ArticleLiterature Review

Clinical Results of ProDisc-II Lumbar Total Disc Replacement: Report from the United States Clinical Trial

August 2005
Orthopedic Clinics of North America 36(3):301-13

August 2005
36(3):301-13

DOI:10.1016/j.ocl.2005.03.004

Source
PubMed

Authors:

Hyun Bae

Cedars-Sinai Medical Center

Ben B Pradhan

In the musculoskeletal arena, low back pain is a veritable epidemic in our society today. The treatment for this common ailment, both nonoperative and operative, can often be frustrating. The current surgical standard of care, spinal fusion, is often associated with mediocre results, long recovery time, significant postoperative morbidity, and future adjacent segment degeneration. Artificial disc replacement has proven to be a promising alternative to other surgical treatments of chronic low back pain and may obviate the stigmas associated with spinal fusion. The US IDE Pivotal Clinical Trial, which has recently completed enrollment at selected clinical sites, will provide valuable information comparing this new technology to the current mainstay treatment of spinal fusion. The intermediate-term results from our site demonstrate that the objective of decreasing postoperative morbidity and improving recovery has been met. Patients who received the disc replacement as opposed to fusion had a significant improvement in pain and functional status in the early postoperative period. Over the intermediate-term, the prosthetic disc does serve to preserve motion at the surgical level(s). The more important benefit of protection of adjacent levels can only be assessed with completion of the multi-center study and long-term follow-up.

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

Article

Full-text available

Jul 2019

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.

Health economic aspects of low back pain-Gylfi Olafsson

Thesis

Full-text available

Feb 2019

Gylfi Olafsson

Treating Discogenic Back Pain with Bone Marrow Concentrate is Superior to Lumbar Disc Replacement at Two-Year Follow-up

Article

Full-text available

Jan 2019

Objective: Millions of patients suffer chronic back pain from degenerated lumbar discs. Surgical options for one or two levels of discogenic back pain are fusion or lumbar artificial disc replacement [LADR]. Study Design: This study compares the complications, reoperations, cost, and clinical outcomes of bone marrow concentrate [BMC] versus LADR for the treatment of discogenic back pain. The BMC study is prospective non-randomized class 2 data. The LADR studies were prospective randomized class 1 data. All operations were performed at the same private clinic. All studies had IRB approval. Follow up on all the studies was two years. Methods: The BMC was a 30-minute procedure involving aspiration of 55ml of bone marrow from the iliac wing, concentrating via centrifugation to a volume of 6ml and then injecting approximately 2ml of bone marrow concentrate per symptomatic lumbar disc. Clinical success in the LADR and BMC studies required a 50% improvement in ODI and VAS from pre-operative through two-year follow-up. Results: Clinical failure of LADR occurred in 27% (24 of 89 patients) at two-year follow-up. Five patients in the BMC study had surgery within two years of the BMC injection and were considered failures (19%). The remaining 21 BMC patients improved an average of 64% in ODI and 72% in VAS. Conclusions: These results indicate a BMC injection may be a reasonable non-surgical option for patients with symptomatic discogenic back pain. Keywords: Mesenchymal Stem Cells; Stem cells; Cell-based therapy; Bone Marrow Concentrate, Lumbar Spine, Disc Replacement.

Treating Discogenic Back Pain with Bone Marrow Concentrate is Superior to Lumbar Disc Replacement at Two-Year Follow-up

Article

Full-text available

Jan 2019

STIFFNESS-A KEY MECHANICAL FACTOR IN NORMAL, DEGENERATE AND ARTIFICIAL LUMBAR INTERVERTEBRAL DISCS

Thesis

Full-text available

Jan 2011

Ray Ross

This thesis describes the development of artificial disc technology for the replacement of intervertebral discs in the human lumbar spine. The clinical problem is back pain. There may be a relationship between certain forms of back pain and disc degeneration. The mechanical properties of human intervertebral discs are examined in detail. The genetic basis of disc degeneration is presented. The hypothesis is that such degeneration leads to a loss of normal stiffness in the segments affected leading to abnormal mechanical behaviour which in turn leads to pain. The evidence for this is presented. The development of surgical solutions to relieve back pain, from fusion through first generation mechanical artificial discs to elastomeric designs, is traced. The author‘s personal contributions to this area of knowledge are set out. The appreciation of the requirement for a restoration of physiological stiffness is argued throughout, showing where fusion and first generation discs have not met the clinical aim of pain relief, because they have not restored physiological stiffness. The path to an elastomeric, viscoelastic, polyhydrocarbon, rubber solution in the form of the “Freedom“ disc has filled 17 years of the author‘s academic pursuits. It will be shown that this technology may represent a possible solution to the clinical problem. Failure is part of all new advancement and this too is presented, to show how that has influenced thinking, producing original ideas to overcome these failures. Providing lessons are learned from these failures then our patients in the future will benefit.

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

Article

Full-text available

May 2016

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.

Lumbar Disc Arthroplasty: History and Analysis

Article

Full-text available

Jan 2024

Degenerative disc disease describes a ubiquitous condition involving the natural deterioration of an intervertebral disc. Conservative methods such as physical therapy and anti-inflammatories are recommended as first-line therapies for noninvasive management. However, when these interventions fail to reduce pain, surgical intervention is indicated. While laminectomies, discectomies, and spinal fusion procedures have been considered the standard treatment throughout the 20th century, the development of artificial discs has introduced an alternative surgical intervention in the form of total disc replacement. Initially, the novel devices garnered significant attention, thus leading to a rise in the rates of disc replacement procedures performed. However, several years after FDA approval of the first device, the prevalence of procedures steadily decreased. Several factors may have contributed to the downward trend, including the growing financial burden of hospitalization, stringent inclusion criteria indicating the procedure, and lack of provider familiarity and comfort with the procedure. Although the expected prevalence of disc arthroplasty remains unrealized, there is significant potential for an expanded role in the contemporary treatment of degenerative disc disease. This review illustrates the timeline and course of lumbar disc arthroplasty by describing its development, followed by its introduction in Europe and eventual arrival in the United States. The initial growth in popularity due to promising results is explained along with the surgery’s swift decline primarily due to lack of sufficient evidence promoting replacement, poor insurance coverage, lack of clear indications and complications. This review encapsulates all components and describes future directions and clinical value of lumbar disc arthroplasty.

Spine Surgery: A Narrative Review About Recent Updates and Future Directions

Article

Full-text available

Apr 2022

Background: Advances in case selection, operative methods, and postsurgical care have facilitated spine surgeons to manage complex spine cases with short operative times, decreased hospital stay and improved outcomes. Methods: This is an overview of recent updates and future directions in the field of spine surgery. All the articles were obtained through a literature review on PubMed. Results: Minimally invasive spine procedures like Endoscopic spine surgeries, Oblique Lumbar Interbody Fusion, use of retractor systems, etc. are emerging in rapidly in modern world. Fusion surgeries are associated with adjacent level disease hence, motion preservation surgeries that mimic the natural biomechanics of the spine are being explored as alternatives. In view of risks to vital structures, nerve injury due to mal-positioning, etc.; robotic spine surgery has paved a way to allow surgeons real-time procedural manipulation along with instrument control, real-scale magnification. Many high-impact discoveries in cancer research, stereotactic radiotherapy, newer combinations of chemotherapy, and tumor-specific antibodies have increased our understanding of spine oncology. Past two decades have seen many advancements in treatment of spine deformities right from initial radiographic assessment, surgical planning to postoperative care. Conclusion: All in all, all stakeholders in innovation including the industry, scientists and surgeons must work in an open and honest collaboration to benefit the future patients and continue the evolution in Spine Surgery.

Fundamental Mechanisms of Load Transfer in the Human Vertebral Body Following Lumbar Total Disc Arthroplasty

Thesis

Full-text available

Sep 2020

Noah B. Bonnheim

This dissertation comprises a series of computational experiments conducted on human cadaveric lumbar vertebrae using a combination of high-resolution micro-computed tomography image data with parallel linear and nonlinear finite element analysis implemented on a peta-scale supercomputing cluster. The goals of these studies are to assess mechanisms of load transfer and stress development in the bone, including how tissue-level stress depends on the loading mode of the implant, its size and material characteristics, and inter-individual variations in the structural features of the vertebral body.

Mid- to long-term results of total disc replacement for lumbar degenerative disc disease: A systematic review

Article

Full-text available

Dec 2018
J Orthop Surg Res

Background Lumbar total disc replacement (TDR) has shown satisfactory clinical outcomes with few complications and reoperations at short-term follow-up, but the mid- to long-term results are not clear. Purpose The objective of this study was to evaluate the mid- to long-term clinical outcomes of artificial TDR for lumbar degenerative disc diseases. Patients and methods A systematic search was conducted using the PubMed database to identify studies of TDR surgery that included at least 3 years of follow-up. The search keywords were as follows: lumbar, total disc replacement, and arthroplasty. The following data were extracted: patient demographics, visual analogue scale (VAS) and Oswestry disability index (ODI) scores, satisfactory rate, clinical success rate, complications, and reoperations. Results Thirteen studies, including eight prospective studies and five retrospective studies, met the criteria. A total of 946 patients were identified who reported at least 3 years of follow-up results. The artificial prostheses in these studies were ProDisc-L, Charité, AcroFlex, Maverick, and XL TDR. Patients with lumbar TDR demonstrated significant improvements in VAS scores of 51.1 to 70.5% and of − 15.6 to − 44.4 for Oswestry disability index (ODI) scores at the last follow-up. Patient satisfaction rates were reported in eight studies and ranged from 75.5 to 93.3%. Complication rates were reported in 11 studies, ranging from 0 to 34.4%. The overall reoperation rate was 12.1% (119/986), ranging from 0 to 39.3%, with eight of the 13 studies reporting a reoperation rate of less than 10%. Conclusions This review shows that lumbar TDR effectively results in pain relief and an improvement in quality of life at mid- to long-term follow-up. Complication and reoperation rates were acceptable. However, this study did not provide sufficient evidence to show that lumbar TDR is superior to fusion surgery. To answer that question, a greater number of high-quality randomized controlled trials (RCTs) are needed.

