BACKGROUND CONTEXT Cervical total disc replacement (TDR) has demonstrated outcomes comparable or superior to anterior cervical discectomy and fusion, including reoperation rates. However, a complication unique to TDR is osteolysis, characterized by significant bone loss in the vertebral bodies at the implanted level, which may necessitate revision surgery. PURPOSE To evaluate the occurrence of cervical TDR removal due to osteolysis and identify associated risk factors. STUDY DESIGN/SETTING Retrospective study of a consecutive series from a multisite spine specialty center. PATIENT SAMPLE A total of 2476 patients undergoing cervical TDR beginning in 2003, with a minimum of 12 months postoperative follow-up. OUTCOME MEASURES Incidence of TDR removal or revision due to osteolysis. METHODS Patient records were reviewed to identify cases requiring TDR removal for osteolysis. Variables including age, sex, body mass index (BMI), device type, and number of operated levels were analyzed using stepwise logistic regression to identify factors associated with revision. RESULTS TDR removal due to osteolysis occurred in 23 of 2476 cases (0.9%; 95% CI 0.61%–1.40%). Device type was the only factor significantly associated with revision. Age, sex, BMI, and number of operated levels were not significant predictors. Among 11 device types used, two designs—M6-C and Simplify—demonstrated higher revision rates (8.1% and 4.2%, respectively). The mean time to removal was 36.6 months (range, 9–80 months). In most cases, the TDR was removed and converted to anterior cervical discectomy and fusion (ACDF). In select cases with less severe but progressive osteolysis, the TDR was replaced with a different device. CONCLUSIONS Osteolysis is an uncommon but important complication of cervical TDR, with an overall low incidence. The risk appears to be associated with specific device designs. These findings are consistent with existing literature, though limited sample sizes for certain devices may affect interpretation. FDA Device/Drug Status M6-C, Secure-C, and PCM (approved for single-level use); Simplify, Mobi-C, ProDisc-C, and Prestige (approved for one- and two-level use). No devices are approved for hybrid or multi-level (>2) applications; remaining devices were investigational.

INTRODUCTION:Lumbar and cervical total disc replacements (TDR) have been used for decades. As with most devices, in Food and Drug Administration (FDA) trials, patient selection criteria are narrow, potentially not maximizing applicability of the device. The literature provides strong support for TDR, reporting outcomes similar or superior to fusion and often with a lower re-operation rate. Expanding indications is a natural extension as surgeons gain experience with a technology. With responsible expanding indications, benefits of TDR can be available to more patients. AREAS COVERED:For lumbar and cervical TDR, there is an overview of clinical outcomes, on-label indications, then expanded indications. TDR use has expanded to hybrid (TDR at one level and fusion at another), treatment of adjacent segment degeneration after prior fusion, and treatment of more than 2 levels. The literature included in this review was derived from searches involving PubMed, OVID, and an extensive internal electronic library to identify articles related to lumbar and cervical TDR, with focus on indications. EXPERT OPINION:The authors support responsible expansion of indications for TDR, based on literature-based evidence. While expanding indications is appropriate, this should be undertaken in small steps with patient safety at the forefront.

Study Design.This was a retrospective study.Objective.The purpose of the study was to determine the incidence and reasons of intraoperative conversion from planned cervical total disc replacement (TDR) to anterior cervical discectomy and fusion (ACDF).Summary of Background Data.TDR currently offers an alternative treatment with results similar or superior to ACDF. Once individual surgeons become comfortable using a device, they will typically expand indications for its use, however, patient safety must remain at the forefront. To reduce reoperations, surgeons must use strict selection criteria to determine which patients are most appropriate to receive TDR. Despite those criteria, situations may arise when surgeons convert from TDR to ACDF intraoperatively.Materials and Methods.A comprehensive surgery log was reviewed to identify cases of planned TDR converted intraoperatively to ACDF. All cases were performed at a single institution by 28 attending surgeons beginning with the first case experience in November, 2003 and ending with cases performed in November, 2023. Retrospective chart review was performed to collect demographic data and determine reasons for conversion.Results.During the 20-year period, a total of 2188 consecutive cases of planned TDR were examined. The total number of planned TDR levels was 2939. The rate of intraoperative conversion of TDR to ACDF was 0.55% (12/2188 cases; 95% CI: 0.30%-0.90%). With respect to the number of operated levels, the intraoperative rate of conversion was 0.48% (14/2939 levels; 95% CI: 0.30%-0.80%).Conclusion.There was a very low incidence of intraoperative conversion of cervical TDR to ACDF. However, surgeons performing this procedure should be prepared for the possibility of intraoperative conversion from TDR to ACDF and educate patients of this possibility.

