Aims. To identify the incidence and risk factors for five-year same-site recurrent disc herniation (sRDH) after primary single-level lumbar discectomy. Secondary outcome was the incidence and risk factors for five-year sRDH reoperation. Methods. A retrospective study was conducted using prospectively collected data and patient-reported outcome measures, including the Oswestry Disability Index (ODI), between 2008 and 2019. Postoperative sRDH was identified from clinical notes and the centre’s MRI database, with all imaging providers in the region checked for missing events. The Kaplan-Meier method was used to calculate five-year sRDH incidence. Cox proportional hazards model was used to identify independent variables predictive of sRDH, with any variable not significant at the p < 0.1 level removed. Hazard ratios (HRs) were calculated with 95% confidence intervals (CIs). Results. Complete baseline data capture was available for 733 of 754 (97.2%) consecutive patients. Median follow-up time for censored patients was 2.2 years (interquartile range (IQR) 1.0 to 5.0). sRDH occurred in 63 patients at a median 0.8 years (IQR 0.5 to 1.7) after surgery. The five-year Kaplan-Meier estimate for sRDH was 12.1% (95% CI 9.5 to 15.4), sRDH reoperation was 7.5% (95% CI 5.5 to 10.2), and any-procedure reoperation was 14.1% (95% CI 11.1 to 17.5). Current smoker (HR 2.12 (95% CI 1.26 to 3.56)) and higher preoperative ODI (HR 1.02 (95% CI 1.00 to 1.03)) were independent risk factors associated with sRDH. Current smoker (HR 2.15 (95% CI 1.12 to 4.09)) was an independent risk factor for sRDH reoperation. Conclusion. This is one of the largest series to date which has identified current smoker and higher preoperative disability as independent risk factors for sRDH. Current smoker was an independent risk factor for sRDH reoperation. These findings are important for spinal surgeons and rehabilitation specialists in risk assessment, consenting patients, and perioperative management. Cite this article: Bone Joint J 2023;105-B(3):315–322

Studies on recurrent disc herniation quote rates of recurrence without regard to the times of recurrence and the influence of longer follow-up. Our objective was to assess the use of survival analysis to measure the rate of revision after lumbar microdiscectomy. We undertook a retrospective analysis of the hospital records of 993 patients who underwent lumbar microdiscectomy over a period of ten years. After calculating the overall rate of revision for the mean length of follow-up, we carried out a survival analysis using the life-table method. During the study period 49 patients had a revision microdiscectomy. This gave an overall rate of revision of 4.9% at a mean follow-up of 5.25 years. Using survival analysis, the rate of revision was 7.9% at a follow-up of ten years when the number at risk was 84. Survival analysis gives a more accurate estimation of the true rate of recurrence for patients undergoing lumbar microdiscectomy. The method allows better comparison between different interventions for disc herniation

Aim: To investigate the effectiveness of Adcon-L in re-discectomy and/or surgical neurolysis compared to autologous fat graft. Methods: A total of 50 patients with recurrent disc herniation (n=30) and/or epidural þbrosis (n=20) were included. All had failed in conservative treatment and suffered from predominantly radicular pain. MRI scans proofed the re-herniation (same segment, same side) and/or epidural þbrosis. Standard preoperative and follow-up examinations were carried out. Follow-up examination was performed by an independend investigator. Data were analysed using the intention-to-treat principle. Result: The clinical outcome showed no statistically difference between both groups one year after revision surgery. Conclusion: Due to our results, and as we know that the rate of clinically relevant cerebrospinal ßuid leakage is increased after the application of Adcon-L, we prefer the use of autologous graft as an antiadhesive in revision surgery of the spinal canal

Background: Publications concerning recurrent disc disease quote percentage recurrence without regard to the times of recurrence and the influence of longer follow-up.

Objective: To assess the use of survival analysis to measure revision rate after lumbar microdiscectomy.

