Lumbar Total Disc Replacement Research Articles

81. Mobility parameters in two level-lumbar TDR vs hybrid construct: clinical results in 235 patients

<h3>BACKGROUND CONTEXT</h3> Lumbar total disc replacement (TDR) is a treatment option with 30 years experience and extensive publications on clinical results. However, there are few publications on mid- and long-term mobility. There is also sparse literature on the quality of mobility or the difference between L4-S1 2-level TDR vs TDR/ALIF hybrid constructs. <h3>PURPOSE</h3> To measure mobility parameters in flexion-extension for two groups (L4-S1 TDR vs hybrid); compare motion at L4–L5; participation of pelvis mobility; global lumbar motion; and flexion-extension effectiveness by measuring L1 race. Besides determining the difference of mobility between TDR and hybrid, we discussed potential compensations above and below L5-S1 fusion/L4-L5 TDR, as compared to two-level TDR. <h3>STUDY DESIGN/SETTING</h3> Retrospective clinical study. <h3>PATIENT SAMPLE</h3> This study included 235 patients, operated between 2003-2013: 170 patients received 2-level TDR (TDR group) and 65 received L4-L5 TDR and L5-S1 ALIF (hybrid group). <h3>OUTCOME MEASURES</h3> Data collected included radiographic, neurological/physical assessment, self-evaluation using the Oswestry Disability Index (ODI) and visual analog back and leg pain scores (VAS). Complication, reoperation/revision rates, and perioperative data points were also assessed. <h3>METHODS</h3> Both groups were equivalent in age, body habitus and preoperative clinical parameters (ODI, VAS). Patient selection for evaluation was based on presence of clinical success criteria and pre- and postoperative sagittal X-rays and dynamic flexion-extension films at minimum 24-month follow-up. Pelvic parameters (Incidence, Pelvic Tilt, Sacral Slope) were measured. L4-L5 and L5-S1 flexion-extension range of motion (ROM) was measured pre- and postoperatively. Pelvic motion was determined by measuring sacral slope in flexion-extension. The influence on lumbar lordosis (L1-S1) was also analyzed. To show the effect the lumbopelvic complex has on global motion, we measured L1 race (flexion-extension L1 ROM). <h3>RESULTS</h3> The absolute motion and relative gain of 2-level TDR shows its superiority over hybrid constructs in all measured parameters. When L5-S1 is fused, there is no compensation from pelvic motion to overcome the loss of mobility. TDR group shows a pelvi-femoral ROM gain of 16.77°, vs a gain of only 6.11° in the Hybrid group. L5-S1 fusion also reduces L4-L5 TDR mobility in Hybrid group, compared to 2-level TDR, and decreases flexion compared to baseline. There is a mean reduction in ROM of 1.53° in Hybrid group vs 20.02° gain in TDR group. L1 race also reflects the superiority of 2-level TDR vs hybrid with a gain of 32.58° in TDR vs 4.68° in hybrid, demonstrating that reduced global motion is principally due to loss of L5-S1 motion. <h3>CONCLUSIONS</h3> This comparison between 2-level TDR and hybrid demonstrates a lack of compensation through lumbar mobility and pelvic motion when L5-S1 is fused, and debunks these preconceived ideas. Although clinical measures of activity (ODI) and pain (VAS back and leg pain) are equivalent between the groups, functional superiority of 2-level TDR is confirmed. Two new ROM parameters introduced here—pelvic motion and L1 race—must be integrated in all ROM studies as they quantify pelvic participation in mobility and the functional effectiveness of motion preservation. In this first long-term comparison of mobility between 2-level TDR vs L4-S1 hybrid, 2-level TDR demonstrates overall superiority. Consequently, 2-level TDR must be systematically indicated whenever TDR is indicated for both levels, and accepted as the "gold standard" for reimbursement purposes. <h3>FDA DEVICE/DRUG STATUS</h3> Prodisc L 1- and 2-level (Approved for this indication), Prodisc L hybrid constructs (Not approved for this indication)

