Lumbar Total Disc Replacement Research Articles

Clinical Outcome of Lumbar Hybrid Surgery in a Consecutive Series of Patients with Long-term Follow-up.

This was a retrospective study combined with attempted prospective patient contact to collect current data. The purpose of this study was to investigate long-term clinical outcome of patients undergoing lumbar hybrid surgery (total disc replacement (TDR) at one level and fusion at an adjacent level. Many patients with symptomatic lumbar disc degeneration are affected at more than one level. Lumbar TDR was introduced as a fusion alternative; however, some disc levels are not amenable to TDR and fusion is preferable at such levels. Hybrid surgery was introduced as an option to fusing multiple levels. A consecutive series of 305 patients undergoing lumbar hybrid surgery was identified beginning with the first case experience in 2005. Operative and clinical outcome data including visual analog scales (VAS) assessing back and leg pain, Oswestry Disability Index (ODI), and re-operations were collected. The mean follow-up duration was 67.1 months. There were statistically significant improvements (P<0.01) in the mean values of all three clinical outcome measures: VAS back pain scores improved from 6.7 to 3.3; leg pain improved from 4.3 to 2.0; and ODI scores improved from 45.5 to 24.6. There were no significant differences in pain and function scores for patients with minimum 10-year follow-up vs. those with shorter follow-up duration. Re-operation occurred in 16.1% of patients, many of which involved removal of posterior instrumentation at the fusion level (6.2% of study group, 38.8% of re-operations). Re-operation involving the TDR level occurred in 9 patients (2.9%), only 3 of which (1.0%) involved TDR removal/revision. This study supports that for many patients with multilevel symptomatic disc degeneration, hybrid surgery is a viable surgical option. Significant improvements were demonstrated in pain and function scores with no diminished improvement in scores among patients with more than 10-year follow-up.

Lumbar Total Disk Replacement Device Removals and Revisions Performed During a 20-Year Experience with 2141 Patients.

This was a retrospective study with prospective patient contact attempted to collect current data. The purpose was to investigate the incidence and reasons for lumbar total disk replacement (TDR) removal or revision. A concern regarding lumbar TDR was safety, particularly the need for device removal or revision. This may be particularly important considering removal/revision requires repeat anterior exposure with an increased risk of vascular injury. Data were collected for a series of 2141 lumbar TDR patients, beginning with the first case experience in 2000. The mean follow-up was 78.6 months. For each case of device removal/revision, the reason, duration from index surgery, and procedure performed were recorded. Of 2141 patients, 27 (1.26%) underwent TDR removal or revision. Device removal was performed in 24 patients (1.12%), while three patients underwent revision (0.14%). Of the 24 removals, 12 were due to migration and/or loosening, three developed problems post-trauma, two developed lymphocytic reaction to device materials, two had ongoing pain, and there was one case of each: TDR was too large, vertebral body fracture (osteoporosis), lytic lesion, device subsidence and facet arthrosis, and infection seeded from a chest infection 146 months post-TDR. The three revisions were for Core repositioning (technique error), device repositioning after displacement, and core replacement due to wear/failure. With respect to timing, 37.0% of removals/revisions occurred within one-month postimplantation. Of note, 40.7% of removals/revisions occurred in the first 25 TDR cases performed by individual surgeons. There was one significant vascular complication occurring in a patient whose TDR was removed due to trauma. This was also the only patient among 258 with ≥15-year follow-up who underwent removal/revision. In this large consecutive series, 1.26% of TDRs were removed/revised. The low rate over a 20 year period supports the safety of these devices.