Total disc replacement versus fusion for lumbar degenerative disc disease: a systematic review of overlapping meta-analyses

Article

Full-text available

Mar 2017
EUR SPINE J

Purpose Although many meta-analyses have been performed to compare total disc replacement (TDR) and fusion for treating lumbar degenerative disc disease (LDDD), their findings are inconsistent. This study aimed to conduct a systematic review of overlapping meta-analyses comparing TDR with fusion for treating LDDD, to assist decision makers in selection among conflicting meta-analyses, and to provide treatment recommendations based on the best available evidence. Methods This study was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) statement. Multiple databases were comprehensively searched for meta-analyses comparing TDR with fusion for treating LDDD. Meta-analyses only comprising randomised controlled trials (RCTs) were included. Two authors independently assessed meta-analysis quality and extracted data. The Jadad decision algorithm was used to ascertain which meta-analyses represented the best evidence. Results A total of five meta-analyses were included. All these studies only included RCTs were determined as Level-II evidence. The scores of Assessment of Multiple Systematic Reviews (AMSTAR) ranged from 6 to 9 (median 7). A high-quality Cochrane review was chosen according to the Jadad algorithm. This best available evidence found that statistical significances were observed between TDR and fusion for LDDD regarding disability, pain relief, and pain in the short term, but it was not over clinically important differences. The prevent effects on adjacent segment and facet joint degeneration, as the primary goal of adopting TDR stated by the manufacturers, were not appropriately evaluated. Conclusions There is discord in results from meta-analyses that assessed TDR and fusion for LDDD. According to this systematic review of overlapping meta-analyses comparing TDR and fusion for LDDD, the current best available evidence suggests that TDR may be an effective technique for the treatment of selected patients with LDDD, and is at least equal to lumbar fusion in the short term. However, considering that disadvantages may appear after years, spine surgeons should be cautions about performing TDR on a large scale.

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

Article

Jan 2016

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.

Complications and Rates of Subsequent Lumbar Surgery Following Lumbar Total Disc Arthroplasty and Lumbar Fusion

Article

Jan 2016
SPINE

Study design: Retrospective analysis. Objective: To examine complications and rates of subsequent surgery following lumbar spinal fusion (LF) and lumbar total disc arthroplasty (TDA) at up to 5-year follow-up. Summary of background data: LF is commonly used in the management of degenerative disc disease causing pain refractory to nonoperative management. Lumbar TDA was developed as an alternative to fusion with the theoretical advantage of reducing rates of adjacent segment pathology and reoperation. Most prior reports comparing these 2 interventions have come from industry-sponsored investigational device exemption trials and no large-scale administrative database comparisons exist. Methods: The California Office of Statewide Health Planning and Development discharge database was queried for patients aged 18 to 65 years undergoing lumbar TDA and LF for degenerative disc disease from 2004 to 2010. Patient characteristics were collected, and rates of complications and readmission were identified. Rates of repeat lumbar surgery were calculated at 90-day and 1-, 3-, and 5-year follow-up intervals. Results: A total of 52,877 patients met the inclusion criteria (LF = 50,462, TDA = 2415). Wound infections were more common following LF than TDA (1.03% vs. 0.25%, P < 0.001). Rates of subsequent lumbar surgery at 90-day and 1-year follow-up were lower with lumbar TDA than LF (90-day-TDA: 2.94% vs. LF: 4.01%, P = 0.007; 1-yr-TDA: 3.46% vs. LF: 4.78%, P = 0.009). However, there were no differences in rates of subsequent lumbar surgery between the 2 groups at 3-year and 5-year follow-up. Conclusion: Lumbar TDA was associated with fewer early reoperations, though beyond 1 year, rates of reoperation were similar. Lumbar TDA may be associated with fewer acute infections, though this may be approach related and unrelated to the device itself. Level of evidence: 3.

Total Disc Replacement in Lumbar Degenerative Disc Diseases

Article

Full-text available

Nov 2015

Chun Kun Park

More than 10 years have passed since lumbar total disc replacement (LTDR) was introduced for the first time to the world market for the surgical management of lumbar degenerative disc disease (DDD). It seems like the right time to sum up the relevant results in order to understand where LTDR stands on now, and is heading forward to. The pathogenesis of DDD has been currently settled, but diagnosis and managements are still controversial. Fusion is recognized as golden standard of surgical managements but has various kinds of shortcomings. Lately, LTDR has been expected to replace fusion surgery. A great deal of LTDR reports has come out. Among them, more than 5-year follow-up prospective randomized controlled studies including USA IDE trials were expected to elucidate whether for LTDR to have therapeutic benefit compared to fusion. The results of these studies revealed that LTDR was not inferior to fusion. Most of clinical studies dealing with LTDR revealed that there was no strong evidence for preventive effect of LTDR against symptomatic degenerative changes of adjacent segment disease. LTDR does not have shortcomings associated with fusion. However, it has a potentiality of the new complications to occur, which surgeons have never experienced in fusion surgeries. Consequently, longer follow-up should be necessary as yet to confirm the maintenance of improved surgical outcome and to observe any very late complications. LTDR still may get a chance to establish itself as a substitute of fusion both nominally and virtually if it eases the concerns listed above.

Anterior Lumbar Interbody Fusion for Degenerative Discogenic Low Back Pain: Evaluation of L4-S1 Fusion

Article

Full-text available

Oct 2015
MEDICINE

The treatment of degenerative discogenic pain is controversial, and anterior lumbar fusion for the treatment of degenerative discogenic low back pain has also been a controversial topic for over a generation. The aim of this systematic review was to evaluate the outcome of different anterior lumbar fusion levels for degenerative discogenic low back pain. In this study, we performed a clinical outcome subgroup analysis. The outcomes of 84 consecutive patients who underwent anterior lumbar interbody fusion from 2004 to 2009 were reviewed. The operative time, intraoperative blood loss, hospital stay, Oswestry Disability Index (ODI), visual analog scale (VAS) results, and complication rate were recorded separately. Medical indications were degenerative disc disease (73.8%), postdiscectomy disc disease (16.1%), and disc herniation (9.5%). Patients with severe spondylolysis or disc degeneration, with more than 3 or multilevel lesions, were excluded. The mean operative time was 124.5 ± 10.9 min (range 51–248 min), the mean intraoperative blood loss was 242.1 ± 27.7 mL (range 50–2700 mL), the mean hospital stay was 3.9 ± 1.1 days (range 3–6 days), the mean preoperative VAS score was 7.5 ± 1.4, and the mean preoperative ODI score was 60.0 ± 5.7. At the 1-year follow-up, the mean postoperative VAS score was 3.3 ± 1.3 and the mean postoperative ODI score was 13.6 ± 3.4 (P < 0.05). L4–L5 disc fusion led to better clinical results than 2-level L4–L5/L5–S1 disc fusion. Additionally, the 2-level fusion of L4–L5/L5–S1 had better clinical results than the L5–S1 disc fusion at both the 1 and 2-year postoperative follow-ups regarding the VAS score and the ODI score. The rate of complications was more frequent in the 2-level L4–L5/L5–S1 group (27.3%) (group C) than in the L4–L5 group (9.1%) (group A) and the L5–S1 group (12.5%) (group B). There was no difference between the L4–L5 group (9.1%) and the L5–S1 group (12.5%). A venous tear occurred during surgery and was successfully repaired in 6 of the 84 patients. Also, out of the 84 patients, 6 were found with pseudarthrosis during the follow-up, and these patients underwent a spinal fusion with instrumentation, with a posterior approach after a mean of 1 year. The complications secondary to the surgical approach were persistent abdominal pain (1/84, 1.2%) and wound dehiscence (1/84, 1.2%). Anterior lumbar interbody fusion for L4–L5 had better clinical results than the 2-segmental L4–L5/L5–S1 disc fusion, and the 2-segmental L4–L5/L5–S1 disc fusion had better clinical results than the L5–S1 disc fusion. Also, the 2-segmental L4–L5/L5–S1 disc fusion had a higher complication rate (27.3%), but there was no difference between the L4–L5 group (9.1%) and the L5–S1 group (12.5%).

Chapter 18 Nucleus Arthroplasty ™ Technology: Approach-Related Considerations

Article

Full-text available

Anterolateral retroperitoneal approach (ARPA) with the patient in the supine position permits access for nucleus arthroplasty proce-dures from L2 to S1, through a limited, muscle-splitting incision. • Annular exposure of only 20mm, from one o'clock to three o'clock, is all that is required to permit an annulotomy of approximately 17-18mm. • In contrast to total disc arthroplasty and anterior spinal fusion, vascular mobilization is necessary only on a de minimus basis at L5-S1 and L4-L5; no mobilization is required at L3-L4 or L2-L3. • In terms of revision surgery, the risk profile of nucleus arthro-plasty procedures will be more favorable than those associated with total disc arthroplasty and anterior spinal fusion, due to minimal vascular mobilization. • Exposure for nucleus arthroplasty procedures preserves options for subsequent anterior spinal surgical procedures by avoiding anterior exposure of the spine from eleven o'clock to one o'clock.

Cost-Effectiveness of Total Disc Replacement Versus Multidisciplinary Rehabilitation in Patients With Chronic Low Back Pain

Article

Full-text available

Jan 2014
SPINE

Study design: Randomized clinical trial with 2-year follow-up. Objective: To evaluate the cost-effectiveness of total disc replacement (TDR) versus multidisciplinary rehabilitation (MDR) in patients with chronic low back pain (CLBP). Summary of background data: The existing studies on CLBP report cost-effectiveness of fusion surgery versus disc replacement and fusion versus rehabilitation. This study evaluated the cost-effectiveness of TDR versus MDR. Methods: Between April 2004 and May 2007, 173 patients with CLBP (>1 yr) were randomized to TDR (n = 86) or MDR (n = 87). Treatment effects (Euro Qol 5D [EQ-5D] and Short Form 6D [SF-6D]) and relevant direct and indirect costs at 6 weeks and at 3, 6, 12, and 24 months after treatment were assessed. Gain in quality-adjusted life years (QALYs) after 2 years was estimated. Cost-effectiveness was expressed as an incremental cost-effectiveness ratio. Results: The mean QALYs gained (standard deviation) using EQ-5D was 1.29 (0.53) in the TDR group and 0.95 (0.52) in the MDR group, a significant difference of 0.34 (95% confidence interval 0.18-0.50). The mean total cost per patient in the TDR group was &OV0556;87,622 (58,351) compared with &OV0556;74,116 (58,237) in the MDR group, which was not significantly different (95% confidence interval: -4041 to 31,755). The incremental cost-effectiveness ratio for the TDR procedure varied from &OV0556;39,748 using EQ-5D (TDR cost-effective) to &OV0556;128,328 using SF-6D (TDR not cost-effective). The dropout rate was 20% (15% TDR group, 24% MDR group). Five patients moved from the MDR to the TDR group, whereas 9 patients randomized to TDR declined surgery. Using per-protocol analysis instead of intention-to-treat analysis indicated that TDR was not cost-effective, irrespective of the use of EQ-5D or SF-6D. Conclusion: In this study, TDR was cost-effective compared with MDR after 2 years when using EQ-5D for assessing QALYs gained and a willingness to pay of &OV0556;74,600 (kr500,000/QALY). TDR was not cost-effective when SF-6D was used; therefore, our results should be interpreted with caution. Longer follow-up is needed to accurately assess the cost-effectiveness of TDR. Level of evidence: 2.

