cases (15.6 %) in the arthroplasty group. Both groups had 69% male patients. The mean VAS dropped from 7.5 to 3.7 (p< 0.001) in the arthroplasty group and from 7.3 to 3.5 (p< 0.001) in the fusion group. The mean LBOS improved from 22.0 to 36.5 (p< 0.001) in the arthroplasty group and from 19.6 to 37.1 (p< 0.001) in the fusion group.

There was no apparent difference between the clinical improvement in VAS and LBOS (p=0.91 and p=0.45 respectively) for each group. Analysis of the power of the comparison showed an 86% power for comparison of VAS improvement using a clinically important difference (delta) of 1 VAS point and there was 98% power for the LBOS improvement comparison using a clinically important difference (delta) of 10 LBOS points. Complications appeared higher in the arthroplasty group with foraminal encroachment requiring revision in 3 cases and one case of polyethylene failure in the Charité group at 3 years. This case occurred with an 8mm polyethylene insert (since removed from inventory by the manufacturer)

Discussion: Disc arthroplasty in the lumbar spine appears to offer similar short term results to that of fusion for chronic low back pain. The surgical complication rate may be higher in the early learning curve of the procedure.

Intervertebral disc (IVD) degeneration is a pathological process often associated with chronic back pain and considered a leading cause of disability worldwide. 1. During degeneration, progressive structural and biochemical changes occur, leading to blood vessel and nerve ingrowth and promoting discogenic pain. 2. In the last decades, several cytokines have been applied to IVD cells in vitro to investigate the degenerative cascade. Particularly, IL-10 and IL-4 have been predicted as important anabolic factors in the IVD according to a regulatory network model based in silico approach. 3. Thus, we aim to investigate the potential presence and anabolic effect of IL-10 and IL-4 in human NP cells (in vitro) and explants (ex vivo) under hypoxia (5% O2) after a catabolic induction. Primary human NP cells were expanded, encapsulated in 1.2% alginate beads (4 × 106 cells/ml) and cultured for two weeks in 3D for phenotype recovery while human NP explants were cultured for five days. Afterwards, both alginate and explant cultures were i) cultured for two days and subsequently treated with 10 ng/ml IL-10 or IL-4 (single treatments) or ii) stimulated with 0.1 ng/ml IL-1β for two days and subsequently treated with 10 ng/ml IL-10 or IL-4 (combined treatments). The presence of IL-4 receptor, IL-4 and IL-10 was confirmed in human intact NP tissue (Fig 1). Additionally, IL-4 single and combined treatments induced a significant increase of proinflammatory protein secretion in vitro (Fig. 2A-C) and ex vivo (Fig. 2D and E). In contrast, no significant differences were observed in the secretome between IL-10 single and combined treatments compared to control group. Overall, IL-4 containing treatments promote human NP cell and explant catabolism in contrast to previously reported IL-4 anti-inflammatory performance. 4. Thus, a possible pleiotropic effect of IL-4 could occur depending on the IVD culture and environmental condition. Acknowledgements: This project was supported by the Marie Skłodowska Curie International Training Network “disc4all” under the grant agreement #955735. For any figures and tables, please contact the authors directly

Lumbar fusion remains the gold standard for the treatment of discogenic back pain. Total disc replacement has fallen out of favor in many institutions. Other motion preservation alternatives, such as nucleus replacement, have had limited success and none are commercially available at this time. Two prospective, nonrandomized multicenter studies of lumbar disc nucleus replacement using the PerQdisc 2.0 nucleus replacement device in patients with lumbar discogenic back pain. Early clinical results are presented. A total of 16 patients from 4 international sites (Germany, Paraguay, Canada and Belgium) were enrolled in the trial between May 2019 and February 2021. Data collection points include baseline and postoperatively at 1, 2, 6, and 12 months. Clinical outcome measures were obtained from the Visual Analog Scale (VAS) for back and leg pain, Oswestry Disability Index (ODI), SF-12V2, Analgesic Score (AS), and radiographic assessments. Prospectively gathered data on patient reported outcomes, neurological outcome, surgical results, radiological analysis, and any adverse events. 16 patients had successful implantation of the device. There have been no expulsions of the device. Early postoperative results are available in 13/16 patients at 6 months and 11/16 patients at 12 months. There have been 4 (25%) revision surgeries 3–12 months post implantation between the two trials. 12 of 13 (92%) patients had Minimal Clinically Important Difference (MCID) in ODI at 6 months and 10 of 11 (91%) at 12 months. Mean decrease in ODI from baseline to 12 months was 44.8. At 12 months 8 (73%) patients are not taking pain medication, 1 (9%) patient is taking a narcotic for pain management. 73% of patients are working without restrictions at 12 months post implant. Early clinical and technical results are encouraging. Long term follow up is essential and is forthcoming. Additional patient recruitment and data points are ongoing. FDA/Drug Status Investigational/Not approved

Introduction: Lumbar total disc replacement (TDR) is intended to address discogenic pain and preserve functional motion between two vertebral bodies in patients with symptomatic degenerative disc disease. TDR may thus prevent long-term subsequent accelerated degeneration at adjacent disc levels. The ProDisc®-L TDR (Synthes Spine Company, L.P., West Chester, PA) was compared to circumferential spinal fusion for the treatment of discogenic pain at one vertebral level between L3-S1 and was found to be safe, effective, and superior to fusion in patients who meet the study inclusion criteria. However the safety and efficacy of lumbar TDR at two vertebral levels is still unproven. The purpose is to compare the safety and effectiveness of the ProDisc®-L TDR to circumferential spinal fusion for the treatment of discogenic pain at two vertebral levels between L3-S1. Methods: A prospective, randomized, multi-center, FDA-regulated IDE clinical trial was conducted at 16 sites, utilizing a 2:1 randomization ratio (ProDisc®-L: Fusion). Patients were assessed pre-operatively and post-operatively at 6 weeks, 3, 6, 12, 18, and 24 months post-surgery. Each evaluation included patient self-assessments, physical and neurological examinations, and radiographic evaluation. Results: 237 patients were treated on protocol. The patient follow-up rate was 89.6% at 24 months. Overall patient demographics showed no statistically significant differences between treatment groups in age, gender, race, smoking status, height, weight, body mass index (BMI), baseline Oswestry Low Back Pain Disability Questionnaire [Oswestry Disability Index (ODI)], or prior surgical treatment. Intra-operative data showed the ProDisc®-L group was significantly lower with regard to intra-operative time (ProDisc®-L = 132 min (range 66 – 430) min; Fusion = 275 min (range 86– 515 min), p < 0.0001), estimated blood loss (ProDisc®-L = 250 ml (range 0 – 3000 ml); Fusion = 400 ml (range 0 – 2000 ml, p = 0.0006) and hospital stay (ProDisc®-L = 4 days (range 1 – 10 days); Fusion = 5 days (range 2 – 14 days), p < 0.0001). At 24 months, 90.0% of ProDisc®-L and 86.7% of Fusion patients reported improvement in ODI from pre-operative levels and 73.3% of ProDisc®-L and 55.9% of Fusion patients met the 15 point ODI improvement criteria. Overall neurological success in the ProDisc®-L group was superior to the Fusion group (ProDisc®-L = 89.2%, Fusion = 77.9%; p = 0.0260). At all follow-up time points, the ProDisc®-L patients recorded SF-36 scores significantly higher than the Fusion group (p = 0.0523). The Visual Analog Scale (VAS) pain assessment showed statistically significant improvement from pre-operative scores regardless of treatment (p < 0.0001); at 24 months, the ProDisc®-L group showed significantly higher pain reduction than the Fusion group (p = 0.0466). VAS patient satisfaction at 24 months showed a statistically significant difference favoring ProDisc®-L patients over the Fusion group (p = 0.002). Radiographic range of motion was maintained within a normal functional range. Discussion: Currently the ProDisc®-L TDR is only FDA approved for single level use. However, in this study, it has been found to be effective for the treatment of discogenic pain at two vertebral levels. In properly chosen patients, ProDisc®-L has been shown to be superior to circumferential fusion at two levels by multiple clinical criteria

Aim: To investigate the use of the Graf Dynamic Stabilisation System for the treatment of multi-level discogenic pain associated with symptoms of ‘instability’. Introduction: Indications for the use of the Graf Ligament system remain controversial. There is a small group of patients who present with severely disabling pain with failed conservative treatment, of discogenic origin at more than one level, and associated with symptoms of so-called ‘instability’ (acute pain related to position and movement), for whom treatment is extremely difficult. Methods: Twenty-two consecutive adult patients of working age with this clinical picture, with discogenic pain at two or three levels confirmed by discography, were treated with the Graf Ligament System. They were prospectively studied, and reviewed by an independent assessor. Results: At an average of three year follow up, 50% had good or excellent results including return to work, 18% fair, and 32% were no better. None were worse. Correlation with pre-operative MRI findings and complications will be discussed. Conclusions: Whilst such dynamic systems may have a role in the treatment of discogenic pain, the success rate in this series does not justify its continued use for this indication without further research into the theoretical basis of the action of such dynamic stabilisation systems and the entry of all cases into prospective controlled trials

The anatomical studies, basic to our understanding of lumbar spine innervation through the sinu-vertebral nerves, are reviewed. Research in the 1980s suggested that pain sensation was conducted in part via the sympathetic system. These sensory pathways have now been clarified using sophisticated experimental and histochemical techniques confirming a dual pattern. One route enters the adjacent dorsal root segmentally, whereas the other supply is non-segmental ascending through the paravertebral sympathetic chain with re-entry through the thoracolumbar white rami communicantes. Sensory nerve endings in the degenerative lumbar disc penetrate deep into the disrupted nucleus pulposus, insensitive in the normal lumbar spine. Complex as well as free nerve endings would appear to contribute to pain transmission. The nature and mechanism of discogenic pain is still speculative but there is growing evidence to support a ‘visceral pain’ hypothesis, unique in the muscloskeletal system. This mechanism is open to ‘peripheral sensitisation’ and possibly ‘central sensitisation’ as a potential cause of chronic back pain

Objective: To report a randomised controlled trial (RCT) of the therapeutic efficacy of intradiscal steroid injection for the treatment of discogenic back pain after two years. Introduction: Discography remains the main method to assess whether a degenerate disc is the source of back pain. The treatment of such discogenic pain is difficult. There is only one previous RCT of the use intradiscal steroids, but with a short follow-up. Patients and Methods: 120 consecutive patients with positive discography were randomised intra-operatively to receive an intradiscal injection of saline or 40mgs Depomedrone. Outcome was assessed using a back pain questionnaire at six weeks, three and six months, and at two years. Pain (using a visual analogue score), disability (the Oswestry Disability Index), and psychological status (DRAM score) were measured. The results were correlated with Modic changes and high intensity zones on MRI scan. Results: An initial improvement of back pain in the steroid group is not maintained at two years, with no statistical difference between the two groups. Correlation of the results with the MRI findings will be presented. Conclusion: This study demonstrates the need for long-term follow-up of such intradiscal therapeutic methods of treating discogenic pain

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

Intervertebral discs (IVDs) degeneration is one of the major causes of back pain. Upon degeneration, the IVDs tissue become inflamed, and this inflammatory microenvironment may cause discogenic pain. Cellular senescence is a state of stable cell cycle arrest in response to a variety of cellular stresses including oxidative stress and adverse load. The accumulation of senescent IVDs cells in the tissue suggest a crucial role in the initiation and development of painful IVD degeneration. Senescent cells secrete an array of cytokines, chemokines, growth factors, and proteases known as the senescence-associated secretory phenotype (SASP). The SASP promote matrix catabolism and inflammation in IVDs thereby accelerating the process of degeneration. In this study, we quantified the level of senescence in degenerate and non-degenerate IVDs and we evaluated the potential of two natural compounds to remove senescent cells and promote overall matrix production of the remaining cells. Human IVDs were obtained from organ donors. Pellet or monolayer cultures were prepared from freshly isolated cells and cultured in the presence or absence of two natural compounds: Curcumin and its metabolite vanillin. Monolayer cultures were analyzed after four days and pellets after 21 days for the effect of senolysis. A cytotoxicity study was performed using Alamar blue assay. Following treatment, RNA was extracted, and gene expression of senescence and inflammatory markers was evaluated by real-time q-PCR using the comparative ΔΔCt method. Also, protein expression of p16, Ki-67 and Caspase-3 were evaluated in fixed pellets or monolayer cultures and total number of cells was counted on consecutive sections using DAPI and Hematoxylin. Proteoglycan content was evaluated using SafraninO staining or DMMB assay to measure sulfated glycosaminoglycan (sGAG) and antibodies were used to stain for collagen type II expression. We observed 40% higher level of senescent cells in degenerate compare to the non-degenerate discs form unrelated individuals and a 10% increase when we compare degenerate compare to the non-degenerate discs of the same individual. Using the optimal effective and safe doses, curcumin and vanillin cleared 15% of the senescent cells in monolayer and up to 80% in pellet cultures. Also, they increased the number of proliferating and apoptotic cells in both monolayer and pellets cultures. The increase in apoptotic cell number and caspase-3/7 activity was specific to degenerate cells. Following treatment, mRNA expression levels of SASP factors were decreased by four to 32-fold compared to the untreated groups. Senescent cell clearance decreased, protein expression of MMP-3 and −13 by 15 and 50% and proinflammatory cytokines levels of IL-1, IL-6 and IL-8 by 42, 63 and 58 %. Overall matrix content was increased following treatment as validated by an increase in proteoglycan content in pellet cultures and surrounding culture media. This work identifies novel senolytic drugs for the treatment of IVD degeneration. Senolytic drugs could provide therapeutic interventions that ultimately, decrease pain and provide a better quality of life of patients living with IVDs degeneration and low back pain