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

Systematic Review. To systematically review the clinical outcomes, re-operation, and complication rates of lumbar TDR devices at mid-to long-term follow-up studies for the treatment of lumbar degenerative disc disease (DDD). A systematic search was conducted on PubMed, SCOPUS, and Google Scholar to identify follow-up studies that evaluated clinical outcomes of lumbar TDR in patients with DDD. The included studies met the following criteria: prospective or retrospective studies published from 2012 to 2022; a minimum of 5years post-operative follow-up; a study sample size >10 patients; patients >18years of age; containing clinical outcomes with Oswestry Disability Index (ODI), Visual Analog Scale (VAS), complication or reoperation rates. Twenty-two studies were included with data on 2284 patients. The mean follow-up time was 8.30 years, with a mean follow-up rate of 86.91%. The study population was 54.97% female, with a mean age of 42.34years. The mean VAS and ODI pain score improvements were 50.71 ± 6.91 and 30.39 ± 5.32 respectively. The mean clinical success and patient satisfaction rates were 74.79% ± 7.55% and 86.34% ± 5.64%, respectively. The mean complication and reoperation rates were 18.53% ± 6.33% and 13.6% ± 3.83%, respectively. There was no significant difference when comparing mid-term and long-term follow-up studies for all clinical outcomes. There were significant improvements in pain reduction at last follow-up in patients with TDRs. Mid-term follow-up data on clinical outcomes, complication and reoperation rates of lumbar TDRs were maintained longer term.

Average 10-Year Follow-Up Outcomes of Lumbar Total Disc Replacement in 109 Patients

Average 10-Year Follow-Up Outcomes of Lumbar Total Disc Replacement in 109 Patients

Average 10-Year Follow-Up Outcomes of Lumbar Total Disc Replacement in 109 Patients

Average 10-Year Follow-Up Outcomes of Lumbar Total Disc Replacement in 109 Patients

171. A novel monolithic 3D-printed titanium lumbar total disc replacement device results in biomechanics similar to the intact spine: a finite element study

171. A novel monolithic 3D-printed titanium lumbar total disc replacement device results in biomechanics similar to the intact spine: a finite element study

168. Long-term outcome of lumbar total disc replacement: impact of prior spine surgery

168. Long-term outcome of lumbar total disc replacement: impact of prior spine surgery

169. Outcome of 2-level lumbar total disc replacement: results of a long-term follow-up study

169. Outcome of 2-level lumbar total disc replacement: results of a long-term follow-up study

165. Seven- to 21-year clinical and radiographic analysis on 2- vs 3-levels of lumbar total disc replacement

165. Seven- to 21-year clinical and radiographic analysis on 2- vs 3-levels of lumbar total disc replacement

Lumbar arthroplasty for treatment of primary or recurrent lumbar disc herniation.

Microdiscectomy is the current gold standard surgical treatment for primary lumbar disc herniations that fail non-surgical measures. Herniated nucleus pulposus is the manifestation of underlying discopathy that remains unaddressed with microdiscectomy. Therefore, risk remains of recurrent disc herniation, progression of the degenerative cascade, and on-going discogenic pain. Lumbar arthroplasty allows for complete discectomy, complete direct and indirect decompression of neural elements, restoration of alignment, restoration of foraminal height, and preservation of motion. In addition, arthroplasty avoids disruption of posterior elements and musculoligamentous stabilizers. The purpose of this study is to describe the feasibility of the use of lumbar arthroplasty in the treatment of patients with primary or recurrent disc herniations. In addition, we describe the clinical and peri-operative outcomes associated with this technique. All patients that underwent lumbar arthroplasty by a single surgeon at a single institution from 2015 to 2020 were reviewed. All patients with radiculopathy and pre-operative imaging demonstrating disc herniation that received lumbar arthroplasty were included in the study. In general, these patients were those with large disc herniations, advanced degenerative disc disease, and a clinical component of axial back pain. Patient-reported outcomes of VAS back, VAS leg, and ODI pre-operatively, at threemonths, oneyear, and at last follow-up were collected. Reoperation rate, patient satisfaction, and return to work were documented at last follow-up. Twenty-four patients underwent lumbar arthroplasty during the study period. Twenty-two (91.6%) patients underwent lumbar total disc replacement (LTDR) for a primary disc herniation. Two patients (8.3%) underwent LTDR for a recurrent disc herniation after prior microdiscectomy. The mean age was 40years. The mean pre-operative VAS leg and back pain were 9.2 and 8.9, respectively. The mean pre-operative ODI was 22.3. Mean VAS back and leg pain was 1.2 and 0.5 at threemonths post-operative. The mean VAS back and leg pain was 1.3 and 0.6 at oneyear post-operative. The mean ODI was 3.0 at oneyear post-operative. One patient (4.2%) underwent re-operation for migrated arthroplasty device which required repositioning. At last follow-up, 92% of patients were satisfied with their outcome and would undergo the same treatment again. The mean time for return-to-work was 4.8weeks. After returning to work, 89% of patients required no further leave of absence for recurrent back or leg pain at last follow-up. Forty-four percent of patients were pain free at last follow-up. Most patients with lumbar disc herniations can avoid surgical intervention altogether. Of those that require surgical treatment, microdiscectomy may be appropriate for certain patients with preserved disc height and extruded fragments. In a subset of patients with lumbar disc herniation that require surgical treatment, lumbar total disc replacement is an effective option by performing complete discectomy, restoring disc height, restoring alignment, and preserving motion. The restoration of physiologic alignment and motion may result in durable outcomes for these patients. Longer follow-up and comparative and prospective trials are needed to determine how the outcomes of microdiscectomy may differ from lumbar total disc replacement in the treatment of primary or recurrent disc herniation.

