Maverick Total Disc Research Articles

Lumbar disc arthroplasty versus anterior lumbar interbody fusion: 5-year outcomes for patients in the Maverick disc investigational device exemption study.

Despite evidence of its safety and effectiveness, the use of lumbar disc arthroplasty has been slow to expand due in part to concerns about late complications and the risks of revision surgery associated with early devices. More recently, FDA approval of newer devices and improving reimbursements have reversed this trend in the United States. Additional long-term data on lumbar disc arthroplasty are still needed. This study reports the 5-year results of the FDA investigational device exemption clinical trial of the Medtronic Spinal and Biologics' Maverick total disc replacement. Patients with single-level degenerative disc disease from L4 to S1 were randomized 2:1 at 31 investigational sites. In the period from April 2003 to August 2004, 405 patients received the investigational device and 172 patients underwent the control procedure of anterior lumbar interbody fusion. Outcome measures included the Oswestry Disability Index (ODI), numeric rating scales (NRSs) for back and leg pain, the SF-36, disc height, interbody motion, heterotopic ossification (investigational device), adverse events (AEs), additional surgeries, and neurological status. Treatment was considered an overall success when all of the following criteria were met: 1) ODI score improvement ≥ 15 points over the preoperative score; 2) maintenance or improvement in neurological status compared with preoperatively; 3) disc height success, that is, no more than a 2-mm reduction in anterior or posterior height; 4) no serious AEs caused by the implant or by the implant and the surgical procedure; and 5) no additional surgery classified as a failure. Compared to that in the control group, improvement in the investigational group was statistically greater according to the ODI and SF-36 Physical Component Summary (PCS) at 1, 2, and 5 years; the NRS for back pain at 1 and 2 years; and the NRS for leg pain at 1 year. The rates of heterotopic ossification increased over time: 1.0% (4/382) at 1 year, 2.6% (9/345) at 2 years, and 5.9% (11/187) at 5 years. Investigational patients had fewer device-related AEs and serious device-related AEs than the control patients at both 2 and 5 years postoperatively. Noninferiority of the composite measure overall success was demonstrated at all follow-up intervals; superiority was demonstrated at 1 and 2 years. Lumbar disc arthroplasty is a safe and effective treatment for single-level lumbar degenerative disc disease, resulting in improved physical function and reduced pain up to 5 years after surgery.Clinical trial registration no.: NCT00635843 (clinicaltrials.gov).

Maverick total disc arthroplasty performs well at 10 years follow-up: a prospective study with HRQL and balance analysis

The treatment of low back pain associated to Disc Degenerative Disease (DDD) is still controversial. Segmental Fusion is the gold standard, but many studies have reported that motion-preserving devices bring substantial clinical benefits to patients. Concerns on the associated complications and on the long-term clinical effectiveness of such instrumentations are still present and have led recently to a decrease of the number of Lumbar Total Disk Replacements (TDR). The objective of this prospective study is to present the clinical and radiographic outcomes of the Maverick Lumbar disk prostheses (Medtronic, TE, Memphis, USA) at long-term follow-up. Prospective, single center study of clinical outcome of the treatment with Maverick lumbar Prosthesis of patients with low back pain from DDD resistant to conservative treatment. Patients were examined preoperatively and at 3months, 2 and 10years post-operatively. Patients were examined preoperatively and at 3months, 2 and 10years post-operatively. Visual analog scale (VAS), Oswestry disability index (ODI) and 36-Item Short Form Health Survey questionnaire were assessed to study clinical outcomes. Radiographic studies allowed measurements of range of motion, adjacent segment disease and pelvic and lumbar parameters. From an initial cohort of 87 patients who underwent TDR between 2003 and 2007 with the Maverick prosthesis, 61 were available at Final follow-up (70%). The clinical outcomes measured by VAS and ODI showed a significant improvement in all the postoperative stages of the follow-up (FU). At 10years-FU, ODI experienced a mean decrease of 21.1 points, VAS for back pain decreased up to 3.85 and substantial clinical benefit was reached for 55.6% of the patients. Although Mobility of the prosthesis was preserved in 76.8% of the cases, TDR was not clearly protective against ALD. A significant, clinically relevant, and lasting reduction of back pain has been achieved in patients who underwent a total disk arthroplasty or a Hybrid construct with Maverik prosthesis. TDR is a safe and effective technique to decrease pain in patients with one or two levels of DDD.