STUDY DESIGN:This was a retrospective study with patient contact attempted to collect current follow-up data. OBJECTIVE:The purpose of this study was to compare rates of disk-related surgery during long-term follow-up in disks that underwent discography versus those that did not. SUMMARY OF BACKGROUND DATA:Some studies reported discography causes normal disks to degenerate due to the needle puncture and/or the injectate. However, other studies suggest discography does not damage disks. MATERIALS AND METHODS:Data collected for 196 patients included descriptives, discography information, and reoperation details. Only patients with a minimum 10-year follow-up (mean: 152.9 mo, range: 120-247) were included. Data were analyzed at the disk level. Included levels were: L3-4, L4-5, L5-S1, or L2-3 or L1-2 that underwent discography or were adjacent to an operated level. Disks were excluded if they had undergone an interbody procedure. The study included 244 disks that received discography and 122 disks that did not. Rates of surgery for disk degeneration or herniation after the index surgery were compared in these two groups. RESULTS:Reoperation rates for disk-related pain were not greater among disks that underwent discography versus those that did not (10.2% vs. 8.3% P >0.50). Forward conditional regression analysis found the factor most strongly related to disk-related reoperation was the discogram results (not simply having a discogram). The only other variable significantly related to reoperation was the individual lumbar level. Age, body mass index, sex, or having a discographic injection were not related to subsequent disk-related surgery. Surgery rates for disk-related pathology were similar for disks not receiving discography (8.3%) and those that were discographically normal (5.2%). These were both significantly less than the 18.8% among disks not normal on discography. CONCLUSION:There was no significant difference in disk-related surgery rates based on discographic injection. These findings support that discographic injection does not injure normal disks.

STUDY DESIGN:This was a retrospective study combined with attempted prospective patient contact to collect current data.OBJECTIVE: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.SUMMARY OF BACKGROUND DATA: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.METHODS: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.RESULTS: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.CONCLUSION: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.

Study Design/Setting:Analysis of 24-month postoperative flexion-extension range of motion (ROM) data from 1-level and 2-level clinical trials of cervical disc arthroplasty (CDA). Objective:To investigate the influence of (a) 1-level versus 2-level implantations, and (b) prosthesis design, on the proportions of reconstructed segments that achieved physiological mobility (5-16 degrees). Summary of Background Data:The functional goals of CDA are to restore enough ROM to reduce the risk of accelerated adjacent segment degeneration but also limit excessive motion to obtain a biomechanically stable segment. This motion range is termed "physiological" and is defined as 5-16 degrees based on scientific evidence. Methods:We analyzed 24-month post-CDA flexion-extension (FE) ROM data from investigational device exemption studies of artificial disc prostheses approved for both 1-level and 2-level use (Mobi-C, Prestige LP, and Simplify). Only the Prestige LP and Mobi-C trials had data presenting how many implanted levels yielded postoperative ROM of a given degree, and only these 2 discs are included in this analysis. Eight hundred thirty-five patients participated in the 1-level and 2-level clinical trials. We calculated the proportion of implanted levels with postoperative FE-ROM in the following motion ranges: hypomobile (0-4 degrees), physiological (5-16 degrees), and hypermobile (>= 17 degrees). Results:On average, two-thirds of implanted levels in these clinical trials yielded FE-ROM of 9.5 +/- 3.1 degrees (physiological mobility). Twenty-five percent of the levels moved 2.4 +/- 1.2 degrees (hypomobility), and 9% had ROM of 19.8 +/- 2.9 degrees (hypermobility). Prestige LP disc had significantly fewer patients exhibiting hypermobility at 24 months in both single-level and 2-level cases than the Mobi-C disc (P<0.01). In 2-level Mobi-C constructs, the superior level was where most of that hypermobility occurred. Conclusions:Two-level arthroplasty did not significantly influence the likelihood of achieving post-CDA motion in the physiological range when compared with 1-level CDA (P=0.58). Prosthesis design did influence segmental mobility in both 1-level and 2-level constructs. Surgeons may choose to use a specific implant depending on whether a more- or less-constrained design would be best in a specific clinical situation.