Impact of previous lumbar spine surgery on the outcome of lumbar total disc replacement: analysis of prospective 5-year follow-up study data.

It is sometimes anticipated that patients with prior spine surgery will have a compromised outcome from future procedures. The purpose of this study was to compare TDR outcomes in patients with prior lumbar spine surgery to those with no previous surgery. Post hoc analysis was performed on 5-year follow-up data collected prospectively in the multi-centre FDA-regulated trial for the activL® Artificial Disc which involved 376 patients treated for single-level symptomatic disc degeneration. Clinical outcome measures included the Oswestry Disability Index (ODI), visual analog scales (VAS) assessing back and leg pain, SF-36, adverse events, and re-operations. Radiographic outcomes included flexion/extension range of motion (ROM) and translation of the operated segment. Patients were divided into two groups: Prior Lumbar Surgery (PLS, n = 92) and No Prior Lumbar Surgery (NPLS, n = 284). Baseline demographics were similar in the two groups. ODI, VAS, and SF-36 Physical Component Scale scores improved significantly (p < 0.05) from baseline in both groups with improvements maintained through 5-year post-TDR with no significant differences between groups. There were no statistically significant differences in rates of serious device-related events, procedure-related events, or re-operations. While ROM was significantly less prior to TDR surgery in the PLS group, there was no significant difference in ROM at post-operative points. Prior lumbar spine surgery was not associated with compromised outcomes following TDR. These results are in line with reports from earlier studies with shorter follow-up, finding that non-destabilizing prior surgery is not a contra-indication for TDR provided that selection criteria are met. Diagnostic: individual cross-sectional studies with the consistently applied reference standard and blinding.

Long-Term Results of Charité Lumbar Disc Replacement: A 17-Year Follow-Up in a Workers' Compensation Cohort.

Lumbar total disc replacement (TDR) is an alternative to lumbar fusion for the management of degenerative disc disease. This study aims to provide insight into the long-term clinical outcomes of lumbar TDR with a mean follow-up of 17.2 years in a group of workers' compensation patients. A total of 26 workers' compensation patients with radiographically confirmed discogenic low back pain were treated with the Charité total lumbar disc replacement. Visual analog scale (VAS) scores were assessed before and after the surgery. At follow-up, patients were assessed on quality of life, employment, further lumbar spine surgeries, and associated complications. Simple nonparametric statistical analysis was performed by the first author using Microsoft Excel. Sixteen patients (62%) were able to be contacted with a mean follow-up time of 17.2 years. VAS scores at 17 years were significantly lower than their preoperation level. Of those 16 patients, 81% returned to work and worked for an average of 9.1 years after surgery. Additionally, 6 (38%) patients underwent further lumbar spinal surgery, of whom 4 underwent fusions of the adjacent segment. Nearly all patients (94%) were satisfied with the surgery. This study suggests lumbar TDR may be a useful treatment for degenerative disc disease in select workers' compensation patients. Clinically relevant improvements in pain and employment can be achieved with the charite lumbar TDR in the treatment of degenerative disc disease in workers' compensation patients. These results are sustained over the long term.

