CHARITE Artificial Disc Research Articles

P77. What happened to patients who received the Charite lumbar artificial disc?

P77. What happened to patients who received the Charite lumbar artificial disc?

Comparison of 2 Lumbar Total Disc Replacements

This was a prospective, randomized, controlled multicenter study with 24-month follow-up. The purpose of this study was to evaluate the safety and efficacy in a Food and Drug Administration Investigation Device Exemption of a new lumbar total disc replacement (TDR) by comparing it to an earlier TDR approved for sale. Randomized trials have reported TDR to produce results similar or superior to lumbar fusion. Results for various TDRs seem to be similar, but differences in study design and outcome measures pose challenges in definitively comparing devices. The purpose of this study was to perform a direct comparison of 2 lumbar TDRs in a prospective, randomized trial. TDR was performed in 457 patients from 21 sites (261 patients in the investigational group (Kineflex-L Disc; metal-on-metal design anchored with keels, 204 randomized and 57 nonrandomized training cases), and 196 in the control group (CHARITE artificial disc; metal with polyethylene core with teeth for anchoring; 190 randomized and 6 nonrandomized training cases). All patients were treated nonoperatively for single-level symptomatic disc degeneration for at least 6 months prior to surgery. Perioperative data were collected. Clinical outcome data were collected prospectively, as approved by the Food and Drug Administration, through 24-month follow-up. Primary outcome measures used were the Oswestry Disability Index, visual analogue scales assessing pain, patient satisfaction, and reoperations. Success was defined to be at least 15-point improvements in Oswestry Disability Index scores, no reoperation, and no major adverse events. Radiographical measures included range of motion, disc space height, and assessment for device migration, subsidence, and fusion at the TDR level. There were no significant differences between the groups when comparing operative time, blood loss, or length of hospital stay. Both groups improved significantly on Oswestry Disability Index and visual analogue scale scores (P < 0.01) with no differences between the groups. Success rates were similar (68.1% investigational vs. 67.4% control). At 24-month follow-up, 94.1% of the investigational group and 91.9% of controls were satisfied with outcome. Reoperation was performed in 10.3% of the investigational group and 8.4% of the control group. This prospective, randomized, controlled study comparing 2 TDRs, the first to the authors' knowledge, found the devices produced very similar clinical outcomes. Both groups improved significantly by 6 weeks postoperatively and remained improved throughout follow-up with a high patient satisfaction rate.

120. Retrospective Measurement Study on the Placement Accuracy of the Charite Artificial Disc

BACKGROUND CONTEXT: McAffee et al showed correlation between accurate placement of the Charité implant and desirable clinical results. Due to image intensification and gantry angle inaccuracies under fluoroscopy, accurate placement of anterior devices in the lumbar spine can be challenging. In response navigation platforms for the lumbar spine are currently in development phases.

Radiographic total disc replacement angle measurement accuracy using the Oxford Cobbometer: precision and bias

Total disc replacement (TDR) clinical success has been reported to be related to the residual motion of the operated level. Thus, accurate measurement of TDR range of motion (ROM) is of utmost importance. One commonly used tool in measuring ROM is the Oxford Cobbometer. Little is known however on its accuracy (precision and bias) in measuring TDR angles. The aim of this study was to assess the ability of the Cobbometer to accurately measure radiographic TDR angles. An anatomically accurate synthetic L4-L5 motion segment was instrumented with a CHARITE artificial disc. The TDR angle and anatomical position between L4 and L5 was fixed to prohibit motion while the motion segment was radiographically imaged in various degrees of rotation and elevation, representing a sample of possible patient placement positions. An experienced observer made ten readings of the TDR angle using the Cobbometer at each different position. The Cobbometer readings were analyzed to determine measurement accuracy at each position. Furthermore, analysis of variance was used to study rotation and elevation of the motion segment as treatment factors. Cobbometer TDR angle measurements were most accurate (highest precision and lowest bias) at the centered position (95.5%), which placed the TDR directly inline with the x-ray beam source without any rotation. In contrast, the lowest accuracy (75.2%) was observed in the most rotated and off-centered view. A difference as high as 4 degrees between readings at any individual position, and as high as 6 degrees between all the positions was observed. Furthermore, the Cobbometer was unable to detect the expected trend in TDR angle projection with changing position. Although the Cobbometer has been reported to be reliable in different clinical applications, it lacks the needed accuracy to measure TDR angles and ROM. More accurate ROM measurement methods need to be developed to help surgeons and researchers assess radiological success of TDRs.