Current Management Considerations for Total Intervertebral Disc Replacement

Article

Sep 2023

Oral and maxillofacial devices

Chapter

Oct 2011

Shikha Gupta

Teaching mechanical and structural biomaterials concepts for successful medical implant design, this self-contained text provides a complete grounding for students and newcomers to the field. Split into three sections: Materials, Mechanics and Case Studies, it begins with a review of sterilization, biocompatibility and foreign body response before presenting the fundamental structures of synthetic biomaterials and natural tissues. Mechanical behavior of materials is then discussed in depth, covering elastic deformation, viscoelasticity and time-dependent behavior, multiaxial loading and complex stress states, yielding and failure theories, and fracture mechanics. The final section on clinical aspects of medical devices provides crucial information on FDA regulatory issues and presents case studies in four key clinical areas: orthopedics, cardiovascular devices, dentistry and soft tissue implants. Each chapter ends with a list of topical questions, making this an ideal course textbook for senior undergraduate and graduate students, and also a self-study tool for engineers, scientists and clinicians.

Mechanical behavior of structural tissues

Chapter

Oct 2011

Fracture mechanics

Chapter

Oct 2011

Jevan Furmanski

Viscoelasticity

Chapter

Oct 2011

Complications of Motion-Sparing Technology

Chapter

Jan 2007

Disk Arthroplasty Using the ProDisc-L® Total Disk Replacement

Chapter

Jan 2007

Multiple-Level Lumbar Total Disk Replacement: A Prospective Clinical and Radiographic Analysis of Motion Preservation at 24–72 Months

Article

Aug 2018

Background: Recent studies demonstrate the efficacy of lumbar arthroplasty using the ProDisc-L. Patients frequently present with multilevel pathology and may be candidates for multilevel disk replacement. Purpose: To evaluate clinical outcomes and sagittal range of motion of operated levels and adjacent lumbar motion segments in multiple-level ProDisc-L constructs after 2-6 years follow-up. Patient sample: A total of 159 patients underwent adjacent 2-level (n=114), 3-level (n=41), or 4-level (n=4) lumbar total disk replacement (TDR). Study-design: This is a prospective cohort. Outcome measures: Clinical measures: Oswestry Disability Index and Visual Analog Score of patient satisfaction (VAS-S) and pain (VAS-P) data were collected. Radiographic measures: sagittal motion on preoperative and postoperative lumbar radiographs at each operative segment and adjacent segment. Methods: Patients were evaluated with radiographic and clinical outcomes measures preoperatively, at 6 weeks, 3 months, 6 months, and annually for 24-72 months postoperatively. Results: Radiographic: at the motion segment adjacent to the TDR, mean preoperative range of motion (ROM) was 8.20±2.88 degrees, compared with 8.40±2.4 degrees postoperatively at last follow-up (P>0.05). Between the 3 TDR groups, there were no significant differences in ROM at any time point except at L5-S1. Across both groups for TDR motion segments, the mean preoperative ROM was 10.15±2.71 versus 12.30±2.25 degrees postoperatively (P=0.011) at last follow-up. At L5-S1 mean preoperative motion was 7.60±3.90 versus 5.81±3.1 degrees postoperatively (P=0.60). Clinical: at 24-72 months postoperatively, all patients had significant reductions in Oswestry Disability Index, VAS-P, and VAS-S scores (P<0.05). At up to 72 months of follow-up, no patient underwent adjacent-level surgery but there were 3 cases of index-level revision surgery. Conclusions: Multilevel TDR preserves ROM at the individual TDR levels. Most significantly, the nonoperative adjacent level maintains its preoperative ROM at 2-6 years postoperatively. At up to 6 years of follow-up, there has been no need for revision or adjacent-segment surgery. Patients also demonstrate significant improvement in pain and disability at latest follow-up.

We Need to Talk about Lumbar Total Disc Replacement

Article

Aug 2018

STEPHEN BEATTY

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.

Time Course of Radiologic Changes After Lumbar Total Disc Replacement: Experience of Single Institute With Minimum 5-Year Follow-up

Article

May 2018

Study design: This was a retrospective observatory analysis study. Objective: The purpose of this study was to evaluate long-term safety and therapeutic effectiveness of the lumbar total disc replacement (TDR) using ProDisc-L by analyzing the radiologic changes at the index and adjacent levels in minimum 5-year follow-up. Summary of background data: Early successful clinical results of lumbar TDR have been reported. However, few reports have published its therapeutic effectiveness and radiologic degenerative changes at the index and adjacent segments in the long term. Materials and methods: Forty-three patients were followed-up for at least 60 months. Radiologic changes were assessed by segmental range of motion (ROM) at the index and adjacent levels, global lumbar lordosis, and disc space height (DSH). The magnetic resonance imaging and computed tomographic scans were used to determine the facet arthrosis and intervertebral disc degeneration at the index and adjacent levels. Results: Gradual decrements of DSH restoration were observed until the last follow-up. Mean global and segmental ROM of index segments were significantly reduced (P=0.044, 0.00) at the last visit. There were 21 patients (48.8%) with no motion at index segment (ROM<0.5 degrees) at the last visit. Among the 56 segments operated on, progression of facet arthrosis was observed in 30.3% of index segments and 10.9% of adjacent segments. None of the postoperative radiologic parameters included in the present study presented significant correlation with clinical outcome. Conclusions: The study demonstrates that only half of the lumbar TDR patients can maintain segmental motion at the index level >5-year after surgery and TDR provides a good clinical outcome postoperatively regardless of motion preservation or DSH height preservation at the last follow-up. After TDR, the degenerative changes in the index and adjacent segments advanced as compared with our previous report of 2-year follow-up, however, these changes did not appear to exert negative influence upon clinical outcomes.

100 Consecutive Cases of Degenerative Lumbar Conditions Using a Non-Threaded Locking Screw System With a 90-Degree Locking Cap

Article

Full-text available

Jan 2009

Total Disc Arthroplasty and Anterior Interbody Fusion in the Lumbar Spine Have Relatively Few Differences in Readmission and Short-term Adverse Events

Article

Jul 2017

Study design: Retrospective matched cohort study of prospectively collected data. Objective: To compare rates of adverse events and readmission between lumbar total disc arthroplasty (TDA) and anterior lumbar interbody fusion (ALIF) using the American College of Surgeons National Surgical Quality Improvement Program (NSQIP) database. Summary of background data: TDA and ALIF may be considered for similar degenerative indications. However, there have been few large-cohort comparison studies of short-term clinical outcomes for these procedures. Methods: The 2011-2015 NSQIP databases were retrospectively queried to identify patients who underwent elective stand-alone ALIF and TDA. After propensity matching, the association of procedure type with adverse events and readmission was determined using McNemar's test. Operative time and postoperative length of stay were compared using multivariate linear regression. Risk factors for adverse events were determined using multivariate Poisson regression. Results: In total, 1,801 ALIF and 255 TDA patients were identified. After matching with propensity scores, there were no significant differences in the rates of any adverse event, serious adverse events, individual adverse events or readmission other than blood transfusion, which occurred more frequently in the ALIF cohort (3.92% versus 0.39%, p = 0.007). Operative time was not significantly different between the two cohorts, but postoperative length of stay was significantly longer for ALIF cases (+0.28 days, p < 0.001). When evaluating ten preoperative variables as potential risk factors for adverse events and readmission after TDA and ALIF, the majority of results were similar. Conclusions: The only identified differences in perioperative outcomes between TDA and ALIF were a 3.53% higher incidence of blood transfusion and 0.28-day longer length of stay for the ALIF group. These results suggest overall similar short-term general-health outcomes between the two groups, and that the choice between the two procedures, for the appropriately selected patient, should be based on longer-term functional outcomes. Level of evidence: 3.

Total disc replacement for chronic low‐back pain

Article

Jan 2010

Comparative Effectiveness of Treatments for Chronic Low Back Pain: A Multiple Treatment Comparison Analysis

Article

Nov 2016

Study design: A systematic review and network meta-analysis. Objective: To determine current treatment options of chronic low back pain (LBP) as defined by randomized controlled trials (RCTs) and to compare effectiveness of those treatments using a mixed-treatment comparison (MTC). Summary of background data: It is important to provide an evidence-based assessment of the treatment options that exist for LBP. Methods: A systematic search of RCTs was conducted in MEDLINE and the Cochrane Collaboration Library from 1990 to 2014. From the selected studies, we extracted preoperative and postoperative ODI and VAS back pain scores, additional surgeries, and complications. Standard and network meta-analytic techniques were used. Results: Twelve RCTs were included in the analysis: 5 total disk replacement (TDR) versus fusion; 1 TDR versus exercise and cognitive behavioral therapy (CBT); 5 fusion versus exercise and CBT; and 1 fusion versus physical therapy (PT). On the basis of MTC, with respect to ODI change scores, the pooled mean difference favoring fusion over exercise and CBT was 2.0 points (95% CI, -1.2 to 4.8). The pooled mean difference favoring TDR over exercise and CBT was 6.4 points (95% CI, 3.2-9.3). The pooled mean difference favoring fusion over PT was 8.8 points (95% CI, 4.1-13.6). The pooled mean differences favoring TDR over fusion was 4.4 points (95% CI, 2.37-6.63). For PT versus structured exercise with CBT, the pooled mean difference favoring exercise with CBT over PT was 6.8 points (95% CI, 1.5-12.8). For TDR versus PT, the pooled mean difference favoring TDR over PT was 13.2 points (95% CI, 8.0-18.4). Additional surgery rates were similar between treatment options. Conclusions: All 4 treatments provided some benefit to patients with chronic LBP. According to the MTC analysis, TDR may be the most effective treatment and PT the least effective treatment for chronic LBP. This review is based on a limited number of RCT studies and does not support any 1 treatment modality for all patients.

