A meta-analysis of artificial total disc replacement versus fusion for lumbar degenerative disc disease

Fatty Infiltration in Paraspinal Muscles: Predicting the Outcome of Lumbar Surgery and Postoperative Complications

Lumbar spine disorders often cause lower back pain, lower limb radiating pain, restricted movement, and neurological dysfunction, which seriously affect the quality of life of middle-aged and older people. It has been found that pathological changes in the spine often cause changes in the morphology and function of the paraspinal muscles (PSMs). Fatty infiltration (FI) in PSMs is closely associated with disc degeneration and Modic changes. And FI causes inflammatory responses that exacerbate the progression of lumbar spine disease and disrupt postoperative recovery. Magnetic resonance imaging can better distinguish between fat and muscle tissue with the threshold technique. Three-dimensional magnetic resonance imaging multi-echo imaging techniques such as water-fat separation and proton density are currently popular for studying FI. Muscle fat content obtained based on these imaging sequences has greater accuracy, visualization, acquisition speed, and utility. The proton density fat fraction calculated from these techniques has been shown to evaluate more subtle changes in PSMs. Magnetic resonance spectroscopy can accurately reflect the relationship between FI and the degeneration of PSMs by measuring intracellular and extracellular lipid values to quantify muscle fat. We have pooled and analyzed published studies and found that patients with spinal disorders often exhibit FI in PSMs. Some studies suggest an association between FI and adverse surgical outcomes, although conflicting results exist. These suggest that clinicians should consider FI when assessing surgical risks and outcomes. Future studies should focus on understanding the biological mechanisms underlying FI and its predictive value in spinal surgery, providing valuable insights for clinical decision-making.

Prosthesis optimization and mechanical analysis of artificial lumbar disc replacement

BACKGROUND

Artificial lumbar disc replacement is an effective method for the treatment of lumbosacral degenerative diseases. An appropriate artificial intervertebral disc device is of great significance for the maintenance of spinal stability and activity.

METHODS

Two finite element models of ProDisc-L prosthesis replacement and improved prosthesis replacement were constructed by using the finite element model of complete lumbar L1-L5 segment established by CT image data. The mechanical properties of the surgical models before and after improvement were analyzed and evaluated.

RESULTS

The ProDisc-L group and the improved group showed similar lumbar's ROM and maintained a similar ROM with the normal lumbar spine. There was no significant change in the intervertebral disc's pressure between the adjacent segments of the two prosthesis groups compared with the normal group, but the stress value of the improved prosthesis group was slightly lower than that of the ProDisc-L group. In addition, the improved prosthesis replacement has more reasonable stress distribution.

CONCLUSIONS

Compared with the ProDisc-L prosthesis, the improved prosthesis can reduce the pressure in the intervertebral disc of the adjacent segment, the contact stress of the facet joint and the artificial prosthesis, which provides reference for the subsequent design of the prosthesis structure.

Lumbar Total Disc Replacements for Degenerative Disc Disease: A Systematic Review of Outcomes With a Minimum of 5 years Follow-Up

STUDY DESIGN

Systematic Review.

OBJECTIVES

To systematically review the clinical outcomes, re-operation, and complication rates of lumbar TDR devices at mid-to long-term follow-up studies for the treatment of lumbar degenerative disc disease (DDD).

METHODS

A systematic search was conducted on PubMed, SCOPUS, and Google Scholar to identify follow-up studies that evaluated clinical outcomes of lumbar TDR in patients with DDD. The included studies met the following criteria: prospective or retrospective studies published from 2012 to 2022; a minimum of 5 years post-operative follow-up; a study sample size >10 patients; patients >18 years of age; containing clinical outcomes with Oswestry Disability Index (ODI), Visual Analog Scale (VAS), complication or reoperation rates.

RESULTS

Twenty-two studies were included with data on 2284 patients. The mean follow-up time was 8.30 years, with a mean follow-up rate of 86.91%. The study population was 54.97% female, with a mean age of 42.34 years. The mean VAS and ODI pain score improvements were 50.71 ± 6.91 and 30.39 ± 5.32 respectively. The mean clinical success and patient satisfaction rates were 74.79% ± 7.55% and 86.34% ± 5.64%, respectively. The mean complication and reoperation rates were 18.53% ± 6.33% and 13.6% ± 3.83%, respectively. There was no significant difference when comparing mid-term and long-term follow-up studies for all clinical outcomes.

CONCLUSIONS

There were significant improvements in pain reduction at last follow-up in patients with TDRs. Mid-term follow-up data on clinical outcomes, complication and reoperation rates of lumbar TDRs were maintained longer term.

Cervical and Lumbar Disc Arthroplasty: A Review of Current Implant Design and Outcomes

While spinal disc pathology has traditionally been treated using fusion-based procedures, recent interest in motion-preserving disc arthroplasties has grown. Traditional spinal fusion is associated with loss of motion, alteration of native spine kinematics, and increased risks of adjacent segment disease. The motion conferred by disc arthroplasty is believed to combat these complications. While the first implant designs resulted in poor patient outcomes, recent advances in implant design and technology have shown promising radiographic and clinical outcomes when compared with traditional fusion. These results have led to a rapid increase in the utilization of disc arthroplasty, with rates of cervical arthroplasty nearly tripling over the course of 7 years. The purpose of this review was to discuss the evolution of implant design, the current implant designs utilized, and their associated outcomes. Although disc arthroplasty shows significant promise in addressing some of the drawbacks associated with fusion, it is not without its own risks. Osteolysis, implant migration, and the development of heterotopic ossification have all been associated with disc arthroplasty. As interest in these procedures grows, so does the interest in developing improved implant designs aimed at decreasing these adverse outcomes. Though they are still relatively new, cervical and lumbar disc arthroplasty are likely to become foundational methodologies for the treatment of disc pathology.

A meta-analysis comparing the short- and mid- to long-term outcomes of artificial cervical disc replacement(ACDR) with anterior cervical discectomy and fusion (ACDF) for the treatment of cervical degenerative disc disease

PURPOSE

Anterior cervical discectomy and fusion (ACDF) surgery is commonly performed to treat cervical degenerative disc disease (CDDD). The lost of range of motion (ROM) is also found after ACDF, which contributes to degenerate in adjacent segment disease (ASD). Artificial cervical disc replacement (ACDR), an alternative to ACDF, is developed to preserve the ROM and reduce ASD. This article aims to compare the outcomes between ACDR and ACDF in the short-, mid-, and long-term.

METHODS

Databases including Cochrane, Embase, PubMed, and Web of Science were searched. Only RCTs were included in this meta-analysis, and the search strategy followed the requirements of the Cochrane Handbook. The strength of evidence was assessed using GRADE. Two reviewers independently assessed the methodological quality of each included study and extracted the relevant data.

RESULTS

Thirty prospective RCTs were included. Prolonged operative duration, better overall success, neurological success, and NDI success rates were found in ACDR group in all follow-up periods, with lower dysphagia/dysphonia during short-term follow-up. Moreover, a lower ASD was found in ACDR group during long-term follow-up and overall analysis, with lower reoperation rates in all follow-up periods. Comparable length of hospital stay and blood loss were found in both groups. Moreover, ASD was similar in short- and mid-term follow-ups, while dysphagia/dysphonia incidence was similar in mid- and long-term follow-ups. The incidence of implant events was comparable in all follow-up periods (p > 0.05).

CONCLUSIONS

ACDR is as effective as ACDF and superior for some success rates. Disc replacement can reduce the risk of dysphagia/dysphonia, ASD, and re-operation.

Lumbar Total Disc Replacement: Current Usage

Low back pain is the leading cause of disability worldwide in industrialized nations. The pathology underlying chronic low back pain is associated with numerous factors. Lumbar degenerative disc disease is a potential major source of low back pain. There are numerous treatment modalities and options. Nonsurgical treatment options exist in the form of pain management through a combination of anti-inflammatory medications and steroid injections, physical therapy and lifestyle modifications. This article reviews the history and current trends in use for lumbar toral disc arthroplasty for degenerative disc disease treatment. Furthermore, indications, contraindications, and complications management are discussed.

Periprosthetic Osteolysis in Cervical Total Disc Arthroplasty: A Single Institutional Experience

BACKGROUND

Cervical disc arthroplasty (CDA) affords an excellent alternative to cervical fusion for the treatment of symptomatic patients with degenerative disc disease. As more surgeons perform CDAs, an understanding of the complications associated with this technique is crucial. Periprosthetic osteolysis (PO) is a rare potential complication associated with CDA.

OBJECTIVE

To highlight potential complications associated with CDA.

METHODS

A retrospective chart review of patients who underwent CDA at our institution was performed. Patient outcomes and relevant clinical and radiographical data were analyzed in addition to associated complications. Explanted devices were subjected to macroscopic and microscopic analyses.

RESULTS

A total of 88 patients were included: 68 patients underwent 1-level CDA and 20 patients had 2-level CDA. Implants used in this series included Mobi-C (Zimmer Biomet), Prestige LP (Medtronic), Secure C (Globus), Advent (Orthofix), and ProDisc C (DePuy). One patient demonstrated symptoms of myeloradiculopathy that correlated with radiographical periprosthetic osteolysis and required surgical intervention in the form of disc explantation, corpectomy, and cervical instrumented fusion. Device retrieval analysis demonstrated evidence of elevated oxidation levels and increased wear in the presence of high concentrations of metal ions and debris in the surrounding tissue. The tissue did not exhibit any immune response, infection, or acute inflammation.

CONCLUSION

PO is a potential complication of CDA that occurs irrespective of the type of implant used. We describe its occurrence and management and highlight the importance of being aware of this understated phenomenon.