A 6 year follow-up prospective study of 289 patients with the Charite artificial disc prosthesis

Duplex ultrasonography emerged as a noninvasive diagnostic test for splanchnic artery stenosis in the early 1980s.4 Prior to this, arteriography had been not only the gold standard but essentially the only objective means to evaluate stenosis in the celiac artery (CA) and superior mesenteric artery (SMA). Investigations have since proceeded from the evaluation of normal mesenteric arteries and the assessments of gastrointestinal physiology to the delineation of splanchnic artery stenosis. Although duplex ultrasonography can identify splanchnic artery stenosis, the determination of chronic mesenteric ischemia remains a clinical diagnosis made by appropriate history, physical examination, and arteriographic confirmation of high-grade stenosis or occlusion of the splanchnic arteries.

Revision and Explantation Strategies Involving the CHARITÉ Lumbar Artificial Disc Replacement

A large case series of anterior revision surgery in patients who had complications following lumbar total disc replacement with the CHARITE artificial disc. To analyze and discuss the etiology of implant-related complications and to present a strategy that can be applied to lumbar intervertebral disc prostheses in cases where anterior revision surgery is necessary. This report represents the largest single-site, consecutive case series reported in the literature of anterior revision surgery following lumbar disc arthroplasty. A total of 18 patients are included in this study. All patients required an anterior revision procedure for repositioning or removal of the prosthesis. The mean time to revision was 6 months (range, 9 days to 4 years). In 17 of 20 cases, implant removal was required and the patient was converted to a fusion. In 3 cases, primary revision of the CHARITE artificial disc was performed. Six revision cases were performed within the early postoperative period, defined as 7 to 14 days. All early cases were approached via reexploration of the original anterior midline retroperitoneal incision. Late revision was required in 14 cases, ranging from 3 weeks to 4 years following initial arthroplasty. A variety of surgical approaches were used in late revisions, including the lateral transpsoas approach at L3-L4 or L4-L5 (n = 5), expanded ipsilateral left retroperitoneal approach at L4-L5 (n = 2), contralateral right retroperitoneal approach at L5-S1 (n = 6), and transperitoneal approach (n = 1). Following 20 consecutive, anterior revision procedures, implant revision was successfully achieved in all cases. Total disc replacement implant revisions occur largely as a result of technical errors in positioning and sizing of the implant. In addition, adherence to strict patient selection criteria will eliminate many cases of implant failure. When necessary, anterior revision surgery can be performed safely when a strategic approach is used.

Long-term Results of One-Level Lumbar Arthroplasty

A retrospective chart and radiographic review. To determine the long-term clinical results, radiographic results, and incidence of complications in a large patient cohort with one-level lumbar total disc replacement (TDR). Prior authors have described short-term, mid-term, and long-term clinical and radiographic results in patients with lumbar TDR with highly variable results. From January 1989 to November 1995, 108 patients, with a mean age of 36.4 years, underwent lumbar TDR with the CHARITE Artificial Disc, with 106 available for follow-up. A modified Stauffer-Coventry scale was used to determine clinical outcome. Return to work, work level, and the incidence of complications were assessed. Dynamic lateral flexion-extension and lateral bending radiographs were performed and segmental range of motion (ROM) was measured using the Cobb method. Mean follow-up time was 13.2 years (range, 10-16.8 years). Of the 106 patients, 87 (82.1%) had either an excellent or good clinical outcome. Of the 96 patients working before surgery, 86 returned to work (89.6%), including 77.8% of patients with hard labor level employment (28 of 36) returning to the same level of work. The mean ROM in flexion-extension was 10.1 degrees , in lateral bending it was 4.4 degrees , and 90.6% of implanted prostheses were still mobile. Eight patients (7.5%) required posterior instrumented fusion. There were 5 cases (4.6%) of postoperative facet arthrosis, 3 cases (2.8%) of subsidence, 3 cases (2.8%) of adjacent-level disease, and 2 cases (1.9%) of core subluxation. This retrospective study demonstrates the safety and efficacy of the CHARITE Artificial Disc at one level, either L4-L5 or L5-S1, in the long-term. Clinical outcomes and the rate of return to work were excellent overall. The rate of adjacent-level disease requiring surgical intervention was considerably lower (2.8%) compared with reports in the literature for lumbar fusion. As with any surgical procedure, proper indications play a pivotal role in clinical success.