Kapitel 4. Lumbale Bandscheibenvollprothesen

Chapter

Dec 2011

Two- and five-year follow-up of lumbar total disc replacement compared to fusion: A meta-analysis

Article

Feb 2016
Int J Clin Exp Med

Lumbar fusion surgery has been a gold standard for treating lumbar disc degenerative disease (LDDD). But the adjacent segment pathology (ASP) became a problem, which could have been caused by the increased motion and stress concentration at the adjacent segment. So, artificial total disc replacement (TDR) as an alternative to spinal fusion has recently been applied for treatment of LDDD. However, up to now, a controversy whether TDR is better than fusion still persists. We performed the research of database including Pubmed/Medline, EMBASE, and Ovid. Our studies were classified into short-term (2 years) and midterm (5 years) follow-up. Twelve randomized controlled trials involving 1479 cases were included in the study. The repetitive data from them were excluded. Significant difference in visual analogue scale (VAS) and Oswestry disability index (ODI) could be found at 2 year follow-up, and TDR group was better than fusion group in both of them (VAS: I2=0%, P<0.0006; ODI: I2=0%, P<0.00001). No difference was found in reoperation rate at 2 year follow-up (I2=18%, P=0.22). However, the reoperation rate at the index level in TDR group was significantly lower than that in fusion group at 5 year follow-up (I2=0%, P=0.006). The incidence of ASP in TDR group was lower compared with fusion group at 5 year follow-up (I2=0%, P<0.0002) but not at 2 year follow-up (I2=0%, P<0.08). TDR shows the efficacy and safety comparable to lumbar fusion at 2 and 5 year follow-up. Besides, TDR has significant superiority in a lower incidence of ASP at 5 year follow-up.

An Evaluation of Information on the Internet of a New Device The Lumbar Artificial Disc Replacement

Article

Feb 2009
J SPINAL DISORD TECH

Study Design: An analysis of websites. accessible to the public, was conducted pertaining to the lumbar artificial disc replacement. Objective: The objective was to investigate the content of information available on the Internet pertaining to the lumbar artificial disc replacement. Summary of Background Data: The Internet is widely used by patients as an educational tool for health care information. Additionally, the Internet is used as a medium for direct-to-consumer marketing. Recent approval of the lumbar artificial disc replacement has led to the emergence of numerous websites offering information about this procedure. It is thought that patients can be influenced by information Found on the Internet; therefore, it is imperative that this information be accurate and as complete as possible. Methods: Three commonly used search engines were used to locate 105 (35/search engine) websites providing information about the lumbar artificial disc replacement. Each website was evaluated with regard to authorship and content. Results: Fifty-nine percent of the websites reviewed were authorized by a private physician group, 9% by an academic physician group, 6% by industry, 11% were news reports, and 15% were not otherwise categorized. Seventy-two percent offered a mechanism for direct contact and 30% provided clear patient selection criteria. Benefits were expressed in 87% of websites, whereas associated risks were described in 28% or less. European experiences were noted in 53%, whereas only 22% of websites detailed the current US experience. Conclusions: The results of this Study demonstrate that much of the content of Internet-derived information pertaining to the lumbar artificial disc replacement is potentially misleading. Until long-term data are available, patients Should be cautioned when using the Internet as it source for health care information, particularly with regard to the lumbar artificial disc replacement.

The Decision to Operate: Advanced Concepts

Chapter

Jan 2016

Low back pain and degenerative disk disease remain vexing problems affecting many patients. The art of patient selection for surgical candidates remains challenging as well. A thorough history and physical examination, meticulous review of diagnostic imaging, and the judicious use of pain management techniques for diagnostic and therapeutic purposes are the essential elements of a reliable protocol in the management of this patient population.

Lumbar Spine Disc Replacement

Article

Dec 2013

Trends in Materials for Spine Surgery

Chapter

Oct 2011

The human vertebral column serves to transfer loads from the head, trunk, and upper body to the pelvis to provide flexibility in motion while also helping to protect the spinal cord. The main load-bearing entity of the spine is the intervertebral disc, which is subject to degeneration due to normal aging or injury due to loading. Many treatments have been developed to address disorders of the spine including disc degeneration, vertebral fracture, and disc herniation. These range from invasive surgical techniques to noninvasive procedures to treat various tissues of the spine through several stages of damage and degeneration. Early techniques such as spinal fusion to stabilize the spine and alleviate discogenic pain have now become established procedures.

Efectividad y seguridad de la artroplastia total discal en lumbalgia crónica. Revisión sistemática y metaanálisis.

Book

Full-text available

Aug 2015

Executive summary Background Chronic low back pain can have a multifactor etiology that hinders its exactly origin identification and it is often associated with the presence of degenerative disc disease at L4-S1 level. Despite being a problem with a conservative medical treatment resolution in most cases, it can become a chronic problem affecting the quality of life of patients. In cases where appears neurological events and no-remission persists, the use of surgical techniques is necessary. The surgical method used to prevent further deterioration of the discs has been the spinal fusion but due to the decreased mobility and increased of adjacent segment degeneration, other techniques have been developed. Thus techniques such as total disc arthroplasty were developed and so wedetectedthe need to evaluate their effectiveness and safety compared to spinal fusion. Objectives To asses the effectiveness in terms of clinical severity, general improvement, functional status, quality of life and patient satisfaction, and safety in terms of mortality and complications, of the total disc arthroplasty in patients with chronic low back pain associated with degenerative disc disease. Materials and methods The following data sources were consulted: MedLine, EMBASE and Web of knowledge. Also were explored INAHTA through CRD, Cochrane Library, NICE, AUnETS and CADTH web. The search was carried out in two stages. The first step was to identify assessment health technologies reports, systematic reviews and meta-analysis and the second one to update the selected systematic review in the step before, by the exploration of the same sources of information and with its publication date limit (from 22 December 2011 to 4November 2013), for primary studies. The included design in the second search was only randomized clinical trials with patients suffering chronic low back pain associated with degenerative discs disease treated with total disc arthroplasty compared tospinal fusion. Data extraction and quality evaluation were carried out in pairs. The critical analysis was developed on the basis described by the Cochrane Back Review Group. The synthesis of the results was conducted in a qualitative and quantitative way, assessing heterogene ity and its clinical relevance. A sensitivity analysis was performed to assess the effect of risk of bias on outcomes . Result s 288 citations were retrieved during the first search, selecting a Cochrane review with meta - analysis for further update. With the second search we identified 118 references after removing duplicates, finally, we included 4 clinical trials. At a short to me dium follow - up period (2 - 5 years), the effectiveness of the intervertebral prosthesis was clinically comparable to the use of lumbar fusion procedures. The clinical parameters that showed statistically significant differences between the two techniques wer e improving low back pain ( p = 0.004), functional disability measured with the questionnaire Oswestry Disability Index (ODI) ( p = 0.0005), percentage of patients with improvements in functional capacity measured by ODI ( p = 0.02) and patient satisfaction ( p = 0.0003), all at 2 years follow - up and favouring total disc replacement. Among the described radiological findings that showed significant differences were found: implant mobility at one and two years of follow - up ( p < 0.00001), adjacent segment degener ation at 5 years ( p = 0.003) and the existence of subsidence at two years ( p = 0.0009), all in favor of the total disc arthroplasty. No clinical significance was found in any of the main parameters analyzed. Regarding the safety analysis, the total disc ar throplasty was presented as a relatively safe procedure and not associated with serious adverse events. Limita tion s The results should be treated with caution due to the limitation on the amount of items recovered at a short - moderate follow - up period (maximum 5 years), to the heterogeneity of prostheses employed and the high risk of detection bias due to lack of blinding of both patients and assessors. Conclusion s With the scientific evidence identified we can not conclude that the benefits of surgery with total disc replacement outweigh the spinal fusion in the treatment of chronic low back pain associated with disc degeneration disease, obtaining comparable results between the two techniques. Regarding the safety , the total disc arthroplasty is presen ted as a relatively safe procedure in a short to medium term, not associated with serious adverse events. However, since it is possible that damage and complications P RÓTESIS DISCALES EN LUMBALGIA 23 might occur in a longer period of time, the adoption of this intervention on a large scale must be cautious. Recommendations For treatment of patients with chronic low back pain associated with degenerative disc disease between L4 - S1 levels , which do not respond to conservative medical treatment, should be considered individually the benefits and risks of performing a total disc arthroplasty versus an spinal fusion.

Why Lumbar Artificial Disc Replacements (LADRs) Fail

Article

Jun 2015

Retrospective review of prospectively collected data. To determine why artificial disc replacements (ADRs) fail by examining results of 91 patients in FDA studies performed at a single Investigational Device Exemption (IDE) site with minimum two-year follow-up. Patients following lumbar ADR generally achieve their 24-month follow-up results at three months postoperative. Every patient undergoing ADR at one IDE site by two surgeons was evaluated for clinical success. Failure was defined as less than 50% improvement in ODI and VAS or any additional surgery at index or adjacent spine motion segment. Three ADRs were evaluated: Maverick™ (M) 25 patients, Charité™ (C) 31 patients, Kineflex™(K) 35 patients. All procedures were one-level operations performed at L4-5 or L5-S1. Demographics and inclusion/exclusion criteria were similar and will be discussed. Overall clinical failure occurred in 26%, (24 of 91 patients) at two-year follow up. Clinical failure occurred in: (M) 28%, (7 of 25 patients); (C) 39%, (12 of 31 patients); (K) 14%, (5 of 35 patients). Causes of failure included facet pathology, 50% of failure patients (12 of 24). Implant complications occurred in 5% of total patients and 21% of failure patients (5 of 24). Only five patients went from a success to failure after three months. Only one patient went from a failure to success after a facet rhizotomy one year after ADR. Seventy-four percent of patients after ADR met strict clinical success after two-year follow-up. The clinical success verses failure rate did not change from their three-month follow-up in 85 of the 91 patients (93%). Overall clinical success may be improved most by patient selection and implant type.

