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

The study was designed to observe the patients emotional and physical response to total disc replacement surgery in the cervical spine. A prospective cohort study of patients undergoing Cervical total disc replacement (TDR) surgery at our institution. Surgery was carried for radicular and or axial neck pain. The Activ-C TDR (Aesculap) was used. Pre and post operative data was collected using validated questionnaires. 13 Consecutive patients from Nov 2007 to Aug 2008 were studied. All patients were planned for surgical intervention for symptomatic degenerative cervical disc disease at single or multiple levels. 7 male, 6 female. The Centre for Epidemiological Studies Depression Scale (CES-D) was used to assess the psychological impact. The Neck Disability Index (NDI) and a visual analogue scale (VAS) were used to assess the physical impact of the surgery. NDI shows a significant improvement at 6 and 12 months (p= 0.002 and p=0.02 respectively). The VAS also shows significant improvement at 6 and 12 months (p=0.004 and 0.008 respectively) The CES-D improved but failed to show any significant improvement at either interval. In our patient population surgical intervention with TDR for degenerative disc disease offers significant physical benefit over the short term. This does not correlate with an improvement in their emotional state

School of Mechanical Engineering, University of Birmingham, Birmingham, UK. This study investigated the effects on friction of changing the dimensions of a ball-and-socket Total Disc Arthroplasty (TDA). A generic ball-and-socket model was designed and manufactured based on the dimensions and geometry of a metal-on-metal Maverick (Medtronic, Minneapolis, USA) device. Keeping the radial clearance similar to the Maverick, the ball and socket dimensions varied between 10 to 16 mm and 10.015 to 16.015 mm, respectively, in order to enable the comparison between different dimensions. The implants were made out of Cobalt Chrome Molybdenum alloy, with a surface roughness of 0.05 μm. A Bose spine simulator (Bose Corporation, ElectroForce Systems Group, Minnesota, USA) was used to apply an axial compressive force to the TDA. Axial rotation of ±2° was then applied at various frequencies and the resulting frictional torque measured. The tests were performed under an axial load of 50, 600 and 1200 N and frequencies of 0.5, 1.0, 1.5 and 2.0 Hz, for four different samples of radii 10, 12, 14 and 16 mm (48 combinations in total). The results showed variation of frictional torque in different frequencies for all four samples under constant axial load. It was observed that the frictional torque had the lowest value for the implant with ball radius of 16mm. It might be concluded that the implant with larger ball radius may create less friction and hence offer a longer life

To determine the cost-effectiveness of Lumbar Total Disc Replacement (LTDR) with circumferential spinal fusion surgery. Cost utility analysis. We prospectively reviewed a cohort of 32 consecutive patients who underwent LTDR between 2004 and 2008 with a mean follow-up for 3.75 years. Identical data was compared to a similar group of patients (n=37) who underwent fusion in our institution. Oswestry Disability Index, visual analogue scale, quality of life (SF-36) and NHS resource use. Cost-effectiveness was measured by the incremental cost per quality-adjusted life year (QALY) gained. QALY gains were estimated from SF-36 data using standard algorithms. There was no significant intergroup difference in the ODI, VAS and SF-36 pre and post-op. Both treatments produced statistically significant and equivalent improvements in mean health state utility at the 24-month follow-up (0.078 for LTDR, 0.087 for fusion). Costs were significantly lower with LTDR than with fusion due to a shorter mean procedure time (193.6 vs 377.4 minutes) and shorter length of stay (5.8 vs 7 days). The mean cost difference was £2,878 per patient. At 2 years, the cost per QALY gain of the lower-cost option (LTDR) was £48,892 although the cost effectiveness ratio would fall to below £30,000 if it is assumed that the patient benefits of LTDR last for at least 4 years. Both treatments led to significant improvements in patient outcomes which were sustained for at least 24 months. Costs were lower with LTDR which is effective and a more cost-effective alternative