Introduction The aim of the study was to determine the prevalence of different causes of neck pain in a private practice clinic by a retrospective audit of records. Methods The study included all consecutive patients attending a private spine pain clinic in the state of Washington, USA, seen between January 2003 and January 2005, in whom a diagnosis of neck pain was made. The records of all patients were examined to determine the prevalence of various diagnostic entities determined by history, examination, and invasive tests such as controlled diagnostic blocks and provocation discography. Using different denominators, the prevalence of various conditions was determined in all patients who presented with neck pain, in patients in whom investigations were undertaken, and in patients who completed investigations. Results A large proportion of patients (35%) did not pursue investigations, which diluted the crude prevalence of various conditions. A further 17% deferred completing investigations. Amongst the 48% of patients who completed investigations, the prevalence of zygapophysial joint pain was 55%, discogenic pain was 16%, and lateral atlanto-axial joint pain was 9%. A diagnosis remained elusive in only 17% of those patients who completed investigations. Discussion In a private practice setting, a patho-anatomic diagnosis for chronic neck pain can be established in over 80% of patients, provided that appropriate investigations are undertaken. The prevalence of cervical zygapophysial joint pain encountered in the present study corroborates the prevalence rates established in academic studies. The observed prevalence of discogenic pain is probably an underestimate because not all eligible patients underwent discography

Introduction: The role of discography before lumbar fusion had been discussed in the literature. No study discussed its role before total lumbar disc replacement (TDR). Degenerate discs are not necessarily painful, even if they show Modic changes or HIZ. Moreover, discogenic pain might not be the predominant element in the patient’s symptoms and most of the back pain could be originating form other spinal structures. The aim of our prospective cohort study is to show whether or not provocative discography plays any significant role before TDR and to define that role. Methods: Twenty patients (11 females and 9 males) had “Prodisc” TDR. Mean age = 38.5 years (range: 20–56). All patients had mechanical low back pain with degenerative disc disease diagnosed by MRI scan. 65% (N=13) had radicular pain as well. The mean duration of back pain = 66.9 months (range: 16–240). Pre-operative provocative discography was performed in all cases. The clinical outcome was assessed by comparing the preoperative SF36-v2, ODI and VAS scores’ means to the 3, 6, 12 and 24 months post-operative ones and also comparing the last follow up SF36-v2 scores with the, age and sex adjusted, normative data for the general UK population obtained from the Oxford Healthy Lifestyle Survey III. All patients were followed up for a minimum of 2 years. Results: 90% (N=18) experienced a clinically significant improvement of their back pain (MCID for SF36-v2 scales=1SD, ODI=10 points and VAS=2 points). There has been a statistically significant improvement in the follow up outcome measures (P< 0.05) at 3, 6, 12 and 24 mths. SF 36-v2 scores of 15% of patients (N=3) reached or exceeded the normative values for the UK general population. Conclusion: Provocative discography is an important diagnostic tool before TDR. It is the only dynamic method to diagnose discogenic pain and is indispensable to exclude the painless levels in cases of multilevel disc degeneration

Disc degeneration in the human spine is characterised by progressive fraying and dehydration of the nucleus pulposus associated with formation of clefts within the annulus fibrosus. These have been classified on the basis of autopsy studies into radiating, circumferential and peripheral tears (rim lesions). Outer tears allow neovascularisation of the outer third of the annulus fibrosus and ingrowth of nerve fibres. Correlation with discographic findings had suggested the relevance of peripheral defects in the pathogenesis of discogenic pain. Outer annular tears are likely to be linked to tensile strain onto the collagen fibres and, therefore, may have a mechanical aetiology. In the animal model, peripheral tears of the outer annulus were proven to induce degenerative changes within the inner annulus and the nucleus pulposus. The increased understanding of the role of discrete peripheral defects of the annulus in discogenic pain may support the potential therapeutic effects of thermal treatment using radiofrequency waves and specially designed probes. At present, however, no in vivo studies have been able to demonstrate healing of outer annulus defects and reversibility of mechanical lesions to the intervertebral discs by thermal therapy. While it is highly likely that discrete defects of the outer annulus may be responsible for acute episodes of self-limiting low back pain, it is unclear if annular pathology may be as relevant for chronic disabling back pain. Recent studies using discography and other semi-invasive techniques have suggested that the main discriminating factors between benign, self limiting and chronic disabling back pain may not be anatomical but psycho-social. The challenge remains, in the 21st Century as in the past, to devise appropriate strategies that may lessen the socio-economic burden of back pain. Surgery, however, is highly unlikely to play a significant role in the future

Introduction: Biacuplasty is an innovative intervention for the treatment of discogenic pain. It involves inserting electrodes bilaterally into the posterolateral corner of the anulus fibrosus. Radiofrequency current is passed between the electrodes, but each electrode is water-cooled. This prevents coagulation occurring around the surface of the electrode, which allows a three-dimensional lesion to develop between the electrodes. Theoretically this lesion would seal radial and circumferential fissures, and coagulate nerve endings throughout the posterior anulus. Methods: As part of a multi-centre, limited release of biacuplasty, a prospective audit of outcomes was undertaken in 8 patients with chronic low back pain, in whom discography reproduced their pain and post-discography CT demonstrated a radial fissure. They were 6 men and 2 women, aged between 34 and 58 years, who had back pain for longer than 4 years. Four were still working but four were on workers compensation. At the time of writing, all patients had completed clinical assessments before treatment and at one, two, three, and six months after treatment, using a visual analogue scale for pain, and the Oswestry Disability Questionnaire (ODQ) and the SF36 for disability and function. Results: Performed under local anaesthesia, the procedure was painless, and took less than one hour to complete. No complications occurred, and no patient suffered any side-effects. Group pain scores (median; interquartile range) at inception (69; 53–78) improved significantly at one month (35; 11–65) (p = 0.05); deteriorated by three months (41; 14–72) (p = 0.14); but were stable at 6 motns (40; 22–69). Scores for disability (54; 42–67) and physical functioning (33; 13–48) improved (to 50; 29–62 and 50; 20–59, respectively) but did not achieve statistical significance. In categorical terms, however, four patients obtained no benefit, one patient obtained partial, but worthwhile, reduction in pain, but three patients achieved greater than 50% relief of pain at three months, and four did so at 6 months. Reduction in pain was corroborated by a decrease in disability on the ODQ by 11 (5,2) points at three months, and 10 (−4, 15) points at 6 months; and increases in physical functioning on the SF36 by 15 (6,2) points at three months, and 5 (2,2) points at six months. Discussion: These results in Australian patients echo those reported in one of the US arms of the study, in which 8 of 13 patients reduced their pain scores by at least 30 points. Attractive about this new procedure was its ease of execution and painlessness. Although the success rate is modest, this procedure could emerge as an entertainable option for the management of discogenic pain, if its effectiveness can be corroborated in a larger sample and for a longer time

Background. Fissures in the anulus fibrosus are common in disc degeneration, and are associated with discogenic pain. We hypothesise that anulus fissures are conducive to the ingrowth of blood vessels and nerves. Purpose. To investigate the mechanical and chemical micro-environment of anulus fissures. Methods. Six thoracolumbar spine specimens, comprising three vertebrae and two discs, were obtained from cadavers aged 68-83 yr. Discs were injected with blue dye to reveal the location of complete anulus fissures. Each specimen was then subjected to 1000 N compression, while intradiscal compressive stress was investigated by pulling a miniature pressure transducer through the disc, in planes likely to cross the anulus fissures. Some additional disc fragments were removed at surgery from patients with discogenic back pain, and examined histologically to gauge the concentration of collagen and proteoglycans within radial fissures, using a qualitative method. Results. Stress profiles were obtained perpendicular to major anulus fissures in seven discs. A marked local reduction in vertically-acting compressive stress usually coincided with fissure location (confirmed at dissection), and stress reductions were inversely proportional to average pressure in the nucleus (r. 2. =0.56, p<0.05). Surgical disc samples showed local depletion of proteoglycans around the margins of radial and circumferential fissures, leaving a collagen-rich scaffold of the type known to support nerve and blood vessel growth. Conclusion. Compressive stresses within anulus fissures are reduced most when the disc nucleus is decompressed, because this facilitates internal displacements of disrupted tissue. Anulus fissures provide a micro-environment that is mechanically and chemically conducive to the ingrowth of blood vessels and nerves

Introduction. Lumbar spinal pain can be a consequence of discogenic pain. After failure of conservative management, lumbar fusions are popular and considered the gold standard. However, these techniques are associated with significant morbidity. A percutaneous trans-sacral technique may address these for L4/L5 and/or L5/S1 alone spinal fusions. Our unit has adopted this technique and presents our initial experience of 51 patients and preliminary results. Method. Patients with a confirmed clinical and radiological evidence of degenerate intervertebral disc with or without prior surgical intervention were selected. Patients with a history of pelvic surgery/radiotherapy were excluded. Data was collected prospectively using the Global Patient Outcome Scoring System and Oswestry Disability Index (ODI) scores at clinical follow-up. Results. 51 patients received the procedure and 30 achieving a minimum of 6 months follow-up. Patients had a median age of 46(range 20-78) and included 19 male and 32 females with on average 40 months of pain. The mean ODI score improved after surgery from pre-operative levels 52.9(SEM 3.0) to 6 month scores of 38.4(SEM 3.9), t(29)=4.2, p<0.0002 . This difference remained statistically significant at 12 month follow-up with a mean ODI scores 34.3 (SEM 5.2), t(18)=4.37, P<0.0004 (Mean difference of 21.1 SEM 4.8). A sub-analysis of confounding factors identified patients with previous surgery, claiming state benefits, pursuing litigation, mainly leg pain and requiring pedicular fusion failed to achieve statistical significance. Patients receiving a 360 degree fusion with facet screws alone improved sooner and achieving a mean difference in ODI score of 27.6(SEM 8.2). Conclusion. Our initial results confirm this to be an effective alternative treatment modality for lumbar spine fusion in the management of primary discogenic back pain. Patients receiving 360 degree fusion and not claiming state benefits or pursuing litigation appear to have a better outcome

Lumbar Total Disc Replacement (LTDR) is an alternative to fusion for the surgical management of discogenic back pain not responding to conservative therapy. Theoretical advantages include preservation of motion and possible reduction in adjacent segment degeneration. The aim is to review the early results of LTDR in an Auckland private practice. A prospective study was carried out on 32 consecutive patients treated with LTDR. Discogenic back pain was confirmed with plain radiographs, MRI and CT lumbar discogram. The Charité TDR was used in 19 patients and A-MAV in 13. Follow-up was to a minimum of two years. Patients completed Modified Roland Questionnaires (MRQ), Visual Analogue Pain Scores (VAPS) and Lower Back Outcome Scores (LBOS) pre and post-operatively. Patients’ notes and radiographs were reviewed. All outcomes measures improved significantly. Mean MRQ scores improved from 14.2 to 6.4 and 4.8 (at one and two years respectively). Mean VAPS improved from 5.3 to 2.5 and 1.7. Mean LBOS improved from 33 to 52 and 57. 84% had radiographic evidence of motion at the level of the prosthesis. There were four major complications. A retroperitoneal haematoma, an incisional hernia, a ureteric stenosis and subsidence of the prosthesis each occurred in separate patients. These all occurred in the first ten patients of the study and were related to the approach. There were no major thrombo-embolic or infective complications and no revision surgery was required. LTDR is a safe and effective surgical treatment of discogenic back pain. There is however, a steep learning curve with regard to the approach and a higher risk of complications during this time. Initial results are encouraging, but longer term follow-up needs to be performed

Cite this article: Bone Joint Res 2023;12(3):199–201.