26. Clinical outcome of lumbar hybrid surgery in a consecutive series of patients including long-term follow-up

<h3>BACKGROUND CONTEXT</h3> Many patients with symptomatic lumbar degenerative disc disease (DDD) are affected at more than one level. When nonoperative treatment fails to provide adequate relief, multilevel surgery may be considered. Lumbar total disc replacement (TDR) was introduced as an option to fusion. Some disc levels are not amenable to TDR and fusion is preferable at that level. Hybrid surgery, involving TDR at one level and fusion at the adjacent segment, has been introduced as an option to fusing multiple levels. <h3>PURPOSE</h3> The purpose of this study was to investigate the long-term clinical outcome of patients undergoing lumbar hybrid surgery for treating symptomatic lumbar DDD at more than one level. <h3>STUDY DESIGN/SETTING</h3> The study was a retrospective record review combined with a mailing and/or telephone calls to patients to collect current outcome data. <h3>PATIENT SAMPLE</h3> A consecutive series of 296 patients undergoing lumbar hybrid surgery was identified beginning with the first case experience in 2005. All patients were treated for painful disc degeneration unresponsive to nonoperative care and were at least two years postoperative. <h3>OUTCOME MEASURES</h3> The primary outcome measures were visual analog scales (VAS) separately assessing back and leg pain, and the Oswestry Disability Index (ODI). Data on re-operations were also collected. <h3>METHODS</h3> General descriptive data, surgical data and outcomes were collected for the consecutive series of hybrid patients. For patients who had not been seen recently in the clinic, mailing and/or telephone calls were conducted to collect VAS, ODI, and re-operation data. <h3>RESULTS</h3> The mean follow-up duration was 71.4 months with a maximum of 196 months. A total of 649 levels were operated with TDR implanted in 318 levels and 331 levels undergoing either stand-alone ALIF or combined anterior/posterior fusion. The most common combination for hybrid surgery was TDR at L4-5 and fusion at L5-S1. The mean blood loss was 99.1 ml. There were statistically significant improvements (p <0.001) in the mean values of all three clinical <h3>OUTCOME MEASURES</h3> VAS back pain scores improved from 6.7 to 3.2; VAS leg pain scores improved from 4.2 to 2.0; and ODI scores improved from 45.7 to 25.4. There were no significant differences in the pain and function scores for patients with minimum 10-year follow-up vs those with shorter follow-up duration. Re-operation occurred in 16.2% of patients. The most common reason for re-operation was the removal of painful posterior instrumentation at the fusion level of the hybrid (31.3% of re-operations; 6.1% of the study group). Re-operations involving the TDR level occurred in 9 patients (3.0%). These included 3 cases of TDR migration, 1 posterior fusion for facet joint arthrosis, 4 patients underwent decompression at the TDR and fusion levels, and one patient underwent re-operations at both hybrid levels related to multilevel deformity. One patient reported multiple re-operations on the returned mailing, but insufficient detail was provided to determine the procedure(s) performed. <h3>CONCLUSIONS</h3> The results of this study support that for many patients with symptomatic DDD arising from more than one disc, hybrid surgery is a viable surgical option. Significant improvement was demonstrated in pain and function scores with no difference in scores among patients with more than 10-year follow-up. The most commonly occurring re-operation was removal of painful posterior fixation, unrelated to the TDR. <h3>FDA DEVICE/DRUG STATUS</h3> Charite, ProDisc-L, activL (Not approved for this indication)

134. Lumbar total disc replacement for the treatment of adjacent segment degeneration after lumbar fusion

<h3>BACKGROUND CONTEXT</h3> One of the potential problems associated with lumbar fusion is the development of adjacent segment degeneration. While there may be debate over the incidence and causes of ASD, it does exist and for patients with significant symptoms, merits treatment. There is little information available specifically on the treatment of this condition. <h3>PURPOSE</h3> The purpose of this study was to investigate the outcome of lumbar TDR used to treat adjacent segment degeneration after prior lumbar fusion. <h3>STUDY DESIGN/SETTING</h3> This study was based on retrospective record review combined with a mailing to collect current outcome data. <h3>PATIENT SAMPLE</h3> The study was based on 30 consecutive patients, beginning with first case experience in 2005, who underwent lumbar TDR at one or more levels adjacent to a prior fusion to treat symptomatic disc degeneration unresponsive to nonoperative care. The median number of lumbar spine surgeries prior to TDR was 2. <h3>OUTCOME MEASURES</h3> The outcome measures used in the study included visual analog scales (VAS) assessing back and leg pain, the Oswestry Disability index (ODI), and the occurrence of re-operations. <h3>METHODS</h3> Records of patients undergoing TDR were reviewed and those who had previously undergone lumbar fusion were identified. Charts were reviewed to collect general patient data, surgical details, and clinical outcome measures. Mailings were sent to patients who had not been seen recently in the clinic to collect current outcome data. <h3>RESULTS</h3> The mean follow-up duration after TDR was 76.6 months. A total of 40 TDRs were implanted in the 30 patients. The most frequently operated level was L4-5 above a prior L5-S1 fusion. The VAS back pain and ODI scores improved significantly from pre-TDR to final follow-up (VAS back pain from 7.3 to 4.6, p <0.001 and ODI scores 48.9 to 32.4, p <0.025). VAS leg pain scores improved, but not significantly (4.4 to 3.6). Three patients (10.0%) underwent additional lumbar spinal surgery after the TDR procedure. These included one patient undergoing a discectomy at an upper lumbar level following a fall, one patient underwent multiple surgeries at a remote facility to perform instrumented posterior fusion at the TDR level and the level fused anteriorly prior to the TDR surgery, and the third patient received a spinal cord stimulator after TDR and reported he later had surgery performed remotely to add posterior supplemental fixation at the TDR level due to instability. <h3>CONCLUSIONS</h3> While there is much literature discussing the occurrence and possible mechanisms of lumbar adjacent segment degeneration following lumbar fusion, less information is available on the treatment of this condition. The current study found that TDR can be used effectively for treating adjacent segment degeneration providing the patient is an appropriate candidate for this procedure. In evaluating these patients, particular attention must be paid to the condition of the facet joints to ensure TDR is not contra-indicated. <h3>FDA DEVICE/DRUG STATUS</h3> Charite, ProDisc-L, activL (Not approved for this indication)

In which cases do surgeons specializing in total disc replacement perform fusion in patients with symptomatic lumbar disc degeneration?