Prevalence of Heterotopic Ossification Following Total Disc Replacement

Despite reports of good clinical outcomes in patients treated with lumbar and cervical disc replacements, varying degrees of heterotopic bone have been observed around these devices. The purposes of the present study were to determine the prevalence of heterotopic ossification following lumbar disc replacement and to investigate whether heterotopic ossification results in loss of motion or negatively affects clinical outcome. All preoperative and postoperative radiographs from a completed prospective, randomized, United States Food and Drug Administration-regulated trial comparing replacement with the CHARITE Artificial Disc with anterior interbody arthrodesis were analyzed. In each of 276 patients treated with disc replacement, heterotopic ossification was categorized with use of a validated 5-point radiographic classification system both preoperatively and at all protocol-specified follow-up intervals to two years. The range of motion on flexion and extension radiographs made preoperatively was compared with that on radiographs made two years postoperatively, and the motion was correlated with the presence or absence of heterotopic ossification. Similarly, validated clinical outcome measures were correlated with the presence or absence of heterotopic ossification at two years. The prevalence of heterotopic ossification in the 276 consecutive patients treated with lumbar disc replacement with the CHARITE Artificial Disc was 4.3%. There were four cases of Class-I heterotopic ossification and eight cases of Class-II heterotopic ossification. In five of the twelve patients, heterotopic bone was visible as early as six weeks postoperatively, and eleven of the twelve patients had evidence of heterotopic ossification by three months postoperatively. The postoperative range of motion exceeded the preoperative range in all of the patients with heterotopic ossification. With the numbers available, no difference in either the range of motion or the clinical outcome at twenty-four months postoperatively was found between the patients who had and those who did not have heterotopic ossification. Heterotopic ossification is infrequent in patients treated with the CHARITE Artificial Disc, and it does not impact the range of motion or clinical outcome.

Artificial Spinal Disk Superior to Fusion for Treating Degenerative Disk Disease

THE PLACEMENT OF AN ARTIFICIAL intervertebral disk can provide better functional results than spinal fusion in treating select patients with discogenic pain and spine instability, according to findings recently presented at the North American Spine Society’s annual meeting, in Seattle. The device, called the ProDisc-L (Synthes Spine Inc, West Chester, Penn), was approved by the US Food and Drug Administration (FDA) in August for the treatment of pain associated with degenerative disk disease. Although artificial disks for total disk replacement surgery have been commercially available in markets outside the United States since 1990, the ProDisc is only the second artificial disk to obtain FDA clearance, preceded by the 2004 approval of the Charite Artificial Disc (DePuy Spine Inc, a Raynham, Mass– based subsidiary of Johnson & Johnson). However, trial findings that were the basis for approving the Charite disk showed only that outcomes of patients treated with the device were no worse than those of patients who had undergone standard spinal fusion. Unlike the Charite disk, which has a free-floating central core, the ProDisc is a semiconstrained prosthesis intended to lend added stability and minimize device migration and subsidence. “The ProDisc artificial implant is the first motion-sparing disk implant ever shown to be superior to fusion,” said Rick B. Delamarter, MD, medical director of the Spine Institute at St John’s Health Center in Los Angeles. Delamarter, an independent researcher with no financial ties to the manufacturer of the ProDisc-L artificial disk, presented the trial findings, which were the basis for the FDA’s approval of the device. “There will always be a role for fusion to treat problems of spinal deformity, severe facet arthritis, and instability, but the pendulum is now shifting to nonfusion technology,” added Delamarter.