Purpose of this study is to compare the reduction of discogenic pain associated with disk herniation in two groups. Group A (31 patients) with lumbago, with/ without sciatica, with no neurologic deficit followed consernative treatment (antiflammatory drugs, physiotherapies) and the group B (31 patients) with the same symptoms submitted in percutaneous disc decompression after six weeks consernative treatment with poor results. Follow up had a period of six months, one year and two years in two groups. All patients in both groups evaluated clinically and the symptoms registrated in special protocol that included pain distribution, sensation, muscle strength and reflections (ahilleus and patellar). All of them submitted in X-ray and MRI so that the two groups have the presuppositions for percutaneous decompression of disc (absense of a free, non-contained or sequestered fragment, remained disc height > 50%, no neurologic deficit, no arthritis in facets). An AVS scale on a questionnaire adapted to Greek population helped assessing pain relief degree, life quality and mobility improvement. The method that we used is t-test for small independent patterns. We found a statisticasignificant decrease on terms of pain relief, mobility and life improvement during the one and two years follow-up in group B which submitted in percutaneus decompression of intervertebral disks comparetively with A

Introduction. Risk factors for disc degeneration depend on how the condition is defined, i.e. on the specific disc degeneration “phenotype”. We present evidence that there are two major and largely-distinct types of disc degeneration. Methods. The relevant research literature was reviewed and re-interpreted. Evidence. In the . upper. lumbar and thoracic spine, disc degeneration is closely associated with endplate defects and with inflammatory changes in the vertebral bodies. It has a relatively high heritability (i.e. a strong genetic influence), and its incidence does not increase markedly with age. In the . lower. lumbar spine, disc degeneration is closely associated with radial fissures and nucleus herniation. Here it has a relatively low heritability, and a correspondingly stronger association with mechanical loading, and its incidence increases steadily throughout life. Mechanical experiments on cadaveric spines show that endplate fracture and nucleus herniation can be caused by compressive loading, and by bending combined with compression, respectively. Both lesions cause an immediate decompression of the nucleus, so that it becomes difficult to create subsequently the other lesion in the same disc. This suggests distinct phenotypes. Interpretation. The two types of disc degeneration are not entirely distinct, because disc herniation sometimes occurs at upper lumbar levels. Nevertheless, it may be useful to recognise two phenotypes when it comes to explaining and treating discogenic pain. Some other common disc changes (such as water loss and bulging) are attributable to ageing rather than degeneration, whereas disc narrowing probably represents a final common pathway for both types of disc degeneration. Conflicts of Interest. None. Source of Funding. None. This abstract has not been previously published in whole or in part; nor has it been presented previously at a national meeting

Introduction. Discogenic pain is associated with ingrowth of blood vessels and nerves, but uncertainty over the extent of ingrowth is hindering development of appropriate treatments. We hypothesise that adult human annulus fibrosus is such a dense crosslinked tissue that ingrowth via the annulus is confined to a) peripheral regions, and b) fissures extending into the annulus. Methods. Disc tissue was examined from 61 patients (aged 37–75 yrs) undergoing surgery for disc herniation, degeneration or scoliosis. 5 µm sections were stained with H&E to identify structures and tissue types. 30 µm frozen sections were examined using confocal microscopy, following immunostaining for CD31 (an endothelial cell marker), PGP 9.5 and Substance P (general and nociceptive nerve markers, respectively). Fluorescent tags were attached to the antibodies. ‘Volocity’ software was used to calculate numbers and total cross-sectional area of labelled structures, and to measure their distance from the nearest free surface (disc periphery, or annulus fissure). Results. Maximum penetration of blood vessels and nerves from the peripheral annulus was 4,800 µm and 2,200 µm respectively. Maximum distance of nerves and vessels from the nearest free surface was 236 µm and 888 µm. Substance P (but not PGP 9.5) was co-localised with blood vessels, and both number and area of Substance P-stained structures were inversely correlated with grade of disc degeneration. Interpretation. Thick sections and fluorescent markers can show reliably where labelled structures are not present. Results therefore support our hypothesis: deep penetration of nerves into the human annulus occurs only if fissures are present. No conflicts of interest. No funding obtained. This abstract has not been previously published in whole or in part; nor has it been presented previously at a national meeting

Purposes. To develop disease-specific quality indicators for patients with low-back-pain presenting to Danish chiropractic clinics. Methods and results. A cross-disciplinary group of healthcare providers (the indicatorgroup) prioritized nine evidensbased indicators and standards in a systematic consensus process. A pilot test including 206 low-back-pain patients was carried out in eight chiropractic clinics. An audit meeting with the test-clinics was conducted after the test-period, and the indicatorgroup designed the final set of indicators. The indicator domains were: Anamnesis, test for discogenic back pain, neurology, radiology, classification, exercise therapy, outcome assessment (process and result) and re-evaluation. Two indicators: outcome assessment as a process-indicator (standard ≥ 95 %, standard reached (95% CI): 95.8 % (91.6 – 98.3)) and outcome assessment as a result-indicator (standard ≥ 50 %, standard reached: 67.7 % (59.9 – 74.8)) met the standards set by the indicatorgroup. After evaluating the test-results the indicatorgroup decided to maintain all nine indicators, however, lowering the standards on anamnesis, discogenic back pain and classification. Conclusion. It was possible to identify the patient population and collect data with regard to the nine indicators. At the time being primary care chiropractic clinics in Denmark do not meet the quality standards set by professionals. This may however be partly due to practical problems in the data collecting process. Both the indicatorgroup and the test-clinics, recommend future nationally widespread implementation of the developed indicators. This could be the first step in joining the Danish healthcare accreditation programme

Background: Severe and chronic back pain often originates from degenerated intervertebral discs, probably from lesions in the outer posterior anulus. Unlike the nucleus, the outer anulus has a high cell density and adequate metabolite transport. The outer annulus can heal after injury in small and young experimental animals, but little is known about the healing potential of adult human discs. Purpose: We seek evidence that healing of the human outer anulus follows the three stages of tendon healing: inflammation, repair, remodelling. If so, then manual therapy and self-treatment techniques known to facilitate tendon healing could be adapted to treat discogenic back pain. Methods: Anulus tissue was removed at surgery (usually posteriorly) from 14 patients with discogenic back pain. Tissue was paraffin embedded and sectioned at 5 μm for histology and immunohistochemistry. Apoptosis was detected using an antibody for caspase-3. Results: Fissures in the peripheral posterior annulus, and herniated tissue fragments, were associated with blood vessels, inflammatory cells, and with focal loss of proteoglycans. Cell density decreased with distance from fissures from the disc periphery. Overall cell density decreased with age. Apoptosis was greater in the nucleus than in the annulus, and was particularly associated with cell clusters, and with anulus fissures. Conclusion: These preliminary results suggest an inflammatory healing response in the outer anulus, strongly associated with radial fissures. Loss of proteoglycan from fissure margins may facilitate the ingrowth of capillaries and nerves, which then stimulate local healing in the vicinity of the fissures. Conflicts of Interest: None. Source of Funding: BackCare

We studied 135 lumbar discs from 27 spines removed post-mortem from subjects of an average age of 31.5 years. Defects of the annulus fibrosus were classified as peripheral, circumferential or radiating; the nucleus pulposus as normal, moderately or severely degenerate. Peripheral tears were more frequent in the anterior annulus, except in the L5-S1 disc. Circumferential tears were equally distributed between the anterior and the posterior annulus. Almost all the radiating tears were in the posterior annulus, and closely related to the presence of severe nuclear degeneration. Histology suggested that peripheral tears were due to trauma rather than biochemical degradation, and that they developed independently of nuclear degeneration. The association of peripheral annular lesions with low back pain is uncertain but our study suggests that they may have a role in the pathogenesis of discogenic pain

It has been thought that lumbar intervertebral discs were innervated segmentally. We have previously shown that the L5-L6 intervertebral disc in the rat is innervated bilaterally from the L1 and L2 dorsal root ganglia through the paravertebral sympathetic trunks, but the pathways between the disc and the paravertebral sympathetic trunks were unknown. We have now studied the spines of 17 rats to elucidate the exact pathways. We examined serial sections of the lumbar spine using immunohistochemistry for calcitonin gene-related peptide, a sensory nerve marker. We showed that these nerve fibres from the intervertebral disc ran through the sinuvertebral nerve into the rami communicantes, not into the corresponding segmental spinal nerve. In the rat, sensory information from the lumbar intervertebral discs is conducted through rami communicantes. If this innervation pattern applies to man, simple decompression of the corresponding nerve root will not relieve discogenic pain. Anterior interbody fusion, with the denervation of rami communicantes, may be effective for such low back pain

Introduction. Severe ‘discogenic’ back pain may be related to the ingrowth of nerves and blood vessels, although this is controversial. We hypothesise that ingrowth is greater in painful discs, and is facilitated in the region of annulus fissures. Methods. We compared tissue removed at surgery from 22 patients with discogenic back pain and/or sciatica, and from 16 young patients with scoliosis who served as controls. Wax-embedded specimens were sectioned at 7μm. Nerves and blood vessels were identified using histological stains, and antibodies to PGP 9.5 and CD31 respectively. Results. Blood vessels were identified in 77% of ‘painful’ discs compared to 44% of scoliotic discs (p=0.013), and they were more common in the anterior anulus compared to the posterior (p=0.026). Maximum penetration of blood vessels from the peripheral anulus was 4.7 mm (in ‘painful’ discs) and 2.0 mm (in control discs), and penetration increased with histological grade of disc degeneration in the ‘painful’ discs (p=0.002). In 16/17 ‘painful’ discs, blood vessels were within 1 mm of an anulus fissure, or the disc periphery. Nerves were found in 36% of ‘painful’ discs (all with blood vessels) and 25% of control discs. Nerve ingrowth was always less than or equal to blood vessel ingrowth, with a maximum observed penetration of 1.5 mm from the annulus periphery. Discussion. In degenerated and painful discs, the ingrowth of nerves appears to follow that of blood vessels, and is facilitated in the region of annulus fissures. No nerves were seen >2mm from the annulus periphery, suggesting that previous reports of nerves in the disc nucleus may refer to vertical growth from a vertebral endplate rather than radial growth through the annulus. Results support the view that discogenic back pain is associated with pain-sensitisation events in the disc periphery. Acknowledgements. Research funded by BackCare. M Stefanakis would like to thank the Greek Institute of Scholarships (I.K.Y) for financial support

The purpose of this prospective study is to evaluate the benefits of intra discal electrothermal treatment (IDET) for discogenic back pain. 40 patients with chronic discogenic back pain underwent this therapy. All the patients had a failed trial of conservative treatment. Patients with a positive provocative discogram were selected for IDET. The outcome is assessed using a SF36 questionnaire pre-procedure and then at 3,6,12,18 and 24 months post-operatively. The mean age group of the patients was 37 years (range 15–58 years). All the patients had a minimum follow up of 18 months. Out of the 40 patients 5(12.5%) had no improvement and had to undergo an interbody fusion within 6 months following IDET and hence were excluded from the study. No patient developed any neurological complications. Of the rest of the 35 patients at a minimum of 18 months follow-up 56 % (p=0.042) patients had improvement in physical function scores and 52% (p=0.034) had improvement in pain scores as per the SF36. Conclusion: IDET appears to be an effective alternative to control pain in patients who might otherwise be candidates for spinal fusion

The multiplicity of factors that influence the clinical evolution of discopathies, determine a great diversity in its presentation. The barely known genetic predisposition, the individual morphological aspects, the age and sex, the associated co-morbidities as well as the patient environment define in its all an individual context that influences decisively the treatment for each patient. On the other hand, the identification in each case of the different stages of the multilevel DDD, causes doubts regarding the involvement of each segment in the respective clinical condition. To singly identify all sources of pain, and not only each painful level, is the main challenge poised to the spine surgeon when defining the treatment strategy. The diagnosis aggressiveness must be proportional to its doubts, and the discography, the disco-scanner and the facet blocks are fundamental when the conventional clinical investigation is inconclusive. The use of minimal invasive techniques such as IDET or Coblation can be considerate as alternatives, especially in the early stages of single-level DDD. The nucleoplasthy – nuclear prosthesis- is an interesting alternative in the intermediate stages of the discogenic pain DDD, as well as in the predominant facet pain or in the foraminal dynamic stenosis is the dynamic stabilization. Those are techniques with controversial results and which liability in some cases is yet to be proven. Last, the use of different techniques in different levels in the context of multi-level DDD – ex: fusion + disc replacement; disc replacement + dynamic stabilization with or without decompression procedures in the spinal canal- must be rigorously considered according to the specific dysfunction of each segment and considering the anatomical and functional reconstruction of the spine

INTRODUCTION: Although it is well recognised that the outer annulus is innervated, the relative densities of innervation of different regions of the disc have not been quantitated. We present here the first comparative analysis of the innervation of the innervation of different regions of the lumbar intervertebral disc. METHODS: A sheep model was used allowing evaluation of the whole motion segment. Four sheep spines were used. One was processed for PGP 9.5 immunofluorescence and three were processed for PGP 9.5 immunoperoxidase histochemistry. Serial sagittal sections were obtained and a count was made of the densities of innervation of different regions of the endplate and annulus. These were compared to identify which areas of the disc and endplate are most innervated. RESULTS: The endplate innervation is concentrated centrally adjoining the nucleus. The mean density of innervation of the central endplate was 0.44 (SEM 0.07) nerves/mm2 while the mean density of the peripheral endplate was 0.10 (SEM 0.03) nerves/ mm. 2. (p= 0.0001). There was no significant difference between the overall endplate and annulus innervation densities 0.52 (SEM 0.1) v 0.37 (SEM 0.07) p=0.2. But the peri-annular connective tissue, external to the outer annulus contained the densest innervation of any region in the motion segment 1.05 (SEM 0.16). DISCUSSION: The lumbar intervertebral disc has a meagre innervation. This is concentrated in the peri-annular connective tissue and the central endplate. While receptor threshold is more closely related to noci-ceptive function than innervation density, these findings have important implications for any treatment of discogenic pain