The purpose of this study was to investigate reasons and their frequency for why spine surgeons subspecializing in total disc replacement (TDR) performed lumbar fusion rather than TDR. The study was based on a consecutive series of 515 patients undergoing lumbar TDR or fusion during a 5-year period by three surgeons specializing in TDR. For each fusion patient, the reason for not performing TDR was recorded. TDR was performed in 65.4% (n = 337) of patients and the remaining 34.6% (n = 178) underwent anterior lumbar interbody fusion (ALIF ± posterior instrumentation). Of the 178 fusion patients, the most common reason for fusion was combined factors related to severe degenerative changes (n = 59, 11.5% of the study population). The second most common reason was > Grade 1 spondylolisthesis (n = 32, 6.2%), followed by insurance non-coverage (n = 24, 4.7%), and osteopenia/osteoporosis (n = 13, 2.5%). Fusion patients were significantly older than TDR patients (52.5 vs. 41.6years; p < 0.01). There was no significant difference with respect to gender (41.2% female vs. 43.8% female, p > 0.05) or the percentage of patients with single-level surgery (61.2% vs. 56.7%, p > 0.05). The most common reason for not performing lumbar TDR was related to anatomic factors that may compromise stability of the operated segment and/or TDR functionality. The older age of fusion patients may be related to these factors. This study found that many patients are appropriate candidates for lumbar TDR. However, even among TDR subspecialists, fusion is preferred when there are factors that cannot be addressed with TDR and/or may compromise implant functionality.

Single-Level Total Disc Replacement: Index-Level and Adjacent-Level Revision Surgery Incidence, Characteristics, and Outcomes.

The literature reports that index level (IL) revision spine surgery (RSS) and adjacent level (AL) RSS are diminished in lumbar TDR compared with fusion procedures. There is a paucity of PROMs reported after RSS. To present the incidence of RSS at the IL and AL following single-level lumbar total disc replacement (TDR) and to document patient-related outcome measures (PROMs) associated with RSS. PROMs and timelines were analyzed for 32 RSS patients from a prospective cohort study of 401 patients treated with TDR for single-level degenerative disc disease. The data collected prospectively are analyzed from baseline (prior to index surgery) to latest follow-up following RSS. PROMs, including visual analog scales for back and leg, Oswestry Disability Index, and Roland-Morris Disability Questionnaire, were collected preoperatively; postoperatively at 3, 6, and 12 months; and annually thereafter until RSS. The time to RSS was recorded, and PROMs for RSS (IL, AL, or both) were documented, analyzed, and compared. The median time to RSS in the IL cohort was 35 months (interquartile range [IQR] = 9-51 months). The median time to RSS cohort was 70 months (IQR = 41.3-105.3 months). Timepoints facilitate PROM discussion for RSS. Patients in both groups achieved thresholds for the minimum clinically important difference for pain and disability scores. The small sample size in each group contributed to the variability demonstrated by the 95% CIs, thereby cautioning definitive conclusions. This study reveals that statistically significant and modest clinical improvements in PROMs can be achieved in RSS for lumbar TDR at IL and AL. The surgical approach and technique are reflective of the pathology and suggest that anterior RSS for AL degeneration and posterior RSS for IL pathology yield similar results. Statistical and clinical improvements can be achieved in IL-RSS and AL-RSS following single level TDR. It is essential for clinicians to understand and verify the underlying IL and/or AL pathology to select an appropriate management strategy and to facilitate balanced informed discussions with patients.

Single-Level Total Disc Replacement: Mid- to Long-Term Outcomes.