Revisability of the CHARITÉ Artificial Disc Replacement

A prospective, randomized, multicenter, FDA-regulated Investigational Device Exemption clinical trial. To analyze the incidence of, and reasons for, reoperation in all patients (treatment and control) enrolled in the IDE study. This is the first report of the incidence and nature of reoperations following lumbar TDR as part of a controlled, prospective, multicenter trial. A total of 688 patients meeting the inclusion and exclusion criteria were enrolled in one of three arms of the study at 14 centers across the United States. This cohort includes 71 nonrandomized cases, 205 randomized cases, and 313 continued access cases, all receiving the CHARITE Artificial Disc, as well as 99 randomized cases in the control group (ALIF with threaded fusion cages and autograft). A detailed analysis was performed of clinical chart notes, operative notes, and adverse event reports for all patients requiring reoperation following their index surgery. Of the 589 patients with TDR, 52 (8.8%) required reoperation. Of the 99 patients with lumbar fusion, 10 (10.1%) required reoperation, and an additional 2 required surgery for adjacent level disease (P = 0.7401). There were 24 TDR patients who underwent a repeated anterior retroperitoneal approach, with 22 (91.7%) having had a successful removal of the prosthesis. Seven of the 24 TDR prostheses requiring removal were revised to another CHARITE Artificial Disc. The mean time to reoperation in all patients was 9.7 months. A total of 29 patients (4.9%) in the TDR group required posterior instrumentation and fusion as did 10 (10.1%) in the control group (P = 0.0562). At 2 years or more follow-up, 93.9%(553/589 = 93.9%) of patients receiving TDR with the CHARITE Artificial Disc had a successfully functioning prosthesis with a mean of over 7 degrees of flexion-extension mobility. Lumbar TDR with the CHARITE Artificial Disc did not preclude any further procedures at the index level during primary insertion, with nearly one third being revisable to a new motion-preserving prosthesis and just over two thirds being successfully converted to ALIF and/ or posterior pedicle screw arthrodesis, the original alternative procedure.

Total Disc Replacement with the CHARITE Artificial Disc Was as Effective as Lumbar Interbody Fusion

Total Disc Replacement with the CHARITE Artificial Disc Was as Effective as Lumbar Interbody Fusion

Letter to the Editor concerning “Charité total disc replacement: clinical and radiographical results after an average follow-up of 17 years” (M. Putzier et al.)

I read with interest the paper by Putzier et al. [13] describing long-term clinical and radiographic results in the earliest patients implanted with the CHARITE Artificial Disc. As one of the two inventors of the device; the surgeon of record for all of the first 50 operated patients over several years in conjunction with my doctoral thesis [2]; and having knowledge of the other 21 patients including their clinical outcomes; I believe it is necessary to put the results described in the paper into the proper context.

Reply to the author’s comment to the letters of K. Büttner-Janz and H. D. Link regarding “Charité total disc replacement—clinical and radiographical results after an average follow-up of 17 years (M. Putzier et al.)

The table is prepared with the use of accurately conducted data forms, which each of these first operated 20 patients and the further 30 patients with the CHARITE Artificial Disc pre- and postoperatively received.

Letter to the Editor concerning “Charité total disc replacement: clinical and radiographical results after an average follow-up of 17 years” (M. Putzier et al.)

In diarthrodial joint replacement (hip, knee etc.) it is established that results with joint replacement systems improve over time, parallel to their further development in design and along with the growths of surgeons’ experience. Charnley for instance reported that it took him 14 years to reduce the loosening rate in his series of total hip replacements by 86% [4]. Malchau reflects in the Swedish Hip Study that the cumulative revision rate in Sweden in cemented hip replacement after a comparable follow-up of 11 years dropped from 9% (1979) to 3% (1991) over a time span of 12 years [2] (Fig. 1). Fig. 1 Table reflecting the learning curve in hip arthroplasty in Sweden—from Swedish Hip Register The above paper reports on the long-term follow-up of the initially mixed series of early Charite artificial disc replacements. A large percentage of radiologically confirmed fusions are found and the authors state that “the Charite artificial disc replacement cannot guarantee long-term near to normal function of the spinal motion segment in patients with moderate to severe DDD”. Firstly, are the evaluations in the publication based on all published literature? Secondly, considering the above-mentioned learning curve, is the conclusion drawn from the results of the initial series disc replacements justified?

Lumbar Disc Replacement

Lumbar disc replacement is a developing primary surgical treatment for patients with degenerative disc disease. The goals of disc arthroplasty are to remove the native nucleus pulposus and to preserve motion at that disc level. Devices being developed include artificial replacement of the nucleus pulposus and artificial replacement of the entire disc. With the recent approval by the Food and Drug Administration of the Charite artificial disc, this procedure will be used with increasing frequency. This article reviews pertinent anatomy and pathology of the functional spinal unit as well as the types of devices being developed and the factors related to development of a successful implant. Clinical outcomes and complications are also discussed.

Disc Prosthesis for Degenerative Disease and Axial Instability—CHARITÉ™ Artificial Disc

Spine surgery has entered into a new stage of stabilization with motion preservation and spinal arthroplasty. The Charite Artificial Disc Replacement, one of the first examples, has been developed and refined from 1982 to the present. In a randomized prospective controlled study with single level fusion it was found to be safe and effective and was approved by the FDA in October 2004. To date over 11,000 implantations have been carried out worldwide. This is a demanding procedure that requires strict adherence to proper patient selection, proper implant sizing, and proper implantation technique. While short term follow up is encouraging, long term follow up will answer questions of adjacent segment disease, implant wear, and longevity issues.