Design: A retrospective analysis of the hospital records of all patients undergoing lumbar microdiscectomy over a nine-year period was undertaken. Patients who had a repeat microdiscectomy at the same level as the index procedure were designated ‘revisions’. The overall revision rate was calculated for the average length of follow-up. A survival analysis was then carried out using the life table method, as described by Murray et al for follow-up of hip arthroplasty.

Subjects: Seven hundred and twenty-nine patients underwent primary microdiscectomy during this time period, average age 40 years.

Results: Twenty-seven patients had a revision microdiscectomy during the study period. This gave an overall revision rate of 3.7% at average follow up of five years, one month. Using survival analysis the revision rate was 5.5% at eight years of follow up, number at risk 51.

Conclusions: Survival analysis gives a more accurate estimation of the true recurrence rate for patients undergoing lumbar microdiscectomy. The method would allow better comparison between different interventions for intervertebral disc herniation.

Aims

Lumbar disc prolapse is a frequent indication for surgery. The few available long-term follow-up studies focus mainly on repeated surgery for recurrent disease. The aim of this study was to analyze all reasons for additional surgery for patients operated on for a primary lumbar disc prolapse.

Aims. The aim of the study was to determine if there was a direct correlation between the pain and disability experienced by patients and size of their disc prolapse, measured by the disc’s cross-sectional area on T2 axial MRI scans. Methods. Patients were asked to prospectively complete visual analogue scale (VAS) and Oswestry Disability Index (ODI) scores on the day of their MRI scan. All patients with primary disc herniation were included. Exclusion criteria included recurrent disc herniation, cauda equina syndrome, or any other associated spinal pathology. T2 weighted MRI scans were reviewed on picture archiving and communications software. The T2 axial image showing the disc protrusion with the largest cross sectional area was used for measurements. The area of the disc and canal were measured at this level. The size of the disc was measured as a percentage of the cross-sectional area of the spinal canal on the chosen image. The VAS leg pain and ODI scores were each correlated with the size of the disc using the Pearson correlation coefficient (PCC). Intraobserver reliability for MRI measurement was assessed using the interclass correlation coefficient (ICC). We assessed if the position of the disc prolapse (central, lateral recess, or foraminal) altered the symptoms described by the patient. The VAS and ODI scores from central and lateral recess disc prolapses were compared. Results. A total of 56 patients (mean age 41.1 years (22.8 to 70.3)) were included. A high degree of intraobserver reliability was observed for MRI measurement: single measure ICC was 0.99 (95% confidence interval (CI) from 0.97 to 0.99 (p < 0.001)). The PCC comparing VAS leg scores with canal occupancy for herniated disc was 0.056. The PCC comparing ODI for herniated disc was 0.070. We found 13 disc prolapses centrally and 43 lateral recess prolapses. There were no foraminal prolapses in this group. The position of the prolapse was not found to be related to the mean VAS score or ODI experienced by the patients (VAS, p = 0.251; ODI, p = 0.093). Conclusion. The results of the statistical analysis show that there is no direct correlation between the size or position of the disc prolapse and a patient’s symptoms. The symptoms experienced by patients should be the primary concern in deciding to perform discectomy. Cite this article: Bone Joint J 2022;104-B(6):715–720

The February 2014 Spine Roundup. 360 . looks at: single posterior approach for severe kyphosis; risk factors for recurrent disc herniation; dysphagia and cervical disc replacement or fusion; hang on to your topical antibiotics; cost-effective lumbar disc replacement; anxiolytics no role to play in acute lumbar back pain; and surgery best for lumbar disc herniation