Total disc replacement (TDR) has been shown to be effective for the treatment of lumbar degenerative disc disease (DDD) in carefully selected patients. Previous studies have demonstrated high rates of patient satisfaction and improvement in patient-reported outcome measures (PROMs) compared with preoperative status but most have short-term follow-up or small cohort sizes only. The aim of this study is to report mid- to long-term PROMs from the treatment of symptomatic single-level lumbar DDD with TDR. Data collected prospectively concerning single-level TDR performed via an anterior approach were included for analysis. A preoperative assessment was obtained followed by postoperative follow-up assessments at 3, 6, and 12 months, and yearly follow-up thereafter. PROMs included patient satisfaction, visual analog score back and leg, Oswestry Disability Index, and Roland-Morris Disability Questionnaire. A total of 211 patients (118 men, 93 women) operated on between June 1997 and July 2015 were included in this study. Minimum follow-up was 4 years. The average age was 42.2 (range 24-87) years and median follow-up 96 interquartile range 72-132, range 48-120) months. The operative levels were L5-S1 (160, 75.8%) and L4-L5 (61, 24.2%). Both statistically and clinically significant improvements observed postoperatively were maintained at 10 years. In addition, 92% of patients reported either good (n = 29) or excellent satisfaction (n = 155) with treatment at final review. This study shows that single-level lumbar TDR used appropriately in selected patient results in clinically significant improvements in pain and function, well above the minimum clinically important difference, and good to excellent satisfaction in most patients. Further study to define long-term outcomes and survivorship is required. Statistically significant and clinically relevant improvements can be achieved by single-level lumbar TDR, in the treatment of single-level discogenic axial low back pain, with or without radiculopathy. These outcomes are sustained in the mid- to long-term followup periods.

Impact of heterotopic ossification following lumbar total disk replacement: a systematic review

Background contextLumbar total disc replacement (TDR) is an alternative to lumbar fusion in the treatment of lower back pain and reduces the risk of adjacent segment degeneration. Heterotopic ossification (HO) has been identified as a common complication following lumbar TDR.PurposeThis systematic review aims to determine the prevalence, risk factors and clinical and radiological impact of HO following lumbar TDR.Study DesignSystematic Review.MethodsMEDLINE, Scopus, PubMed and Cochrane Central were searched for articles that referred to lumbar TDR and HO. The hits were assessed against inclusion and exclusion criteria. Data from each included study was extracted and analysed with respect to the study aims.ResultsTwenty-six studies were included in this review and the pooled prevalence of HO was estimated to be between 13.2% (participants) and 15.3% (vertebral levels). TDR clinical outcomes were not found to be reduced by HO and there was insufficient data to identify a given impact upon radiological outcomes. Age and follow up time were identified as potential risk factors for HO.ConclusionsThis review was hampered by inconsistencies in the reporting of HO across the studies. We therefore recommend that a set of guidelines should be produced to aid future researchers and reduce the risk of bias.

Predictors of long-term clinical outcomes in adult patients after lumbar total disc replacement: development and validation of a prediction model.

Long-term outcomes of single-level lumbar arthroplasty are understood to be very good, with the most recent Investigational Device Exemption (IDE) trial showing a < 5% reoperation rate at the close of the 7-year study. This post hoc analysis was conducted to determine whether specific patients from the activL IDE data set had better outcomes than the mean good outcome of the IDE trial, as well as to identify contributing factors that could be optimized in real-world use. Univariable and multivariable logistic regression models were developed using the randomized patient set (n = 283) from the activL trial and used to identify predictive factors and to derive risk equations. The models were internally validated using the randomized patient set and externally validated using the nonrandomized patient set (n = 52) from the activL trial. Predictive power was assessed using area under the receiver operating characteristic curve analysis. Two factors were significantly associated with achievement of better than the mean outcomes at 7 years. Randomization to receive the activL device was positively associated with better than the mean visual analog scale (VAS)-back pain and Oswestry Disability Index (ODI) scores, whereas preoperative narcotics use was negatively associated with better than the mean ODI score. Preoperative narcotics use was also negatively associated with return to unrestricted full-time work. Other preoperative factors associated with positive outcomes included unrestricted full-time work, working manual labor after index back injury, and decreasing disc height. Older age, greater VAS-leg pain score, greater ODI score, female sex, and working manual labor before back injury were identified as preoperative factors associated with negative outcomes. Preoperative BMI, VAS-back pain score, back pain duration ≥ 1 year, SF-36 physical component summary score, and recreational activity had no effect on outcomes. Lumbar total disc replacement for symptomatic single-level lumbar degenerative disc disease is a well-established option for improving long-term patient outcomes. Discontinuing narcotics use may further improve patient outcomes, as this analysis identified associations between no preoperative narcotics use and better ODI score relative to the mean score of the activL trial at 7 years and increased likelihood of return to work within 7 years. Other preoperative factors that may further improve outcomes included unrestricted full-time work, working manual labor despite back injury, sedentary work status before back injury, and randomization to receive the activL device. Tailoring patient care before total disc replacement may further improve patient outcomes.