Background: Lumbar disc replacement is a good alternative to fusion in young patients with degenerative disc disease or discogenic back pain. Despite the increase in the use of anterior lumbar disc replacement, there has been little published data of the specific types and frequencies of the complications associated with its use. Aims & Methods: Purpose of the study is to retrospectively study the perioperative complications associated with CHARITÉ® Artificial Disc replacement. The lumbar spine is retroperitoneally approached, viscera and major vessels retracted and the disc replaced. We reviewed the operative and hospital records of 54 charite disc replacements done by the senior author from 2004 till September 2006. Results: The study group had 23 men and 31 women with a mean age of 38 years (range 31–47). Preoperative diagnosis was degenerative disc disease in 42 patients (78%); discogenic back pain in 12 patients (22%). The most common level replaced was L4/5 (48%) followed by L5/S1 (35%). The most common complication during the procedure was venous injury involving one of the left iliac vein tributary (9 patients, 16%). There was no arterial injury. The median blood loss was 450ml (100–1500ml). There was peritoneum breach in six patients, but no case of bowel, ureter, and bladder or kidney injury. There were two incidences of significant post operative ileus and one developed S1 radiculopathy from lateral disc placement. One developed incisional hernia and two patients had to be revised to fusion. Retrograde ejaculation was reported in 3 patients. No incidence of epidural vein bleed, CSF leak, infection, paraplegia or death. Conclusions: Anterior spinal surgery is a relatively safe procedure with a lower complication rate than was previously reported. Vascular injury was the most frequent complication. The incidence of autonomous dysfunction affecting pelvic floor function appears to be under-estimated and needs further study

Introduction: Eighty percent of individuals experience low back pain in their lifetime. This is often due to disc injury or degeneration. Conservative treatment of discogenic pain is often unsuccessful whilst surgery with the use of spacers or fusion is non-physiological. Aim: To develop an animal model to assess the viability of autologous disc cell therapy. Methods: The fat sand rat (Psammomys obesus obesus) was chosen because of its predisposition to the early development of spondylosis. Using microsurgical techniques fragments of annulus and nucleus were harvested from a single disc in 50 sand rats. Vascular clips were placed on the adjacent psoas muscle to mark the harvested level. Disc material was initially cultured in a monolayer then transferred into a three-dimensional culture medium of agarose. This technique yields greater cellular proliferation and the development of cell growth in colonies. Cells were labelled with bromodeoxyuridine for later immunohistochemical identification. Twenty thousand cells in a carrier medium were then reimplanted at a second operation at an adjacent disc level in the same animal. The rat was subsequently sacrificed and the histology of the disc space was reviewed. Results: To date, 50 primary disc harvests and 30 reimplantations have been performed. Two rats died prior to reimplantation. All histological specimens confirmed the presence of viable transplanted disc cells. Conclusions: Autologous disc cell transplantation can be performed in the rat. Further modification of these techniques may lead to the development of autologous disc cell therapy comparable to that currently successfully used in hyaline cartilage defects of synovial joints in humans

Introduction: Although it is well recognized that the outer annulus is innervated, the relative densities of innervation of different regions of the disc have not been quantitated. We present here the first comparative analysis of the innervation of the innervation of different regions of the lumbar intervertebral disc. Methods: A sheep model was used allowing evaluation of the whole motion segment. Four sheep spines were used. One was processed for PGP 9.5 immunoflourescence and three were processed for PGP 9.5 immunoperoxidase histochemistry. Serial sagittal sections were obtained and a count was made of the densities of innervation of different regions of the endplate and annulus. These were compared to identify which areas of the disc and endplate are most innervated. Results: The endplate innervation is concentrated centrally adjoining the nucleus. The mean density of innervation of the central endplate was 0.44 (SEM 0.07) nerves/ mm. 2. while the mean density of the peripheral endplate was 0.10 (SEM 0.03) nerves/ mm. 2. (p= 0.0001). There was no significant difference between the overall endplate and annulus innervation densities 0.52 (SEM 0.1) v 0.37 (SEM 0.07) p=0.2. But the peri-annular connective tissue, external to the outer annulus contained the densest innervation of any region in the motion segment 1.05 (SEM 0.16). Discussion: The lumbar intervertebral disc has a meagre innervation. This is concentrated in the peri-annular connective tissue and the central endplate. While receptor threshold is more closely related to nociceptive function than innervation density, these findings have important implications for any treatment of discogenic pain

Purposes of the study and background: Diagnostic interventional procedures are often performed on patients who suffer from cervical facet joint pain and discogenic pain emanating from the cervical region. These procedures require radiographic imaging to confirm placement of instruments e.g. needles. However, these techniques are unable to provide real-time images hence prolonging the intervention. It would be of benefit to have an imaging tool that is capable of visualising needle insertion in real-time whilst preventing side effects. The purpose of this study was to determine the ultrasonic appearance of cervical facet joints in vivo and describe a standardized transducer position to visualise intervertebral discs and facet joints. Summary of the methods and the results: 10 healthy volunteers (age range: 21–36 years, 6 females, 4 males) were evaluated using an 8-16MHz linear array transducer (Diasus Dynamic Imaging). Subjects were scanned in a prone, lateral position. The transducer was placed in the posterior triangle orientated longitudinally, initially along the posterior border of sternocleidomastoid and then moved in a cranial-caudal direction. By adjusting the angle (in the antero-posterior direction) of the transducer about a fixed position; facet joints and discs were located. The characteristic V shaped appearance of the facet joint emanates from the hyperechoic signal of the closely spaced transverse processes of adjacent vertebra (Figure1). Disc regions appeared as areas of high signal penetration into the spine with low amplitude signals returning from the disc. Conclusion: The detail of facet joint and disc anatomy captured using ultrasound reveal it to be a viable imaging tool for interventional procedures. Noteworthy advantages of ultrasound include: its ability to provide real-time images economically, the option of portability and no known side effects

Introduction We report the two-year clinical outcome of a prospective randomised trial comparing Femoral Ring Allograft (FRA) to a Titanium Cage (TC) in circumferential lumbar spinal fusion. Methods 83 patients recruited to the study fulfilled strict entry requirements (> 6 months chronic discogenic low back pain, failure of conservative treatment, one or two-level discographically proven discogenic pain source). 38 patients were randomised to receive FRA, 45 patients were randomised to receive TC. Posterior stabilisation was achieved with translaminar or pedicle screws. Patients completed questionnaires including Oswestry Disability Index (ODI), Visual Analogue Scale (VAS) and the Short-Form 36 (SF-36) pre-operatively and 6, 12 and 24 months post-operatively. Results Results were available for all 83 patients with a mean follow-up of 26.5 months (range 24–75 months). Baseline demographic data (age, sex, smoking history, number of operated levels, pre-operative outcome measures) showed no statistical difference between groups (p< 0.05). For patients receiving the FRA, mean VAS (back pain) improved 2.0 points (p=0.01), mean ODI improved 14 points (p=< 0.01), and mean SF-36 scores improved by > 11 points in all domains (p< 0.03) except general health and emotional role. For patients receiving the TC, mean VAS improved 1.2 points (p=0.002), mean ODI improved 5 points (p=0.02); SF-36 improved significantly in only one of eight domains (bodily pain). Discussion Clinical outcome following circumferential lumbar fusion with FRA readily achieves the accepted mean clinically important differences (MCID). Fusion with TC does not achieve the MCID. The use of TC for circumferential lumbar fusion appears not to be justified

Background: Over several decades, investigators have been trying to identify the painful degenerate disc. Their work included two main methods. The first was to set criteria on the radiological investigations, mainly the MRI scan, to describe the severity of the degenerative disc disease (DDD); and the second was to perform discographies. Neither of these two methods precluded the need for the other. Purpose: Using Pfirrmann’s classification, we correlated static MRI images, for the severity of segmental disc degeneration, with dynamic lumbar discography, with the aim to improve the identification of painful ‘disco-genic’ intervertebral segments. Study design: Prospective cohort study. Inclusion criteria included patients with mechanical low back pain who exhausted the conservative measures and required surgical treatment. Patient Sample and Methods: We investigated 69 patients (45 females, 24 males). The average age was 38.9 years (range 20–56). All patients had degenerative disc disease (DDD) on lumbar MRI scans. Provocative discographies were performed in all cases as a routine investigation to identify painful levels prior to fusion or disc replacement surgery. The severity of DDD was graded using Pfirrmann’s classification. A total of 162 discographies were performed using the ‘miss the facet joint, double needle technique’. Outcome measures: During discography typical or concordant pain only was regarded as positive. Among each of the five Pfirrmann grades, the percentage of positive discographies was calculated. Significance and correlation then were investigated using the Chi-squared and Spearman’s correlation tests. Results: 24 discs were classified as Pfirrmann grade I, 33 grade II, 63 grade III, 27 grade IV and 15 grade V. The percentages of positive provocative discography for concordant pain among these groups were 0%, 9.1%, 71.4%, 100% and 100% respectively. Statistical analysis showed a high correlation between the severity of DDD on MRI scan and the result of the provocative discography (Chi2 = 32.96, P < 0.001 and correlation coefficient = 0.756). Conclusion: The higher the grade of segmental DDD, the more likely it will be painful on discography. All discs showing Pfirmann grade IV and V disease were painful on discography. We strongly recommend the Pfirrmann classification for use in grading the severity of lumbar DDD especially when assessing for its association with discogenic pain as determined by provocative discography

Study Design: The effects of heat on porcine intertvertebral disc were studied experimentally. Objective: To assess the effects of in-vitro heating of porcine nucleus pulposus on expression of inducible heat shock protein 70 and subsequent modification of biochemical responses to an inflammatory insult in the heated intervertebral disc tissue. Subjects: Lumbar spines were harvested from six pigs. The nucleus pulposus was dissected from each intervertebral disc, divided into control (37°C) and heat shocked (42°C) groups then cultured in medium for one hour. All samples were then cultured at 37 C for a further two hours. After three hours tissue and supernatant were harvested from one third of the samples and the expression of inducible heat shock protein 70 (HSP70) was quantified via Western immunoblotting and enzyme linked immuno-sorbent assay (ELISA). The remaining samples were cultured either in normal medium or altered (pro-inflammatory) medium containing 5ug/ml bacterial lipopolysaccharide (LPS). At 24 hours the supernatant from these samples was analysed for both interleukin-8 (IL-8) and prostaglandin E2 (PGE2) secretion using ELISA. Outcome Measures: Western immunoblotting and enzyme linked immuno-sorbent assay (ELISA) for heat shock protein 70. ELISA for interleukin-8 (IL-8) and prostaglandin E2 (PGE2). Results: HSP70 expression was significantly increased in the heat shocked specimens. IL-8 and PGE2 secretion were significantly increased in nucleus pulposus exposed to LPS at both temperatures. The concentrations of IL-8 and PGE2 secreted in the heat shocked samples were significantly less than controls, particularly after exposure to LPS (p< 0.05, paired students t test). Conclusions: In vitro heating of porcine nucleus pulposus causes overexpression of HSP70. This heat shock effect can alter aspects of the biochemical response of the intervertebral disc tissue to an inflammatory insult. Intradiscal electrothermal therapy (IDET) may, in theory, reduce discogenic pain at temperatures as low as 42°C by generating similar heat-induced changes in the nuclear biochemistry of degenerate intervertebral discs

Purpose: In this prospective study we present the intermediate results of our experience using the Prodisc disc replacement for lumbar degenerative disc disease. Methods and Results: A total of 29 patients underwent Prodisc disc replacement by the senior author(AAH). There were 9 males and 20 females with a mean age of 39 years(Range 28–60 years). 18 patients had a single level disc replacement (L5/S1-- 14 patients, L4/5-- 4 patients). 11 patients had double level disc replacement (L4/5& L5/S1--7 patients, L3/4& L4/5--3 patients, L2/3& L3/4--1 patient). All patients were assessed pre-operatively with clinical examination, plain films, MRI scans and discography. The indication for surgery was discogenic pain at one or two adjacent segments confirmed with discography, minimum six months of conservative treatment, 20–60 years of age and an Oswestry score > 40%. All patients also agreed to a prearranged follow up protocol. Follow up included clinical examination, plain films and subjective evaluation using the Oswestry scale, Visual Analogue Scale and SF 36 scoring system at 6 weeks, 3 months, 6 months and annually. Results- The follow up range was from 3 months to 2 years. 26 patients had excellent to very good results and 2 patients had good results. There was one complication at 3 months post operatively. This patient sustained a fractured pedicle and underwent revision surgery involving removal of the prosthesis and Anterior Lumbar Fusion. At 6 months post revision a CT scan confirmed fusion. Rapid recovery was the most noticeable aspect of this study as well as rapid return to normal activities. Conclusion: The Prodisc disc replacement is a good treatment option for lumbar degenerative disc disease provided the operative indications are strictly adhered to. The early and mid term results presented are encouraging, however close follow up of these patients is essential to ascertain the long term results