STUDY DESIGN:A retrospective chart review was conducted at a single institution. OBJECTIVE:The purpose of this study was to investigate the clinical outcomes of cervical disc arthroplasty (CDA) used for the treatment of symptomatic adjacent segment disease (ASD) developed after anterior cervical discectomy and fusion (ACDF). BACKGROUND:A major clinical concern following ACDF is the development of ASD. ASD after ACDF is often treated with an additional fusion, but risks include pseudoarthrosis and further ASD. CDA is a motion-preserving alternative that addresses these concerns, and therefore, has been proposed as an alternative treatment for ASD after ACDF. MATERIALS AND METHODS:Patients who underwent CDA at level(s) adjacent to a prior ACDF (n = 120) were identified from a consecutive series of patients who underwent CDA at one institution. Pre-CDA to post-CDA patient-reported outcome measures were compared using the paired Wilcoxon signed-rank test. RESULTS:A total of 142 devices were implanted-98 patients underwent a 1-level CDA, and 22 patients underwent a 2-level CDA. The mean follow-up duration after CDA was 32.11 months. Neck pain, arm pain, and Neck Disability Index scores significantly improved from the preoperative to postoperative time point (respectively: 6.14-3.02, 4.42-1.61, 44.28-28.62, all P < 0.001). In total, 7 patients underwent reoperation (5.83%). One of these patients underwent reoperation for pseudarthrosis at the level of ACDF following a hybrid procedure. The indications for index level reoperations (n = 3) were foraminal stenosis, osteolysis, and postoperative hematoma. All patients with an adjacent level reoperation (n = 3) received surgery at levels adjacent to the prior fusion, not the more recent CDA. CONCLUSION:The results of this study found that CDA was effective for the treatment of ASD following ACDF. CDA appears to be a viable treatment option for ASD after ACDF in appropriately selected patients.

STUDY DESIGN:This was a retrospective study. OBJECTIVE:The purpose of the study was to determine the incidence and reasons of intraoperative conversion from planned cervical total disc replacement (TDR) to anterior cervical discectomy and fusion (ACDF). SUMMARY OF BACKGROUND DATA:TDR currently offers an alternative treatment with results similar or superior to ACDF. Once individual surgeons become comfortable using a device, they will typically expand indications for its use, however, patient safety must remain at the forefront. To reduce reoperations, surgeons must use strict selection criteria to determine which patients are most appropriate to receive TDR. Despite those criteria, situations may arise when surgeons convert from TDR to ACDF intraoperatively. MATERIALS AND METHODS:A comprehensive surgery log was reviewed to identify cases of planned TDR converted intraoperatively to ACDF. All cases were performed at a single institution by 28 attending surgeons beginning with the first case experience in November, 2003 and ending with cases performed in November, 2023. Retrospective chart review was performed to collect demographic data and determine reasons for conversion. RESULTS:During the 20-year period, a total of 2188 consecutive cases of planned TDR were examined. The total number of planned TDR levels was 2939. The rate of intraoperative conversion of TDR to ACDF was 0.55% (12/2188 cases; 95% CI: 0.30%-0.90%). With respect to the number of operated levels, the intraoperative rate of conversion was 0.48% (14/2939 levels; 95% CI: 0.30%-0.80%). CONCLUSION:There was a very low incidence of intraoperative conversion of cervical TDR to ACDF. However, surgeons performing this procedure should be prepared for the possibility of intraoperative conversion from TDR to ACDF and educate patients of this possibility.