Aim. NICE guidance on lumbar total disc replacement (TDR) recommends ongoing audit should be an integral part of disc replacement surgery. We present our ongoing audit data and the extent of problem of patients lost to follow up. Method. 35 patients underwent lumbar TDR surgery over 4.5 years. They were followed prospectively. A database is maintained and ODI and VAS were collected prospectively, including patient satisfaction and any failures. Results. At latest follow up full data was available for 30 out of 35 patients. The mean follow-up was 34 months (range 3-52 months). There were 13 males with a mean age 37.7 years (range 27-62) and 17 females with a mean age of 49.8 years (range 27-62). Surgery was single level in 24 cases and double level in 6 cases. 21 patients rated their outcome as good or very good and 7 as unsatisfactory. There were 2 failures, one secondary to late extrusion of the polyethylene liner (12 months post-surgery) and one early anterior migration of the prosthesis. ODI scores improved by a mean of 28 points (range -4 to 68) whilst VAB scores improved by a mean of 4.9 (range -1 to 9). Five patients had been lost to follow up. One patient migrated out of the area. Two came from out of the area and did not return for follow up after the initial period and two further patients DNAed multiple clinic appointments. Conclusion. We conclude that lumbar disc replacement surgery can provide substantial improvement in pain relief and function. Continued audit of this cohort of patients is essential to comply with NICE guidance. 14% loss to follow up/audit is encountered despite our best effort

This prospective multicentre study was undertaken to determine segmental movement, disc height and sagittal alignment after total disc replacement (TDR) in the lumbosacral spine and to assess the correlation of biomechanical properties to clinical outcomes. A total of 173 patients with degenerative disc disease and low back pain for more than one year were randomised to receive either TDR or multidisciplinary rehabilitation (MDR). Segmental movement in the sagittal plane and disc height were measured using distortion compensated roentgen analysis (DCRA) comparing radiographs in active flexion and extension. Correlation analysis between the range of movement or disc height and patient-reported outcomes was performed in both groups. After two years, no significant change in movement in the sagittal plane was found in segments with TDR or between the two treatment groups. It remained the same or increased slightly in untreated segments in the TDR group and in this group there was a significant increase in disc height in the operated segments. There was no correlation between segmental movement or disc height and patient-reported outcomes in either group. In this study, insertion of an intervertebral disc prosthesis TDR did not increase movement in the sagittal plane and segmental movement did not correlate with patient-reported outcomes. This suggests that in the lumbar spine the movement preserving properties of TDR are not major determinants of clinical outcomes. Cite this article: Bone Joint J 2013;95-B:81–9

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

Aims

The aim of this study was to reassess the rate of neurological, psoas-related, and abdominal complications associated with L4-L5 lateral lumbar interbody fusion (LLIF) undertaken using a standardized preoperative assessment and surgical technique.

Surgical management of symptomatic lumbar degenerative disc disease (DDD) currently consists of fusion or implantation of a first generation total disc replacement (TDR). This study is the first to evaluate an elastomeric one-piece TDR in a 50-patient European study. Fifty patients with single-level, symptomatic lumbar DDD at L4-S1 who were unresponsive to at least 6-months of non-operative therapy were enrolled in a clinical trial of a viscoelastic TDR (VTDR) at three European sites. Patients were assessed clinically and radiographically at 6 weeks, 3 and 6 months, and 1 and 2 years. Oswestry Disability Index (ODI) and Visual Analogue Scale (VAS) were used to assess clinical outcomes. Twenty-eight males and twenty-two females were enrolled in the study. The average age of patients was 39.7 (23 to 61). The operative level was L4/L5 in 13 patients and L5/S1 in 37 patients. There were no intra-operative complications. Quantitative radiographic assessment indicates that the VTDR restores and maintains a physiologically appropriate disc height and angle, while providing range of motion and translation similar to those provided by the natural disc. Mean ODI scores decreased from 48% pre-operatively to 25% at two years follow up. Mean VAS low back pain scores decreased from 7.1 cm pre-op to 3 cm at two years. Median scores indicate that half of the patient population has ODI scores below 13% and VAS back pain scores below 0.5 cm. Clinically and radiologically, this elastomeric disc is performing satisfactorily, and the causes of clinical failures can be more readily identified