Purpose of the study: Conventional treatment for recurrent lumbar disc herniation is repeated discectomy. Other methods such as fusion, ligamentoplasty or implantation of a discal prosthesis are sometimes proposed but all increase morbidity. The purpose of this work was to ascertain the efficacy of isolated repeated radicular release for the treatment of recurrent discal herniation. Material and methods: Thirty-four patients underwent surgery for recurrent discal herniation. Repeated radicular release was used in all patients included in this analysis who completed a self-administered questionnaire at last follow-up to assess the final functional outcome. Results: The cohort included 13 women and 21 men, mean age at surgery 45 years. Mean time from first discectomy to revision surgery for recurrence was 55 months. At the time of the review, four patients had died, all four from cancer. None of these patients had undergone a revision procedure on the lumbar spine. One patient was lost to follow-up so 85% of the cohort was analyzed with 60 months average follow-up. A dural tear occurred during the proscedure in six patients (17%. Five patients (14.7%) required revision surgery, one for deep infection, four for recurrent or persistent lumboradiculalgia (recurrent discal herniation, isthmic fracture, lateral stenosis associated with inflammatory discopathy). The rate of revision for painful failure was 11.4%. The final outcome could be assessed for 25 patients and was satisfactory for 22/25 (88%). The self-administered questionnaire revealed 65% average improvement with more than half of the patients reported better than 80% improvement. Ten patients (40%) complained of lumbar pain and a third had residual, generally intermittent, radiculalgia. Eighteen of 25 patients resumed their work at a comparable level after six months on average; 84% of the patient would accept the same operation again. Discussion: In terms of morbidity and rate of revision, the results are comparable to reports in the literature. Repeated release does not increase the risk of a new recurrence. Conclusion: This work enabled us to demonstrate that in the large majority of patients repeated discectomy provides satisfactory functional outcome with little morbidity

Introduction and Aims: Recurrent disc herniation or sciatica is one of the major complications of discectomy, often leading to a cascade of surgical procedures of increasing magnitude, but decreasing surgical outcome. We undertook a study to see if prolapsed disc fragment type can predict the possibility of recurrence of disc herniation or sciatica. Method: We looked at the records of patients who had a discectomy operation during a 10-year period from 1992–2002. We excluded from the study patients who had a concomitant fusion operation, patients with multiple level disc operations and those who have diabetes. We went through the operation records, looking for the type of the disc fragment, i.e. whether it was contained, extruded or sequestrated disc. In the follow-up notes we recorded the patients that complained of leg pain, starting three months after the operation and continuing despite treatment. We recorded the length of follow-up. Results: Sixty-five patients were entered for the study. There were 31 males and 34 females. The age range at surgery was 16–61 years (average 42.1 year). The follow-up ranged from 18 months to 10 years (average 30 months). We divided the patients into two groups. Group A, those patients with recurrent leg pain; and group B, those patients with no leg pain. There were 18 patients in group A – they were all subjected to further examination with MRI scan. In five of the patients, the scan showed recurrence of disc herniation. It was an ipsilateral reherniation in four patients and contralateral in one patient. Eight of these 18 patients required repeat surgery. In the five patients with reherniation (7.69% of whole series), the repeat surgery was a discectomy. In another three patients the surgery was a wide decompression and fusion. On further analysing the pathology found at the initial discectomy, in the group A patients, six (33%) had extruded discs and 12 (66%) had contained discs. In group B, 34 (72%) had extruded discs and 13 (27%) had contained discs. The statistical significance in this small series is debatable. Conclusion: Patients with extruded discs do much better than those with contained discs. Recurrent disc herniation is more common in contained discs and less common in extruded discs. If we could select pre-operatively those patients with contained disc herniations, we could elect to persist with conservative treatment for longer in this group

The aim of this study was to assess whether the pro-lapsed disc fragment type was predictive of recurrent disc herniation or sciatica after discectomy. The records of 39 patients treated by lumbar discectomy only were reviewed. Within two months of surgery, the type of disc fragment prolapse and state of the annulus were assessed on CT scans or MRI. Patients who presented later with recurrent sciatica or disc prolapse were reviewed with MRI. All other patients were contacted and asked whether they had had recurrent sciatica or had undergone repeat surgery elsewhere. The follow-up period was three years. The results suggest that patients in whom discs required annulotomy at surgery had poorer results than those with extrusion through an annular fissure. The degree of annular competence can be used to assess the risk of recurrence of herniation or sciatica