Clinical and Radiological Outcomes With the Charité™ Artificial Disc

This is the first report of clinical and radiologic outcomes for the CHARITE artificial disc with a minimum follow-up of 10 years. A total of 107 patients indicated for total lumbar disc replacement were implanted with the CHARITE prosthesis. Of these 107, 100 were followed for a minimum of 10 years (range 10-13.4 years). A total of 147 prostheses were implanted with 54 one-level and 45 two-level procedures and 1 three-level procedure. The prostheses were placed through a standard anterior retroperitoneal approach. Clinically, 62% had an excellent outcome, 28% had a good outcome, and 10% had a poor outcome. Of the 95 eligible to return to work, 88 (91.5%) either returned to the same job as prior to surgery or a different job. These included 63.2% (12) of those working in heavy labor employment returning to the same job. Mean flexion/extension motion was 10.3 degrees for all levels (12.0 degrees at L3-L4, 9.6 degrees at L4-L5, 9.2 degrees at L5-S1). Mean lateral motion was 5.4 degrees . In the sagittal plane, 9 (6.1%) were anterior of geometric center, 50 (34.0%) were centered, and 88 (59.9%) were posterior of center. In the frontal plane, 110 (75%) were centered, and 37 (25%) were noted to be lateral to center. Slight subsidence was observed in two patients, but they did not require further surgery. No subluxation of the prostheses and no cases of spontaneous arthrodesis were identified. There was one case of disc height loss of 1 mm. Five patients required a secondary posterior arthrodesis. A good or excellent clinical outcome rate of 90% and a return to work rate of 91.5% compare favorably with results described in the literature for fusion for the treatment of lumbar degenerative disc disease. With a minimum follow-up of 10 years, the CHARITE artificial disc demonstrated excellent flexion/extension and lateral range of motion with no significant complications.

A Prospective, Randomized, Multicenter Food and Drug Administration Investigational Device Exemption Study of Lumbar Total Disc Replacement With the CHARITÉ ™ Artificial Disc Versus Lumbar Fusion

A prospective, randomized, multicenter, Food and Drug Administration-regulated, investigational device exemption clinical trial. To compare the safety and effectiveness of lumbar total disc replacement (TDR) with the CHARITE artificial disc (DePuy Spine, Raynham, MA) to anterior lumbar interbody fusion for the treatment of single-level degenerative disc disease from L4-S1 unresponsive to nonoperative treatment. In addition, to evaluate the radiographic outcomes of lumbar artificial disc replacement at either L4-L5 or L5-S1 with the CHARITE artificial disc as compared to anterior lumbar interbody fusion with cylindrical cages and iliac crest bone graft; and to determine if a correlation exists between clinical outcomes and surgical accuracy of TDR placement within the disc space. Prior investigators have reported excellent radiographic results with the CHARITE artificial disc for the treatment of lumbar degenerative disc disease. These encouraging results are the product of retrospective reviews without a control. Very few studies have reported on the segmental motion of an intervertebral level implanted with an artificial disc, and no studies have reported a correlation of radiographic and clinical outcomes. A prospective, randomized, multicenter, US Food and Drug Administration, investigational device exemption study with 24-month follow-up was performed at 14 centers throughout the United States. A total of 304 subjects were randomized in a 2:1 ratio, with 205 in the investigational group (TDR with the CHARITE artificial disc) and 99 in the control group (anterior lumbar interbody fusion with BAK cages and iliac crest bone graft). A total of 71 TDR training cases were performed (up to 5 at each site) before randomization beginning at each site. Plain radiographs were analyzed for each subject in both groups regarding range of motion (ROM) in flexion/extension, restoration of disc space height, and subsidence. Prosthesis placement in the coronal and midsagittal planes was analyzed for the 276 patients with TDR. Correlations were performed between prosthesis placement and clinical outcomes. Patients in the investigational group had a 13.6% mean increase, and those in the control group an 82.5% decrease in mean flexion/extension ROM at 24 months postoperatively compared to baseline. Patients in the investigational group had significantly better restoration of disc height than the control group (P < 0.05). There was significantly less subsidence in the investigational group compared to the control group (P < 0.05). The surgical technical accuracy of CHARITE artificial disc placement was divided into 3 groups: I, ideal (83%); II, suboptimal (11%); and III, poor (6%), and correlated with clinical outcomes. The flexion/extension ROM and prosthesis function improved with the surgical technical accuracy of radiographic placement (P = 0.003). Preoperative ROM in flexion/extension was restored and maintained in patients receiving a TDR. TDR with the CHARITE artificial disc resulted in significantly better restoration of disc space height, and significantly less subsidence than anterior interbody fusion with BAK cages. Clinical outcomes and flexion/extension ROM correlated with surgical technical accuracy of CHARITE artificial disc placement. In the majority of cases, placement of the CHARITE artificial disc was ideal.