Maverick total disc replacement in a real-world patient population: a prospective, multicentre, observational study.

Controlled trials have shown that total disc replacement (TDR) can provide pain and disability relief to patients with degenerative disc disease; however, whether these outcomes can also be achieved for patients treated in normal surgical practice has not been well documented. This prospective, international study observed changes in disability and back pain in 134 patients who were implanted with Maverick TDR within the framework of routine clinical practice and followed for 2 years post-surgery. Primary and secondary outcomes were the differences from baseline to 6 months post-surgery in the means of the Oswestry Disability Index and the change in back pain intensity assessed on a 10-cm visual analogue scale, respectively. Mean patient age at surgery was 43 years, but ranged up to 65 years. One hundred twenty-three patients had an implant at one level, 10 patients at two levels, and one patient at three levels. Statistically significant improvements in mean disability (-25.4) and low back pain intensity (-4.0) scores were observed at 6 months postoperatively (P < 0.0001 for both) in the hands of experienced surgeons (>10 TDRs per centre). During the study, 56 patients (42 %) experienced a complication or adverse event. This is the first international observational study to report outcomes of TDR in real-world clinical settings. We showed statistically significant improvements in disability and pain scores at 6 months following Maverick TDR, which were maintained for 2 years alongside an acceptable rate of perioperative complications. The safety and tolerability shown in this observational study were comparable to those from controlled trials.

Kinematic evaluation of one- and two-level Maverick lumbar total disc replacement caudal to a long thoracolumbar spinal fusion

Adjacent level degeneration that occurs above and/or below long fusion constructs is a documented clinical problem that is widely believed to be associated with the considerable change in stiffness caused by the fusion. Some researchers have suggested that early degeneration at spinal joints adjacent to a fusion could be treated by implanting total disc replacements at these levels. It is thought that further degeneration could be prevented through the disc replacement's design aims to reproduce normal disc heights, kinematics and tissue loading. For this reason, there is a clinical need to evaluate if a total disc replacement can maintain both the quantity of motion (i.e. range) and the quality of motion (i.e. center of rotation and coupling) at segments adjacent to a long spinal fusion. The purpose of this study was to experimentally evaluate range of motion (ROM-the intervertebral motion measured) and helical axis of motion (HAM) changes due to one- and two-level Maverick total disc replacement (TDR) adjacent to a long spinal fusion. Seven spine specimens (T8-S1) were used in this study (66±19years old, 3F/4M). A continuous pure moment of ±5.0Nm was applied to the specimen in flexion-extension (FE), lateral bending (LB) and axial rotation (AR), with a compressive follower preload of 400N. The 5.0Nm data were analyzed to evaluate the operated segment biomechanics at the level of the disc replacements. The data were also analyzed at lower moments using a modified version of Panjabi's proposed "hybrid" method to evaluate adjacent segment kinematics (intervertebral motion at the segments adjacent to the fusion) under identical overall (T8-S1) specimen rotations. The motion of each vertebra was monitored with an optoelectronic camera system. The biomechanical test was completed for (1) the intact condition and repeated after each surgical technique was applied to the specimen, (2) capsulotomy at L4-L5 and L5-S1, (3) T8-L4 fusion and capsulotomy at L4-L5 and L5-S1, (4) Maverick at L4-L5, and (5) Maverick at L5-S1. The capsulotomy was performed to allow measurement of facet joint loads in a companion study. Paired t tests were used to determine if differences in the kinematic parameters measured were significant. Holm-Sidak corrections for multiple comparisons were applied where appropriate. Under the 5.0Nm loads, L4-L5 ROMs tended to decrease in all directions following L4-L5 Maverick replacement (mean=22%, compared to the fused condition). Two-level Maverick implantation also tended to reduce L4-S1 ROM (mean 18, 7 and 31% in FE, LB and AR, respectively, compared to the fused condition without TDR). Following TDR replacement, the HAM location tended to shift posteriorly in FE (at L5-S1), anteriorly in AR, and inferiorly in LB. However, although the above-mentioned trends were observed, neither one- nor two-level TDR replacement showed statistically significant ROM or HAM change in any of the three directions. At the identical T8-S1 posture identified by the modified hybrid analysis, the L4-L5 and L5-S1 levels underwent significant larger motions, relative to the overall specimen rotation, after fusion. In the hybrid analysis, there were no significant differences between the ROM after fusion with intact natural discs at L4-L5 and L5-S1 and the motions at those levels with one or two TDRs implanted. The present results demonstrated that one or two Maverick discs implanted subjacent to a long thoracolumbar fusion preserved considerable and intact-like ranges of motion and maintained motion patterns similar to the intact specimen, in this ex vivo study with applied pure moments and compressive follower preload. The hybrid analysis demonstrated that, after fusion, the TDR-implanted levels are required to undergo large rotations, relative to those necessary before fusion, in order to achieve the same motion between T8 and S1. Additional clinical and biomechanical research is necessary to determine if such a kinematic demand would be made on these levels clinically and the biomechanical performance of these implants if it were.