Introduction: Anterior lumbar interbody fusion has become a frequently utilised procedure. The trend has been towards less invasive techniques including laparascopic and mini-open techniques. This report examines the results of one procedure and suggests appropriate tools to decrease the learning curve. Methods: Twenty-two patients with a mean age of 41 (17–78) underwent mini-open ALIF with threaded cortical bone dowels. The same senior surgeon performed all procedures (RFD). Indication for the procedure was discogenic pain verified by concordant discography after a failure of a minimum of six months non-operative treatment. Patients were followed at standard intervals. Complications as well as the evolution of surgical technique were recorded prospectively for all patients. Results: Twenty-one of 22 patients had the successful implantation of two dowels at each level. Intraoperative fluoroscopy and auditory EMG monitoring was used in all cases. Thirty-two levels were fused from L2–S1 (Average =1.39 levels). Average length of stay was 2.96 days (1–14). Follow-up averaged 24.93 months (2–36). Fusion was achieved in 15/16(93%) of the one level cases but only 3/6 (50%) of the two level cases. Posterior reoperation with posterolateral fusion and pedicle screws was performed in 2/3 of these patients. Use of a dedicated pin-based anterior lumbar retractor enabled a 45% reduction in incision length with a 40% decrease in operative time. Complications included: massive bleeding (1), post-operative dysesthetic leg pain (2), postoperative kyphosis (2), lateral graft displacement (1). Discussion and conclusion: ALIF remains a formidable surgical procedure. Precise identification of the midline and use of fluoroscopy assures good placement of the devices. Preoperative osteopenia should be recognised and treated with posterior stabilisation. Posterior stenosis should be a relative contraindication. We have abandoned multilevel standalone procedures given the poor fusion rate. A pin-based retractor allows a smaller incision with less operative time. Attention to myriad technical details remains paramount

Purpose/introduction: 80% of individuals experience low back pain in their lifetime. This is often due to disc injury or degeneration. Conservative treatment of discogenic pain is often unsuccessful whilst surgery with the use of spacers of fusion is non-physiological. The aim of this study was to develop an animal model to assess the viability of autologous disc cell therapy. Method: The Fat Sand Rat (Psammomys obesus obesus) was chosen due to its predisposition to the early development of spondylosis. Using microsurgical techniques fragments of annulus and nucleus were harvested from a single disc in 52 sand rats. Vascular clips were placed on the adjacent psoas muscle to mark the harvested level. Disc material was initially cultured in monolayer then transferred into a three dimensional culture media of agarose. This technique yields greater cellular proliferation and the development of cell growth in colonies. Cells were labelled with Bromodeoxyuridine for later immunohistochemical identification. 20 000 cells in a carrier media were then re-implanted at a second operation at an adjacent disc level in the same animal. The rat was subsequently euthanised and the histology of the disc space reviewed. Results: To date 52 primary disc harvests and 20 reimplantations have been performed. 15 rats have been euthanised and sectioned. Average age at primary surgery was 6.8 months reimplantation eight months and euthanisation 11.2 months. Cell colony viability was inversely related to rat age at harvest. Immunohistochemical analysis of colony extracellular matrix revealed production of type 1 and 2 collagen, chondroitin and keratin sulphate Two rats died prior to reimplantation. All histological specimens confirm the presence of viable transplanted disc cells. Transplanted cells did not alter the progression of degenerative changes on x-ray. Conclusion: Autologous disc cell transplantation can be performed in the rat. Further modification of these techniques may lead to the development of autologous disc cell therapy comparable to that currently successfully used in hyaline cartilage defects of synovial joints in humans

A prospective study to evaluate the design, outcome and complications of the AcroFlex titanium/polyolefin artificial lumbar disc replacement. 11 subjects with single-level discographically proven discogenic pain of at least six months duration and refractory to conservative treatment underwent Total Disc Replacement (TDR) using the AcroFlex TDR. Surgery was performed by an anterior retroperitoneal approach. The following outcome measures were recorded pre-operatively, at 6 weeks and 3, 6, 12 and 24 months: Visual Analogue Score (VAS), Oswestry Disability Index (ODI), Low Back Outcome Score (LBOS), and SF-36. Physical examination and radiological assessment (plain radiographs, flexion/extension views, cine-radiography) were performed at the same time intervals. Complications and reoperations were recorded. 11 patients were enrolled since April 1998 (7 male / 4 female). The mean age was 41. 3 years. All patients have been followed for a minimum of two years. Surgery averaged 136 minutes with 143 mls blood loss. There were no operative complications. The average length of stay was 6. 1 days. The mean VAS reduced from 8. 8 to 4. 4 at two years. ODI improved from 51. 3 (mean) to 20. 9 (mean) at 24 months. The mean LBOS of 18. 4 improved to 47. 3 at two years. Patients showed improvement in all subsets of the SF-36. Radiological examination confirmed a mean flexion/extension arc of 6. 6 degrees with restoration of native disc height. Adverse events included one disc expulsion (under radiological observation), one autofusion (F/E views still confirm movement) and one catastrophic rubber failure requiring revision to combined anterior/posterior interbody fusion. As a result of this case all patients underwent ultra fine cut CT scans. An additional 4 cases showed small anterior tears in the rubber and are currently asymptomatic. The two-year outcome of the AcroFlex TDR is reported in 11 patients. Improvements in VAS, ODI, LBOS and all domains of the SF-36 were reported by 10 of 11 patients. Radiological outcome confirmed preservation of movement and restoration of disc height. Adverse events including disc expulsion, autofusion and rubber failure demand continued vigilance

Introduction Historically, lumbar discography has been one of the most controversial subjects in the management of discogenic low back pain. The diagnostic value of normal psychometric specific pain provocation by disc pressurization has emerged. The sensitivity, specificity and accuracy of discography as a diagnostic test are not in doubt. In clinical discography pain reproduction and location are essential elements. There is an accepted rate of 0–10% false positives. This rate is influenced by occupational disability and abnormal psychometric profiles. By contrast, little attention has been given to false negative results and their outcomes if surgically treated. Traditionally, whether or not the test is considered to be positive or negative is determined immediately after completion of the diagnostic procedure. This study shows that patient’s pain reproduction may occur up to 24 hours after the discogram which often initially interpreted as a true negative when it is actually a false negative result. This study verifies the existence and significance of a false negative through the patients’ treatment and outcomes. Methods In this study, 150 patients underwent discography for investigation of chronic persistent low back pain (CPLBP). All patients had a control (morphologically normal) discogram at the level above the degenerative segment. No patients with abnormal psychometric profiles or compensation were included. All patients were followed up 24 hours post discogram by the radiologist to further assess their clinical status. Ten of the patients (7.5%) were considered to have a false negative discogram, as per the Dallas Discogram Scale. The surgeon correlated the delayed response on the subsequent follow-up. These ten patients were diagnosed as having a positive response and were treated surgically for their discogenic pain. VAS-B, VAS-L, ODI, RMD were collected prospectively. Preoperative and 6 month results were reviewed. Results Seven of the 10 patients (70%) reported severe increase CPLBP and reproduction of pain within 8 hours of the discogram, while 3 patients (30%) did so in the ensuing 24 hours after the discogram. Surgical treatment was either by total disc replacement or anterior lumbar interbody fusion. All patients reported greater than 50% reduction in VAS-B and VAS-L and with improvements of greater than 50% in their ODI and RMD scores. Discussion The clinical reliability of discography hinges on the subjective assessment of pain concordance as the discriminating factor in determining false positives from false negatives. Given the limitations of discography, all information about the patient should be considered prior to diagnosis, including clinical, radiological, historical, and psychometric factors. The delayed positive discography response is an important consideration for the patient, the radiologist, and the treating surgeon to be aware of. The results of this study verify the existence of this subgroup and justify their surgical treatment

Many pathological disease processes are manifested by abnormalities in cellular signalling caused by altered protein expression. Our aims, therefore, were to determine whether ‘’degenerative disc disease’’ results in 1) altered proteome expression and 2) such changes might be used as a marker for the disease process. Using gel electrophoresis, we analysed the proteome expression of nucleus pulposus (NP) derived from patients with scoliosis (‘normal’) compared to degenerate samples from patients with 1) back pain undergoing spinal fusion (DDD) and 2) sciatica undergoing discectomy (herniated nucleus pulposus or HNP). Normal NP tissue was also obtained from organ donor patients with no previous history of back pain. All samples were investigated in duplicate. Protein concentrations were measured qualitatively by visual analysis in a blinded manner and categorised into high, medium, low or absent. The Kruskal-Wallis analysis of variance was sued to analyse the data. Subsequent proteins of interest were determined on N-terminal protein sequencing. 15 samples each were collected each from scoliosis, DDD, and HNP, but only 4 samples from the organ donor groups. One major protein band difference was observed whose molecular weight was 15 kDa and N-terminal sequence homologous with lysozyme C (lysozyme-C-like-protein - LCLP). DDD and HNP samples exhibited significantly reduced levels of LCLP compared to scoliosis (P< 0.0001). All NP from donor patients exhibited high levels of LCLP, but numbers were too small for statistical analysis. No statistical correlation existed between age and LCLP levels. The true physiological roles of Lysozyme C remains unclear, but it is a known ubiquitous secretory and hydrolytic protein found in saliva, milk, cerebrospinal fluid and synovial liquid, and thought to function in primary immunity. LCLP loss in degenerate disc tissue might be due to 1) lack of production, 2) increased breakdown through a specific ubiquitin-linked pathway, or 3) polymerisation with tissue-specific amyloid deposition. The inflammatory effects within the NP related to localised LCLP-amyloid deposition offers a plausible hypothesis for patho-physiology of disc degeneration and discogenic pain. Until we determine the true nature and function of LCLP, we are no further in understanding the patho-mechanisms of disc degeneration. Moreover, LCLP loss in the NP of degenerate discs may provide a potential diagnostic marker for degenerative disc disease

Introduction: While anterior cervical decompression and fusion has been shown to be clinically effective in cases of myelopathy or radiculopathy, several studies have suggested an increased risk of development of adjacent segment degeneration. The Bryan Cervical Disc Pros-thesis was developed to address this complication and was fi rst used clinically in Europe in January 2000. The author began to use the device in June of 2001 and since that time has implanted 30 prostheses in 22 patients. The present prospective study was commenced at the time (concurrently with an ASERNIPS study) with a view to examine the clinical efficacy and safety of this device. The results in the author’s first 14 patients are reported, all with a minimum follow-up of 12 months (mean 20 months). Methods: An observational audit of 14 consecutive patients with cervical radiculopathy (6 patients), myelopathy (6 patients) or discogenic neck pain (2 patients) operated upon between July 2001 and November 2002. Average age was 48 years (range 27 – 61 years). 5 patients underwent two level procedures. Operative / post-op complications and clinical / radiological outcomes were recorded at 6 weeks, 3, 6, 12 months and January 2004. Results: Follow-up data is available at > 12 months on 13 of the 14 patients at an average 23 months post op (Range: 14–30 months). The patient for whom data is not available is known to have had a poor clinical outcome. She developed an unusual symptom complex with complex regional pain syndrome and is very unhappy with the surgery. Of the other 13 patients, 12 consider their outcome to have been excellent and 1 fair. In the two patients who underwent surgery purely for discogenic neck pain, substantial relief was reported. In the 8 patients with pre-operative arm pain, 6 reported complete relief, 1 substantial relief and one partial relief. There were no intra-operative complications. Two patients developed dysphagia which resolved after several months, one has described a clicking sensation in his neck for which no cause has been identified and one experiences persistent ‘neural surges’. One patient required surgery for a disc herniation at an adjacent level, 9 months post-op while in another patient, on routine 12 month follow-up MRI scan, an asymptomatic disc herniation adjacent to the operated segment had resolved spontaneously. One patient underwent foraminotomy for recurrent arm pain, 19 months post-op. All prostheses appear mobile on dynamic x-rays but it is apparent that the Bryan device does not correct any pre-operative degenerative deformity using the current technique. Discussion: The current study appears to indicate satisfactory clinical outcomes at an average of 23 months post surgery in this group of patients. Longer follow-up and larger patient numbers are required as well as comparative studies