Rehabilitation Following Lumbar Total Disc Replacement, With a Focus on Lumbar Multifidus Morphology and Function: A Case Report and Review of the Literature

Background Lumbar total disc replacement (TDR) is an option for patients with severe low back pain from degenerative disc disease who have failed conservative treatment. Paraspinal muscles have played an important role in clinical outcomes after lumbar surgery. The purpose of this study was to investigate lumbar multifidus morphology and function in a patient following lumbar TDR and a postoperative rehabilitation exercise program. Case Presentation A 52-year-old man underwent TDR surgery at the L5-S1 level to treat his chronic low back pain, which had been present for several years and unresponsive to previous conservative management. Six weeks after the operation, the patient initiated an 8-week postoperative rehabilitation program focusing on motor control and strengthening exercises. Outcome and Follow-Up The patient experienced clinically important improvements in pain and disability, as well as improvements in lumbar multifidus size ranging from 3.17% to 13.84% and changes in thickness contraction ranging from 4.04% to 16.48%, following the postoperative rehabilitation program. However, differences in lumbar multifidus muscle morphology and function were observed when comparing the surgical site to the superior motion segment. Discussion This case report displays limited evidence regarding the effects and implementation of a motor control and strengthening exercise program following lumbar TDR. Some improvements in muscle morphology and function were observed, along with improvements in pain and disability, after the completion of the exercise program. The importance of including lumbar multifidus morphology and function in the postoperative rehabilitation of this population may warrant further research. JOSPT Cases 2022;2(1):34–41. doi:10.2519/josptcases.2022.10163

A biomechanical analysis of prosthesis disc in lumbar spinal segment using three-dimensional finite element modelling

Lumbar total disc replacement (LTDR) could be an operation for handling of chronic disc illness and spinal mutilation to safeguard a range of motion (ROM). The SB Charité™ is the principal gadget for LTDR however it creates a lot of confusion and long-run problems that lead to a lack of SB Charité™ disc. The advancement of lumbar disc arthroplasty supports the calculations of the biomechanical model through three-dimensional (3D) finite element method (FEM). Accordingly, this paper exhibits a 3D biomechanical FEM model of L1 to L3 human lumbar spine by various kinds of materials and discs. There are some criteria like compressive force, Tresca stress, von Mises stress and strain that are used to estimate the proposed model. This lumbar model instructs spinal surgeons to the predication vision for disc implementation which can consequently turn out recovery from disc degeneration and bolster the surgical outcomes. The COMSOL Multiphysics® software is applied on the intact segment and four implanted models that are Charité™, Activ-L, ProDisc-L and M6-L to determine the endurance and stiffness rate of vertebral endplate at each intervertebral disc.

Single and Multilevel Lumbar Total Disc Replacement Adjacent to L5-S1 ALIF (Lumbar Hybrid): 6 Years of Follow-up

Single and multilevel lumbar arthroplasty has had excellent results, but the L5-S1 level frequently has pathology that precludes arthroplasty. This study evaluated clinical outcomes and sagittal range of motion (ROM) of operated levels and adjacent motion segments in single- and multiple-level ProDisc-L above a simultaneous L5-S1 fusion (hybrid) after a 2- to 6-year follow-up. In this prospective cohort study, 46 patients underwent simultaneous lumbar total disc replacement (TDR) at one to three levels and anterior lumbar interbody fusion (ALIF) at L5-S1. Twenty-three patients had L5-S1 ALIF + L4-5 TDR, 19 patients had L5-S1 ALIF + two-level TDR, and 4 patients had L5-S1 ALIF + three-level TDR. Oswestry disability index (ODI) and visual analog scores (VAS) of patient satisfaction (VAS-S) and pain (VAS-P) were recorded. Sagittal motion on pre- and postoperative lumbar radiographs at each operative segment and adjacent segment was acquired. Patients were evaluated preoperatively and at 6 weeks, 3 months, 6 months, and annually for 24 to 72 months postoperatively. For clinical results, there were no differences among the groups for age, gender, body mass index, tobacco use, or worker's compensation status. At 2-6 years postoperation, all patients had significant reductions in ODI and VAS scores. For radiographic results, at the nonsurgical level adjacent to the TDR + ALIF constructs, the mean preoperative ROM was 9.40 ± 1.80° compared with 10.50 ± 2.25° postoperatively. The mean preoperative ROM at levels undergoing TDR was 10.4 ± 2.71° versus 12.6 ± 2.25° postoperatively. There was no statistically significant difference in ROM at each prosthetic motion segment between patients receiving one-, two-, or three-level TDR. The mean preoperative ROM at the L5-S1 segment to undergo fusion was 2.4 ± 2.44°, with all patients having a postoperative ROM of 0.00°. Multilevel TDR above an L5-S1 ALIF (hybrid procedure) preserves ROM at the individual TDR levels and does not reduce the fusion rate of the L5-S1 fused level. Most significantly, the nonoperative adjacent level maintains its preoperative ROM at 2-6 years postoperatively.

Letter to the Editor Regarding “Clinical-Instrumental Results and Analysis of Functional Activity Restoration in Professional Athletes Following Lumbar Total Disk Replacement”

Letter to the Editor Regarding “Clinical-Instrumental Results and Analysis of Functional Activity Restoration in Professional Athletes Following Lumbar Total Disk Replacement”

Incidence and Resolution Strategies for Early-Onset Postoperative Leg Pain Following Lumbar Total Disc Replacement.