Objectives: A retrospective study of patients undergoing second operation after initial lumbar discectomy, to investigate the reasons associated. Methods: In a period of three years a total number of 30 patients had a reoperation after lumbar discectomy. The initial operation performed before one month to five years. There is a evaluation of intraoperative findings and of a short period of follow up. Data were obtained from Spine Unit of Errikos Dunan Hospital. Results: Among 30 patients, 60% were recurrent disc herniations, 18% were fusions and 22% were decompressions. The follow up is from two months to three years for 25 patients, 4 patients had further spinal surgery. Very satisfied, satisfied were 80% of patients. Conclusion: Although reoperation after lumbar discectomy is uncommon, it is very possible to face it because of the increasing number of initial discectomies performed

In a prospective, consecutive study 93 patients who had had previous lumbar spinal surgery underwent repeat decompression for persistent or recurrent back and leg pain. The previous operations had been discectomies in 65 patients and decompression for spinal stenosis in 28; two of the latter group had also had posterolateral fusion. At the repeat operation, disc herniation was found in 19 patients, lateral spinal stenosis in 19, central spinal stenosis in 20 and periradicular fibrosis in 35. Ninety-one patients were followed up for two years after surgery; the effect of the operation was recorded using a four-scale grading system. The results were significantly related to the diagnosis. Nerve-root compression due to recurrent disc herniation or to bony compression responded well to repeat decompression. In patients with a single nerve-root compression the results were similar to those obtained in primary operations. Sciatica due to nerve-root scarring was seldom improved by the repeat operation

Revision discetomy is a procedure often assumed to give similar results to primary discectomy. There is no level one or level two evidence to support this view and no publications with pre and post surgical spine specific outcome measures. This aim of this study was to evaluate the surgical outcomes of revision discectomies using standard spine instruments and to identify factors which influence the outcome. A prospective cohort study was performed between 1996 and 2004. A revision discectomy was defined as surgery at the same lumbar level as a previous discectomy with a minimum three month interval from the index surgery. Outcome measures were available for all 20 patients from the index primary discectomy. Questionnaires were given to the patients preoperatively and at 2 year follow-up. Among the outcomes measures used were the Oswestry Disability Index (ODI), the Low Back Outcome(LBO), and a Visual Analogue Score(VAS). 20 revision discectomies were performed on 11 males and 9 females, 7 at L4/5 and 13 at L5/S1. The mean age was 41(30–56) and the mean follow-up was 27(24–36) months. The preoperative ODI, LBO and VAS at the index primary discectomy averaged 54(22–82), 19(7–42) and 8(5–10) respectively. The preoperative ODI, LBO and VAS at the revision discectomy averaged 63(34–82), 18(1–46) and 8(1–10) respectively. The ODI, LBO and VAS all improved significantly at follow-up. The ODI averaged 27(2–66) (p< 0.05), the LBO averaged 47 (14–70) (p< 0.05) and the VAS 4(3–9) (p< 0.05). The outcome of revision discectomies is favourable, in this series the average improvement in ODI was 36 points, a clinically significant change. The risk factors which influence the outcome are preoperative ODI, preoperative VAS and Age (p< 0.05). Sex, preoperative LBO, duration between recurrent disc herniation, level of disc herniation and incidental durotomies were not predictive of outcome