BACKGROUND CONTEXT The first Food and Drug Administration (FDA) Investigational Device Exemption (IDE) trial for cervical total disc replacement (TDR) was initiated in May of 2002. Since then, 9 devices have obtained FDA approval. Strengths of IDE trials include well-defined and rigorously applied patient selection criteria and routinely scheduled follow-up visits, which now extent to 10 years or longer. While many studies used different scales and/or instructions to assess pain intensity, all IDE studies used the standardized Neck Disability Index (NDI), providing the unique opportunity to evaluate scores across multiple devices and study durations, as well as comparison to anterior cervical discectomy and fusion (ACDF) control groups. PURPOSE The purpose of this study was to investigate differences in mean NDI scores across time and across cervical TDR devices, with a secondary interest in comparison to ACDF. STUDY DESIGN/SETTING This study was based on a systematic review. PATIENT SAMPLE All patients in the included articles underwent cervical TDR or ACDF at one or two contiguous levels for the treatment of symptomatic disc degeneration with radiculopathy and/or myelopathy enrolled in FDA trials. OUTCOME MEASURES The outcome measure was the mean NDI score at each available follow-up point. METHODS PubMed, Cochrane Library, and ClinicalTrials.gov were searched to identify FDA IDE trials involving cervical TDR with published outcomes. All such studies included the same version of the NDI administered prior to surgery and at each follow-up point, the values for which were recorded. For studies using a propensity-matched ACDF control group generated from data collected from prior TDR trials, only data from the TDR group were included (to avoid representing some of the same patients in the ACDF control groups multiple times). RESULTS NDI data were extracted from 18 studies reporting results of FDA IDE trials involving 10 unique TDR devices with additional 3 trials reporting results for 2-level use. Nine of the trials included a randomized ACDF control group and 4 used a propensity-matched ACDF control group based on data collected from earlier randomized IDE TDR trials. Follow-up duration ranged from 2 to 20 years. Although there were differences in the pre-operative NDI scores between devices, all the TDRs followed the same pattern of statistically significant improvement by 6-week follow-up, with additional improvement between 6 weeks and 3 months and then scores remained stable throughout the study duration (Figure 1). As seen in the figure, there was a high level of consistency in the pattern and maintenance of improvement regardless of the TDR type. Of note, the TDR groups generally had lower NDI scores than the ACDF control groups, reaching statistical significance at some follow-up points in a subset of studies. In none of the studies was there a significant worsening of mean NDI values during long-term follow-up. CONCLUSIONS The multiple trials and long-term follow-up provide unprecedented data for cervical TDR compared with other spine surgery procedures. NDI scores were significantly improved and remained stable during long-term follow-up in patients undergoing cervical TDR. The scores demonstrated a consistent pattern of improvement regardless of TDR device type and scores were generally lower compared to ACDF. Rigorously conducted FDA IDE trials, employing very similar patient selection criteria provided a unique opportunity to examine long-term outcome for a variety of devices. These results suggest that when applying appropriate selection criteria, NDI scores are stable across cervical TDR devices and during long-term follow-up. FDA Device/Drug Status This abstract does not discuss or include any applicable devices or drugs.

BACKGROUND CONTEXT Lumbar total disc replacement (TDR) has been found to be a viable alternative to fusion in appropriately selected patients. In many studies, patients are excluded if they have had prior fusion, and though not generally a formal exclusion criteria, there appears to be reluctance to do TDR in patients with multiple prior discectomies. The concern is that the prior surgery may have created instability of the posterior elements, potentially compromising the safety and/or function of TDR. PURPOSE The purpose of this study was to evaluate outcomes of TDR in patients with symptomatic disc degeneration who have undergone multiple discectomies at the index TDR level(s). STUDY DESIGN/SETTING This was a retrospective study with attempted patient contact to collect current outcome data. PATIENT SAMPLE Records of TDR patients were reviewed and a consecutive series of 112 patients who had multiple previous discectomies at the surgical level were identified. Of the 112 patients (34 females, 78 males) the average age was 42.9+9.6 years, and body mass index (BMI) was 27.9±4.4 kg/m2. OUTCOME MEASURES Outcome assessment included visual analog scales (VAS) separately assessing low back and leg pain, and Oswestry Disability Index (ODI) scores were recorded preoperatively and postoperatively to evaluate changes. Re-operations were also recorded. METHODS Records were reviewed to identify the consecutive series of patients who underwent lumbar TDR for the treatment of multiple recurrent disc herniations at the operated level. Patient descriptive data, VAS, and ODI scores were collected from chart review. For patients not seen recently in the clinic, contact was attempted by mail and/or telephone to collect current data. RESULTS The mean follow-up was 17.1 months. Prior discectomy at the TDR level had been performed twice in 98 (87.5%) patients 3 times in the remaining 14 (12.5%). There was statistically significant improvement in back pain, leg pain, and ODI scores, all p<0.001. The mean scores improved by more than 50% on all 3 measures. Of the 112 surgeries, there were 5 reoperations (4.5%). These included a facet cyst removal at the level above the TDR at 144 months postop, a 2-level decompression for stenosis above the TDR at a remote facility at an unknown timepoint, and 3 due to symptomatic adjacent segment degeneration performed at 16, 29, and 199 months post-TDR. CONCLUSIONS The results of this study found statistically significant improvement in low back and leg pain as well as self-reported disability following TDR in patients with multiple previous discectomies at the same level. Of note, none of the reoperations were performed at the TDR level, indicating no problems with structural integrity related to the motion preserving devices. Patients with multiple prior discectomies merit careful evaluation of the posterior elements prior to TDR to assess for adequate stability to support motion preservation. Provided this is present, the current study supports lumbar TDR is a viable alternative to fusion in these patients. FDA Device/Drug Status This abstract does not discuss or include any applicable devices or drugs.