Spine Fixation Hardware: An Update

OBJECTIVE. The purpose of this article is to provide a review of the imaging of spine fixation hardware. CONCLUSION. As the prevalence of neck and back pain continues to increase, so does the number of surgical procedures used to treat such pain. Accordingly, new techniques and hardware designs are used, and the hardware will be seen on postoperative imaging. It is critical that radiologists understand the appropriate imaging modalities for the assessment of spine fixation hardware, recognize the normal imaging appearance of such hardware, and be able to detect hardware-related complications.

Lumbar Arthroplasty: Past, Present, and Future

Lumbar degenerative disc disease is a pathologic process that affects a large portion of our aging population. In the recent past, surgical treatment has involved fusion procedures. However, lumbar disc arthroplasty and replacement provides an alternative for carefully selected patients. It provides the major advantage of motion preservation and thus keeps adjacent segments from significantly progressive degeneration. The history of lumbar disc replacement has roots that start in the 1960s with the implantation of stainless-steel balls. Decades later, multiple implants with different material design and biomechanical properties were introduced to the market. New third-generation implants have made great strides in improved biomechanics and clinical outcomes. Although there is room for further advancement and studies are warranted to assess the long-term durability and sustainability of lumbar disc arthroplasty, it has certainly proven to be a very acceptable alternative within the surgical armamentarium that should be offered to patients who meet indications. In this review we present an overview of lumbar disc arthroplasty including its history, indications, biomechanics, challenges, and future directions.

Ethanol-mediated compaction and cross-linking enhance mechanical properties and degradation resistance while maintaining cytocompatibility of a nucleus pulposus scaffold

Intervertebral disc degeneration is a complex, cell-mediated process originating in the nucleus pulposus (NP) and is associated with extracellular matrix catabolism leading to disc height loss and impaired spine kinematics. Previously, we developed an acellular bovine NP (ABNP) for NP replacement that emulated human NP matrix composition and supported cell seeding; however, its mechanical properties were lower than those reported for human NP. To address this, we investigated ethanol-mediated compaction and cross-linking to enhance the ABNP's dynamic mechanical properties and degradation resistance while maintaining its cytocompatibility. First, volumetric and mechanical effects of compaction only were confirmed by evaluating scaffolds after various immersion times in buffered 28% ethanol. It was found that compaction reached equilibrium at ~30% compaction after 45 min, and dynamic mechanical properties significantly increased 2-6× after 120 min of submersion. This was incorporated into a cross-linking treatment, through which scaffolds were subjected to 120 min precompaction in buffered 28% ethanol prior to carbodiimide cross-linking. Their dynamic mechanical properties were evaluated before and after accelerated degradation by ADAMTS-5 or MMP-13. Cytocompatibility was determined by seeding stem cells onto scaffolds and evaluating viability through metabolic activity and fluorescent staining. Compacted and cross-linked scaffolds showed significant increases in DMA properties without detrimentally altering their cytocompatibility, and these mechanical gains were maintained following enzymatic exposure. © 2019 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 107B:2488-2499, 2019.

Total disc replacement versus fusion for lumbar degenerative diseases - a meta-analysis of randomized controlled trials

BACKGROUND

Lumbar fusion is considered to the gold standard for treatment of spinal degenerative diseases but results in adjacent segment degeneration and acquired spinal instability. Total disc replacement is a relatively new alternative avoiding the occurrence of the above complications. The systematic review and meta-analysis was designed to evaluate whether total disc replacement exhibited better outcomes and safety.

METHODS

PubMed, Web of Science, Embase, the Cochrane Library, Chinese National Knowledge Infrastructure Database(CNKI), Wangfang database, and VIP database were searched for RCTs comparing total disc replacement with lumbar fusion. All statistical analyses were carried out using the RevMan5.3 and STATA12.0 software.

RESULTS

Of 1116 citations identified by our search strategy, 14 RCTs met the inclusion criteria. Compared to lumbar fusion, total disc replacement significantly improved ODI, VAS, SF-36, patient satisfaction, overall success, reoperation rate, ODI successful, reduced operation time, shortened duration of hospitalization, decreased postsurgical complications. However, total disc replacement did not show a significant difference regarding blood loss, consumption of analgesics, neurologic success and device success with lumbar fusion. And charges were significantly lower for total disc replacement compared with lumbar fusion in the 1-level patient group, while charges were similar in the 2-level group.

CONCLUSION

Total disc replacement is recommended to alleviate the pain of degenerative lumbar diseases, improve the state of lumbar function and the quality of life of patients, provide a high level of security, have better health economics benefits for 1-level patients.

Hypotonicity differentially affects inflammatory marker production by nucleus pulposus tissue in simulated disc degeneration versus herniation

Inflammatory cytokines play an important role in intervertebral disc degeneration. Although largely produced by immune cells, nucleus pulposus (NP) cells can also secrete them under various conditions, for example, under free swelling. Thus, tissue hypotonicity may be an inflammatory trigger for NP cells. The aim of this study was to investigate whether decreased tonicity under restricted swelling conditions (as occurring in early disc degeneration) could initiate an inflammatory cascade that mediates further degeneration. Healthy bovine NP tissue was balanced against different PEG concentrations (0-30%) to obtain various tissue tonicities. Samples were then placed in an artificial annulus (fixed volume) and were cultured for 3, 7, or 21 days, with free swelling NP as control. Tissue content (water, glycosaminoglycan, collagen) was analyzed, and both the tissue and medium were screened for tumor necrosis factor alpha (TNF-α), interleukin-1β (IL-1β), interleukin-6 (IL-6), interleukin-8 (IL-8), prostaglandin-E₂ (PGE₂ ), and nitric oxide (NO). A range of tonicities (isotonic to hypotonic) was present at day 3 in the PEG-treated samples. However, during culture, the tonicity range narrowed as GAGs leached from the tissue. TNF-α and IL-1β were below detection limits in all conditions, while mid- and downstream inflammatory cytokines were detected. This may suggest that the extracellular environment directly affects NP cells instead of inducing a classical inflammatory cascade. Furthermore, IL-8 increased in swelling restricted samples, while IL-6 and PGE₂ were elevated in free swelling controls. These findings may suggest the involvement of different mechanisms in disc degeneration with intact AF compared to herniation, and encourage further investigation. © 2019 The Authors. Journal of Orthopaedic Research® Published by Wiley Periodicals, Inc. on behalf of Orthopaedic Research Society. J Orthop Res.

Chronic low back pain: Relevance of a new classification based on the injury pattern

BACKGROUND

The objectives of this study were to define the role for surgery in the treatment of chronic low back pain (cLBP) and to develop a new classification of cLBP based on the pattern of injury.

HYPOTHESIS

Surgery may benefit patients with cLBP, and a new classification based on the injury pattern may be of interest.

METHOD

A systematic literature review was performed by searching Medline, the Cochrane Library, the French public health database (Banque de Données en Santé Publique), Science Direct, and the National Guideline Clearinghouse. The main search terms were "back pain" OR "lumbar" OR "intervertebral disc replacement" OR "vertebrae" OR "spinal" AND "surgery" OR "surgical" OR "fusion" OR "laminectomy" OR "discectomy".

RESULTS

Surgical techniques available for treating cLBP consist of fusion, disc replacement, dynamic stabilisation, and inter-spinous posterior devices. Compared to non-operative management including intensive rehabilitation therapy and cognitive behavioural therapy, fusion is not better in terms of either function (evaluated using the Oswestry Disability Index [ODI]) or pain (level 2). Fusion is better than non-operative management without intensive rehabilitation therapy (level 2). There is no evidence to date that one fusion technique is superior over the others regarding the clinical outcomes (assessed using the ODI). Compared to fusion or multidisciplinary rehabilitation therapy, disc replacement can produce better function and less pain, although the differences are not clinically significant (level 2). The available evidence does not support the use of dynamic stabilisation or interspinous posterior devices to treat cLBP due to degenerative disease (professional consensus within the French Society for Spinal Surgery). The following recommendations can be made: non-operative treatment must be provided for at least 1 year before considering surgery in patients with cLBP due to degenerative disease; patients must be fully informed about alternative treatment options and the risks associated with surgery; standing radiographs must be obtained to assess sagittal spinal alignment and a magnetic resonance imaging scan to determine the mechanism of injury; and, if fusion is performed, the lumbar lordotic curvature must be restored.

DISCUSSION

This work establishes the need for a new classification of cLBP based on the presumptive mechanism responsible for the pain. Three categories should be distinguished: non-degenerative cLBP (previously known as symptomatic cLBP), in which the cause of pain is a trauma, spondylolysis, a tumour, an infection, or an inflammatory process; degenerative cLBP (previously known as non-specific cLBP) characterised by variable combinations of degenerative alterations in one or more discs, facet joints, and/or ligaments, with or without regional and/or global alterations in spinal alignment (which must be assessed using specific parameters); and cLBP of unknown mechanism, in which the pain seems to bear no relation to the anatomical abnormalities (and the Fear-Avoidance Beliefs Questionnaire and Hospital Anxiety and Depression Scale may be helpful in this situation). This classification should prove useful in the future for constituting well-defined patient groups, thereby improving the assessment of treatment options.

LEVEL OF EVIDENCE

II, systematic review of level II studies.

J, Li Z, Ou Y. The short-term efficacy and safety of artificial total disc replacement for selected patients with lumbar degenerative disc disease compared with anterior lumbar interbody fusion: A systematic review and meta-analysis

Purpose

To systematically compare the efficacy and safety of lumbar total disc replacement (TDR) with the efficacy and safety of anterior lumbar interbody fusion (ALIF) for the treatment of lumbar degenerative disc disease (LDDD).