A Granulomatous Mass Surrounding a Maverick Total Disc Replacement Causing Iliac Vein Occlusion and Spinal Stenosis

Lumbar disc degeneration is a well-known cause of low back pain. The so-called gold standard for definitive operative treatment of discogenic pain is interbody arthrodesis1. Adjacent-level degeneration as well as incomplete pain resolution despite radiographic evidence of fusion has led to dissatisfaction with this technique and became the impetus to develop other surgical options for the treatment of back pain2-5. With the U.S. Food and Drug Administration approval of the CHARITE Total Disc (DePuy Spine, Raynham, Massachusetts) in 2004, total disc replacement became a treatment option for the painful degenerative lumbar disc in the United States. Proponents of this procedure believe that the maintenance of disc height and the preservation of segment motion will facilitate the resumption of more normal activities, decrease pain, and prevent adjacent-segment disease. Unlike the metal-on-ultra-high-molecular-weight-polyethylene sliding core design of the CHARITE total disc, the Maverick total disc replacement (Medtronic Sofamor Danek, Memphis, Tennessee) is a metal-on-metal disc prosthesis made of cobalt-chromium with a ball-and-socket design. The center of rotation of the Maverick prosthesis is fixed posteriorly in comparison with the dynamic center of rotation of the CHARITE prosthesis. The metal end plates are coated with hydroxyapatite and have a central keel for increased stability and fixation2. We present the case of a patient who had development of a granulomatous mass at the level of a Maverick total disc prosthesis three years following implantation that resulted in symptomatic spinal stenosis and iliac vein occlusion with resultant deep venous thrombosis. The patient was informed that data concerning the case would be submitted for publication, and she consented. A thirty-five-year-old woman presented to the emergency department with the acute onset of bilateral lower extremity edema and severe lower extremity pain. The patient had a one-year history of bilateral lower extremity …

4:45129. Maverick Total Disc Replacement: A Study of Device Position and Patient Outcomes at Two Years

gastric decompression. There were no bowel injuries, and no hernias have been reported so far. There were 2 cases of DVT at the calf and one case of ileo-femoral venous thrombosis all presenting approximately a week after surgery. Two of these were treated effectively with anticoagulation, but 1 patient expired due to bleeding from an idiosyncratic reaction to heparin. CONCLUSIONS: This study compares very favorably with published reports of complications for anterior lumbar interbody fusion (ALIF) as well as with the reported approach complication rate in the Charite FDA study, and shows that the approach for lumbar TDR can be performed safely and effectively by experienced access surgeons. The incidence of all venous lacerations at L4-5 continues to demonstrate that this is, by far, the most difficult and more dangerous level to expose. Surgeons with little or no experience in anterior lumbar surgery should attempt lumbar TDR with trepidation, especially at the L4-5 level. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs. CONFLICT OF INTEREST: No conflicts.