Mechanical function and failure of intervertebral discs. In a healthy disc, the nucleus pulposus acts like a pressurised fluid which is restrained by tensile stress within the annulus. With increasing age, the nucleus becomes more fibrous, and biochemical changes cause the whole disc to become less elastic, and more yellow in colour. Mechanically, the hydrostatic nucleus shrinks with age, and concentrations of compressive stress appear in the posterior annulus. Experiments on cadaveric spines have shown that healthy discs can prolapse when loaded severely or repetitively in bending and compression, and that internal disruption of the disc probably follows damage to the vertebral endplates. However, mechanical loading is not necessarily harmful to living discs: on the contrary, moderate repetitive loading may lead to disc hypertrophy rather than injury. Disc degeneration. Degeneration represents some mechanical or biological “insult” superimposed on normal ageing. A defining feature of “degeneration” should be structural failure of the annulus or endplate, because all degenerated discs exhibit structural failure whereas many old discs do not. Degeneration creates high stress concentrations within the annulus. Paradoxically, severe degeneration can lead to gross disc narrowing and reduced stresses in the annulus, presumably because it is “stress shielded” by the apophyseal joints. Animal experiments show that disc degeneration always follows mechanical disruption. In some cases, it may possibly precede it. Disc degeneration and back pain. Pain-provocation studies have shown that severe and chronic back pain often originates in the posterior annulus fibrosus, and can be elicited by relatively moderate mechanical pressure. Anatomical studies indicate that the outer annulus is supplied with complex and free nerve endings from the mixed sinuvertebral nerve. MRI and discographic studies show that back pain is closely correlated with structural features of disc degeneration such as radial fissures and prolapse, although age-related changes in composition are clinically irrelevant. The stress-shielding of severely degenerated discs (see above) suggests that discogenic pain may be most closely associated with intermediate stages of degeneration. The localised stress concentrations found in degenerated cadaveric discs have been directly linked to low back pain in living people. Medico-legal implications. The widely-held belief that a disc will not prolapse unless it is degenerated is no longer compatible with the scientific evidence. Severe loading, which in life usually arises from vigorous muscle contractions, can injure normal discs. On the contrary, it seems likely that severely degenerated discs are too fibrous to prolapse, and that many of the cell-mediated changes associated with disc prolapse occur after prolapse, rather than before. However, genetic inheritance is important in disc degeneration and prolapse, suggesting that some discs are more vulnerable than others to mechanical loading. The nature of this vulnerability is largely unknown, but is likely to involve genetic weaknesses in composition, and previous fatigue damage. It would be desirable to distinguish between these last two factors, but this is likely to prove difficult in practice

Our study aims to evaluate the efficacy of Wallis implant in management of discogenic back pain. We have prospectively studied thirty patients between 2006 and 2007. Average age of patients was 40.8 years. Average follow-up period 20.6 months (9-28). Main inclusion criteria includes failure of conservative management of low back pain due to degenerative disc disease, preservation of 50% of the disc height and positive discographic features. In majority of the patients the implant was put in at the level of L4-L5. Pre-op and post op SF36 and Oswestry Disability Index (ODI) scores were assessed during clinic follow-up and by telephonic interview. Mean SF36 score improved from thirty-seven (8.3 – 54.3) to 51.4. Mean ODI improved from forty-three (20-60) to 26.5(2-60) (p = 0.026). Complications including superficial infection occurred in one patient, deep infection in one patient, erosion of spinous process in one and displacement of the implant in one case. Three (10%) patients had revision surgery due to various reasons. Wallis interspinous dynamic stabilization system could be used as a soft stabilisation device avoiding fusion and short-term results are promising. In selected group of discogenic low back pain patients it is a useful interim procedure. Long-term follow-up of our series is ongoing

Objectives: The purpose of this study was to assess the effect of different types of posterior stabilisation on the fusion rate of anterior lumbar interbody fusion (ALIF). Thin section CT scanning has shown a higher rate of pseudarthrosis with ALIF than previously reported with standard radiological modalities. Cadaveric studies have demonstrated that posterior stabilisation would increase stiffness of the motion segment and is likely to enhance the rate of fusion with ALIF. The results of thin section CT scanning of ALIF, with and without posterior stabilisation, has not been reported previously. Methods: Patients with discogenic back pain confirmed by discography underwent ALIF surgery as a stand alone procedure or with posterior stabilisation – using trans-laminar screws, unilateral pedicle screws or bilateral pedicle screws. Patients were followed up prospectively and thin section CT scanning was used to assess inter-body fusion. Results: The fusion rate for stand alone ALIF was 51%, for patients with supplementary stabilisation with trans-laminar screws 58%, with unilateral pedicle screws 89% and with bilateral pedicle screws 88%. When ALIF was combined with pedicle screw stabilisation a significant difference in the fusion rate was found (p< 0.01). Conclusion: The addition of pedicle screw fixation at the time of ALIF produces a significant increase in the rate of interbody fusion

Introduction: Intervertebral disc (IVD) cell transplantation is used to treat back pain. However, IVD cell activity may also contribute to pathology, e.g. IVD cells can undergo senescence or promote nerve growth, which in the IVD is associated with discogenic back pain. Serum deprivation of bovine IVD cells results in cell senescence. We have examined the influence of oxygen supply combined with serum deprivation on human IVD cells. Methods: Cells from herniated IVD (n=3 patients) were subjected to serum deprivation and then cultured under hypoxic (1%) or atmospheric (21%) conditions for 10 days. IVD cell growth, viability and cell senescence (via Senescence Associated β-galactosidase activity; SA β-gal) were examined. The growth and migration of HMEC-1 (endothelial) and SH-SY5Y (neuronal) cells treated with conditioned medium from the IVD cell cultures (1% versus 21% oxygen) were subsequently monitored. Results: Hypoxia significantly decreased IVD cell proliferation, but was also found to reduce cell senescence. Hence, the proportions of SA β-gal positive IVD cells in 1% and 21% oxygen at day 10 were 18±6% and 56±10%, respectively. There was no marked difference in cell viability (> 95%). Conditioned medium from IVD cells cultured under hypoxia stimulated endothelial and neural cell growth (determined via the MTS assay) and endothelial cell migration and neurite outgrowth to an extent that was significantly greater than conditioned medium from IVD cells cultured at 21% oxygen. Conclusions: The trophic activity of human IVD cells is responsive to oxygen supply. However, hypoxia may influence the capacity of IVD cells to reduce back pain for better or worse. Conflicts of Interest: None. Source of Funding: Institute of Orthopaedics, RJAH Orthopaedic Hospital

Introduction and Aims: Outcome studies in select patient groups in a research environment risk reporting findings that may not be relevant to the large percentage of patients undergoing surgery in private practice in the community. This paper reports an audit of outcomes improvement in Lumbar Fusion patients using the Modified Rowland Questionnaire (MRQ). Method: Two hundred and sixteen patients undergoing lumbar fusion procedures, over a five-year period, completed the MRQ prior to surgery and at the routine one-year follow-up. Changes to the score were documented and analysed in relation to diagnosis, third party compensation coverage, and revision procedures. The MRQ is a validated responsive disease specific functional questionnaire. It ranges from 23 points (maximum disability) to zero (no disability). A four-point improvement is considered clinically significant. Results: Data completion was 88%. Median disability improvement was 10 points on the MRQ (p< 0.0001). Benefit occurred in 80% of patients. Although improvements in degenerative spondylolisthesis and isthmic spondylolisthesis were greater than in fusions for discogenic back pain, this was not significant. There was a trend to lesser functional improvements in those receiving compensation (p=0.073) and those who had undergone previous surgery (p=0.068). Conclusion: This study reports an attempt to audit outcomes in private practice using an instrument applied pre-operatively and at one-year follow-up. The data completion was acceptable. Functional improvements were significant in all diagnositic groups. Outcomes in revision and compensation patients only showed trends to inferior results unlike many other studies

This is to report an audit of outcomes improvement in Lumbar Fusion patients in a private practice setting using routine application of a robust functional outcomes instrument – the Modified Rowland Questionnaire (MRQ). The MRQ is a validated responsive disease specific functional questionnaire. It ranges from 23 points (maximum disability) to zero (no disability). Potential changes in score are 46 points (−23 to 23). A 4 point improvement is clinically significant. Two hundred and sixteen patients undergoing lumbar fusion procedures, over a five year period completed an MRQ prior to surgery and at the routine one-year follow up. Changes to the score were documented and analysed in relation to diagnosis, Accident Compensation corporation (ACC) coverage, and revision procedures. Data completion was 88%. Median disability improvement was 10 points on the MRM questionnaire. Benefit occurred in 80.0% of patients. Improvements were more marked in degenerative spondylolisthesis and isthmic spondylolisthesis than fusions for discogenic back pain although this was not statistically significant. There was a trend to lesser functional improvements in those on ACC and those who had undergone previous surgery. This study reports an attempt to audit outcomes in a spinal sub specialist private practice using an instrument that can be applied preoperatively and at one year follow up without undue additional work load for the patients or staff. The data completion was acceptable. Functional improvements were significant in all diagnostic groups. Outcomes in revision and ACC patients were not significantly inferior, as they have been described in similar overseas studies

The clinical and radiological outcome of 34 patients who were treated with PDN-Solo and PDN-Solo XL devices for symptomatic degenerative lumbar discs is described. 34 patients had PDNs implanted in their lumbar spines between September 2002 and August 2004. Suitable patients, with proven discogenic back pain, who failed at least six months of conservative treatment, were fully consented prior to surgery. The approach was retroperitoneal in all cases except at L5/S1 when it was transperitoneal. The primary clinical outcome measure was the Low Back Outcome Score (LBOS). X-rays were taken at these follow-up points to assess the integrity and effectiveness of the implants. 36 operations were performed in 15 males and 19 females (including 2 early revision PDNs). All patients were between 20 and 65 years old, with a mean age of 42. 17 patients were treated with PDN alone and 17 with PDN as an adjunct to an interbody fusion. There were 10 device related complications, two being amenable to early PDN revision and six requiring revision to fusion. Two patients remain symptom-free. According to the LBOS, only 19 of 29 patients who have not been revised to fusion have had successful outcomes (65.5% of unrevised patients, 56% of all patients). Final follow-up x-rays show that when the PDN remains intact the disc space height is very similar to its neighbours. If the device has dissociated, the disc is narrowed. Fifty years after lumbar disc nucleus replacement was first attempted by Fernstrom, the success rate is no higher and the reasons for revision are the same. Clearly there has to be a major improvement in this technology before it can be widely adopted. Until such a time as that improvement has occurred, we cannot recommend this device as a treatment for back pain

Introduction: This paper reports an audit of outcomes improvement in lumbar fusion patients in a private practice setting using routine application of a robust functional outcomes instrument – the Modified Roland Questionnaire (MRQ). The MRQ is a validated responsive disease specific functional questionnaire. It ranges from 23 points (maximum disability) to zero (no disability). Potential changes in score are 46 points (−23 to 23). A 4 point improvement is clinically significant. Methods: 216 patients undergoing lumbar fusion procedures, over a 5 year period completed an MRQ prior to surgery and at the routine one-year follow-up. Changes to the score were documented and analysed in relation to diagnosis, ACC coverage, and revision procedures. Results: Data completion was 88%. Median disability improvement was 10 points on the MRQ questionnaire. Benefit occurred in 80.0% of patients. Improvements were more marked in degenerative spondylolisthesis and isthmic spondylolisthesis than fusions for discogenic back pain although this was not statistically significant. There was a trend to lesser functional improvements in those on ACC and those who had undergone previous surgery. Discussion: This study reports an attempt to audit outcomes in a spinal sub specialist private practice using an instrument that can be applied preoperatively and at one year follow up without undue additional work load for the patients or staff. The data completion was acceptable. Functional improvements were significant in all diagnostic groups. Outcomes in revision and ACC patients were not significantly inferior, as they have been described in similar overseas studies

Aims: The aim of our study was assess the outcome following intradiscal electrothermal therapy in patients with chronic discogenic back pain. Methods: 57 patients underwent IDET. All patients had an MRI and provocative discography to conþrm that their pain was of disco-genic origin. Pre-IDET, patients completed: a pain visual analogue score (VAS), an employment assessment and a pain diagram. Post-IDET assessment included a VAS, a subjective outcome assessment, an SF36 and an employment assessment. Results: 46 (80.7%) patients with a mean age of 41.2 years (range 16–76) were successfully followed up. IDET performed at one level in 48 patients and at two levels in 9. The mean follow-up was 19 months (Range 12–32 months). There were 27 males and 19 females. There were no serious complications. The mean pain VAS was 6.6 pre-IDET and 6.3 Post IDET (not signiþcant). 54% of patients stated that they were either Ç much better È or Ç a little better È. Subgroup analysis suggests that neither the presence of mild facet joint arthritis nor undergoing IDET at more than one level has an effect on outcome. Ç Non-organic È preoper-ative pain diagrams (as assessed by principles described by Mann et al) had a signiþcant negative effect on outcome, with patients in this group having a having a deterioration in VAS from 6.75 to 8.3 and only 10% stating that their pain was Ç a little better È and none Ç much better È. Conclusion: We believe that our study demonstrates that IDET can achieve satisfactory results in the treatment of chronic discogenic low back pain, but that patient selection is important in achieving this outcome