Total Disc Arthroplasty

Chapter

Dec 2006

Steven Kurtz

This chapter summarizes early total disc replacement designs and current cervical and lumbar disc replacements. The chapter focuses on three historical disc replacement designs evaluated in patients: Fernström spheres, the AcroFlex artificial disc, and the Charité artificial disc. From a historical and implant design perspective Fernström was the first pioneer of disc arthroplasty. His work introduced the notion that a motion-preserving interbody prosthesis might possibly avoid undesirable complications of spine fusion procedures. Fernström's work also provides some evidence, albeit extremely limited, that metallic disc replacement components were biocompatible when implanted as bearing materials in the intervertebral disc space to articulate against the end plates. The AcroFlex artificial disc represents a major evolutionary step in the conceptual design of total disc arthroplasties, especially when juxtaposed against the much simpler design of the Fernström sphere. The Charité design, formally known as the SB Charite artificial disc by its inventors, basically consists of two metallic end plates fixed to the adjacent vertebral bodies, which articulate against a central core fabricated from ultrahigh molecular weight polyethylene (UHMWPE).

Indications for Lumbar Total Disc Replacement: Selecting the Right Patient with the Right Indication for the Right Total Disc

Article

Full-text available

Dec 2014

As with any surgery, care should be taken to determine patient selection criteria for lumbar TDR based on safety and optimizing outcome. These goals may initially be addressed by analyzing biomechanical implant function and early clinical experience, ongoing evaluation is needed to refine indications. The purpose of this work was to synthesize information published on general indications for lumbar TDR. A secondary objective was to determine if indications vary for different TDR designs. A comprehensive literature search was conducted to identify lumbar TDR articles. Articles were reviewed and patient selection criteria and indications were synthesized. With respect to safety, there was good agreement in the literature to exclude patients with osteopenia/osteoporosis or fracture. Risk of injury to vascular structures due to the anterior approach was often addressed by excluding patients with previous abdominal surgery in the area of disc pathology or increased age. The literature was very consistent on the primary indication for TDR being painful disc degeneration unresponsive to at least 6 months of nonoperative care. Literature investigating the impact of previous spine surgery was mixed; however, prior surgery was not necessarily a contra-indication, provided the patient otherwise met selection criteria. The literature was mixed on setting a minimum preoperative disc height as a selection criterion. There were no publications investigating whether some patients are better/worse candidates for specific TDR designs. Based on the literature a proposal for patient selection criteria is offered. Several TDR indications and contra-indications are widely accepted. No literature addresses particular TDR design being preferable for some patients. As with any spine surgery, ongoing evaluation of TDR outcomes will likely lead to more detailed general and device design specific indications.

Lumbar Total Disc Replacement Using ProDisc II

Article

Aug 2006
J SPINAL DISORD TECH

A lumbar total disc replacement (TDR) is believed to be a promising substitute in the surgical treatment for lumbar degenerative disc disease. The purpose of this study is to report the clinical and radiographic outcomes of 36 consecutive patients who underwent lumbar TDR using ProDisc II, and the factors associated with a better clinical outcome after a 2-year minimum follow-up. At the time of the latest follow-up, the success rate was 94% of 36 patients according to the criteria of the US Food and Drug Administration. Of the 10 patients unable to work preoperatively, 7 patients returned to work. Moreover, mean score on the visual analog scale for low back and leg pain improved significantly from 7.5 and 4.7 to 3.0 and 1.2, respectively (P<0.001). In addition, mean Oswestry disability index scores improved significantly from 69.2 to 21.0 (P<0.001). Mean disc height at the operative level increased significantly from 9.0 to 17.6 mm, and mean range of motion increased significantly from 9.7 to 12.7 degrees (P<0.01). Statistical analysis showed that the factors associated with a better clinical outcome were single level, and a higher postoperative segmental ROM at the operative level. At a minimum follow-up of 2 years, the lumbar TDR using ProDisc II showed excellent clinical and radiographic outcomes without any significant complication. However, future efforts need to be directed toward the evaluation of a larger number of patients with longer follow-up.

Long-term Outcomes of 2-Level Total Disc Replacement Using ProDisc-L

Article

May 2014

Study design: A prospective clinical data analysis. Objective: To determine the long-term clinical success of 2-level total disc replacement (TDR) in patients with degenerative disc disease. Summary of background data: Early successful clinical results of 2-level TDR have been reported. Few studies exist that have described this procedure's durability in the long term. Methods: Fifteen patients underwent 2-level lumbar TDR with the ProDisc-L as part of a randomized trial, 13 of whom were available for follow-up. The patients were assessed preoperatively and at 2 years, 5 years, and more than 9 years postoperatively using visual Oswestry Disability Index. At the last follow-up visit, 2 additional questions were asked: satisfaction with surgery and willingness to undergo the same treatment. Finally, clinical success was assessed using a previously described definition. Results: Mean follow-up time was 9.6 years (range, 9.2-10.3 yr). Postoperatively there was a significant improvement in Oswestry Disability Index score from baseline (70.0 vs. 15.7 at 2 yr, P = 0.002) that remained unchanged during the period of follow-up (19.8 at 5 yr, P = 0.003 and 12.9 at 9-10 yr, P = 0.002). Ninety-two percent of patients were "satisfied" or "somewhat satisfied" with treatment and the same number would undergo treatment again. Eighty-five percent of patients achieved clinical success. Conclusion: This prospective study demonstrates the durable clinical success of 2-level lumbar TDR as assessed at more than 9 years postoperatively. Level of evidence: 4.

Tribological examination of lumbar intervertebral disc implants

Article

Jul 2013

The article presents results of friction and wear tests of three-piece systems of the intervertebral disc implant. The number of work cycles proved to have an effect on the coefficient of friction for polyethylene-on-metal and metal-on-metal tribojoints. In addition, for polyethylene-on-metal tribojoints, the effect of compressive force on the coefficient of friction was specified. The influence of working cycles on roughness changes of implant’s working surfaces was analyzed. Based on the microscopic examination of the working surface of implants and morphology of the wear products, the wear mechanism was described. Studies were performed at the Laboratory of Surface Engineering and Tribology in the Metal Forming Institute in Poznan using a SBT-03 simulator.

Comparison of Total Disc Replacement with Lumbar Fusion: A Meta-Analysis of Randomized Controlled Trials

Article

Jan 2015

A meta-analysis was performed to evaluate whether a beneficial clinical effect of the Total Disc Replacement (TDR) over lumbar fusion for the treatment of patients with Degenerative Disc Disease (DDD). An electronic search of PubMed, Cochrane Central Register of Controlled Trials, and EMBASE from their inception to 2012 was completed, and we assessed risk bias and retrieved relevant data, and meta-analysis was performed, if appropriate. Oswestry Disability Index (ODI), Visual Analog Score (VAS), patient satisfaction or VAS patient satisfaction, narcotic use, overall success rate, reoperation rate, work status, "surgery again?", complications and radiographic outcomes were evaluated. Six RCTs were included in this meta-analysis. At 2 years, TDR was demonstrated to be more beneficial for patients compared to lumbar fusion in the following outcomes, including ODI scores (MD:-4.87, 95% CI: -7.77 to -1.97, p=0.001), patient satisfaction (OR:1.91, 95% CI: 1.27 to 2.86, p=0.002) and VAS patient satisfaction (MD:9.10, 95% CI: 3.20 to 14.99, p=0.002), the percentage of using narcotics (OR=0.54, 95%CI: 0.31 to 0.96, p=0.03), overall success rate (OR:1.68, 95% CI: 1.26 to 2.25, p=0.005), the rate of patients to chose the same surgical treatment again (OR:2.38, 95% CI: 1.72 to 3.28, p < 0.001), and complications (OR=0.50, 95%CI: 0.29 to 0.84, p=0.008). Other outcomes, including re-operation rate (OR:0.62, 95% CI: 0.36 to 1.06, p=0.08) and work status (OR=1.05, 95% CI: 0.75 to 1.47, p=0.80), were demonstrated to be no differences between the two groups. In a long-term of follow-up (2 years), TDR shows a significant superiority for the treatment of lumbar DDD compared with fusion.

Lumbar Total Disc Replacement

Article

Oct 2006

Anatomic Surgical Management of Chronic Low Back Pain

Article

Oct 2014
NEUROMODULATION

Objective To review spine surgery management strategies for patients with chronic low back pain (CLBP) that has failed to respond to all nonsurgical treatment options.Materials and Methods Literature review was conducted for spine surgery in the treatment of CLBP without compressive anatomical disease. The main diagnosis identified was degenerated disc disease, and surgical options targeted for the treatment of CLBP were reviewed.ResultsThe history of current spine intervention for CLBP was reviewed, including various surgical options. Surgical treatment options for patients with CLBP include lumbar fusion, lumbar disc arthroplasty, and dynamic stabilization. Lumbar fusion remains the most frequent spine surgery performed for CLBP, but questions still exist regarding its efficacy in comparison with conservative care or interventional pain management. Lumbar disc arthroplasty and dynamic stabilization can both be considered only for select patients with CLBP, and their uses are currently limited.Conclusion Despite the number of spine surgeries that have been performed for CLBP, the surgical outcome still remains questionable. Until a precise identification of the cause of CLBP in any given patient can be precisely determined, surgical solutions will continue to be less than optimal.

Mechanics of Biomaterials: Fundamental Principles for Implant Design

Article

Jul 2012
MRS BULL

Teaching mechanical and structural biomaterials concepts for successful medical implant design, this self-contained text provides a complete grounding for students and newcomers to the field. Split into three sections: Materials, Mechanics and Case Studies, it begins with a review of sterilization, biocompatibility and foreign body response before presenting the fundamental structures of synthetic biomaterials and natural tissues. Mechanical behavior of materials is then discussed in depth, covering elastic deformation, viscoelasticity and time-dependent behavior, multiaxial loading and complex stress states, yielding and failure theories, and fracture mechanics. The final section on clinical aspects of medical devices provides crucial information on FDA regulatory issues and presents case studies in four key clinical areas: Orthopedics, cardiovascular devices, dentistry and soft tissue implants. Each chapter ends with a list of topical questions, making this an ideal course textbook for senior undergraduate and graduate students, and also a self-study tool for engineers, scientists and clinicians.

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

Article

Dec 2013
ARCH ORTHOP TRAUM SU

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.