A Prospective, Randomized, Multicenter Food and Drug Administration Investigational Device Exemptions Study of Lumbar Total Disc Replacement With the CHARITÉ™ Artificial Disc Versus Lumbar Fusion

A prospective, randomized, multicenter, Food and Drug Administration-regulated Investigational Device Exemption clinical trial. The purpose of this study was to compare the safety and effectiveness of lumbar total disc replacement, using the CHARITE artificial disc (DePuy Spine, Raynham, MA), with anterior lumbar interbody fusion, for the treatment of single-level degenerative disc disease from L4-S1 unresponsive to nonoperative treatment. Reported results of lumbar total disc replacement have been favorable, but studies have been limited to retrospective case series and/or small sample sizes. Three hundred four (304) patients were enrolled in the study at 14 centers across the United States and randomized in a 2:1 ratio to treatment with the CHARITE artificial disc or the control group, instrumented anterior lumbar interbody fusion. Data were collected pre- and perioperatively at 6 weeks and at 3, 6, 12, and 24 months following surgery. The key clinical outcome measures were a Visual Analog Scale assessing back pain, the Oswestry Disability Index questionnaire, and the SF-36 Health Survey. Patients in both groups improved significantly following surgery. Patients in the CHARITE artificial disc group recovered faster than patients in the control group. Patients in the CHARITE artificial disc group had lower levels of disability at every time interval from 6 weeks to 24 months, compared with the control group, with statistically lower pain and disability scores at all but the 24 month follow-up (P < 0.05). At the 24-month follow-up period, a significantly greater percentage of patients in the CHARITE artificial disc group expressed satisfaction with their treatment and would have the same treatment again, compared with the fusion group (P < 0.05). The hospital stay was significantly shorter in the CHARITE artificial disc group (P < 0.05). The complication rate was similar between both groups. This prospective, randomized, multicenter study demonstrated that quantitative clinical outcome measures following lumbar total disc replacement with the CHARITE artificial disc are at least equivalent to clinical outcomes with anterior lumbar interbody fusion. These results support earlier reports in the literature that total disc replacement with the CHARITE artificial disc is a safe and effective alternative to fusion for the surgical treatment of symptomatic disc degeneration in properly indicated patients. The CHARITE artificial disc group demonstrated statistically significant superiority in two major economic areas, a 1-day shorter hospitalization, and a lower rate of reoperations (5.4% compared with 9.1%). At 24 months, the investigational group had a significantly higher rate of satisfaction (73.7%) than the 53.1% rate of satisfaction in the control group (P = 0.0011). This prospective randomized multicenter study also demonstrated an increase in employment of 9.1% in the investigational group and 7.2% in the control group.

Lumbar Disc Arthroplasty

Degenerative disc disease is the leading cause of pain and disability in adults in North America, and spinal fusion is the standard treatment. Despite this, it has been discussed among surgeons that (1) spinal fusion deserves reexamination in terms of its long-term consequences and benefits and (2) modern clinical research and development in disc arthroplasty strongly supports its emergence as an alternative. The ability to relieve pain by maintaining motion may be a critical factor in obtaining not only greater pain relief but in preventing adjacent segment degeneration. Early research in arthroplasty devices was promising but cut short. New knowledge in the functional anatomy and biomechanics of the spine has made possible the development of modern arthroplasty devices (eg, Charite Artificial Disc, ProDisc, Maverick device, FlexiCore device) of different constructions and materials (metal-on-plastic, metal-on-metal) and various ranges of motion/mobility that provide a basis for a classification of spinal mode and an assistance in implant selection. Current research also is confronting the critical obstacles of wear and tear and axial compression. Several devices currently are in clinical trials. A detailed review of their characteristics shows the exciting progress of a new treatment era of total disc replacement in spine-lumbar disc arthroplasty.