BACKGROUND CONTEXT One important factor associated with spinal surgery is restoration of spinal sagittal alignment. Lordotic lumbar interbody fusion cages may aid in this restoration through the use of lumbar total disc replacement (TDR) implants, which come in a variety of heights and endplate angles. There is very little information available on the impact of TDR on sagittal alignment. PURPOSE The purpose of this study was to compare pre- to post-TDR sagittal alignment based on full-body imaging. STUDY DESIGN/SETTING Retrospective cohort study. PATIENT SAMPLE The study included a series of 132 patients (mean age 41.1 years; mean BMI 27.7 kg/m2, 69.7% male) who had a full body EOS scan before TDR and at their first post-operative office visit. All patients were treated for symptomatic disc degeneration unresponsive to at least 6 months of nonoperative care. OUTCOME MEASURES Multiple radiographic measurements were made related to spinal alignment including pelvic incidence, sacral slope, pelvic obliquity, coronal balance, spino-sacral angle, thoracic kyphosis, and lumbar lordosis. The disc height and angulation were also measure for each lumbar level. METHODS Data were collected by chart review which included general descriptors and surgery data. Radiographic measurements were completed on SterEOS for both pelvic and postural parameters. Additionally, L1-S1 segmental disc angles and disc heights were measured using PACS applied to the EOS images. RESULTS There were 178 TDR devices implanted, with most operations at 1-level (n=89). There were statistically significant changes in 3 sagittal alignment measurements after TDR surgery: sacral slope, sagittal pelvic tilt, and spino-sacral angle. Both sacral slope and spino-sacral demonstrated an increase while sagittal pelvic tilt decreased. There was a statistically significant increase and decrease in disc angulation of operated levels and nonoperated levels, respectively. There was a statistically significant increase in disc height at the operated level(s) as well as the nonoperated levels, though this was not clinically relevant. CONCLUSIONS The findings demonstrate a significant rotation of the pelvis backwards, increased spino-sacral angulation, and disc space angulation, supporting lumbar TDR’s ability to successfully improve the upright standing position in the sagittal plane. Long-term follow-up will be necessary to determine if these early changes are maintained. FDA Device/Drug Status This abstract does not discuss or include any applicable devices or drugs.

To describe modes of failure of cervical TDR, their related treatment strategies, and to describe a management strategy for the treatment of failed cervical TDR. This retrospective study was based on a consecutive series of 53 cervical TDR patients who underwent removal or revision surgery. Chart review was conducted to collect general descriptive data, reasons for TDR removal/revision, duration from index implantation to re-operation, and the subsequent procedure performed. Among 53 patients, 36 underwent TDR removal and fusion, 16 underwent TDR removal and replacement with another TDR, and one patient’s TDR was revised by repositioning. The mean duration from index surgery to removal/revision was 40.1 months (range: 3 days–222 months). In all cases, removal/revision surgery was completed without complication. The most common reason for removal was severe osteolysis, often involving C. acnes infection, and was primarily associated with one implant type. TDR removal and fusion were performed for subsidence, device migration, treatment of symptoms arising from posterior anatomy (facet joints, etc.), approach-related complications and pain. TDR replacement was feasible for hypermobility, metal allergy, implant locked in kyphosis, and oversized implant use. In one case of TDR malpositioning, the device was successfully revised into appropriate position. After cervical TDR failure, replacing a TDR with another implant can be feasible. Reasons for revision or removal after cervical TDR surgery include biomechanical failure, implant migration, surgeon or technical error, or biological reasons. The type of failure can help the surgeon create a strategy to address these complications.