Aim. To evaluate the level of health resource utilisation by patients after lumbar total disc replacement (TDR) for mechanical low back pain. Method. At our centre, 35 patients underwent TDR and were followed prospectively from surgery. All surgery was performed by the senior author. Patients were followed routinely in clinic at yearly intervals. In addition, the patients and their GPs were contacted via telephone. Information gathered included ODI and VAS, satisfaction with surgery and return to work. We specifically established whether the patients continued to seek healthcare, for persistent back symptoms, from professionals (both NHS and private) including their GP, pain clinic, physiotherapist, acupuncturist, chiropractor or another spinal surgeon, and had any further interventions. Results. We have complete dataset on 30 out of 35 patients and are the subject of this study. There were 13 men, with a mean age of 37.7 years (range 28-45 years), and 17 women with a mean age of 49.8 years (range 27-62 years). Surgery was single level in 26 and two levels in 6 cases. Patients were satisfied with the outcome of surgery in 21 cases (70%), not satisfied in 7. Two cases had implant failures. 25 patients were working pre-operatively and 26 were working postoperatively. Eighteen patients required no further healthcare input. Five had had pain clinic reviews, six had seen their GPs (1-6 visits) and one another spinal surgeon (after late liner extrusion). Seven had facet injections and two had epidurals. One patient underwent posterior fusion for implant migration. Conclusion. In our series TDR is successful in 70% and 60% of the entire cohort needed no further healthcare input. After successful TDR there is almost no ongoing use of health resources

Purpose of the study. To compare safety and efficacy of cervical disc replacement (CRD) in single and multilevel DDD. Patients were followed up at 1, 3, 6, 12 and 24 months. Methods. 249 patients were enrolled. 171 patients were treated at 1-level, 41 treated at 2 levels and 2 patients were treated at 3 levels. Implant was also used adjacent to a fusion with a cage in 35 patients. The diagnosis was cervical degenerative disc disease between C3 and C7 with symptomatic DH. Population was 106 male 143 female, average age 46 (25-71). Clinical assessment included VAS scores for arm and neck pain and Neck Disability Index (NDI). Range of motion (ROM) from flexion/extension lateral view were measured. Results. Of all NDI scores recorded, 86,50 % demonstrated at least 15 points improvement at two years follow up from pre-op scores. 85,1% of VAS arm Pain scores demonstrated an improvement by = 2 points from pre-op scores and 50,8% for VAS neck Pain scores. The breakdown by levels and adjacent to an interbody cage shown that 80% of reported NDI scores demonstrated at least a 15 point improvement post operatively for two level disc replacement. 82,4% demonstrated a greater than 2 points improvement in VAS arm pain and 53,3% for VAS neck pain. For patients that received both implant and an interbody cage, 72,7% demonstrated a greater than 2 point improvement in VAS arm pain and 41,7% for VAS neck pain. Three (1,8%) cases of subsidence and 4 cases of implant loosening/displacement due to inappropriate sizing were reported. Available radiographic findings show on average a ROM of 8,2 ° at 2 years and an overall change in cervical lordosis of 5° from pre-op. Conclusion. Clinical outcomes demonstrated a significant improvement for both the total population (n=249) and for the single level total disc replacement population (n=171). Given these outstanding results single and multilevel TDR with this implant can be considered to be safe. No significant difference was observed between single and multilevel TDR groups regarding clinical, functional and radiological results. Follow up for this series need however to be extended for up to 5 years at least. The role of this implant in multilevel cases as well as in cases to a fused level still need further evaluation although these preliminary results are encouraging

Aims

This study, using a surgeon-maintained database, aimed to explore the risk factors for surgery-related complications in patients undergoing primary cervical spine surgery for degenerative diseases.

This article reviews the current knowledge of the intervertebral disc (IVD) and its association with low back pain (LBP). The normal IVD is a largely avascular and aneural structure with a high water content, its nutrients mainly diffusing through the end plates. IVD degeneration occurs when its cells die or become dysfunctional, notably in an acidic environment. In the process of degeneration, the IVD becomes dehydrated and vascularised, and there is an ingrowth of nerves. Although not universally the case, the altered physiology of the IVD is believed to precede or be associated with many clinical symptoms or conditions including low back and/or lower limb pain, paraesthesia, spinal stenosis and disc herniation.

New treatment options have been developed in recent years. These include biological therapies and novel surgical techniques (such as total disc replacement), although many of these are still in their experimental phase. Central to developing further methods of treatment is the need for effective ways in which to assess patients and measure their outcomes. However, significant difficulties remain and it is therefore an appropriate time to be further investigating the scientific basis of and treatment of LBP.