Methods

The electronic databases PubMed, Web of Science and the Cochrane Library were searched for the period from the establishment of the databases to March 2018. The peer-reviewed articles that investigate the safety and efficacy of TDR and ALIF were retrieved under the given search terms. Quality assessment must be done independently by two authors according to each item of criterion. The statistical analyses were performed using RevMan (version 5.3) and Stata (version 14.0). The random-effect model was carried out to pool the data. The I² statistic was used to evaluate heterogeneity. The sensitivity analysis was carried out to assess the robustness of the results of meta-analyses by omitting the articles one by one.

Results

Six studies (5 randomized controlled trials (RCT) and 1 observational study) involving 1093 patients were included in this meta-analysis. The risk of bias of the studies could be considered as low to moderate. Operative time (MD = 4.95; 95% CI -18.91–28.81; P = 0.68), intraoperative blood loss (MD = 4.95; 95% CI -18.91–28.81; P = 0.68), hospital stay (MD = -0.33; 95% CI, -0.67–0.01; P = 0.05), complications (RR = 0.96; 95% CI 0.91–1.02; P = 0.18) and re-operation rate (RR = 0.54; 95% CI 0.14–2.12; P = 0.38) were without significant clinical difference between groups. Patients in the TDR group had higher postoperative satisfaction (RR = 1.19; 95% CI 1.07–1.32; P = 0.001) and, better improvements in ODI (MD = -10.99; 95% CI -21.50- -0.48; P = 0.04), VAS (MD = -10.56; 95% CI -19.99- -1.13; P = 0.03) and postoperative lumbar mobility than did patients in the ALIF group.

Conclusions

The results showed that TDR has significant superiority in term of reduced clinical symptoms, improved physical function and preserved range of motion for the treatment of LDDD compared to ALIF. TDR may be an ideal alternative for the selected patients with LDDD in the short-term. However, the results of this study cannot suggest the use of TDR instead of ALIF in lumbar spine treatment only in the light of short term results. More studies that are well-designed, that are of high-quality and that have larger samples are needed to further evaluate the efficacy and safety of TDR with at the long-term follow-up.

Level of evidence

Therapeutic Level 3

Osteoarthritis and intervertebral disc degeneration: Quite different, quite similar

Intervertebral disc degeneration describes the vicious cycle of the deterioration of intervertebral discs and can eventually result in degenerative disc disease (DDD), which is accompanied by low-back pain, the musculoskeletal disorder with the largest socioeconomic impact world-wide. In more severe stages, intervertebral disc degeneration is accompanied by loss of joint space, subchondral sclerosis, and osteophytes, similar to osteoarthritis (OA) in the articular joint. Inspired by this resemblance, we investigated the analogy between human intervertebral discs and articular joints. Although embryonic origin and anatomy suggest substantial differences between the two types of joint, some features of cell physiology and extracellular matrix in the nucleus pulposus and articular cartilage share numerous parallels. Moreover, there are great similarities in the response to mechanical loading and the matrix-degrading factors involved in the cascade of degeneration in both tissues. This suggests that the local environment of the cell is more important to its behavior than embryonic origin. Nevertheless, OA is widely regarded as a true disease, while intervertebral disc degeneration is often regarded as a radiological finding and DDD is undervalued as a cause of chronic low-back pain by clinicians, patients and society. Emphasizing the similarities rather than the differences between the two diseases may create more awareness in the clinic, improve diagnostics in DDD, and provide cross-fertilization of clinicians and scientists involved in both intervertebral disc degeneration and OA.

Immunobiology of periprosthetic inflammation and pain following ultra-high-molecular-weight-polyethylene wear debris in the lumbar spine

INTRODUCTION

Wear debris-induced osteolysis is a common cause of arthroplasty failure in several joints including the knee, hip and intervertebral disc. Debris from the prosthesis can trigger an inflammatory response that leads to aseptic loosening and prosthesis failure. In the spine, periprosthetic pain also occurs following accumulation of wear debris through neovascularization of the disc. The role of the immune system in the pathobiology of periprosthetic osteolysis of joint replacements is debatable. Areas covered: We discussed the stimulation of pro-inflammatory and pro-protective and pro-regenerative pathways due to debris from the prosthetics. The balance between the two pathways may determine the outcome results. Also, the role of cytokines and immune cells in periprosthetic inflammation in the etiology of osteolysis is critically reviewed. Expert commentary: Therapies targeting the inflammatory process associated with ultra-high-molecular-weight polyethylene wear debris could reduce implant failure. Additionally, therapies targeting neovascularization of discs following arthroplasty could mitigate periprosthetic pain.

Comparison of Lumbar Total Disc Replacement With Surgical Spinal Fusion for the Treatment of Single-Level Degenerative Disc Disease: A Meta-Analysis of 5-Year Outcomes From Randomized Controlled Trials

STUDY DESIGN

Meta-analysis.

OBJECTIVES

To evaluate the long-term efficacy and safety of total disc replacement (TDR) compared with fusion in patients with functionally disabling chronic low back pain due to single-level lumbar degenerative disc disease (DDD) at 5 years.

METHODS

PubMed and Cochrane Central Register of Controlled Trials databases were searched for randomized controlled trials reporting outcomes at 5 years for TDR compared with fusion in patients with single-level lumbar DDD. Outcomes included Oswestry Disability Index (ODI) success, back pain scores, reoperations, and patient satisfaction. All analyses were conducted using a random-effects model; analyses were reported as relative risk (RR) ratios and mean differences (MDs). Sensitivity analyses were conducted for different outcome definitions, high loss to follow-up, and high heterogeneity.

RESULTS

The meta-analysis included 4 studies. TDR patients had a significantly greater likelihood of ODI success (RR 1.0912; 95% CI 1.0004, 1.1903) and patient satisfaction (RR 1.13; 95% CI 1.03, 1.24) and a significantly lower risk of reoperation (RR 0.52; 95% CI 0.35, 0.77) than fusion patients. There was no association with improvement in back pain scores whether patients received TDR or fusion (MD -2.79; 95% CI -8.09, 2.51). Most results were robust to sensitivity analyses. Results for ODI success and patient satisfaction were sensitive to different outcome definitions but remained in favor of TDR.

CONCLUSIONS

TDR is an effective alternative to fusion for lumbar DDD. It offers several clinical advantages over the longer term that can benefit the patient and reduce health care burden, without additional safety consequences.

Total Disc Replacement Versus Anterior-Posterior Interbody Fusion in the Lumbar Spine and Lumbosacral Junction: A Cost Analysis

STUDY DESIGN

Prospective observational cohort study.

OBJECTIVES

To analyze clinical and economic results in patients with degenerative disc disease in the lumbar area for patients who received combined anterior and posterior fusion or total disc replacement (TDR).

METHODS

The study included 75 patients, 38 in the fusion group and 37 in the TDR group, who received either anterior/posterior fusion or TDR for lumbar disc disease from January 2005 to December 2008 with a minimum follow-up of 24 months. We collected data with regard to clinical parameters, demographics, visual analogue scale scores, Oswestry Disability Index scores, SF-36 and SF-6D data, surgery time, amount of blood loss, transfusion of blood products, number of levels, duration of hospital stay, and complications. For cost analysis, general infrastructure, theatre costs, as well as implant costs were examined, leading to primary hospital costs. Furthermore, average revision costs were examined, based on the actual data. Statistical analysis was performed using t tests for normal contribution and Mann-Whitney test for skew distributed values. The significance level was set to .05.

RESULTS

There was a higher surgery time, more blood loss, and longer hospital stay for the fusion group, compared with the TDR group. In addition, the hospital costs for the primary procedure and revision were 35% higher in the fusion group. The clinical data in terms of SF-36 and SF-6D showed no difference between these 2 groups.

CONCLUSIONS

TDR is a good alternative to anterior and posterior lumbar fusion in terms of short follow-up analysis for clinical data and cost analysis. General advice cannot be given due to missing data for long-term costs in terms of surgical treatment of adjacent level or further fusion techniques.

We Need to Talk about Lumbar Total Disc Replacement

BACKGROUND

Replacement of a diseased lumbar intervertebral disc with an artificial device, a procedure known as lumbar total disc replacement (LTDR), has been practiced since the 1980s.

METHODS

Comprehensive review of published literature germane to LTDR, but comment is restricted to high-quality evidence reporting implantation of lumbar artificial discs that have been commercially available for at least 15 years at the time of writing and which continue to be commercially available.

RESULTS

LTDR is shown to be a noninferior (and sometimes superior) alternative to lumbar fusion in patients with discogenic low back pain and/or radicular pain attributable to lumbar disc degenerative disease (LDDD). Further, LTDR is a motion-preserving procedure, and evidence is emerging that it may also result in risk reduction for subsequent development and/or progression of adjacent segment disease.

CONCLUSIONS

In spite of the substantial logistical challenges to the safe introduction of LTDR to a health care facility, the procedure continues to gain acceptance, albeit slowly.

CLINICAL RELEVANCE

Patients with LDDD who are considering an offer of spinal surgery can only provide valid and informed consent if they have been made aware of all reasonable surgical and nonsurgical options that may benefit them. Accordingly, and in those cases in which LTDR may have a role to play, patients under consideration for other forms of spinal surgery should be informed that this valid procedure exists.