100 Consecutive Cases of Degenerative Lumbar Conditions Using a Non-Threaded Locking Screw System With a 90-Degree Locking Cap

Article

Full-text available

Mar 2009

Background This prospective study analyzes the perioperative outcomes and long-term fusion success of 100 consecutive lumbar degenerative cases. The cases were managed using a non-threaded locking screw system, in conjunction with polyetheretherketone (PEEK) cages, for posterior lumbar interbody fusion (PLIF) procedures. These 100 cases were compared to another prospective study treating patients with the same inclusion and exclusion criteria using conventional plate-based pedicle screw spinal instrumentation augmented with carbon fiber interbody cages.MethodsA total of 167 operative levels were treated in 100 patients (51 single-level, 39 two-level and 10 three-level cases). Eleven cases were revisions and 67 patients received interbody fusion cages. Patients had an average of 22.8 ± 4.0 months follow-up. Results: There was one instrumentation failure but no significant subsidence at the interbody fusion level. The disc space height was restored as part of the surgical procedure at the interbody cage levels: from 7.5 ± 2.3 mm preoperative to 9.0 ± 2.1 mm postoperative. There were 2 cases of pseudarthrosis (2 / 100 = 2%). The average operative time for 1-level cases was 111 ± 25 minutes; for 2-level cases it was 132.4 ± 21.8 minutes; and for 3-level cases it was 162.6 ± 33 minutes. Blood loss averaged 800 ± 473 cc for 1-level cases, 1055 ± 408 cc for 2 levels, and 1155 ± 714 cc for 3 levels. The length of stay was similar between the 3 groups (4.4 ± 1.2 days for single-level cases, 4.7 ± 1.1 for 2 levels, and 5.0 ± 1.1 for 3 levels; P > .05). There were 3 incidental durotomies, and 4 other patients developed infections postoperatively that required reoperation.Conclusion The disc and foraminal heights can be restored and maintained with a unilateral cage and pedicle screw construct. Unilateral transforaminal lumbar interbody fusion using a PEEK cage combined with a non-threaded locking pedicle screw and rod system results in similar fusion rates to those achieved using the bilateral Brantigan interbody fusion cage or a single BAK Vista implant. When compared to the bilateral Brantigan cages, decreased operative time (P < .001), decreased blood loss (P < .001) and reduced incidence of dural tears (P < .001) are advantages of using a non-threaded locking screw system and single PEEK interbody cage for lumbar degenerative conditions without compromising subsequent fusion rates.

A Review of the 2001 Volvo Award Winner in Clinical Studies: Lumbar Fusion Versus Nonsurgical Treatment for Chronic Low Back Pain: A Multicenter Randomized Controlled Trial From the Swedish Lumbar Spine Study Group

Article

Full-text available

Jan 2002

A randomized controlled multicenter study with a 2-year follow-up by an independent observer. To determine whether fusion of the lower lumbar spine could reduce pain and diminish disability more effectively when compared with nonsurgical treatment in patients with severe chronic low back pain (CLBP). The reported results after fusion surgery on patients with CLBP vary considerably, and the evidence of treatment efficacy is weak in the absence of randomized controlled studies. A total of 294 patients referred to 19 spinal centers from 1992 through 1998 were randomized blindly into four treatment groups. Patients aged 25-65 years with CLBP for at least 2 years and with radiologic evidence of disc degeneration at L4-L5, L5-S1, or both were eligible to participate in the study. The surgical group (n=222) included three different fusion techniques, not analyzed separately in this study. Patients in the nonsurgical group (n=72) were treated with different kinds of physical therapy. The surgical group comprised 49.5% men, and the mean age was 43 years. The corresponding figures for the nonsurgical group were 48.6% and 44 years. The patients had suffered from low back pain for a mean of 7.8 and 8.5 years and been on sick leave due to back pain for a mean of 3.2 and 2.9 years, respectively. The Visual Analogue Scale (VAS) was used to measure pain. The Oswestry Low Back Pain Questionnaire, the Million Score and the General Function Score (GFS) were used to measure disability. The Zung Depression Scale was used to measure depressive symptoms. The overall result was assessed by the patient and by an independent observer. Records from the Swedish Social Insurance were used to evaluate work disability. Patients who changed groups were included in the analyses of significance according to the intention-to-treat principle. At the 2-year follow-up 289 of 294 (98%) patients, including 25 who had changed groups, were examined. Back pain was reduced in the surgical group by 33% (64 to 43), compared with 7% (63 to 58) in the nonsurgical group (P=0.0002). Pain improved most during the first 6 months and then gradually deteriorated. Disability according to Oswestry was reduced by 25% (47 to 36) compared with 6% (48 to 46) among nonsurgical patients (P=0.015), according to Million by 28% (64 to 46) compared with 8% (66 to 60) (P=0.004), and accordingtoGFS by 31% (49 to 34) compared with 4% (48 to 46) (P=0.005). The depressive symptoms, according to Zung, were reduced by 20% (39 to 31) in the surgical group compared with 7% (39 to 36) in the nonsurgical group (P=0.123). In the surgical group 63% (122/195) rated themselves as "much better" or "better" compared with 29% (18/62) in the nonsurgical group (P<0.0001). The "net back to work rate" was significantly in favor of surgical treatment, or 36% vs. 13% (P=0.002). The early complication rate in the surgical group was 17%. Lumbar fusion in a well-informed and selected group of patients with severe CLBP can diminish pain and decrease disability more efficiently than commonly used nonsurgical treatment.

Minimally invasive total disc replacement: Surgical technique and preliminary clinical results

Article

Full-text available

Nov 2002

Total disc replacement has become an option for the treatment of degenerative disc disease of the lumbar spine. A new generation of implants has been developed that can be implanted through minimally invasive anterior approaches to the lumbar levels L2/3, L3/4, L4/5 and L5/S1. However mid- and long-term data are still lacking. This paper describes the minimally invasive surgical approach - techniques as well as the preliminary results of our first 34 consecutive patients. The intervertebral spaces L5/S1, L4/5, L3/4 and L2/3 were each approached through slightly different, but standardized, mini-laparotomies either through a retroperitoneal or a transperitoneal route. The clinical results with a follow-up of up to 1 year show satisfactory outcomes in about 80% of the patients. Oswestry score as well as VAS values show significant changes during the postoperative course. There have been three complications (8.8%), two of which were specific to the implantation process, but were resolved with a good clinical outcome in both patients. The preliminary results suggest that total disc replacement may become a reasonable alternative to spinal fusion under the selection criteria used in this study.

2001 Volvo Award Winner in Clinical Studies: Lumbar Fusion Versus Nonsurgical Treatment for Chronic Low Back Pain: A Multicenter Randomized Controlled Trial From the Swedish Lumbar Spine Study Group

Article

Dec 2001

Study design: A randomized controlled multicenter study with a 2-year follow-up by an independent observer. Objectives: To determine whether fusion of the lower lumbar spine could reduce pain and diminish disability more effectively when compared with nonsurgical treatment in patients with severe chronic low back pain (CLBP). Summary of background data: The reported results after fusion surgery on patients with CLBP vary considerably, and the evidence of treatment efficacy is weak in the absence of randomized controlled studies. Patients and methods: A total of 294 patients referred to 19 spinal centers from 1992 through 1998 were randomized blindly into four treatment groups. Patients aged 25-65 years with CLBP for at least 2 years and with radiologic evidence of disc degeneration at L4-L5, L5-S1, or both were eligible to participate in the study. The surgical group (n=222) included three different fusion techniques, not analyzed separately in this study. Patients in the nonsurgical group (n=72) were treated with different kinds of physical therapy. The surgical group comprised 49.5% men, and the mean age was 43 years. The corresponding figures for the nonsurgical group were 48.6% and 44 years. The patients had suffered from low back pain for a mean of 7.8 and 8.5 years and been on sick leave due to back pain for a mean of 3.2 and 2.9 years, respectively. The Visual Analogue Scale (VAS) was used to measure pain. The Oswestry Low Back Pain Questionnaire, the Million Score and the General Function Score (GFS) were used to measure disability. The Zung Depression Scale was used to measure depressive symptoms. The overall result was assessed by the patient and by an independent observer. Records from the Swedish Social Insurance were used to evaluate work disability. Patients who changed groups were included in the analyses of significance according to the intention-to-treat principle. Results: At the 2-year follow-up 289 of 294 (98%) patients, including 25 who had changed groups, were examined. Back pain was reduced in the surgical group by 33% (64 to 43), compared with 7% (63 to 58) in the nonsurgical group (P=0.0002). Pain improved most during the first 6 months and then gradually deteriorated. Disability according to Oswestry was reduced by 25% (47 to 36) compared with 6% (48 to 46) among nonsurgical patients (P=0.015), according to Million by 28% (64 to 46) compared with 8% (66 to 60) (P=0.004), and accordingtoGFS by 31% (49 to 34) compared with 4% (48 to 46) (P=0.005). The depressive symptoms, according to Zung, were reduced by 20% (39 to 31) in the surgical group compared with 7% (39 to 36) in the nonsurgical group (P=0.123). In the surgical group 63% (122/195) rated themselves as "much better" or "better" compared with 29% (18/62) in the nonsurgical group (P<0.0001). The "net back to work rate" was significantly in favor of surgical treatment, or 36% vs. 13% (P=0.002). The early complication rate in the surgical group was 17%. Conclusion: Lumbar fusion in a well-informed and selected group of patients with severe CLBP can diminish pain and decrease disability more efficiently than commonly used nonsurgical treatment.

Distribution-Free and Robust Statistical Methods: Viable Alternatives to Parametric Statistics?

Article

Sep 1995

Stephen M Smith

In much ecological hypothesis testing, Type II errors may be more serious than type I errors; ecologists are encouraged to make an a priori assessment of the relative costs of both types of error. Distribution-free statistics such as the Mann-Whitney procedure are not necessarily more powerful nor more robust than their parametric analogues.