We analysed prospectively 26 patients who had revision operations for ipsilateral recurrent radicular pain after a period of pain relief of more than six months following primary discectomy. They were assessed before the initial operation, between the two procedures and at a minimum of two years after reoperation. MRI was performed before primary discectomy and reoperation. Fifty consecutive patients who had a disc excision during the study period but did not have recurrent radicular pain, were analysed as a control group. Of the study group 42% related the onset of recurrent radicular pain to an isolated injury or a precipitating event, but none of the control group did so (p < 0.001). T2-weighted MRI performed before primary discectomy showed that patients in the study group had significantly more severe disc degeneration compared with the control group (p = 0.02). Intraoperative findings revealed recurrent disc herniation in 24 patients and bulging of the disc in two, one of whom also had lateral stenosis. Epidural scarring was found to be abundant, intraoperatively and on MRI, in eight and in nine patients, respectively. At the last follow-up, the clinical outcome was satisfactory in 85% of patients in the study group and in 88% of the control group (p > 0.05). Work or daily activities had been resumed at the same level as before the onset of symptoms by 81% of the patients in the study group and 84% of the control group. No correlation was found between the amount of epidural fibrosis, as seen intraoperatively and on MRI, and the result of surgery. The recurrence of radicular pain caused no significant changes in the psychological profile compared with the assessment before the primary discectomy

This is a study on the results of fifty consecutive patients who underwent endoscopic removal of herniated lumbar disc by interlaminar extra-dural approach. The indication for surgery was unrelenting, single level, unilateral sciatic pain not relieved by conservative treatment, with supportive evidence of disc herniation in MRI. Surgery was carried out in the lateral position. After localizing the disc space by X-ray, two 5 mm portals were made, one for an arthroscope and the other for working instruments. The spinal canal was entered through the inter-laminar route and under direct vision the herniated lumbar disc was removed. The duration of study is from February 1998 to July 1999 with an average follow-up of 14.58 months. There were 31 herniated, 9 extruded and 10 sequestrated discs. All patients were mobilized the same day and 42 were discharged the next day. There were two patients who suffered partial but permanent nerve root damage, 4 had post-operative headache and one developed transient extra-pyramidal symptoms. Modified McNab criteria were applied to study the results by an independent observer. 40 patients (80%) had a very good outcome (i.e. fully functional with occasional discomfort); 5 patients were considered to have a good outcome (i.e. normal function with some restriction to strenuous activity); 2 patients who had partial nerve root damage were considered as fair results though their final outcome was good. 3 patients suffered recurrent disc herniation and were operated by open surgery. These were classified as failures. We conclude that this technique is a minimally invasive procedure with results comparable to conventional disc surgery. The advantages to the surgeon are the excellent illumination, magnification and visualization. The advantages to the patient are minimal surgical trauma and speedy recovery

Purpose of the study: Discal arthroplasty is warranted as a part of the treatment of discopathy to guarantee mobility after disc removal. Depending on the type of discopathy, the diseased disc can be classified into different categories: absence of herniation (H0), disc herniation (H1), recurrent disc herniation (H2), post discectomy syndrome (H3), or stenosis of a single unit (including grade 1 degenerative spondylolisthesis) (St-SPd). The purpose of this study was to compare clinical outcome after discal arthroplasty for these different clinical situations. Material and methods: This was a prospective study of 152 patients who underwent a single-stage operation for insertion of a lumbar disc prosthesis. Pain was assessed with a visual analog scale for the lumbar level (VAS-L), and for radicular pain (VAS-R) and the Oswestry index (ODI). Patients were classified as follows: 39 H0, 52 H1, 22 H2, 29 H3, 10 ST-SPd). Results: Outcome in patients in groups H0, H1, and St-SPd, i.e. first-intention surgery patients, presented equivalent results for lumbar and radicular pain and for function: VAS-L and VAS-R declined concomitantly. Results at three months postop were equivalent to those observed at 24 months. Patients in groups H2 and H3 who had had prior operation(s) for posterior discectomy experienced rapid relief of lumbar pain but radicular pain persisted postoperatively (6 to 12 m). Discussion: These data confirm the excellent results obtained with single-level disc replacement as assessed by VAS and ODI. The persistence of radiculalgia which then resolves several months later in patients with a history of discal surgery can be explained by the combination of chronic compression, postoperative adherences and restored disc height. In the present series, none of the patients required complementary surgery for posterior radicular release. Conclusion: Discal arthroplasty provides satisfactory results for the different stages of discal disease. The procedure should however be undertaken with prudence for patients who have had prior surgery. A perfect analysis of other factors involved should be helpful in chosing the most appropriate technique and avoid the development of postoperative radiculalgia. The present results could be usefully confirmed with a long-term randomized prospective study comparing discal prosthesis with fusion for the treatment of discal disease