Comparison of therapies in lumbar degenerative disc disease: a network meta-analysis of randomized controlled trials

Aim: To compare the efficacy and safety of total disc replacement, lumbar fusion, and conservative care in the treatment of single-level lumbar degenerative disc disease (DDD). Materials & methods: A network meta-analysis was conducted to determine the relative impact of lumbar DDD therapies on Oswestry Disability Index (ODI) success, back pain score, patient satisfaction, employment status, and reoperation. Odds ratios or mean differences and 95% credible intervals were reported. Results: Six studies were included (1417 participants). Overall, the activL total disc replacement device had the most favorable results for ODI success, back pain, and patient satisfaction. Results for employment status and reoperation were similar across therapies. Conclusion: activL substantially improves ODI success, back pain, and patient satisfaction compared with other therapies for single-level lumbar DDD.

Defining the Ideal Lumbar Total Disc Replacement Patient and Standard of Care

: Lumbar total disc replacement, now in use since 2004, was determined by the panel to be a standard of care for the treatment of symptomatic single-level lumbar degenerative disc disease in the active patient subpopulation as outlined by the investigational device exemption study criteria. The large body of evidence supporting this statement, including surgeons' experiences, was presented and discussed. Consensus statements focusing on decision-making criteria reflected that efficacy, long-term safety, clinical outcomes with validated measures, and cost-effectiveness should form the basis of decision-making by payers. Diagnostic challenges with lumbar degenerative disc disease patients were discussed among the panel, and it was concluded that although variably used among surgeons, reliable tools exist to appropriately diagnose discogenic back pain.

Lumbar disc replacement surgery-successes and obstacles to widespread adoption

PURPOSE OF REVIEW

Lumbar disc replacement has been a surgical alternative to fusion surgery for the treatment of lumbar degenerative disc disease (DDD) for many years. Despite enthusiasm after the approval of the first devices, implantation rates have remained low, especially in the USA. The goal of this review is to provide a general overview of lumbar disc replacement in order to comprehend the successes and obstacles to widespread adoption.

RECENT FINDINGS

Although a large amount of evidence-based data including satisfactory long-term results is available, implantation rates in the USA have not increased in the last decade. Possible explanations for this include strict indications for use, challenging surgical techniques, lack of device selection, fear of late complications or revision surgeries, and reimbursement issues. Recent publications can address some of the past concerns, but there still remain obstacles to widespread adoption. Upcoming data on long-term outcome, implant durability and possible very late complications will determine the future of lumbar disc replacement surgery.

Fat in the lumbar multifidus muscles - predictive value and change following disc prosthesis surgery and multidisciplinary rehabilitation in patients with chronic low back pain and degenerative disc: 2-year follow-up of a randomized trial

Background

Evidence is lacking on whether fat infiltration in the multifidus muscles affects outcomes after total disc replacement (TDR) surgery and if it develops after surgery. The aims of this study were 1) to investigate whether pre-treatment multifidus muscle fat infiltration predicts outcome 2 years after treatment with TDR surgery or multidisciplinary rehabilitation, and 2) to compare changes in multifidus muscle fat infiltration from pre-treatment to 2-year follow-up between the two treatment groups.

Methods

The study is secondary analysis of data from a trial with 2-year follow-up of patients with chronic low back pain (LBP) and degenerative disc randomized to TDR surgery or multidisciplinary rehabilitation. We analyzed (aim 1) patients with both magnetic resonance imaging (MRI) at pre-treatment and valid data on outcome measures at 2-year follow-up (predictor analysis), and (aim 2) patients with MRI at both pre-treatment and 2-year follow-up. Outcome measures were visual analogue scale (VAS) for LBP, Oswestry Disability Index (ODI), work status and muscle fat infiltration on MRI. Patients with pre-treatment MRI and 2-year outcome data on VAS for LBP (n = 144), ODI (n = 147), and work status (n = 137) were analyzed for prediction purposes. At 2-year follow-up, 126 patients had another MRI scan, and change in muscle fat infiltration was compared between the two treatment groups. Three radiologists visually quantified multifidus muscle fat in the three lower lumbar levels on MRI as <20% (grade 0), 20–50% (grade 1), or >50% (grade 2) of the muscle cross-section containing fat. Regression analysis and a mid-P exact test were carried out.

Results

Grade 0 pre-treatment multifidus muscle fat predicted better clinical results at 2-year follow-up after TDR surgery (all outcomes) but not after rehabilitation. At 2-year follow-up, increased fat infiltration was more common in the surgery group (intention-to-treat p = 0.03, per protocol p = 0.08) where it was related to worse pain and ODI.

Conclusions

Patients with less fat infiltration of multifidus muscles before TDR surgery had better outcomes at 2-year follow-up, but findings also indicated a negative influence of TDR surgery on back muscle morphology in some patients. The rehabilitation group maintained their muscular morphology and were unaffected by pre-treatment multifidus muscle fat.

Trial registration

NCT 00394732 (retrospectively registered October 31, 2006).

Operative Management of Lumbar Degenerative Disc Disease

Lumbar degenerative disc disease is extremely common. Current evidence supports surgery in carefully selected patients who have failed non-operative treatment and do not exhibit any substantial psychosocial overlay. Fusion surgery employing the correct grafting and stabilization techniques has long-term results demonstrating successful clinical outcomes. However, the best approach for fusion remains debatable. There is some evidence supporting the more complex, technically demanding and higher risk interbody fusion techniques for the younger, active patients or patients with a higher risk of non-union. Lumbar disc arthroplasty and hybrid techniques are still relatively novel procedures despite promising short-term and mid-term outcomes. Long-term studies demonstrating superiority over fusion are required before these techniques may be recommended to replace fusion as the gold standard. Novel stem cell approaches combined with tissue engineering therapies continue to be developed in expectation of improving clinical outcomes. Results with appropriate follow-up are not yet available to indicate if such techniques are safe, cost-effective and reliable in the long-term.

Prospective Clinical and Radiographic Results of Activ L Total Disk Replacement at 1- to 3-Year Follow-up

STUDY DESIGN

A prospective clinical study.

OBJECTIVE

To assess the clinical and radiographic results of activ L total disk replacement (TDR) on degenerative disk diseases.

SUMMARY OF BACKGROUND DATA

There are few reports on Activ L TDR, and this is the first in China.

MATERIALS AND METHODS

From March 2009 to March 2012, 32 patients with degenerative disk disease underwent either monosegmental or bisegmental lumbar TDR, which was documented in a prospective observational mode. Clinical success was defined as disability [Oswestry Disability Index (ODI)] improvement of at least 15 points versus baseline, no device failure, no major complications, no neurological deterioration. Additional clinical parameters as Visual Analogue Scale and Oswestry Disability Index (ODI) were evaluated preoperatively and postoperatively (1, 2, and 3 y). Radiographic parameters as range of motion (ROM) and intervertebral disk height (IDH) of the index and adjacent segments were also carried out. Prosthesis subsidence and heterotopic ossification were observed during the follow-up period. Work status was tracked for all patients.

RESULTS

Overall, 30 patients (93.7%) were available for a mean follow-up of 28.8 months (12-46 mo) and had complete radiographic data. Their mean age was 45.1 years (32-58 y). At 3 years postoperatively, the success rate was 86.7% (26/30). After surgery, clinical parameters as Visual Analogue Scale score for back and leg pain, and ODI score showed statistically significant improvement (P<0.001), and the situation was well maintained during the follow-up time points. At 3 years postoperatively, the mean IDH at the index segment and upper and lower adjacent segments were 12.87, 12.61, and 11.62 mm, respectively, showing no significant difference compared with preoperative data (P1=0.0597, P2=0.6669, P3=0.9813). The ROM of the index and upper adjacent segment showed a slight but significant increase at the 3-year follow-up compared with baseline (P1=0.0128, P2=0.0007). The changes of ROM at the lower adjacent segment were not significant (P=0.6637). Tears of the iliac vein were observed in 2 patients. Prosthesis subsidence was observed in 3 patients (1 at 12 mo postoperatively, 1 at 24 mo postoperatively, and 1 at 32 mo postoperatively). Heterotopic ossification was observed in 1 patient at 36 mo postoperatively. At the 3-year follow-up, only 8 patients went back to their original work, and 15 patients changed jobs, whereas the last 7 patients stopped working.

CONCLUSIONS

The 1- to 3-year follow-up of this cohort of patients showed satisfactory clinical outcomes. The IDHs at index and adjacent segments were well maintained after the surgery. The ROM at the lower adjacent segment remained unchanged, but the ROM at the index and upper adjacent segments showed a slight increase. The long-term results of activ L TDR was to be investigated.

The activL(®) Artificial Disc: a next-generation motion-preserving implant for chronic lumbar discogenic pain

Degeneration of the lumbar intervertebral discs is a leading cause of chronic low back pain in adults. Treatment options for patients with chronic lumbar discogenic pain unresponsive to conservative management include total disc replacement (TDR) or lumbar fusion. Until recently, only two lumbar TDRs had been approved by the US Food and Drug Administration - the Charité Artificial Disc in 2004 and the ProDisc-L Total Disc Replacement in 2006. In June 2015, a next-generation lumbar TDR received Food and Drug Administration approval - the activL(®) Artificial Disc (Aesculap Implant Systems). Compared to previous-generation lumbar TDRs, the activL(®) Artificial Disc incorporates specific design enhancements that result in a more precise anatomical match and allow a range of motion that better mimics the healthy spine. The results of mechanical and clinical studies demonstrate that the activL(®) Artificial Disc results in improved mechanical and clinical outcomes versus earlier-generation artificial discs and compares favorably to lumbar fusion. The purpose of this report is to describe the activL(®) Artificial Disc including implant characteristics, intended use, surgical technique, postoperative care, mechanical testing, and clinical experience to date.