Long-term outcomes following lumbar total disc replacement with M6-L

BackgroundThe motion preserving benefits of lumbar total disc replacement (LTDR) are well established. There is a paucity of long-term follow-up data on the M6-L prosthesis. The aim was to evaluate the clinical and radiographic outcomes of patients undergoing LTDR with M6-L and make comment about its effectiveness and durability.MethodsA retrospective single center chart review was performed of all patients who underwent LTDR with M6-L between January 1, 2011, and January 1, 2021, either as standalone device or combined with a caudal anterior lumbar interbody fusion (ALIF) (hybrid procedure). Preoperative, postoperative, and final follow-up patient reported outcome measures (PROMs) (VAS back, VAS leg, ODI, and SF-12) and patient satisfaction were recorded prospectively. Device range of motion (ROM), adjacent segment degeneration/disease and heterotopic ossification (HO) were obtained from flexion and extension lumbar radiographs at most recent follow-up.ResultsSixty patients underwent LTDR with the M6-L device. Mean age was 41 [16–71] years and 38 (63%) were male. Sixteen (26.7%) underwent standalone LTDR, 42 (70.0%) a hybrid procedure, and 2 (3.3%) a 3-level procedure. Twenty-three (38.3%) patients were lost to follow-up. Thirty-seven (61.7%) were followed for a mean of 4.3 [1–10] years with 36/37 reviewed at a minimum of 2-years and 13/37 followed for over 5-years. Only one patient with osteopenia needed index level revision LTDR surgery for subsidence requiring supplemental posterior instrumentation. There were no osteolysis induced device related failures. Thirty patients obtained long-term follow-up radiographic data. Six patients had adjacent segment degeneration; none required surgery for adjacent segment disease (ASD). Three patients presented with clinically significant HO (2 with McAfee class III, 1 with class IV). The average M6-L ROM was 8.6 degrees. Mean preoperative baseline PROMs demonstrated statistically significant improvements postoperatively and were sustained at last follow-up (P<0.05).ConclusionsTotal disc replacement (TDR) with M6-L showed clinically significant improvement in PROMs that were sustained at long-term follow-up. There were no osteolysis induced device related failures. The device ROM was maintained and showed a downward trend over the 10-year study follow-up period. This paper demonstrated that the M6-L was an effective and durable arthroplasty device in this series.

101. Lumbar total disc replacement: occurrence of device removal or revision surgery during a 20-year experience with 1,775 patients

<h3>BACKGROUND CONTEXT</h3> A concern expressed about lumbar total disc replacement (TDR) has been safety. One measure of safety is the need for subsequent surgery for implant removal or revision. This may be of particular importance considering TDR removal/revision generally requires re-operation through the anterior approach with the corresponding increased risk of vascular injury. <h3>PURPOSE</h3> The purpose of this study was to analyze the incidence of, and reasons for, lumbar TDR removal or revision. <h3>STUDY DESIGN/SETTING</h3> The study was based on retrospective record review followed by a mailing and/or telephone call to collect current information from patients who had not been seen recently in the clinic. <h3>PATIENT SAMPLE</h3> A consecutive series of 1,775 lumbar TDR patients, beginning with the first case experience in 2000, was reviewed to identify those undergoing re-operation for TDR removal or revision. Only patients who were at least 2 years postoperative were included. All patients were treated for symptomatic disc degeneration unresponsive to nonoperative care. <h3>OUTCOME MEASURES</h3> The primary outcome measure was the occurrence of TDR removal or revision. <h3>METHODS</h3> The mean follow-up was 89.0 months with a median of 76 months and maximum of 251 months. For each case of device removal/revision, the reason, duration from index surgery and procedure performed were recorded. <h3>RESULTS</h3> In the series of 1,775 patients, 26 (1.46%) underwent TDR removal or revision. Removal was performed in 23 patients (1.29%) and 3 patients underwent TDR revision (0.17%). Based on the total number of 2,082 TDRs implanted in the 1.775 patients, the rates of removals and revisions were 1.15% and 0.14%, respectively. Removals included: 10 for migration and/or loosening, 3 developed problems after a trauma, 3 had ongoing pain, 2 developed lymphocytic reaction to device materials, and one each of: TDR was too large and replaced with a smaller device, vertebral body fractures (osteoporosis), developed a lytic lesion, device subsidence and facet arthrosis, and infection seeded from a chest infection at 146-month post-TDR. The 3 revisions were: repositioning the core (technique error), repositioning device after displacement, and core replacement due to wear/failure. With respect to timing, 34.6% of removals/revisions occurred within one month after the index implantation. Of note, 42.3% of revisions/removals occurred in the first 25 TDR cases performed by individual surgeons. Vascular complication during TDR removal occurred in one patient with an iliac vein tear whose TDR was removed due to trauma including spinal fracture. The series included 264 patients with verified minimum 15-year follow-up. In this subset, only one patient underwent removal/revision surgery 15 or more years after TDR. This was the patient who underwent TDR removal due to trauma-related spinal fracture. <h3>CONCLUSIONS</h3> In this large consecutive patient series, 1.5% of lumbar TDRs were removed/revised. Only one revision was related to device failure or wear. Many of the removals/revisions were performed within a month of implantation. Also of note, many occurred within the first 25 TDR cases for individual surgeons, suggesting a learning curve. The low rate of removal/revision in this large institutional experience over a 20-year period provides support for the safety of these devices. <h3>FDA DEVICE/DRUG STATUS</h3> Charite and activL, approved for 1-level (Approved for this indication), ProDisc-L for 1- and 2-level (Approved for this indication), Hybrid, devices other than ProDisc for 2-level, adjacent to prior fusion (Not approved for this indication), All devices other than Charite, ProDisc-L, and activL (Investigational/Not Approved)