The volume of spinal procedures have increased over the last two decades (220% in lumbar region). A simultaneous increase in re-operation rates (up to 20%) has been reported. Our aim was to compare with literature the reoperation rates and complications for various spinal procedures from a peripheral unit and to provide this information to the patients. This was a retrospective study of all patients who underwent spinal surgery during the period 1995 to 2005 by one surgeon. Using ICDM-9 codes and private notes patients were identified and medical records were used to gather relevant data. The following information was extracted-demographics, diagnosis, ASA criteria, primary procedure, any complication/s, secondary procedures, duration of follow up and to secondary procedure. The index procedures were grouped into regional and according to indication. Both complications and reoperations were grouped into early (within three months) or delayed (after three months) from the index operation. Reoperation rates and complications were calculated and compared with literature. Four hundred and thirty-nine patients formed the study population. Five patients had inadequate data and were excluded. 23 patients have since died. Demographics showed 22% were smokers and 9% were either unemployed or sickness beneficiary. The commonest diagnosis in the lumbar spine was disc herniation (194). Stenosis and disc degeneration were the next most common surgical indications. In the cervical spine 27 patients had disc herniation and 15 patients were operated for trauma. Lumbar discectomy was the commonest procedure-191 patients with one third having microdiscectomy. Instrumented fusion was performed in 97 while 37 patients underwent decompression only. The majority of cervical spine patients (46) had discectomy and fusion. Stabilisation for trauma formed a reasonable workload in both cervical and lumbar regions. Early complications included dural tears (seven), neurological symptoms (eight), wound infections (12) and pulmonary embolism (one) and repeat disc herniation. Delayed problems included repeat disc herniation, pseudoarthrosis and implant related symptoms. Overall re-operation rate was 14.52% with 5.02% early and 9.4%delayed repeat surgery. Repeat discectomy (eight) and decompression and exploration (seven) were the common early reoperation whereas fusion post discectomy (19) and recurrent disc herniation (12) were indications for delayed intervention. Removal of metalware (8) was another large late re-operation group. Our re-operation rates fall within the quoted figures in literature. However our early re-operation rates are somewhat higher. These figures help us to inform patients better at the time of consent for the primary procedure especially lumbar disc surgery as most of the re-operation were required after discectomy