Quality assessment of systematic reviews for surgical treatment of low back pain: an overview

BACKGROUND CONTEXT

Low back pain is one of the most frequent reasons for medical appointments. Surgical treatment is widely controversial, and new surgical techniques and treatment modalities have been developed within the last decade. Treatment for low back pain should be evidence-based through systematic reviews and meta-analysis. Thus, the quality of these reviews is sometimes put into question as methodological mistakes are frequently seen.

PURPOSE

The aim of this study was to gather all systematic reviews for the surgical treatment of low back pain and analyze their outcomes, quality, and conclusion.

STUDY DESIGN/SETTING

This is an overview of systematic reviews.

OUTCOME MEASURES

The outcome measures were the AMSTAR (A MeaSurement Tool to Assess systematic Reviews) score, PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) statement, and conclusion supported by descriptive statistics.

METHODS

A literature search for systematic reviews containing low back pain surgical treatment was conducted through different medical databases. Two investigators independently assessed all titles and abstracts for inclusion. Studies should have at least one surgical procedure as an intervention. Diagnoses were categorized as lumbar disc herniation, spondylolisthesis, stenosis, facet joint syndrome, and degenerative disc disease. Quality was assessed through the PRISMA and AMSTAR questionnaires. Study quality related to its PRISMA or AMSTAR score percentage was rated as very poor (<30%), poor (30%-50%), fair (50%-70%), good (70%-90%), and excellent (>90%). Articles were considered conclusive if they had a conclusion for their primary outcome supported by descriptive statistical evidence. This study was funded exclusively by the authors' own resources. None of the authors have any potential conflict of interest to declare.

RESULTS

Overall, there were 40 systematic reviews included. According to AMSTAR and PRISMA scores, 5% to 7.5% of the systematic reviews were rated as excellent and most of them were rated as a fair review. AMSTAR indicated that 22.5% of the reviews have very poor quality, whereas PRISMA stated that 7.5% were of very poor quality. For both tools, performing a meta-analysis made the reviews' quality significantly better. The best-rated diagnosis groups according to PRISMA were spondylosis, lumbar disc herniation, and degenerative disc disease. Considering the studies' conclusions, 25 (62.5%) out of the 40 systematic reviews had a conclusion to their primary outcome, and only 11 (27.5%) were supported by descriptive statistical analysis. This means that 44% of the systematic reviews with a conclusion were evidence-based. There were 15 (37.5%) systematic reviews that did not reach a conclusion to their primary objectives.

CONCLUSIONS

In conclusion, most systematic reviews for low back pain do not reach very good or excellent quality, and only 27.5% of them have evidence-based conclusions. Including a meta-analysis is a significant factor to improve quality and evidence for systematic reviews.

Clinical outcomes of single-level lumbar artificial disc replacement compared with transforaminal lumbar interbody fusion in an Asian population

INTRODUCTION

The objective of this study was to examine the clinical outcome of single-level lumbar artificial disc replacement (ADR) compared to that of transforaminal lumbar interbody fusion (TLIF) for the treatment of symptomatic degenerative disc disease (DDD) in an Asian population.

METHODS

This was a retrospective review of 74 patients who had surgery performed for discogenic lower backs that involved only the L4/5 and L5/S1 levels. All the patients had lumbar DDD without radiculopathy or spondylolithesis, and concordant pain with discogram at the pathological level. The patients were divided into two groups--those who underwent ADR and those who underwent TLIF.

RESULTS

A trend suggesting that the ADR group had better perioperative outcomes (less blood loss, shorter operating time, shorter hospital stay and shorter time to ambulation) than the TLIF group was observed. However, a trend indicating that surgical-approach-related complications occurred more frequently in the ADR group than the TLIF group was also observed. The rate of revision surgery was comparable between the two groups.

CONCLUSION

Our findings suggest that for the treatment of discogenic lower back pain, lumbar ADR has better perioperative outcomes and a similar revision rate when compared with TLIF. However, the use of ADR was associated with a higher incidence of surgical-approach-related complications. More studies with bigger cohort sizes and longer follow-up periods are needed to determine the long-term efficacy and safety of ADR in lumbar DDD.

Retrospective study on effectiveness of activ L total disc replacement: clinical and radiographical results of 1- to 3-year follow-up

STUDY DESIGN

Retrospective case series study.

OBJECTIVE

To assess the effectiveness of activ L total disc replacement (TDR) on degenerative disc diseases with the clinical and radiographical results.

SUMMARY OF BACKGROUND DATA

There are few reports on activ L TDR. This is the first one from China.

METHODS

From March 2009 to March 2012, 32 patients with degenerative disc diseases underwent mono- or bisegmental lumbar TDR. Mean age was 45.1 years (32-58 yr). Clinical outcomes were measured by Oswestry Disability Index and Visual analogue scale pre- and postoperatively (1, 2, and 3 yr). Radiographical parameters as range of motion and intervertebral disc height of the index- and adjacent segments were also measured. Prosthesis subsidence and heterotopic ossification were observed during the follow-up period. Work status was also tracked.

RESULTS

Thirty patients were available for a mean follow-up of 28.8 months and had complete radiographical data. At the final follow-up, the success rate was 86.7%. Visual analogue scale score for low back pain and leg pain, and Oswestry Disability Index scores significantly improved after surgery. Average intervertebral disc heights of patients with more than 3 years' follow-up at the index segment and upper and lower adjacent segments were 12.87 mm, 12.61 mm, and 11.62 mm, respectively, showing no significant difference compared with preoperative scores. The range of motion of the index and upper adjacent segments showed a significant increase for patients with more than 3 years' follow-up. Changes of range of motion at lower adjacent segment were not significant. We observed tears of the iliac vein in 2 patients, prosthesis subsidence in 3 patients, and heterotopic ossification in 1 patient. At the final follow-up, 18 patients went back to their original work, 8 patients changed jobs, and 4 patients stopped working.

CONCLUSION

The 1- to 3-year follow-up of this cohort of patients showed satisfactory clinical outcomes. The long-term results of activ L TDR need more investigation.

LEVEL OF EVIDENCE

2.

Retrospective lumbar fusion outcomes measured by ODI sub-functions of 100 consecutive procedures

INTRODUCTION

Low back pain has been quite prevalent in the general population. Chronic low back pain can be defined as back pain lasting for more than 12 weeks. For chronic symptoms, fusion surgeries are the most common surgeries to alleviate the pain. Visual Analog Scale (VAS) is a measurement for subjective characteristics or attitudes that can be difficult to be directly measured. Respondents specify their level of agreement to a statement by indicating a position along a continuous line between two end points.

AIM

The purpose of this study is to investigate patient-reported pain using our own modified ODI with sub-functions. This allowed the study to show how patient outcomes differ with and without co-morbidity as well as functional outcomes after spinal fusion for degenerative disk disease (DDD) with the consistency of using one device and all procedures performed by the same surgeon.

MATERIALS AND METHODS

One hundred patients with DDD were treated with spinal fusion using one device. All procedures were performed by the same surgeon over a 3-year period. Patients were evaluated with discography and MRI preoperatively. Diagnosis of DDD was made when imaging showed bony segment erosion with decreased disc space >50%. Fifty-six patients participated in the initial questionnaire and their data were tabulated and statistically analyzed. Twenty male patients aged 49-85 (median: 67, mean: 66), and thirty-six female patients aged 30-84 (median: 67, mean 64) responded to the questionnaire. There were no differences in pain total by gender, fusion level, single/multiple fusions, degenerative versus deformity condition, type of graft, and lumber area (all p values ≥ 0.15).

RESULTS

Five-year pain measurements used by the VAS questionnaire as well as pain and functional outcomes measured by the ODI after lumbar fusion were superior to the results at 2 years (p = 0.025). Improvement was seen in all of the ODI sub-scores after 5 years, however, only physical function and social function reached statistical significance (p = 0.016 and 0.061, respectively).

CONCLUSION

Successful outcomes were demonstrated for each of the categories assessed and no statistical differences were seen in the ODI % for any comparison after 5 years on 19% of data reported which may have limited forecast reliability. Our data suggest that post-operative outcome is independent of preoperative condition, procedure to be preformed, age, and BMI. Our data support the continual practice of spinal fusion for the treatment of degenerative disk disease.

Total disc arthroplasty for treating lumbar degenerative disc disease

STUDY DESIGN

Lumber disc arthroplasty is a technological advancement that has occurred in the last decade to treat lumbar degenerative disk diseases.

PURPOSE

The aim of this retrospective study was to establish the impact and outcomes of managing patients with lumbar degenerative disk disease who have been treated with lumbar total disc arthroplasty (TDA).

OVERVIEW OF LITERATURE

Several studies have shown promising results following this surgery.

METHODS

We reviewed the files of 104 patients at the Department of Neurosurgery in Colmar (France) who had been operated on by lumbar spine arthroplasty (Prodisc) between April 2002 and October 2008.

RESULTS

Among the 104 patients, 67 were female and 37 were male with an average age of 33.1 years. We followed the cases for a mean of 20 months. The most frequent level of discopathy was L4-L5 with 62 patients (59.6%) followed by L5-S1 level with 52 patients (50%). Eighty-three patients suffered from low back pain, 21 of which were associated with radiculopathy. The status of 82 patients improved after surgery according to the Oswestry Disability Index score, and 92 patients returned to work.

CONCLUSIONS

The results indicate that TDA is a good alternative treatment for lumbar spine disk disease, particularly for patients with disabling and chronic low back pain. This technique contributes to improve living conditions with correct patient selection for surgery.