Lumbar total disc replacement (TDR) has produced results similar or superior to fusion in treating symptomatic disc degeneration. Some patients have reported onset of leg pain early after surgery. Little information is available specifically on this problem. The purpose of this study was to investigate the incidence of early-onset postoperative leg pain following lumbar TDR and to describe strategies for its treatment. The study was based on a post hoc analysis of prospectively collected adverse event data from 283 patients in the activL Food and Drug Administration investigational device exemption study. Early-onset leg pain was defined as occurring between 0 and 4 weeks postprocedure, and the baseline visual analog scale score in the affected leg(s) was <25 (of 100). The treatment types these patients received were analyzed. Among 283 patients, 26 (9.2%) had an early-onset leg pain event. The majority of these events resolved (20/26, 76.9%). Of those resolving, 55% (11/20) did so within 3 months. Most patients received at least 1 drug treatment for leg pain (92.3%). Of those receiving drug therapy, the most common type was neurogenic (61.5%), followed by narcotics (46.2%). Steroid use was prescribed in 30.8%. The majority of resolved cases were not on narcotics and resolved with neurogenic drugs. Three patients went on to have surgery, none of whom benefited from it. Age, body mass index, and baseline disability scores were predictive of time to resolution. Early-onset postoperative leg pain occurred in approximately 10% of lumbar TDR patients. The majority of events resolved, often within 3 months. Treatment with conservative care, including medication(s), was more effective in resolving symptoms rather than surgery. This study provides useful information for providers and patients on the incidence, treatment, and resolution of leg pain with onset after lumbar TDR and not related to direct neural compression identified by imaging. 2.

166. Lumbar total disc replacement as a part of adult scoliosis surgical treatment of 205 patients with minimum of 2 years of follow-up

<h3>BACKGROUND CONTEXT</h3> Surgical scoliosis treatment in adults must face beyond the curve correction, degeneration disc disease, dislocations, spondylolisthesis with sagittal and frontal unbalance and lumbar kyphosis. Two technical components of the surgery have been used to resolve those difficult problems: the fixation through the pelvis, with a complete loss of lumbar mobility and its consequences. The higher rate of pseudarthrosis, despite complex contracts, on one hand, and the necessity of posterior lumbar osteotomies to restore an acceptable lordosis with severe risk of complications on the other hand. <h3>PURPOSE</h3> To explore the capacity to maintain or restore part of mobility and lumbar lordosis, using total disc replacement TDR), by anterior approach (with or without ALIF) in association with the posterior reduction, fixation. <h3>STUDY DESIGN/SETTING</h3> Retrospective clinical study. <h3>PATIENT SAMPLE</h3> A total of 205 patients, 40M, 165F, 18-82 year old (average age 57 yo). Of these, 112 idiopathic scoliosis never operated before, 43 degenerative scoliosis in adults never operated on, and 50 cases already operated on by posterior approach (below prior surgery). A total of 286 TDR Prodisc were implanted (129 - 1 level, 71 - 2 levels, 5 – 3 levels). <h3>OUTCOME MEASURES</h3> The patients' analysis includes the perioperative, preop and postop VAS and ODI (3, 6, 12, 24, late follow-up), mobility of the disc replacement and the evolution of the curve (Cobb, sagittal parameters). <h3>Methods</h3> Between 2000 and 2018, 123 patients with scoliosis and lumbar disc degeneration have received one or more TDR and eventually ALIF, before or after their posterior fixation reduction. The posterior device associated classically hooks, screws, and the rods. The choice of the TDR is one of the key points as with the deformity, there is a need for semi-constrained (fixed center) prosthesis, to neutralize the shear forces and compensate the deficit of anterior and posterior longitudinal ligaments. <h3>Results</h3> ODI preop was 24/50 and declined to 10 in 24 months, VAS lumbar 7.2, radicular 5.7 prep went to 2.6 and 2.1 at 24 months and stabilized at latest follow-up. The mobility measurement at 24 months showed: 151 of 205 patients had a ROM at the TDR level more than 10° in flexion-extension at 24 months. The lordosis capacity of the implants eventually associated to and ALIF with appropriated angulation, allowed the sagittal balance restoration, with T1 axe correction and pelvic tilt reduction. There were no major complications, 4 anterior hematomas (2 drainages, 2 surgical treatments), 2 partial neurological deficits (1 L4, 1 L5). We had no implant TDR complications, no displacements, no explantation required. 2 cases of screw revised, 6 Posterior device removal (2 total, 4 partial), 2 complementary laminectomies, and 2 extension of posterior instrumentation. <h3>Conclusions</h3> The choice of TDR, with a semi – constrained prosthesis and loss restoration of motion and sagittal balance in adult scoliosis. It shows interest in the results, as a clinical and mobility point of view that is maintained in long-term follow up. That allows to avoid the pelvic fixation in majority of cases, escaping for the clinical bad results and complications of the lawn posterior constructions extend it to the pelvis and also illuminates the risks of posterior transpedicular osteotomies. In elderly people, there is a need for osteodensitometry measurement and eventually cementopalsty of the vertebrae that receive the prosthesis. <h3>FDA DEVICE/DRUG STATUS</h3> This abstract does not discuss or include any applicable devices or drugs.