4:19 Lumbar disc replacement

Article

Sep 2002
SPINE J

Thierry Marnay

Purpose of study: Total disc replacement is a surgical procedure that can be considered as an alternative to spinal fusion, for the treatment of patients with chronic low back pain secondary to degenerative disc disease. Total disc replacement allows pathological disc removal while maintaining or restoring disc height and preserving motion of the involved segment. Methods used: Prodisc is made up of an inferior and superior titanium plate. Each plate has two notched keels designed to provide mechanical interlocking with the vertebral end plate. The surfaces of the plates in contact with bone are plasma sprayed with titanium allowing the bone ingrowth and providing long-term stability. A convex shape dome of polyethylene inserted in the inferior plate articulates with superior plate and allows motion between the vertebral bodies. Patients enrolled in this study had a history of chronic low back pain and had failed conservative therapy. Patients were clinically evaluated for low back pain and leg pain using a visual analog scale (VAS); neurological examination and the use of pain medication. Patients were interviewed on daily activity, work recovery, sport, and the Oswestry scale and Short Form (SF)-36 were recorded. Preoperative and follow-up Beaujon score, including evaluation of low back pain, leg pain, neurological status, walking capacity, medication and everyday life evaluation, were compared. Radiographs and computed tomography scans were evaluated. Radiographic measurement included height of implant, resorption around the implant, flexion/extension and lateral bending motion and subsidence. of findings: From 1990 to 1993, 93 prostheses were implanted in 64 patients by anterior approach from L2 to S1: 39 cases, one level; 21 cases, 2 levels; 4 cases 3 levels. To date, no implants have been explanted. Five patients with ongoing pain have been fused by a posterior approach. Radiographically, all implants are stable and show no migration of subsidence. The last follow-up patients were at 8.6 years average of postsurgery. Complications included vascular (1) and sexual temporary dysfunction (2) and were related to the anterior approach. The patients' back pain measured by VAS was on average 8.5 preoperatively and 3.0 at the final follow-up. For leg pain, VAS showed 7.1 preoperatively and 1.9 at the final follow-up. At the long-term follow-up, 65% of the patients reported that they were “entirely satisfied,” 28% “satisfied” and only 7% “not satisfied.” These overall patient satisfaction data were supported by the Oswestry score (average, 8.3) as well as the SF-36 results and Beaujon score (average preoperative 7/20 SD=3, postoperative 16/20 SD=3, relative gain 0.69, SD 0.23). Relationship between findings and existing knowledge: These results demonstrate that the Prodisc can remain mechanically stable and provide significant pain relief and improvement in functional status while maintaining motion in patients at 7 to 11 years of follow-up. Total disc replacement may represent an option for the surgical treatment of mechanical low back pain secondary to degenerative disc disease that removes the pathological disc but preserves motion. Disc arthroplasty constitutes a promising alternative to fusion. Overall significance of findings: It may actually be associated with the development of less adjacent disc disease than an arthrodesis because of the preservation of motion. However, further research is necessary, and a prospective, randomized trial is necessary to compare these two techniques for the treatment of degenerative disc disease. Disclosures: No disclosures. Conflict of interest: Thierry Marnay, consultant, and stockholder: Spine Solutions Inc.

The Oswestry Low Back Pain Questionnaire

Article

Sep 1980
PHYSIOTHERAPY

The questionnaire is divided into ten sections selected from a series of experimental questionnaires designed to assess limitations of various activities of daily living. The chosen sections were those found to be most relevant to the problems suffered by people with low back pain. Each section contains six statements. A study of 25 patients with primary low back pain has already been mentioned. Their symptoms tended to resolve quickly and changes in their mean disability score can be seen over the first three weeks after referral to the spinal disorders department. The disability score was also used to demonstrate that there was no difference in the severity of symptoms in two sub-groups of patients in the same study. All new patients referred to the department complete the questionnaire when they first attend. The disability score is used as a guide to a patient's treatment programme. It cannot be used in isolation since it makes no allowance for the demands of a patient's job, his age or psychological make-up. However, it does ensure that important aspects of disability which are often forgotten are recorded in the patient's notes. Later, changes in the score may be used in monitoring the subsequent progress of the patient through treatment.

Basic Biomechanics of the Spine

Article

Aug 1980

The purpose of this presentation is to provide basic biomechanical information concerning the spine, its components, and the spinal cord. It is shown that this information is helpful in understanding the fundamental functions of the spinal column. The experimentally determined physical properties of the vertebra, various spinal ligaments, the disc, and the spinal cord under many different loading conditions are described. The role of the special characteristics of the spine ligaments in allowing physiological motions of the spine, preventing excessive motions between vertebrae, and protecting the spinal cord during trauma are discussed. Movements of the spinal cord within the spinal canal and associated changes of its section during physiological movements of the spine are also described. The kinematics of the various regions of the spine are discussed and their clinical significance is presented. The problems of spinal trauma and is associated spinal instability are analyzed. Guidelines are recommended to assess spinal stability. The proper application of such guidelines will provide the basis for sound clinical judgments.

Outcome of Unoperated Discogram-Positive Low Back Pain

Article

Oct 1995

No previous discography study has addressed the nonoperative outcome of low back pain. This study was undertaken to retrospectively analyze the outcome of patients with documented single-level discogenic pain who were considered candidates for surgery but did not receive it. The natural history of "discogenic" low back pain is unknown, and its treatment is controversial. Although positive discography is viewed as a valid diagnostic technique, the results of fusion surgery are often disappointing. Twenty-five individuals (16 women, 9 men) underwent comprehensive evaluation (examination, radiography, objective disability determination). Study criteria included incapacitating low back pain, single-level + morphologic + provocative discogram, no surgery, and a minimum follow-up period of 3 years. Average age of patients at discography was 43 years and at study was 48 years; level of involvement in 10 patients was L4-L5 and in 15 patients were L5-S1. The mean follow-up period was 4.9 years (range, 3.3-7.0 years). The condition of 17 (68%) patients improved, two (8%) stayed the same, and six (24%) worsened. Improved patients had a shorter history of low back pain (3.5 yr vs. 11.0 yr) and older age at onset (45 versus 33 yrs.) Psychiatric disease was present in 66.7% (4 of 6) patients whose conditions worsened. Eighty percent (12 of 15) of patients receiving workers' compensation improved. There was no correlation between disc level, gender, smoking, and outcome. Discogenic low back pain improved in patients without psychiatric disease. Older age at onset and shorter duration of low back pain were favorable indicators. These results are comparable with or better than those reported for surgical treatment of this condition.

Outcome of unoperated discogram positive low back pain

Article

Jul 1996

B S Hinkley

The Roland???Morris Disability Questionnaire and the Oswestry Disability Questionnaire

Article

Jan 2001

The RDQ is a short and simple method of a self-rated assessment of physical function in patients with back pain. Its ease of use makes it suitable for following up on the progress of individual patients in clinical settings and for combining with other measures of function (e.g., psychological or work disability) in research settings. The ODI is likewise an effective method of measuring disability in patients with back pain with a wide degree of severity and causes. Both instruments have stood the test of time and have been used in a wide variety of clinical situations, in the United Kingdom, the United States, and many other countries. Both instruments perform as well as most other currently available instruments and better than some. The RDQ may be better suited to settings in which patients have mild to moderate disability and the ODI to situations in which patients may have persistent severe disability. The availability of the two instruments in a wide range of languages permits comparison between studies performed in numerous countries.

Microsurgical Anterior Approaches to the Lumbar Spine for Interbody Fusion and Total Disc Replacement

Article

Dec 2002

Anterior approaches to the lumbar spine for the treatment of various degenerative or postoperative abnormalities associated with low back pain have always been a matter of debate. They are known to be associated with considerable surgical trauma, high postoperative morbidity, and, occasionally, unacceptably high complication rates. In 1997, we inaugurated two new microsurgical modifications of conventional anterior approach techniques, which have been applied in anterior lumbar interbody fusion and more recently in total disc replacement. This article describes the results of microsurgical anterior interbody fusion in a consecutive series of 171 patients as well as preliminary results of these techniques for total disc replacement in 26 patients. The approaches are performed with the use of a surgical microscope. Lumbar segments L2-L5 are exposed through a lateral retroperitoneal approach. L5-S1 can be reached through a midline retroperitoneal or transperitoneal approach. Both approaches can be performed through a limited skin incision of 4 cm. An independent observer evaluated results of anterior lumbar interbody fusion in 171 patients during a 2-year follow-up period. The clinical follow-up demonstrated low perioperative and postoperative morbidity with an average blood loss of less than 100 ml at the fusion site. Pseudoarthrosis rates were less than 5%, and clinical results, as evaluated in accordance with the scoring system developed by Prolo et al., did not differ significantly from conventional open techniques. Total disc replacement through a microsurgical anterior approach seems to be a promising alternative to fusion procedures with even less intraoperative and perioperative morbidity. Microsurgical anterior approaches to the lumbar spine provide a reasonable surgical alternative to conventional approaches for anterior interbody fusion and total disc replacement.

Indications for full prosthetic disc arthroplasty: A correlation of clinical outcome against a variety of indications

Article

Nov 2002

In this prospective study, a total of 134 prosthetic discs were replaced in 108 patients undergoing total disc replacement surgeries for degenerative disc disease. It was the aim of this study to correlate the clinical findings and the outcome of our patients treated with Prodisc II prostheses for various indications and to formulate indication criteria for disc replacement surgeries. The discs were implanted at L5/S1 in 61 patients, L5/L6 in 3 patients, L4/L5 in 31 patients, L3/L4 in 7 patients, and L2/L3 in 3 patients. There were 12 patients with two-level implants: from L4 to S1 in 11 of them and from L2 to L5 in the remaining one. Two patients also had three-level implants, from L3 to S1. Follow-up evaluation included plain radiographs, physical evaluation, and subjective evaluation by the patient using the Oswestry scale, the visual analog pain scale, and the SF-36V2 well-being questionnaire. The evaluation exercise showed that 90.8% of patients had excellent results, 7.4% had good results and 1.8% had fair results, with no poor results seen. Postoperatively, the average vertebral motion was increased in all patients at the operated level. Progression of disc degeneration at the adjacent levels was noted in ten patients. The average time to resuming activities of daily living unaided was 2.3 weeks. No implant failures or complications due to surgery were encountered in this study. Total prosthesis disc replacement for degenerative disc disease was found to be a good treatment modality, provided proper patient selection and criteria are adhered to. We were able to formulate indication criteria based on this.