Motion preservation surgery in the spine

The primary goal of motion preservation surgery in the spine is to maintain normal or near normal motion in an attempt to prevent adverse outcomes commonly seen with conventional spinal fusion, most notably the development of adjacent-level degenerative disc disease. Several different surgical approaches have been developed to preserve motion in the lumbar spine, including total disc replacement, partial disc (nucleus) replacement, interspinous spacers, dynamic stabilization devices, and total facet replacement devices. The design of devices varies greatly. The devices are created using a similar rationale but are unique in design relative to their lumbar counterparts.

Posterolateral transforaminal selective endoscopic diskectomy with thermal annuloplasty for discogenic low back pain: a prospective observational study

STUDY DESIGN

A prospective observational study on 113 patients with 3 years of follow-up.

OBJECTIVE

To evaluate the clinical results of therapy for discogenic low back pain (DLBP) with posterolateral transforaminal selective endoscopic diskectomy and thermal annuloplasty (PEDTA).

SUMMARY OF BACKGROUND DATA

Currently, various minimally invasive techniques are widely used to treat chronic DLBP with variable clinical outcomes. PEDTA is considered to be a novel, minimally invasive technique for treating chronic DLBP, but the evidence supporting this technique is very limited, and there are no studies demonstrating at least 3 years of follow-up.

METHODS

One hundred thirteen consecutive patients with DLBP with positive concordant pain in discography underwent PEDTA from March 2008 to March 2010. These patients included 64 males and 49 females with a mean age of 43.7 years (range, 16-75 yr). The visual analogue scale score, Japanese Orthopedic Association score, and Oswestry Disability Index were evaluated before therapy and each year after surgery. The clinical global outcomes were assessed on the basis of modified MacNab criteria at 3 years after surgery.

RESULTS

Ninety-six patients underwent a single-level procedure, and 17 patients underwent multilevel procedures. One hundred one (89.4%) cases were followed up for 3 years. There were no serious complications observed during follow-up. The success rate (excellent and good) was 73.8%. The visual analogue scale score, Japanese Orthopedic Association score and Oswestry Disability Index had significantly improved at each year after surgery (P < 0.01, compared with presurgery). The success rate in patients who underwent a single-level procedure was remarkably higher than that in patients who underwent multilevel procedures (78.2% vs. 50.0%, P = 0.041).

CONCLUSION

PEDTA presents a safe and effective treatment for carefully selected groups of patients with DLBP. Better clinical results occurred in patients with single-level discogenic pain.

Extended costotransversectomy to achieve circumferential fusion for pathologies causing thoracic instability

BACKGROUND CONTEXT

Conventional circumferential stabilization for pathologies causing instability of the thoracic spine requires a two or even a three-staged procedure. The authors present their tertiary care center experience of single-staged procedure to establish a circumferential fusion through an extended costotransversectomy approach.

OBJECTIVE

To demonstrate neural canal decompression, removal of the pathology, achieve circumferential fusion, and correcting the deformity through a single procedure.

STUDY DESIGN

Prospective and observational.

PATIENT SAMPLE

Forty-six patients with pan thoracic column instability due to various pathologies.

OUTCOME MEASURES

Neurologic condition was evaluated using American Spinal Injury Association and Eastern Cooperative Oncology Group grading systems. Outcome was evaluated with regard to the decompression of neural canal, correction of deformity, and neurologic improvement. All patients were evaluated for neural canal compromise and degree of kyphosis preoperatively, early, and late postoperatively.

METHODS

All patients had severe spinal canal compromise (mean, 59%±9%) and loss of vertebral body height (mean, 55%±10%). A single-stage circumferential fusion was performed (four-level pedicle screw fixation along with a ventral cage fixation after a vertebrectomy or corpectomy) through an extended costotransversectomy approach.

RESULTS

The pathologies included trauma (21), tuberculosis (18), hemangioma (2), aneurysmal bone cyst (1), recurrent hemangioendothelioma (1), solitary metastasis (1) and plasmacytoma (1), and neurofibromatosis (1). Thirty-five of 46 patients (76%) demonstrated improvement in the performance status. The major complications included pneumonitis (3), pneumothorax (3) and neurologic deterioration (3; improved in two), deep venous thrombosis (2), and recurrent hemoptysis (1). No implant failures were noted on last radiology follow-up. There were two mortalities; one because of myocardial infarction and another because of respiratory complications.

CONCLUSIONS

The following study demonstrated that extended costotrasversectomy approach is a good option for achieving single-staged circumferential fusion for correcting unstable thoracic spine due to both traumatic and nontraumatic pathologies.

Artificial total disc replacement versus fusion for lumbar degenerative disc disease: a meta-analysis of randomized controlled trials

OBJECTIVE

The purpose of this study is to compare the effectiveness and safety of artificial total disc replacement (TDR) with fusion for the treatment of lumbar degenerative disc disease (DDD). Spinal fusion is the conventional surgical treatment for lumbar DDD. Recently, TDR has been developed to avoid the negative effects of the fusion by preserving function of the motion segment. Controversy still surrounds regarding whether TDR is better.

METHODS

We systematically searched six electronic databases (Medline, Embase, Clinical, Ovid, BIOSIS and Cochrane registry of controlled clinical trials) to identify randomized controlled trials (RCTs) published up to March 2013 in which TDR was compared with the fusion for the treatment of lumbar DDD. Effective data were extracted after the assessment of methodological quality of the trials. Then, we performed the meta-analysis.

RESULTS

Seven relevant RCTs with a total of 1,584 patients were included. TDR was more effective in ODI (MD -5.09; 95% CI [-7.33, -2.84]; P < 0.00001), VAS score (MD -5.31; 95% CI [-8.35, -2.28]; P = 0.0006), shorter duration of hospitalization (MD -0.82; 95% CI [-1.38, -0.26]; P = 0.004) and a greater proportion of willing to choose the same operation again (OR 2.32; 95% CI [1.69, 3.20]; P < 0.00001). There were no significant differences between the two treatment methods regarding operating time (MD -44.16; 95% CI [-94.84, 6.52]; P = 0.09), blood loss (MD -29.14; 95% CI [-173.22, 114.94]; P = 0.69), complications (OR 0.72; 95% CI [0.45, 1.14]; P = 0.16), reoperation rate (OR 0.83; 95% CI [0.39, 1.77]; P = 0.63) and the proportion of patients who returned to full-time/part-time work (OR 1.10; 95% CI [0.86, 1.41]; P = 0.47).

CONCLUSION

TDR showed significant safety and efficacy comparable to lumbar fusion at 2 year follow-up. TDR demonstrated superiorities in improved physical function, reduced pain and shortened duration of hospitalization. The benefits of operating time, blood loss, motion preservation and the long-term complications are still unable to be proved.

Evidence for surgery in degenerative lumbar spine disorders

We aimed to evaluate the available evidence on the effectiveness of surgical interventions for a number of conditions resulting in low back pain (LBP) or spine-related irradiating leg pain. We searched the Cochrane databases and PubMed up to June 2013. We included systematic reviews and randomised controlled trials (RCTs) on degenerative disc disease (DDD), herniated disc, spondylolisthesis and spinal stenosis due to degenerative osteoarthritis. We included comparisons between surgery and conservative care and between different techniques. The quality of the systematic reviews was evaluated using assessment of multiple systematic reviews (AMSTAR). Twenty systematic reviews were included which covered the following diagnoses: disc herniation (n = 9), spondylolisthesis (n = 2), spinal stenosis (n = 3), DDD (n = 4) and combinations (n = 2). For most of the comparisons, no significant and/or clinically relevant differences between interventions were identified. In general, surgery is only indicated for relief of leg pain in clear indications such as disc herniation, spondylolisthesis or spinal stenosis.

Lumbar total disc replacement: correlation of clinical outcome and radiological parameters

BACKGROUND

The objective of this study was to correlate various radiological parameters with clinical outcome in patients who had undergone lumbar total disc replacement (TDR). Lumbar TDR is one possible treatment option in patients with low back pain (LBP), offering an alternative to lumbar fusion. Favourable clinical outcome hinges on a number of radiological parameters, such as mobility, sintering, and-most importantly-accurate positioning of the implant.

METHODS

A total of 46 patients received a prosthetic disc because of degenerative lumbar disc disorders. Follow-up evaluation included analysis of radiographs and subjective rating of the clinical status by the patient using the North American Spine Society (NASS) patient questionnaire, visual analogue scale (VAS) for pain and state of health, and the EuroQol EQ-5D. Radiological follow-up took place after 2 years. Coronal and sagittal positions of the prosthesis, intervertebral disc height, facet joint pressure, mobility, sintering, and calcification were evaluated. Optimal positioning of the prosthesis was defined as a central coronal position and a most dorsal position in the sagittal plane. Based on the radiologically determined placement of the prosthesis, the patient population was divided into three groups, i.e., prosthesis ideally placed (<2 mm), discretely shifted (2-3 mm), or suboptimally placed (>3 mm).

RESULTS

Overall, 81 % of patients stated that they would undergo the operation again. Health status was stable at a VAS score of 7.04 points 2 years after TDR, compared to 3.97 points before TDR. Mean working capacity had increased from 53 % preoperatively to 88 % 2 years after TDR. Overall, 39 % of the prostheses were rated as ideally positioned, while 13 % were discretely shifted and 48 % were suboptimally placed with respect to one of the radiological criteria. In 80.4 % of patients, follow-up assessment after ≥2 years indicated good mobility at the operated segment, while calcification was noted in 4 % and sintering was detected in 15 % of the implants.