Analytical and finite element analysis of shape memory polymer for use in lumbar total disc replacement

One-piece bearing is the latest type of total disc replacement (TDR) design that is used for the treatment of lumbar degenerative disc disease (DDD). Due to the unique properties of the shape memory polymers (SMPs), such as self-healing, shape-memory, adhesion control, and self-deployable ability, they may be a good candidate for the core of such a design. The purpose of the present study is to use an analytical method combined with a numerical analysis (finite element analysis (FEA)) to determine the mechanical responses of an SMP intervertebral disc (IVD) model, under pure torsion (axial rotation) and pure compression, two loading conditions to which natural intervertebral discs (IVDs) are subjected in vivo. We considered the SMP IVD model to be positioned at L4-L5 because most cases of lumbar DDD are reported at this segment. For the analytical method, an appropriate constitutive equation for an SMP was determined and, then, an analytical solution for the torsional response of a circular SMP IVD model, in a full cycle of stress-free strain recovery, was derived. The developed equations were implemented in finite element modeling to determine responses of the IVD disc model under pure torsion. Additionally, responses of the SMC IVD model, under a compressive load, and different conditions were determined. The analytical and FEA results were compared to experimental results give in the literature for intact lumbar spine segments as the core in a one-piece lumbar TDR. Based on this study, we suggest that SMPs can be used for TDR, as they are strong enough to bear the torsional and compressive loads that IVD is subjected through its life.

Final Long-Term Reporting from a Randomized Controlled IDE Trial for Lumbar Artificial Discs in Single-Level Degenerative Disc Disease: 7-Year Results.

This study compared 7-year safety and efficacy outcomes of activL and ProDisc-L lumbar total disc replacements in patients with symptomatic, single-level lumbar degenerative disc disease (DDD). The objectives are to report 7-year outcomes of the trial, evaluate the outcomes for patients lost to follow-up, and determine whether early outcomes predict long-term outcomes. This was a prospective, multicenter, randomized, controlled investigational device exemption study. Eligible patients with symptomatic, single-level lumbar DDD had failed ≥6 months of nonsurgical management. Patients (N = 283) were randomized to receive activL (n = 218) or ProDisc-L (n = 65). At 7 years, data were available from 206 patients (activL, 160; ProDisc-L, 46). Logistic regression models were fit to predict 7-year outcomes for patients lost to follow-up after 2 years. At 7 years, the activL group was noninferior to the ProDisc-L group on the primary composite endpoint (P = .0369). Both groups showed significant reductions in back/leg pain severity and improvements in disability index and quality-of-life relative to baseline (P < .0001). In both groups, opioid use was significantly reduced at 7 years (0%) relative to baseline (P < .01), and the overall reoperation rates were low (4.6%). activL patients showed a significantly better range of motion (ROM) for flexion-extension rotation than ProDisc-L patients (P = .0334). A significantly higher proportion of activL patients did not report serious adverse events (activL, 62%; ProDisc-L, 43%; P = .011). Predictive modeling indicated that >70% of patients (depending on outcome) lost to follow-up after 2 years would show clinically significant improvement at 7 years if improvements were achieved at 2 years. The benefits of activL and ProDisc-L are maintained after 7 years, with significant improvements from baseline observed in pain, function, and opioid use. activL is more effective at preserving ROM than ProDisc-L and has a more favorable safety profile. Improvements in other primary and secondary outcomes were similar between both disc designs. 1.

The Lateral Approach in Lumbar Total Disc Replacement: A Literature Review

Lumbar disc replacement has become an area of interest for many practicing spine surgeons. As newer technology emerges focusing on motion sparing devices, novel techniques are being employed to better serve patients and increase post-operative outcomes.

Long-term clinical and radiological outcomes after total lumbar disc replacement at the lumbosacral junction