Lumbar disc replacement - Preliminary results with ProDisc II after a minimum follow-up period of 1 year

Article

Sep 2003
J SPINAL DISORD TECH

Total disc replacement has the potential to replace fusion as the gold standard surgical treatment of degenerative disc disease. Potential advantages of disc replacement over fusion include avoidance of pseudarthrosis, postoperative orthoses, and junctional degeneration. After observing satisfactory clinical results at 7-11 years' follow-up with the ProDisc first-generation implant, a second-generation prosthesis was designed. This study is a prospective analysis of the early results of total disc replacement with the ProDisc II total disc prosthesis. Fifty-three patients had single-level or multilevel disc replacement and were evaluated clinically and radiographically preoperatively and at mean 1.4-year follow-up. There were clinically and statistically significant improvements in back and leg pain Visual Analog Scale and Oswestry disability scores that were maintained at final follow-up. The clinical results of patients with single- and multilevel surgery were equivalent. Satisfactory results were achieved in 90% of patients who had previous lumbar surgery. Complications occurred in 9% of patients and included vertebral body fracture, transient radicular pain, implant malposition, and transient retrograde ejaculation. Three patients (6%) required reoperation to address complications. No mechanical failure of the implants or loosening was observed, and the prostheses retained motion. Randomized, prospective, long-term studies will be necessary to compare the effectiveness of arthrodesis with total disc replacement.

Lumbar Spine Arthroplasty: Early Results Using the ProDisc II: A Prospective Randomized Trial of Arthroplasty Versus Fusion

Article

Aug 2003
J SPINAL DISORD TECH

This study represents the first 39 patients with at least 6-month follow-up enrolled in a prospective randomized Food and Drug Administration study evaluating the safety and efficacy of the ProDisc II versus the control, a 360 degrees lumbar spinal fusion. Data were collected preoperatively and at 6 weeks, 3 months, and 6 months postoperatively. Visual Analog Scale (VAS), Oswestry Low Back Pain Disability Questionnaire (ODQ), and patient satisfaction rates were evaluated at these intervals, as well as range of motion, return to work, and recreational and ambulatory status. There were 28 ProDisc patients and 11 who underwent fusion. Six patients had two-level surgery. Estimated blood loss (ProDisc = 69 mL versus fusion = 175 mL) and operative time (ProDisc = 75 minutes versus fusion = 219 minutes) were significantly different (P < 0.01). Hospital stays were shorter (ProDisc = 2.1 days versus fusion = 3.5 days [P < 0.01]) for ProDisc patients. There was a significantly greater reduction in the ODQ scores at 3 months in the ProDisc group compared with the fusion group (P < 0.05). No difference was noted in VAS. A trend was identified at 6 months in patient satisfaction rates favoring ProDisc versus fusion (P = 0.08), and motion was significantly improved in ProDisc patients compared with the fusion group (P = 0.02). Ambulatory status as well as recreational activity improved faster in the ProDisc group. The data suggest that total disc arthroplasty may be an attractive option as opposed to lumbar fusion for the surgical treatment of disabling mechanical low back pain secondary to lumbar disc disease.

The Fate of the Adjacent Motion Segments After Lumbar Fusion

Article

Sep 2003
J SPINAL DISORD TECH

Philippe Gillet

Lumbar spine fusion is a commonly performed procedure in various pathologic conditions of the spine. Its role remains debated, and moreover, delayed complications may occur, among which is transitional segment alteration leading to recurrence of back pain, gross instability, and neurologic symptoms. Little is known about the long-term prevalence of this complication because of a lack of specific studies. We analyzed the fate of the transitional segments in a homogeneous group of patients operated on during a 14-year period for degenerative conditions of the lumbar spine resistant to conservative treatment. Follow-up ranged from 2 to 15 years. Seventy-five percent of our study group had a minimal 5-year follow-up. In this subgroup, 41% of the patients developed transitional segment alterations, and 20% needed a secondary operation for extension of the fusion. Potential risk factors such as postoperative delay, length of fusion, and spine imbalance were recognized. The frequency of delayed alterations of the adjacent segment and the severity of symptoms related to this complication in this study raise questions about the justification of fusion procedures in degenerative conditions of the spine without threatening instability. Data from the literature confirm the severity of the problem, but many uncertainties remain because of the lack of homogeneous and complete data on both the normal evolution of motion segments of the lumbar spine with age and the fate of the same segments when transformed in transitional segments. Future prospective studies on the subject are needed and must deal with homogeneous groups of patients. More reconstructive surgical procedures need to be developed to lessen the need for fusion procedures.

Long-Term Flexion-Extension Range of Motion of the Prodisc Total Disc Replacement

Article

Oct 2003
J SPINAL DISORD TECH

The rationale for total disc replacement is avoidance of the junctional degeneration seen after arthrodesis by preservation of segmental motion. To justify the use of disc prostheses, it is essential to document maintained range of motion (ROM) and sagittal alignment at long-term follow-up. This is a retrospective radiographic study of 42 patients who had placement of 58 first-generation Prodisc prostheses at a mean follow-up of 8.7 years. Flexion-extension ROM was measured by Cobb's method. Junctional levels were evaluated for junctional degeneration. Pre- and postoperative global and segmental lordosis were measured. Prognostic patient factors predicting ROM of <2 degrees were evaluated. We observed ROM of at least 2 degrees in 66% of Prodisc prostheses at 8.7-year follow-up, although ROM was less than that reported in asymptomatic normal individuals. Mean ROM for disc prostheses with motion was 7.5 degrees at L3-L4, 6.2 degrees at L4-L5, and 4.1 degrees at L5-S1. Mean ROM for all prostheses was 3.8 degrees. The incidence of radiographic junctional degeneration was 24%, although no patients required surgery for symptomatic junctional degeneration. Mean ROM of prostheses below a degenerated junctional disc was 1.6 degrees compared with 4.7 degrees below a normal junctional disc (P < 0.035). Females were 3.5 times more likely to have ROM of <2 degrees. This is the longest published follow-up study of a lumbar disc replacement. The data show that ROM is preserved at long-term follow-up in the majority of patients. Global and segmental sagittal alignment improve after surgery. Furthermore, there is an association between ROM of disc prostheses and the development of junctional degeneration.

ProDisc Artificial Total Lumbar Disc Replacement: Introduction and Early Results From the United States Clinical Trial

Article

Oct 2003
SPINE

Multicenter prospective randomized study of artificial disc replacement (ProDisc) versus circumferential fusion (standard of care) for one- and two-level degenerative disc disease. This is an interim analysis on patients seen at the Spine Institute Saint John's Health Center, Santa Monica, California. To evaluate early pain and functional outcomes of patients treated with disc replacement or fusion and to assess the capacity of this intervertebral disc replacement for preserving motion in the lumbar spine. Disc replacement is intended to reduce pain via removal of the diseased disc while restoring physiologic motion and height at the affected level. The long-term physiologic advantage of disc replacement to fusion is that preservation of motion may prevent additional degeneration at adjacent levels. Patients meeting inclusion criteria were consented for study. Randomization was performed using a 2 to 1 ratio of disc replacement procedure to a fusion procedure. Patients rated their pain on the Visual Analogue Scale and completed the Oswestry Disability Index questionnaire. Radiographs were taken. Assessments were made before surgery and after surgery at 6 weeks, 3 months, 6 months, and 1 year (ongoing). Changes from preoperative pain, disability, or motion were separately evaluated as a function of treatment using repeated measures mixed design analysis of variance. This analysis includes data up to 6 months from the first 53 randomized patients. There were 35 patients who underwent disc replacements, and 18 patients had fusion procedures. Disc replacement patients had a significant reduction in pain and disability at earlier evaluations. By 6 months, the relative improvement on both the Visual Analogue Scale and Oswestry (both, P < 0.05) were similar for disc replacement and fusion patients. Greater motion was found at L4-L5 for disc replacement patients (P < 0.05) than fusion patients. A similar trend was noted at L5-S1 (P was not significant). Disc replacement patients reported significantly less pain (Visual Analogue Scale) and disability (Oswestry) in the early period following surgery compared to fusion patients. This difference disappeared by 6 months. When compared to fusion, the disc replacement allowed preservation of motion at L4-L5 with a similar trend at L5-S1.

Lumbar Total Disc ReplacementSeven to Eleven-Year Follow-Up

Article

Apr 2005

Symptomatic lumbar degenerative disc disease is a challenging entity to treat. The results of arthrodesis may be compromised in the short term by pseudarthrosis and in the long term by pain at the iliac-crest donor site and by junctional degeneration. Total disc replacement has the potential to provide long-lasting relief to these patients. The purpose of this study was to present the clinical and radiographic results assessed seven to eleven years following a Prodisc total lumbar disc replacement. Sixty-four patients had single or multiple-level implantation of a total lumbar disc replacement between 1990 and 1993. The mean duration of follow-up was 8.7 years. Clinical results were evaluated by assessing preoperative and postoperative lumbar pain, radiculopathy, disability, and modified Stauffer-Coventry scores. Preoperative and postoperative radiographs were evaluated as well. Subgroup analysis was performed to determine if gender, an age of less than forty-five years, previous surgery, or multilevel surgery had an effect on outcome. At an average of 8.7 years postoperatively, there were significant improvements in the back-pain, radiculopathy, disability, and modified Stauffer-Coventry scores. Thirty-three of the fifty-five patients with sufficient follow-up had an excellent result, eight had a good result, and fourteen had a poor result. Neither gender nor multilevel surgery affected outcome. An age of less than forty-five years and prior lumbar surgery had small but significant negative effects on outcome. Radiographs did not demonstrate loosening, migration, or mechanical failure in any patient. Five patients had approach-related complications. The Prodisc lumbar total disc replacement appears to be effective and safe for the treatment of symptomatic degenerative disc disease. Gender and multilevel surgery did not affect the outcomes, whereas prior lumbar surgery or an age of less than forty-five years was associated with slightly worse outcomes. Longer follow-up of this cohort of patients and randomized trials comparing disc replacement with arthrodesis are needed.

ProDisc randomized multicenter trials

J E Zigler

Zigler JE. ProDisc randomized multicenter trials. Total disc replacement precourse. 18th Annual Meeting of the North American Spine Society, San Diego, CA, 2003.

Lumbar disc arthroplasty: 8-10 year results using titanium plates with a polyethylene inlay component

T Marnay

Marnay T. Lumbar disc arthroplasty: 8 – 10 year results using titanium plates with a polyethylene inlay com-ponent. American Academy of Orthopaedic Surgeons annual meeting, San Francisco, CA, 2001.

Arthrodeses lombaires: resultats apres plus de 10 ans

Jan 1985
263

Cauchoix

Cauchoix J, David T. Arthrodeses lombaires: resultats apres plus de 10 ans. Rev Chir Orthop 1985;71:263 – 8.

Clinical Results of ProDisc-II Lumbar Total Disc Replacement: Report from the United States Clinical Trial

Abstract

No full-text available

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