CONCLUSIONS

Our data indicate poor correlation between clinical outcome and position of the prosthesis. Although 48 % of the implants were suboptimally placed in either the coronal or sagittal plane, most of the patients reached a very good clinical outcome. However, suboptimally placed devices appeared to cause significantly more neurological symptoms in long-term follow-up.

The evidence on surgical interventions for low back disorders, an overview of systematic reviews

PURPOSE

Many systematic reviews have been published on surgical interventions for low back disorders. The objective of this overview was to evaluate the available evidence from systematic reviews on the effectiveness of surgical interventions for disc herniation, spondylolisthesis, stenosis, and degenerative disc disease (DDD). An earlier version of this review was published in 2006 and since then, many new, better quality reviews have been published.

METHODS

A comprehensive search was performed in the Cochrane database of systematic reviews (CDSR), database of reviews of effectiveness (DARE) and Pubmed. Two reviewers independently performed the selection of studies, risk of bias assessment, and data extraction. Included are Cochrane reviews and non-Cochrane systematic reviews published in peer-reviewed journals. The following conditions were included: disc herniation, spondylolisthesis, and DDD with or without spinal stenosis. The following comparisons were evaluated: (1) surgery vs. conservative care, and (2) different surgical techniques compared to one another. The methodological quality of the systematic reviews was evaluated using AMSTAR. We report (pooled) analyses from the individual reviews.

RESULTS

Thirteen systematic reviews on surgical interventions for low back disorders were included for disc herniation (n = 6), spondylolisthesis (n = 2), spinal stenosis (n = 4), and DDD (n = 4). Nine (69 %) were of high quality. Five reviews provided a meta-analysis of which two showed a significant difference. For the treatment of spinal stenosis, intervertebral process devices showed more favorable results compared to conservative treatment on the Zurich Claudication Questionnaire [mean difference (MD) 23.2 95 % CI 18.5-27.8]. For degenerative spondylolisthesis, fusion showed more favorable results compared to decompression for a mixed aggregation of clinical outcome measures (RR 1.40 95 % CI 1.04-1.89) and fusion rate favored instrumented fusion over non-instrumented fusion (RR 1.37 95 % CI 1.07-1.75).

CONCLUSIONS

For most of the comparisons, the included reviews were not significant and/or clinically relevant differences between interventions were identified. Although the quality of the reviews was quite acceptable, the quality of the included studies was poor. Future studies are likely to influence our assessment of these interventions.

Lumbar spine fusion for chronic low back pain due to degenerative disc disease: a systematic review

STUDY DESIGN

Systematic literature review.

OBJECTIVE

To categorize published evidence systematically for lumbar fusion for chronic low back pain (LBP) in order to provide an updated and comprehensive analysis of the clinical outcomes.

SUMMARY OF BACKGROUND DATA

Despite a large number of publications of outcomes of spinal fusion surgery for chronic LBP, there is little consensus on efficacy.

METHODS

A MEDLINE and Cochrane database search was performed to identify published articles reporting on validated patient-reported clinical outcomes measures (2 or more of visual analogue scale, Oswestry Disability Index, Short Form [36] Health Survey [SF-36] PCS, and patient satisfaction) with minimum 12 months of follow-up after lumbar fusion surgery in adult patients with LBP due to degenerative disc disease. Twenty-six total articles were identified and stratified by level of evidence: 18 level 1 (6 studies of surgery vs. nonoperative treatment, 12 studies of alternative surgical procedures), 2 level 2, 2 level 3, and 4 level 4 (2 prospective, 2 retrospective). Weighted averages of each outcomes measure were computed and compared with established minimal clinically important difference values.

RESULTS

Fusion cohorts included a total of 3060 patients. The weighted average improvement in visual analogue scale back pain was 36.8/100 (standard deviation [SD], 14.8); in Oswestry Disability Index 22.2 (SD, 14.1); in SF-36 Physical Component Scale 12.5 (SD, 4.3). Patient satisfaction averaged 71.1% (SD, 5.2%) across studies. Radiographical fusion rates averaged 89.1% (SD, 13.5%), and reoperation rates 12.5% (SD, 12.4%) overall, 9.2% (SD, 7.5%) at the index level. The results of the collective studies did not differ statistically in any of the outcome measures based on level of evidence (analysis of variance, P > 0.05).

CONCLUSION

The body of literature supports fusion surgery as a viable treatment option for reducing pain and improving function in patients with chronic LBP refractory to nonsurgical care when a diagnosis of disc degeneration can be made.

ProDisc-L learning curve: 24-Month clinical and radiographic outcomes in 44 consecutive cases

Background

Total disc replacement (TDR) promises preservation of spine biomechanics in the treatment of degenerative disc disease but requires more careful device placement than tradition fusion and potentially has a more challenging learning curve.

Methods

A cohort of 44 consecutive patients had 1-level lumbar disc replacement surgery at a single institution by a single surgeon. Patients were followed up clinically and radiographically for 24 months. Patients were divided into 2 groups of 22 sequential cases each. Clinically, preoperative and postoperative Oswestry Disability Index, visual analog scale, Short Form 12 (SF-12) Mental and Physical Components, and postoperative satisfaction were measured. Radiographically, preoperative and postoperative range of motion (ROM) dimensions, prosthesis deviation from the midline, and disc height were measured. TDR-related complications were noted. Logarithmic curve–fit regression analysis was used to assess the learning curve.

Results

Operative time decreased as cases progressed, with an asymptote after 22 cases. The operative time for the later group was significantly lower (P < .0005), but hospital stay was significantly longer (P = .03). There was no significant difference in amount of blood loss (P = .10) or prosthesis midline deviation (P = .86). Clinically, there was no significant difference in postoperative scores between groups in Oswestry Disability Index (P = .63), visual analog scale (P = .45), SF-12 Mental Component (P = .66), SF-12 Physical Component (P = .75), or postoperative satisfaction (P = .92) at 24 months. Radiographically, there was no significant difference in improvement between groups in ROM (P = .67) or disc height (P = .87 for anterior and P = .13 for posterior) at 24 months. For both groups, there was significant improvement for all clinical outcomes and disc height over preoperative values. One patient in the later group had device failure with subluxation of the polyethylene, which required revision.

Conclusions/level of evidence

Early experience can quickly reduce operative time but does not affect clinical outcomes or ROM significantly (level IV case series).

Clinical relevance

Lumbar TDR is a rapidly learnable technique in treatment of degenerative disc disease.

Do lumbar motion preserving devices reduce the risk of adjacent segment pathology compared with fusion surgery? A systematic review

STUDY DESIGN

A systematic review of the literature.

OBJECTIVE

To compare total disc replacement (TDR) with fusion, other motion-sparing devices with fusion, and motion-sparing devices with other motion-sparing devices to determine which devices may be associated with a lower risk of radiographical or clinical adjacent segment pathology (ASP).

SUMMARY OF BACKGROUND DATA

Adjacent segment pathology, also termed adjacent segment disease (ASD) or adjacent segment degeneration, is a controversial phenomenon that can occur after a spinal fusion; it is thought to be either related to the altered mechanics or loss of motion from the fusion or to be part of the natural history of progressive arthritis. Motion preservation devices theoretically may decrease or prevent ASP from occurring.

METHODS

A systematic search was conducted in PubMed and the Cochrane Library for literature published between January 1990 and February 2012. For all key questions, we identified all cohort studies and randomized controlled trials, making the comparison of interest independent of the outcomes measured. We searched each full-text article to determine whether it reported any type of structural or degenerative condition specifically occurring at an adjacent segment. We included articles reporting adult lumbar patients who had degenerative disc disease, disc herniation, radiculopathy, kyphosis, scoliosis, and spondylolisthesis, and who were treated with TDR, other motion-sparing procedures, or fusion. The overall strength of the evidence for each key question was rated using the Grades of Recommendation Assessment, Development and Evaluation (GRADE) criteria.

RESULTS

There is moderate evidence to suggest that patients who undergo fusion may be nearly 6 times more likely to be treated for ASP than those who undergo TDR. From 2 randomized trials, the pooled risk of clinical ASP treated surgically was 1.2% and 7.0% in the TDR and fusion groups, respectively (P = 0.009). The increased risk of clinical ASP treated surgically associated with fusion is 5.8%. For every 17 operations, one might expect a new clinical ASP event requiring surgery when treated with fusion in those otherwise not harmed by TDR. There was insufficient literature to answer the other key questions, resulting in low to insufficient evidence that other motion-sparing operations are superior to fusion in preventing clinical ASP.

CONCLUSION

There does seem to be a low rate of ASP after lumbar spinal fusion. The evidence suggests that the risk of clinical ASP following fusion is higher when compared with TDR, but there is limited evidence that fusion may increase the risk of developing clinical ASP compared with other motion-sparing procedures.

CONSENSUS STATEMENT

1. Evidence demonstrates that the risk of clinical ASP requiring surgery is likely greater after fusion but the risk is still quite rare. The increased risk compared to TDR could be as small as less than 1% or as great as 10%. Strength of Statement: Weak. 2. There is insufficient evidence to make a definitive statement regarding fusion versus other motion-sparing devices with respect to the risk of ASP.

Total disc replacement for chronic back pain in the presence of disc degeneration

BACKGROUND

In the search for better surgical treatment of chronic low-back pain (LBP) in the presence of disc degeneration, total disc replacement has received increasing attention in recent years. A possible advantage of total disc replacement compared with fusion is maintained mobility at the operated level, which has been suggested to reduce the chance of adjacent segment degeneration.

OBJECTIVES

The aim of this systematic review was to assess the effect of total disc replacement for chronic low-back pain in the presence of lumbar disc degeneration compared with other treatment options in terms of patient-centred improvement, motion preservation and adjacent segment degeneration.