INTRODUCTION: Intervertebral degeneration is characterised by instability due to permanent decrease in the stiffness of the intervertebral segment and concentration of stress upon the posterior portion of the disc, and by morphologic changes in the posterior elements due to posterior displacement of loading, notably enlargement of the lamina and zygapophyseal joints. These changes lead to reduction in the cross-sectional area of the vertebral canal. In order to counterbalance these changes, an implant has been developed with an interspinous blocker and an artificial ligament made of Dacron. This obviates the need for a permanent fixation in the vertebral bone, avoiding the risk of loosening. Inhibition of hyperextension limits narrowing of the posterior canal, resulting in an increase in its cross-sectional area of up to 40%. A first-generation implant for nonrigid stabilisation of lumbar segments was developed in 1986 with a titanium interspinous blocker. Following an initial observational study in 1988 and a prospective controlled study from 1988 to 1993, more than 300 patients have been treated for degenerative lesions with significant resolution of residual low back pain with no serious adverse effects. After careful analysis of the points that could be improved,a second-generation,improved implant called the ‘Wallis implant’ was developed with a redesigned blocker made of PEEK (polyetheretherketone), a more resilient material. METHODS: Biomechanical studies were used to verify the effectiveness of this implant in increasing intervertebral stiffness, reducing mobility, and unloading the facet joints and the posterior portion of the disc. A prospective multicenter international observational study was begun a year ago. RESULTS: Preliminary results confirm the clinical efficacy of this treatment on low back pain and nerve root symptoms, especially in recurrent disc herniation and canal stenosis. DISCUSSION: Nonrigid intervertebral fixation with the Wallis implant clearly appears to be a useful technique in the management of initial forms of degenerative intervertebral lumbar disc disease. The method should rapidly assume a specific role along with total disc prostheses in the new step-wise surgical strategy to obviate definitive fusion of degenerative intervertebral segments. Moreover, dynamic stabilisation with the Wallis system is totally reversible and leaves all other options open. Wallis is recommended for patients with lumbar disc disease who have: (i) discectomy for massive herniated disc leading to substantial loss of disc material, (ii) a second discectomy for recurrence of herniated disc, (iii) discectomy for herniation of a transitional disc with sacralization of L5, (iv) degenerative disc disease at a level adjacent to a previous fusion or prosthesis, (v) isolated disc resorption, notably with concomitant type-1 Modic changes, associated with low back pain, or (vi) symptomatic narrow canal treated by resection of the superior aspect of the laminae

Background: To asses the safety and efficacy of the Wallis Stabilization System in degenerative disorders of the lumbar spine. Methods: A prospective international multicentre clinical and radiological outcome assessment study. The study is ongoing. The study group comprises 260 consecutive patients meeting inclusion and exclusion criteria with respect to diagnosis (and levels affected), age, medical conditions and prior surgery. 61% were male, 39% female and the mean age was 44 years. The principal diagnosis was massive disc herniation in 37%, degenerative disc disease (with Modic type I change) in 27%, canal stenosis in 13%, recurrent disc herniation in 9% and disc herniation above a transitional segment in 5%. L4/5 was the operated level in 88%. Clinical assessment has been performed using a p atient completed questionnaire incorporating SF-36, JOA (Japanese Orthopaedic Association score), VAS (lumbar pain Visual Analogue Score, 0–100), ODI (Oswestry Disability Index) and Odem’s Criteria. Any adverse or serious adverse events were documented. Pre-operative static and dynamic radiographs and MRI scans have been undertaken, and the radiographs are then repeated at 3 and 6 months post-operatively and yearly thereafter. Post-operative MRI scans are obtained on a yearly basis up to 5 years post-surgery. Results: Mean operating time has been 74 minutes overall, with mean implantation time of 19 minutes. Blood loss averaged 180 mls. The pre-operative mean VAS of 71 improved to 21 at 3 months (p< 0.01) with further improvement at 6 months (VAS 18) and 1 year (VAS 11). SF-36 scores improved in every category from 3 months onwards, this improvement being statistically significant in all categories except general health. At 1 year SF-36 scores were not distinguishable from an age and sex matched general population. JOA scores improved significantly from 6.1 (15 point scale) pre-operatively to 12.5 at 3 months and 13.7 at 12 months (p< 0.01). Odem’s criteria provide additional evidence of efficacy, with 80% of subjects categorized as ‘good’ or ‘excellent’ at 3 months, this proportion improving to 89% at 1 year. Of those graded as ‘fair’ at 3 months, half had improved to ‘good’ or ‘excellent’ by 1 year. From the series of 260 cases there were only 3 implant related complications (1.2%). Conclusion: Previous biomechanical and finite element analysis studies have shown that the Wallis stabilization system off-loads the intervertebral disc and improves the biomechanical characteristics of the degenerative lumbar motion segment. The surgical procedure is simple, minimally invasive and non destructive, preserving surgical options for the future. This study provides preliminary evidence with respect to the safety and efficacy of the Wallis Stabilization System