Introduction: Intradiscal electrothermal therapy (IDET) is a novel minimally invasive treatment for discogenic back pain. It involves inserting a catheter into discs which are suspected of being symptomatic in order to heat certain regions of the disc matrix and thereby influence the pain process. The clinical efficacy of IDET appears to be variable, and the scientific evidence suggests that the heating effect on disc tissues is very local to the catheter. We test the hypothesis that IDET can affect the internal mechanical functioning of lumbar intervertebral discs. Methods: Eighteen cadaveric lumbar “motion segments” (aged 64–97 yrs) were used, 16 of which had degenerated intervertebral discs. Following incubation at 37°C, a miniature pressure transducer, side mounted in a 1.3mm diameter needle, was used to measure the distribution of compressive “stress” along the mid-sagittal diameter of each disc while it was compressed at 1.5 kN. Measurements were repeated in three simulated postures. IDET was then performed, using biplanar radiography to confirm placement of the heating element, and an independent thermocouple to measure temperature in the inner lateral annulus. Stress profilometry was repeated immediately after IDET. Results: Peak temperatures in the inner lateral annulus during IDET averaged 40°C (STD 2.3°). Differences between stress measurements repeated before IDET never exceeded 8% (NS), and a sham IDET procedure produced no consistent changes. After IDET, pressure in the nucleus fell significantly by 6–13%, and stress peaks in the annulus were reduced (P< 0.008). In 12/18 specimens, annulus stress peaks were reduced by more than 8%, and in these “responders”, the mean reduction was 78%. Stress concentrations were increased by more than 8% in two specimens. Conclusion: IDET has a significant but inconsistent affect on compressive stresses within intervertebral discs. These results may partly explain the variable clinical success of IDET

Introduction: 360 degree combined anterior and posterior fusion is an accepted surgical treatment for the management of discogenic back pain. Controversy exists to the optimal technique of posterior fixation. Proponents of translaminar screw fixation cite lower morbidity as a result of less dissection. Despite reports of high fusion rates with this technique, there are concerns over the biomechanical inferiority of this construct compared to pedicle screw fixation. Previous studies on translaminar screws have used only plain radiographs to assess fusion. The objective of this paper is to compare radiographic outcomes, using high definition CT scans, and clinical outcomes between these two methods of posterior fixation. Methods: During 2001, 31 patients underwent combined anterior and posterior fusion by the two senior surgeons for the management of back pain. Anterior interbody fusion was performed using the Syncage in all patients. 16 patients underwent translaminar screw posterior fixation and 15 underwent pedicle screw posterior fixation. Fusion was assessed by high definition CT scan at one year postoperatively. Function was assessed with pre- and postoperative Low Back Outcome Score and visual analogue scores. Results: Minimum follow-up was 12 months. The incidence of pseudarthrosis in the translaminar group was over 75% which was five times greater than that seen in the pedicle screw group (p = 0.01). There were trends towards greater improvements in the LBOS and VAS scores in the pedicle screw group and amongst those patients who achieved a successful fusion. There were two surgical complications in the translaminar screw group and one in the pedicle screw group. Discussion: With the numbers that are available, there are no clinical differences between the two methods of fixation, although there were trends towards improved function and reduced pain in the pedicle screw group. Furthermore there does not appear to be any difference in regards to complications. However, translaminar screws are associated with a significantly higher rate of pseudarthrosis compared to pedicle screws

INTRODUCTION: 360 degree combined anterior and posterior fusion is an accepted surgical treatment for the management of discogenic back pain. Controversy exists to the optimal technique of posterior fixation. Proponents of translaminar screw fixation cite lower morbidity as a result of less dissection. Despite reports of high fusion rates with this technique, there are concerns over the biomechanical inferiority of this construct compared to pedicle screw fixation. Previous studies on translaminar screws have used only plain radiographs to assess fusion. The objective of this paper is to compare radiographic outcomes, using high definition CT scans, and clinical outcomes between these two methods of posterior fixation. METHODS: During 2001, 31 patients underwent combined anterior and posterior fusion by the two senior surgeons for the management of back pain. Anterior interbody fusion was performed using the Syncage in all patients. 16 patients underwent translaminar screw posterior fixation and 15 underwent pedicle screw posterior fixation. Fusion was assessed by high definition CT scan at one year post-operatively. Function was assessed with pre- and post-operative Low Back Outcome Score and visual analogue scores. RESULTS: Minimum follow-up was 12 months. The incidence of pseudarthrosis in the translaminar group was over 75% which was five times greater than that seen in the pedicle screw group (p = 0.01). There were trends towards greater improvements in the LBOS and VAS scores in the pedicle screw group and amongst those patients who achieved a successful fusion. There were two surgical complications in the translaminar screw group and one in the pedicle screw group. DISCUSSION: With the numbers that are available, there are no clinical differences between the two methods of fixation, although there were trends towards improved function and reduced pain in the pedicle screw group. Furthermore there does not appear to be any difference in regard to complications. However, translaminar screws are associated with a significantly higher rate of pseudarthrosis compared to pedicle screws

Recently there has been considerable interest in the role of inflammatory mediator production by herniated degenerate discs. Modic has described MR endplate changes which have an inflammatory appearance and have been linked with discogenic back pain. To date there has been no biomechanical investigation of discs with associated Modic changes. The aim of this study is to determine if degenerate discs with associated Modic changes have higher levels of pro-inflammatory mediator production than those without Modic changes. Intervertebral disc tissue was obtained from 52 patients undergoing spinal surgery for sciatica [40] and discogram proven discogenic low back pain [12]. The tissue was cultured and the medium analysed for interleukin-6, interleukin-8 and prostaglandin E2 using an enzyme linked immunoabsorbetn assay method. Preoperative MR images of the patients were examined by a double blinded radiologist to determine the Modic status of the cultured disc level. Forty percent of patients undergoing surgery for discogenic low back pain had a Modic 1 change compared to only 12.5% of patients undergoing surgery for sciatica [p< .05] There was a statistically significant difference between levels of IL-6, IL-8 and PGE2 production by both the Modic1 [M1] and Modic2 [M2] groups compared to the Modic negative [NEG] group. IL-6:NEGvM1 p< .001, NEG v M2 p< .05, IL-8: NEG v M1 p< .01, NEG v M2 p> .05, PGE2: NEG v M1 p< 01, NEG v M2 p< .05. Modic changes have been associated with positive provocative discography by a number of authors. Pain generation requires the presence of nerves and hyperalgsia inducing mediators. Both IL-8 and PGE2 are known to induce hyperalgesia. The fact that Modic changes are associated with high levels of production of these mediators supports their role as an objective marker of discogenic low back pain

The role of nucleus pulposus (NP) biology in the genesis of sciatica is being increasingly investigated. The aim of this study was to examine the ability of control and degenerate human nucleus pulposus to respond to an exogenous pro-inflammatory stimulus. Control disc material was obtained from surgical procedures for scoliosis and degenerate disc tissue from surgical procedures for sciatica and low back pain. Disc specimens were cultured using a serumless technique under basal and lipopolysaccharride (LPS) stimulated conditions and the media harvested, aliquoted and stored at –80°C for subsequent analysis. Levels of IL-1β,TNFα, LTB4, GM-CSF, IL-6, IL-8, MCP-1, PGE2, bFGF and TGFβ-1 in the media were estimated using commercially available enzyme linked immunoabsorbent assay kits. Neither basal nor LPS stimulated control or degenerate NP produced detectable levels of IL-1β, TNFα, LTB4 or GM-CSF. Control disc IL-8 secretion increased significantly with LPS stimulation, p< .018. Degenerate disc IL-6, IL-8 and PGE2 production increased significantly with LPS stimulation, p< .01, p< .001 and p< .005 respectively. LPS stimulated degenerate NP secreted significantly more IL-6, IL-8 and PGE2 than LPS stimulated control NP, p < 0.05, 0.02 and 0.003 respectively. LPS induces an increase in both control and degenerate NP mediator production demonstrating the ability of human NP to react to a noxious stimulus by producing pro-inflammatory mediators. The difference in levels of basal and LPS stimulated mediator production between control and degenerate discs show that as a disc degenerates it increases both its level of inflammatory mediator production and its ability to react to a pro-inflammatory stimulus. The increased sensitivity of degenerating human NP to noxious stimuli and increased ability to respond with inflammatory mediator production support the role of NP as an active participant in the genesis of lumbar radiculopathy and discogenic back pain

To investigate the efficacy of the navigable intradiscal catheter in the treatment and relief of lumbar discogenic back pain. Twenty-three (23) consecutive patients, at this site, were enrolled into the study by this investigator from normal practice. Inclusion criteria included presentation with predominant low back pain with or without referral leg pain lasting longer than 6 months, diagnosis of DDD or IDD confirmed by plain x-rays, MRI, and positive, low pressure discography, and failure of at least 6 weeks conservative treatment. Outcomes were assessed by clinical exam and administration of the SF-36 Health Survey during the baseline, 3, 6, and 12 month visits. All treatments were performed on an outpatient basis. Following the administration of conscious sedation and local anesthetic, a 17-gauge introducer needle was placed by an extrapedicular approach into the symptomatic disc using fluoroscopic x-ray guidance. A navigable catheter was placed circumferentially to the posterior annular wall. Treatment time was 17 minutes at a maximum tissue temperature of approximately 90°C. Intradiscal antibiotics were employed post procedure and all patients were discharged the day of procedure without complications. Thirty-three (33) lumbar discs were treated. Ten patients had single levels treated; thirteen had double levels treated. Twelve month results show significant improvements in pain as measured by a visual analogue scale (56% decrease, p = 0.035), and the SF-36 sub-scales measuring Bodily Pain (93% decrease, p = 0.011 at 6 months), Physical Functioning (65% increase, p = 0.035), and Role Physical (173% increase, p = 0.020). Overall, 80% of the patients were satisfied with their outcomes (p = 0.004). The intradiscal navigable catheter has proven to be effective in the reduction of pain and an increase in functional abilities for patients who suffer discogenic low back pain due to IDD or DDD

Introduction: Abnormal pain drawings have been shown in some studies to correlate well with psychological characteristics predicting poor outcome in spinal procedures. Our study evaluated whether pain drawings are a useful predictive tool for outcome following Intradiscal Electrothermal Therapy (IDET). Method: 56 Patients underwent IDET for chronic discogenic lumbar pain as demonstrated by MRI and provocative discography. They were assessed pre and post operatively. Preoperatively patients were assessed by means of a questionnaire. Pain was measured using a visual analogue scale (VAS), a pain drawing was completed and demographic details and employment status were recorded. Post IDET patients were followed up by means of a postal questionnaire. The same details were recorded, in addition to which patients completed a Short Form 36 UK Version 1 and a subjective outcome assessment. Pain drawings were classified as organic or non-organic according to the principle described by Mann et al. Results: 46 (80.7%) patients were successfully followed up. Mean age was 41.2 years (Range 16–76), 27 were female and 19 male. 73.9% of pain drawings were classified as organic and 26.1% as non-organic. The pain diagram was a good predictive tool for outcome following IDET. Patients with “organic” pain drawings showed an improvement in mean pain VAS (Pre-6.7, Post 5.9), high patient satisfaction (Better 67.6%, Same 11.8%, Worse 20.6%), and higher physical component scores of the SF36 (Physical 64.1, Physical Role 45.6, Pain 54.0) compared to the “non-organic” group who demonstrated a deterioration in mean pain VAS (Pre-6.5, Post 8.2), low patient satisfaction (Better 8.3%, Same 58.3%, Worse 33.3%), and lower physical component scores of the SF36 (Physical 38.3, Physical Role 20.8, Pain 26.5). Conclusion: We believe that our study demonstrates that a pre procedure pain diagram can be reliably used as a tool to predict outcome following IDET

Introduction: Intradiscal electrothermal therapy (IDET) is a novel treatment for discogenic back pain. A heating element is inserted percutaneously into a disc in order to denature the collagen of the posterior annulus. Clinical success is claimed, although laboratory studies indicate that temperature increases may be insufficient to cause widespread collagen denaturation, or denervation, and that IDET has little effect on gross mechanical properties. We report on changes in internal disc mechanics following IDET. Methods: Ten cadaveric lumbar ‘motion segments’ (aged 72–79 yrs) were stored at −17°C. Subsequently, each was equilibrated at 37°C. A miniature pressure transducer was used to measure the distribution of compressive stress along the mid-sagittal diameter of each disc while it was compressed at 1.5kN. IDET was performed, using bi-planar radiography to confirm placement of the heating element, and an independent thermocouple to measure temperature in the inner lateral annulus. Stress profilometry was repeated irnmediately after IDET. Results: Before IDET, all discs exhibited stress concentrations typical of mild degeneration. Accurate placement of the element was confirmed in all discs. Temperatures in the inner lateral annulus during IDET reached only 40.9°C (STD 2.3°C). Differences between stress measurements repeated before IDET never exceeded 8% (NS). After IDET, peak stresses (above nucleus pressure) were reduced by more than 8% in 6/10 specimens (mean reduction 55%), increased in 2/10, and were unchanged in 2/10. Nucleus pressure fell by 13% (n=10 0, P=0.05). Discussion: IDET had a variable effect on these 10 degenerated discs. In six of them, stress concentrations in the annulus were reduced, suggesting that IDET can cause disc material to resist compression in a more coherent fashion, possibly by ‘bonding’ fragmented tissue together, and thereby distributing load more evenly across the endplate. Reduction in nucleus pressure following IDET suggests load transfer to the neural arch, although this could not be confirmed. Reducing annulus stress concentrations could conceivably reduce pain in some individuals