4:57131. Maverick Total Disc Replacement: Initial Report of 24-Month Clinical Outcomes from Six Investigational Centers

BACKGROUND CONTEXT: Total lumbar disc arthroplasty provides an alternative to spinal fusion for single-level degenerative disc disease that may restore and maintain normal disc height and motion, and may avoid potential adjacent level degeneration.

9:31153. Facet Changes after Maverick Total Disc Replacement: A Study of Patient Outcomes at 24 Months

9:31153. Facet Changes after Maverick Total Disc Replacement: A Study of Patient Outcomes at 24 Months

5:40 110. MAVERICK total disc replacement: a review of 12-month data from five investigational centers

BACKGROUND CONTEXT: The gold standard of treatment for lumbar degenerative disc disease is surgical arthrodesis. Total disc arthroplasty provides an alternative to spinal fusion that restores disc height and motion, potentially avoiding adjacent level degeneration. With multiple disc prostheses expected to be available in the near future, surgeons will scrutinize closely the opportunity for both short-term clinical success and long-term health of adjacent levels. This is the first study to report clinical results of the MAVERICK Total Disc Replacement (Medtronic Sofamor-Danek).

The effect of single-level, total disc arthroplasty on sagittal balance parameters: a prospective study.

A prospective radiographic study of the influence of total disc replacement on spinal sagittal balance. The goal of this study was to prospectively determine the effect of a single-level, total disc replacement on the sagittal balance of the spine, especially on sacral tilt (ST), pelvic tilt (PT), and lumbar lordosis. It has been shown that lumbar fusion may deleteriously alter the sagittal balance of the spine, including a decrease in the ST and lumbar lordosis. Clinically, postfusion pain has been shown to be significantly related to a decreased ST, increased PT, and decreased lumbar lordosis, independent of other factors such as pseudoarthrosis. To our knowledge, the influence of total disc replacement on spinal sagittal balance has not yet been reported in the literature. This is a prospective study of 35 patients who received a single level disc replacement using the Maverick Total Disc Arthroplasty system (Medtronic Sofamor Danek, Memphis, Tennessee) by a single surgeon at one institution from March 2002 to September 2003. The preoperative and postoperative radiographic evaluation included standing anteroposterior and lateral full spine films that included the femoral heads. The parameters studied were ST, PT, global and segmental lordosis, and global kyphosis. The average age of the 35 patients studied was 44.3 years (range 35-57). There were 18 females and 17 males. The disc arthroplasty was performed at the L4-L5 level in 19 patients and at the L5-S1 level in 16 patients. The average follow-up was 14 months (range 6-22 months). The preoperative values of global lordosis, ST, and PT were 51.5 degrees , 37.8 degrees , 16.9 degrees and, at last follow-up, they were 51.4 degrees , 37.4 degrees , and 17.5 degrees , respectively. These changes were not significantly different. When the groups were separated according to the level operated, there was still no statistical difference with regard to the overall lordosis, ST, PT or kyphosis from pre- to postoperative period or when the two groups were compared with each other. The level above the prosthesis has always significantly less lordosis. In the present study with use of a motion-preserving Maverick prosthesis, it appears that the patient is able to maintain the preoperative sagittal balance. The prosthesis has enough freedom of motion to allow the patient to maintain the natural sagittal and spinopelvic balance needed to prevent potential undue stress on the muscles and the sacroiliac joint. Although the number of patients is small, this is the first study to our knowledge that evaluates the sagittal balance after motion-preserving total disc arthroplasty.

Design rationale and biomechanics of Maverick Total Disc arthroplasty with early clinical results

This paper reviews the design criteria, biomechanical and biological (wear and safety) testing of this chrome cobalt metal-on-metal, ball and socket design prosthesis. The surgical technique and early clinical results of the initial implantations are also reviewed. Initial results of 7 Maverick implantations showed all 7 patients attaining a 15 point Oswestry improvement within 3 months after implantation. This early result in a small sample is significantly quicker in recovery and improvement when compared to the historical control of the LT cage with Infuse IDE study. Longer term results and more careful study are needed of this interesting and optimistic finding.