The study objective is to analyze long-term clinical and radiological outcomes in patients after performing total lumbar disc replacement at the level of the lumbosacral junction.Materials and methods. A multicenter retrospective observational cohort study was performed. The study included medical records of patients who underwent total lumbar disc replacement at the level of the lumbosacral junction. Both clinical and instrumental parameters were assessed. According to the eligibility criteria, 93 patients were included in the study (38 men, 55 women, mean age 39.9 ± 7.5 years). The average postoperative observation period for the respondents was 33.4 ± 9.5 months.Results. The severity of pain in the lumbar spine on a visual analogue scale significantly decreased (from 7.3 ± 2.5 to 1.9 ± 2.2 cm, p &lt;0.001). The indicators of the quality of life according to the Oswestry Disability Index and according to the Short Form-36 scale (including the mental and physical components) of the studied group of respondents significantly improved (from 43.4 ± 17.6 to 18.9 ± 16.0 %, р &lt;0.001 and from 30.8 ± 8.5 to 52.3 ± 12.4 %, p &lt;0.001, respectively). From the 12th month of observation of the respondents, a significant decrease in the values of the range of motions of the operated segment was noted from 5.3 ± 3.2° to 4.1 ± 3.6° (p &lt;0.009). Also, from the 12th month of postoperative observation, a slight decrease in the values of the range of motions of the adjacent segment from 8.6 ± 4.1° to 7.8 ± 3.8° (p &gt;0.05) was verified. The value of global lumbar lordosis after the installation of a lumbar intervertebral disc prosthesis at the level of the lumbosacral junction significantly increased from 49.1 ± 4.8° to 55.6 ± 5.5° (p &lt;0.001). Intervertebral disc prostheses with a lordotic angle of 10° reliably positively correlate with an increase in the values of segmental lordosis, in contrast to implants with an angle of 6° (rS = 0.86, p = 0.04). The severity of pain in the lumbar spine according to visual analogue scale and the range of motion of the operated segment has a significant negative correlation in the late periods of postoperative follow-up (24 and 36 months, rS = -0.74, p = 0.015).Conclusion. The total lumbar disc replacement technique is an effective method of surgical treatment of patients with degenerative diseases of the intervertebral discs of the lumbosacral spine, including at the level of the lumbosacral junction.

Evaluation of the EQ-5D-3L and 5L versions in low back pain patients

BackgroundThe EuroQol EQ-5D is one of the most widely researched and applied patient-reported outcome measures worldwide. The original EQ-5D-3L and more recent EQ-5D-5L include three and five response categories respectively. Evidence from healthy and sick populations shows that the additional two response categories improve measurement properties but there has not been a concurrent comparison of the two versions in patients with low back pain (LBP).MethodsLBP patients taking part in a multicenter randomized controlled trial of lumbar total disc replacement and conservative treatment completed the EQ-5D-3L and 5L in an eight-year follow-up questionnaire. The 3L and 5L were assessed for aspects of data quality including missing data, floor and ceiling effects, response consistency, and based on a priori hypotheses, associations with the Oswestry Disability Index (ODI), Pain-Visual Analogue Scales and Hopkins Symptom Checklist (HSCL-25).ResultsAt the eight-year follow-up, 151 (87%) patients were available and 146 completed both the 3L and 5L. Levels of missing data were the same for the two versions. Compared to the EQ-5D-5L, the 3L had significantly higher floor (pain discomfort) and ceiling effects (mobility, self-care, pain/discomfort, anxiety/depression). For these patients the EQ-5D-5L described 73 health states compared to 28 for the 3L. Shannon’s indices showed the 5L outperformed the 3L in tests of classification efficiency. Correlations with the ODI, Pain-VAS and HSCL-25 were largely as hypothesized, the 5L having slightly higher correlations than the 3L.ConclusionThe EQ-5D assesses important aspect of health in LBP patients and the 5L improves upon the 3L in this respect. The EQ-5D-5L is recommended in preference to the 3L version, however, further testing in other back pain populations together with additional measurement properties, including responsiveness to change, is recommended.Trial registration: retrospectively registered: https://clinicaltrials.gov/ct2/show/NCT01704677.

Clinical-Instrumental Results and Analysis of Functional Activity Restoration in Professional Athletes After Lumbar Total Disk Replacement

To analyze the clinical and biomechanical outcome of professional athletes after lumbar total disk replacement, with a focus on restoration of the functional activity. This nonrandomized retrospective single-center study included 11 professional athletes who underwent lumbar disc replacement surgery using the prosthesis M6-L (Spinal Kinetics, Schaffhausen, Switzerland). The average postoperative follow-up was 3.18 ± 1.14 years. The following outcomes were evaluated: intensity of pain in the lumbar spine and lower limbs, Oswestry Disability Index, Short-Form 36, complications, time of return to previous sports activity, range of movement, degree of lumbar lordosis, degenerative changes of the adjacent levels, and degree of heterotopic ossification. The operated patients reported significant decrease of pain on visual analog scale (P < 0.001) as well as significant improvement of Oswestry Disability Index (P= 0.001) and Short-Form 36 (P < 0.001). For the duration of follow-up, the patients maintained segmental range of motion at L4-L5 (P= 0.04) and L5-S1 (P= 0.03) levels. There was also some statistically insignificant increase of global lumbar lordosis (P= 0.84). We did not identify any significant degeneration of the adjacent intervertebral disks (P > 0.05) or progression of the facet joint degenerative changes at the implantation level and in the adjacent segments (P > 0.05). One patient (9.1%) developed grade I heterotopic ossification 5 years after surgery and in 1 patient (9.1%), a lesion of superior hypogastric plexus was recorded. The average time of return to previous sports activity was 9.72 ± 3.03 weeks. Total lumbar disc replacement using M6-L prosthesis in professional athletes made it possible to achieve statistically significant reduction of pain and facilitated early return to normal sports activities. In our opinion, preservation of movement of the operated lumbar segment can help to reduce the mechanical stress with beneficial impact on the rate of degeneration of the adjacent level.