SEARCH METHODS

A comprehensive search in Cochrane Back Review Group (CBRG) trials register, CENTRAL, MEDLINE, EMBASE, BIOSIS, ISI, and the FDA register was conducted. We also checked the reference lists and performed citation tracking of included studies.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) comparing total disc replacement with any other intervention for degenerative disc disease.

DATA COLLECTION AND ANALYSIS

We assessed risk of bias per study using the criteria of the CBRG. Quality of evidence was graded according to the GRADE approach. Two review authors independently selected studies and assessed risk of bias of the studies. Results and upper bounds of confidence intervals were compared against predefined clinically relevant differences.

MAIN RESULTS

We included 40 publications, describing seven unique RCT's. The follow-up of the studies was 24 months, with only one extended to five years. Five studies had a low risk of bias, although there is a risk of bias in the included studies due to sponsoring and absence of any kind of blinding. One study compared disc replacement against rehabilitation and found a statistically significant advantage in favour of surgery, which, however, did not reach the predefined threshold for clinical relevance. Six studies compared disc replacement against fusion and found that the mean improvement in VAS back pain was 5.2 mm (of 100 mm) higher (two studies, 676 patients; 95% confidence interval (CI) 0.18 to 10.26) with a low quality of evidence while from the same studies leg pain showed no difference. The improvement of Oswestry score at 24 months in the disc replacement group was 4.27 points more than in the fusion group (five studies; 1207 patients; 95% CI 1.85 to 6.68) with a low quality of evidence. Both upper bounds of the confidence intervals for VAS back pain and Oswestry score were below the predefined clinically relevant difference. Choice of control group (circumferential or anterior fusion) did not appear to result in different outcomes.

AUTHORS' CONCLUSIONS

Although statistically significant, the differences between disc replacement and conventional fusion surgery for degenerative disc disease were not beyond the generally accepted clinical important differences with respect to short-term pain relief, disability and Quality of Life. Moreover, these analyses only represent a highly selected population. The primary goal of prevention of adjacent level disease and facet joint degeneration by using total disc replacement, as noted by the manufacturers and distributors, was not properly assessed and not a research question at all. Unfortunately, evidence from observational studies could not be used because of the high risk of bias, while these could have improved external validity assessment of complications in less selected patient groups. Non-randomised studies should however be very clear about patient selection and should incorporate independent, blinded outcome assessment, which was not the case in the excluded studies. Therefore, because we believe that harm and complications may occur after years, we believe that the spine surgery community should be prudent about adopting this technology on a large scale, despite the fact that total disc replacement seems to be effective in treating low-back pain in selected patients, and in the short term is at least equivalent to fusion surgery.

Outcomes of Instrumented Posterolateral Fusion for Patients Over 70 Years with Degenerative Lumbar Spinal Disease: A Minimum of 2 Years Follow-up

Objective

To determine the outcome of posterolateral fusion (PLF) for patients over 70 years of age with degenerative lumbar spinal disease.

Methods

The authors reviewed 18 patients (13 women and 5 men) over 70 years of age who underwent PLF with a minimum 2-years follow-up at a single institution. The parameters for analysis were clinical outcome, intraoperative bleeding, operating time, transfusion amount, fusion rate, decreased disc height at the operated level, and the incidence of adjacent disc degeneration.

Results

The mean age and follow-up duration were 74.1 years and 44.7 months, respectively. The mean fusion level was 2.5 levels. 12 patients (66.7%) reported good or excellent outcomes, and 4 patients complained of poor outcomes. The fusion rate was 61.1%. The rate of adjacent segment degeneration was 61.1%. Among all of the patients, 5 had decreased intervertebral disc heights compared to their initial statuses. In correlative comparison analyses of parameters, a significant correlation was observed between a "good" or better clinical outcome and fusion (p=0.034). Also, there were significant relationships between a "fair" or better clinical outcome and fusion (p=0.045) and decreased disc height at the operated level (p=0.017). Other factors did not have a significant relationship with the clinical outcome.

Conclusions

Before performing instrumented PLF in patients over 70 years old, problems related to the low fusion rate and adjacent segment degeneration should be considered and relevant information should be provided to the patients and the family.

Spinal fusion-hardware construct: Basic concepts and imaging review

The interpretation of spinal images fixed with metallic hardware forms an increasing bulk of daily practice in a busy imaging department. Radiologists are required to be familiar with the instrumentation and operative options used in spinal fixation and fusion procedures, especially in his or her institute. This is critical in evaluating the position of implants and potential complications associated with the operative approaches and spinal fixation devices used. Thus, the radiologist can play an important role in patient care and outcome. This review outlines the advantages and disadvantages of commonly used imaging methods and reports on the best yield for each modality and how to overcome the problematic issues associated with the presence of metallic hardware during imaging. Baseline radiographs are essential as they are the baseline point for evaluation of future studies should patients develop symptoms suggesting possible complications. They may justify further imaging workup with computed tomography, magnetic resonance and/or nuclear medicine studies as the evaluation of a patient with a spinal implant involves a multi-modality approach. This review describes imaging features of potential complications associated with spinal fusion surgery as well as the instrumentation used. This basic knowledge aims to help radiologists approach everyday practice in clinical imaging.

Clinical outcomes of two revision strategies for failed total disc replacements

PURPOSE

To compare mid-term clinical outcomes of two revision strategies for patients with failed SB Charité III total disc replacements (TDRs).

METHODS

Eighteen patients with a failed TDR underwent posterolateral instrumented fusion (fusion group); in 21 patients, the TDR was removed and the intervertebral defect was filled with a bone strut graft, followed by an instrumented posterolateral fusion (removal group). Visual analogue scale (VAS) for pain and Oswestry Disability Index (ODI) were completed pre- and post-revision surgery. Intra- and post-operative complications of both revision strategies were assessed.

RESULTS

Mean follow-up was 3.7 years (range 1.0-6.4) in the removal group and 4.4 years (range 0.7-11.0) in the fusion group. Although the removal group showed a significantly lower VAS and ODI score post-revision surgery as compared to preoperative (P < 0.01 and P = 0.01, respectively), no significant differences were found between the removal and fusion groups before and after revision surgery in VAS and ODI. A clinical relevant improvement in VAS and ODI was found in 47 and 21 % respectively in the removal group, and in 22 and 27 % respectively in the fusion group. Substantial complications were observed only in the removal group.

CONCLUSIONS

Both procedures showed improvement clinically. There were no significant additional benefits of removing the TDR as compared to fusion alone at mid-term follow-up. The clinical decision to remove the TDR should be carefully weighed up against potential risks and complications of this procedure.

Clinical, radiological, histological and retrieval findings of Activ-L and Mobidisc total disc replacements: a study of two patients

INTRODUCTION

This study evaluates the short-term clinical outcome, radiological, histological and device retrieval findings of two patients with second generation lumbar total disc replacement (TDR).

MATERIALS AND METHODS

The first patient had a single level L4-L5 Activ-L TDR, the second patient a L4-L5 Mobidisc and L5-S1 Activ-L TDR. The TDRs were implanted elsewhere and had implantation times between 1.3 and 2.8 years.

RESULTS

Plain radiographs and CT-scanning showed slight subsidence of the Activ-L TDR in both patients and facet joint degeneration. The patients underwent revision surgery because of recurrent back and leg pain. After removal of the TDR and posterolateral fusion, the pain improved. Histological examination revealed large ultrahigh molecular weight polyethylene (UHMWPE) particles and giant cells in the retrieved tissue surrounding the Mobidisc. The particles in the tissue samples of the Activ-L TDR were smaller and contained in macrophages. Retrieval analysis of the UHMWPE cores revealed evidence of minor adhesive and abrasive wear with signs of impingement in both TDR designs.

CONCLUSION

Although wear was unrelated to the reason for revision, this study demonstrates the presence of UHMWPE particles and inflammatory cells in second generation TDR. Long-term follow-up after TDR is indicated for monitoring wear and implant status.

Clinical outcome of monosegmental total disc replacement for lumbar disc disease with ball-and-socket prosthesis (Maverick): prospective study with four-year follow-up

BACKGROUND

Arthrodesis is considered to be the reference treatment for degenerative disc disease (DDD), if the symptoms are refractory to conservative management. The drawback of arthrodesis is, besides a percentage of non-union, the reduced mobility that might generate an increased load and risk for degeneration of the adjacent levels. Total disc replacement (TDR) implants may overcome this problem. The long-term clinical effect and radiographic evaluation of motion preservation after implantation, however, have been subject to several nonconclusive studies. This study evaluated the long-term clinical and radiographic results and the safety of TDR with the Maverick prosthesis for surgical treatment of monosegmental DDD.

METHODS

TDR was performed in 50 consecutive patients with monosegmental DDD using the Maverick device. Patients were followed prospectively for disability, quality of life, pain intensity and frequency, as well as working status and return to sports, during 48 months. Motion preservation was assessed on neutral and dynamic radiographs at 48 months.

RESULTS

The disability, pain intensity and frequency, and quality of life improved significantly at the 6-week follow-up, which was maintained over the full 48 months following Maverick implantation. Preoperatively, 80% of the patients stopped working and 86% halted sports activities. Four years after surgery, 85% of patients were again working and 79% took up their normal sports activities. Radiographic assessment showed that motion at the index level is maintained 48 months after TDR. No major complications were encountered.

CONCLUSION

In this study, TDR with the Maverick prosthesis at one lumbar segment reduced pain and disability and improved quality of life as well as the general condition. Motion was preserved at the operated level, 48 months after surgery. The long-term effect on adjacent levels needs further follow-up.