Introduction: Europe has no equivalent of the US Food and Drug Administration (FDA). As a result, spinal implants can be adopted into clinical use in Europe earlier than in the US with a lesser regulatory burden. This may benefit patients, but if a device fails due to design changes that are not fully evaluated, outcomes can be compromised. The classic example in the past was the Capital Hip. If Europe had an equivalent to the FDA, oversight of implant design and design changes might prevent such occurrences. The Prosthetic Disc Nucleus (PDN) is an implant designed to replace the nucleus of the lumbar disc in early stage symptomatic disc degeneration. The PDN originally was a paired device. Due to technical difficulties encountered by surgeons these were converted to a single implant (PDN Solo range). Mechanical testing suggested the new device would function as well as the original paired device. However, the implant was introduced into clinical practice, outside of the US, without any clinical evaluation. Study Design: Prospective cohort study with 3 to 5 year clinical and radiological follow-up. Objective of Study: To review the outcome of PDN Solo implanted anteriorly in the lumbar spine, define the mode of failure and describe revision strategies. Patients and Methods: PDN Solo was used in 35 patients from September 2002 to January 2005 with a median follow-up of 49 months. Patients with discogenic back pain causing significant disability were offered nucleus replacement after an extensive process of consent. The approach was anterior retroperitoneal with the exception of L5/S1 which was transperitoneal. 17 patients were treated with PDN alone and 18 with a PDN to treat a degenerate level adjacent to an interbody fusion. Outcome measures were the Low Back Outcome Score and a Patient Satisfaction Evaluation. Results: 14 patients have needed PDN revision. The mean time to failure was 16.5 months. There were three early extrusions, two replaced with PDNs and one converted to a fusion. Revision procedures included seven conversions to STALIF, two circumferential fusions and five posterolateral fusions. Four more unrevised patients were identified as clinical failures. The total failure rate was therefore 51.4%. In patients with a successful outcome there was a 33 point improvement in the mean LBOS score. In all cases of failure the PDN jacket became disrupted with concomitant fragmentation of the hydrogel core. Conclusions: Modification of the paired PDN to a single device was introduced outside the US without any clinical evaluation. In the US, the original PDN and the Solo version failed to gain regulatory approval and following the failure of the Solo it has been redesigned again. This study raises questions regarding implant design, testing and approval considering that more than 4500 PDN replacements have been carried out worldwide since 1996. Do these events call for a European equivalent to the FDA?

Introduction: Intervertebral disc degeneration occurs with ageing and is often associated with back pain. During such degeneration, gross morphological differences between the central nucleus pulposus (NP) and outer annulus fibrosus (AF) are lost and the disc loses hydration and height due to decreased proteoglycan content. The cartilage endplate may also become calcified and this blocks the passage of nutrients into the disc, causing cell death and further degeneration. A potential therapy of degeneration is “re-inflation” of the disc with the use of hydrogels seeded with autologous disc cells. In this study, we have assessed the ability of a variety of hydrogels to support intervertebral disc cell growth. Method: Intervertebral disc cells were isolated enzymatically from bovine tails and cultured as a monolayer in 10% foetal calf serum in DMEM containing antibiotics and ascorbic acid. This stimulates the cells to proliferate and thereby produces increased cell numbers. The cells were then seeded onto various hydrogels including hyaluronic acid (HA), 2-hydroxyethyl methacrylate (HEMA), N’N’ dimethyl methacrylate (NNDMA) and polyacryloyl morpholine (AMO) before harvesting at set time points of 1, 3, 6 and 9 days for hyaluronic acid and 1, 7, 14, 21, and 28 days for the other hydrogels. Cell number, morphology, viability and adherence to or migration into the hydrogels were assessed. Cell proliferation was also determined by immunostaining for the Ki67 antigen. Results: Disc cells became incorporated in the HA gel, adopted a spherical morphology and remained viable for up to nine days. However, after a few days, a large proportion of the cells began to migrate through the gel to form a monolayer on the bottom of the tissue culture well. These monolayered cells became fibroblastic and proliferated. NP cells appeared to proliferate to a greater extent than AF cells both in monolayer and in suspension. Ki67 antigen immunostaining confirmed cell proliferation. On the non-porous HEMA, NNDMA and AMO, both cell types adhered and adopted a fibroblast-like morphology. Cell adhesion was greatest to the HEMA. NNDMA and AMO had lower levels of cell adherence. Both cell types became incorporated into the porous materials and adopted a rounded morphology. Cell incorporation appeared to be greatest into porous HEMA. Conclusion: These initial studies show that intervertebral disc cells will adhere to or migrate into a variety of hydrogels and remain viable. The morphology and proliferative capacity of cells derived from both the AF and NP were responsive to the structure of the hydrogel with which they were cultured. Thus, cells were able to become fibroblastic or chondrocytic. Further analyses will reveal whether matrix synthesis by disc cells is similarly responsive to the hydrogel format. The results of these experiments suggest that the hydrogels tested have potential as support matrices in intervertebral disc repair to provide relief from discogenic low-back pain

This short contribution aims to explain how intervertebral disc ‘degeneration’ differs from normal ageing, and to suggest how mechanical loading and constitutional factors interact to cause disc degeneration and prolapse. We suggest that disagreement on these matters in medico-legal practice often arises from a misunderstanding of the nature of ‘soft-tissue injuries’.

To clarify the pathomechanisms of discogenic low back pain, the sympathetic afferent discharge originating from the L5-L6 disc via the L2 root were investigated neurophysiologically in 31 Lewis rats. Sympathetic afferent units were recorded from the L2 root connected to the lumbar sympathetic trunk by rami communicantes. The L5-L6 discs were mechanically probed, stimulated electrically to evoke action potentials and, finally, treated with chemicals to produce an inflammatory reaction. We could not obtain a response from any units in the L5-L6 discs using mechanical stimulation, but with electrical stimulation we identified 42 units consisting mostly of A-delta fibres. In some experiments a response to mechanical probing of the L5-L6 disc was recognised after producing an inflammatory reaction. This study suggests that mechanical stimulation of the lumbar discs may not always produce pain, whereas inflammatory changes may cause the disc to become sensitive to mechanical stimuli, resulting in nociceptive information being transmitted as discogenic low back pain to the spinal cord through the lumbar sympathetic trunk. This may partly explain the variation in human symptoms of degenerate discs.

Little information is available about the incidence and outcome of incidental dural tears associated with microendoscopic lumbar decompressive surgery. We prospectively examined the incidence of dural tears and their influence on the outcome six months post-operatively in 555 consecutive patients (mean age 47.4 years (13 to 89)) who underwent this form of surgery. The incidence of dural tears was 5.05% (28/555). The risk factors were the age of the patient and the procedure of bilateral decompression via a unilateral approach. The rate of recovery of the Japanese Orthopaedic Association score in patients with dural tears was significantly lower than that in those without a tear (77.7% vs 87.6%; p < 0.02), although there were no significant differences in the improvement of the Oswestry Disability Index between the two groups. Most dural tears were small, managed by taking adequate care of symptoms of low cerebrospinal fluid pressure, and did not require direct dural repair. Routine MRI scans were undertaken six months post-operatively; four patients with a dural tear had recurrent or residual disc herniation and two had further stenosis, possibly because the dural tear prevented adequate decompression and removal of the fragments of disc during surgery; as yet, none of these patients have undergone further surgery.

Cite this article: Bone Joint J 2014;96-B:641–5.

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.

Sacral insufficiency fractures are traditionally treated with bed rest and analgesia. The importance of early rehabilitation is generally appreciated; but pain frequently delays this, resulting in prolonged hospital stay and the risk of complications related to immobility. We describe three women with sacral insufficiency fractures who were treated with percutaneous sacroiliac screws and followed up for a mean of 18 months (12 to 24). They had immediate pain relief, uncomplicated rehabilitation and uneventful healing.

We carried out a prospective study to determine whether the addition of a recombinant human bone morphogenetic protein (rhBMP-2) to a machined allograft spacer would improve the rate of intervertebral body fusion in the spine. We studied 77 patients who were to undergo an interbody fusion with allograft and instrumentation. The first 36 patients received allograft with adjuvant rhBMP-2 (allograft/rhBMP-2 group), and the next 41, allograft and demineralised bone matrix (allograft/demineralised bone matrix group). Each patient was assessed clinically and radiologically both pre-operatively and at each follow-up visit using standard methods. Follow-up continued for two years.

Every patient in the allograft/rhBMP-2 group had fused by six months. However, early graft lucency and significant (> 10%) subsidence were seen radiologically in 27 of 55 levels in this group. The mean graft height subsidence was 27% (13% to 42%) for anterior lumbar interbody fusion, 24% (13% to 40%) for transforaminal lumbar interbody fusion, and 53% (40% to 58%) for anterior cervical discectomy and fusion. Those who had undergone fusion using allograft and demineralised bone matrix lost only a mean of 4.6% (0% to 15%) of their graft height.

Although a high rate of fusion (100%) was achieved with rhBMP-2, significant subsidence occurred in more than half of the levels (23 of 37) in the lumbar spine and 33% (6 of 18) in the cervical spine. A 98% fusion rate (62 of 63 levels) was achieved without rhBMP-2 and without the associated graft subsidence. Consequently, we no longer use rhBMP-2 with allograft in our practice if the allograft has to provide significant structural support.

Posterior lumbar interbody fusion (PLIF) is indicated for many patients with pain and/or instability of the lumbar spine. We performed 36 PLIF procedures using the patient’s lumbar spinous process and laminae, which were inserted as a bone graft between two vertebral bodies without using a cage. The mean lumbar lordosis and mean disc height to vertebral body ratio were restored and preserved after surgery. There were no serious complications.

These results suggest that this procedure is safe and effective.

The purpose of this study was to evaluate whether concerns about the release of metal ions in metal-on-metal total hip replacements (THR) should be extended to patients with metal-bearing total disc replacements (TDR).

Cobalt and chromium levels in whole blood and serum were measured in ten patients with a single-level TDR after a mean follow-up of 34.5 months (13 to 61) using inductively-coupled plasma mass spectrometry. These metal ion levels were compared with pre-operative control levels in 81 patients and with metal ion levels 12 months after metal-on-metal THR (n = 21) and resurfacing hip replacement (n = 36). Flexion-extension radiographs were used to verify movement of the TDR.

Cobalt levels in whole blood and serum were significantly lower in the TDR group than in either the THR (p = 0.007) or the resurfacing group (p < 0.001). Both chromium levels were also significantly lower after TDR versus hip resurfacing (p < 0.001), whereas compared with THR this difference was only significant for serum levels (p = 0.008). All metal ion levels in the THR and resurfacing groups were significantly higher than in the control group (p < 0.001). In the TDR group only cobalt in whole blood appeared to be significantly higher (p < 0.001). The median range of movement of the TDR was 15.5° (10° to 22°).

These results suggest that there is minimal cause for concern about high metal ion concentrations after TDR, as the levels appear to be only moderately elevated. However, spinal surgeons using a metal-on-metal TDR should still be aware of concerns expressed in the hip replacement literature about toxicity from elevated metal ion levels, and inform their patients appropriately.

Discogenic low back pain is a common cause of disability, but its pathogenesis is poorly understood. We collected 19 specimens of lumbar intervertebral discs from 17 patients with discogenic low back pain during posterior lumbar interbody fusion, 12 from physiologically ageing discs and ten from normal control discs. We investigated the histological features and assessed the immunoreactive activity of neurofilament (NF200) and neuropeptides such as substance P (SP) and vasoactive-intestinal peptide (VIP) in the nerve fibres.

The distinct histological characteristic of the painful disc was the formation of a zone of vascularised granulation tissue from the nucleus pulposus to the outer part of the annulus fibrosus along the edges of the fissures. SP-, NF- and VIP-immunoreactive nerve fibres in the painful discs were more extensive than in the control discs. Growth of nerves deep into the annulus fibrosus and nucleus pulposus was observed mainly along the zone of granulation tissue in the painful discs. This suggests that the zone of granulation tissue with extensive innervation along the tears in the posterior part of the painful disc may be responsible for causing the pain of discography and of discogenic low back pain.