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

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

172. Seven-year progression and 10-year prediction of adjacent level degeneration and disease after lumbar total disc replacement: A post hoc analysis of a prospective clinical trial with 7-year follow-up

<h3>PURPOSE</h3> To understand the progression of radiographic adjacent-level degeneration (ALDeg) seven years after lumbar total disc replacement (TDR) and the relationship of these changes with range of motion (ROM) and symptomatic adjacent-level disease (ALDis) using the seven-year follow-up data from a prospective, multicenter activL Food and Drugs Administration (FDA) Investigational Device Exemption (IDE) randomized controlled trial. <h3>METHODS</h3> Patients with single-level, symptomatic lumbar disc degeneration who were unresponsive to 6 months of nonoperative care, received activL or ProDisc-L, and had radiographs available were analyzed for the incidence for ALDeg and progression of ALDeg (ΔALDeg). ALDeg presence was determined using a modified, four-point, Kellgren-Lawrence scale. Incidence of ALDis was identified in patients who received activL or ProDisc-L with or without available radiographs. ALDis was defined as the need for reoperation at the segment adjacent to the index segment. The possible relationship between ROM and ΔALDeg was also investigated. Logistic regression modeling was used to predict ALDeg and ALDis outcomes to 10 years. <h3>RESULTS</h3> At baseline, 25% of patients had ALDeg. By seven-year follow-up, 33% of patients had ALDeg and 80% of these patients showed no ΔALDeg. Only a small percentage (3.4%) of patients had severe ΔALDeg by seven-year follow-up; the majority of patients had mild (75.9%) or moderate (20.7%) ΔALDeg by seven years. Incidence of ALDis was identified in 4 patients through seven-year follow-up (2.4%). Three patients received fusion at an adjacent level and one patient underwent fusion at the index and adjacent levels to treat stenosis at both levels along with symptomatic disc degeneration at the adjacent level. Improvement in ROM from baseline ranged from 0°to 16.4° at seven-year follow-up. For each degree in ROM gained at the TDR level, there was a consistent decrease in the percent of patients with ΔALDeg. Of patients having any improvement in ROM from baseline at the TDR level, only 16.9% had ΔALDeg; of patients having a 10°improvement in ROM, 0% of patients had ΔALDeg. The predicted probability of ALDeg after lumbar TDR was 53.9% by 10 years. In contrast, the predicted probability of clinical ALDis was only 2.8% by 10 years. <h3>CONCLUSIONS</h3> Post hoc analysis of seven-year data from a prospective trial confirm relatively low rates of ALDeg, ALDeg progression, and clinical ALDis after TDR over the long-term, with predicted rates being low through to 10 years. Improvement in ROM may be associated with reduced ΔALDeg. <h3>FDA DEVICE/DRUG STATUS</h3> activL total disc replacement (Approved for this indication), prodisc-L total disc replacement (Approved for this indication).

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.