BACKGROUND CONTEXT As with any spine surgery, there are failures with cervical total disc replacement (TDR). These may generally be classified as surgeon or technical error (including patient selection), biomechanical failure, biological (osteolysis, allergy, etc.) or other reasons. Surgeons performing TDR should be aware of the types of failure leading to the need for subsequent surgery and have a strategy to address these situations. PURPOSE The purpose of this study was to describe modes of failure of cervical TDR and related treatment strategies. STUDY DESIGN/SETTING The study was based on detailed record review. PATIENT SAMPLE This study included a consecutive series of 51 cervical TDR patients who were re-operated on 65 TDR levels during removal or revision surgery. OUTCOME MEASURES The outcome measures were the occurrence of cervical TDR removal/revision, reason for removal/revision, and the treatment strategy. METHODS A surgery log was reviewed to identify patients undergoing cervical TDR removal/revision surgery, including those whose index TDR was implanted at remote facilities. Chart review was conducted to collect general descriptive data, reasons for TDR removal/revision, duration from index implantation to reoperation, and the subsequent procedure performed. RESULTS Among the 51 patients, 36 patients underwent TDR removal and ACDF, 14 patients underwent TDR removal and replacement with another TDR, and one patient underwent repositioning of the index TDR. The mean blood loss was 35.9 ml (range 5-150 ml). The mean duration from the index surgery to removal/revision was 39.6 months (range: 0 to 222 months). In all cases, removal/revision surgery was completed without complication. The most common reason for removal was severe osteolysis (21.6%), often involving C. acnes infection, which was primarily associated with one implant type. TDR removal and fusion were also performed in cases of subsidence, device migration, treatment of symptoms arising from posterior anatomy (facet joints, posterior osteophytes, stenosis, etc.) or approach-related complications and pain. TDR replacement was feasible in cases with hypermobility, metal allergy (after a nonmetallic device became available), and for oversized implant use (provided a smaller implant design was available). In one case of symptoms related to TDR malpositioning, the device was successfully revised into appropriate position. CONCLUSIONS For cases of cervical TDR failure, replacing a TDR with another such implant is feasible in some patients. Reasons for revision or removal after C TDR surgery include biomechanical failure, implant migration, surgeon or technical error, or biological reasons (osteolysis, metal allergy, etc.). The type of failure can help the surgeon create a strategy to address these complications. FDA Device/Drug Status This abstract does not discuss or include any applicable devices or drugs.

BACKGROUND CONTEXT Lumbar discography has been controversial for many years. Some of the controversy has been based on concerns about the needle causing harm to the injected, nonoperated discs. However, other studies suggest discography does not damage discs. Long-term follow-up of injected discs may be helpful to determine if discography was related to development of clinically relevant disc degeneration, evidenced by subsequent surgery. PURPOSE The purpose of this study was to compare rates of disc-related surgery during long-term follow-up in discs that underwent discography vs those that did not. STUDY DESIGN/SETTING This was a retrospective cohort study. PATIENT SAMPLE Study data were collected from 200 patients who had undergone lumbar total disc replacement with minimum 10-year follow-up data available. OUTCOME MEASURES The primary outcome measure was the occurrence of a surgery to treat discogenic pain at a level not included in the index TDR surgery. METHODS Patients were identified from a large-scale retrospective study evaluating lumbar TDR outcomes. Data collected included patient descriptives, discography information, and details of re-operations. For patients not seen recently in the clinic, mailings and telephone calls were conducted trying to collect current follow-up data, including reoperation. Only patients for whom minimum 10-year follow-up data were available were included to better assess the potential development of disc degeneration postdiscography. The mean follow-up was 156.1 months (range: 120 to 254 months). Data were analyzed by individual disc level. A level was included if it was: L3-4, L4-5, L5-S1, or L2-3 that underwent discography or was adjacent to an operated disc. Discs were excluded if they underwent TDR as the index surgery or had previously undergone TDR or interbody fusion. The study included 251 discs that received discographic injection and 124 discs that did not. Rates of surgery for disc degeneration or herniation after the index surgery for these two groups were compared. RESULTS The rate of surgery for disc-related pain was not greater among discs that underwent discography vs those that were not injected (10.8% vs 8.1% p>0.40). Forward conditional binary logistic regression analysis found that the factor most strongly related to subsequent disc-related surgery was the individual lumbar level. Once in the equation the only other variable significantly related to reoperation was the result of the discogram (not simply having a discogram itself). Age, body mass index, sex, or having a discographic injection were not significantly related to subsequent disc-related surgery. Based on the results of the regression analysis, relationships between subsequent surgery and level and discography results were investigated further. Reoperation for disc-related pain was most common at L5-1 (19.6%) and L4-5 (13.6%), regardless of discography performed or not. Rates of surgery for disc-related pathology were similar for discs not receiving discography (8.1%) and those that were normal on discography (6.3%). These were both significantly less than the rate of 18.4% among discs that were not normal on discography (painful upon injection and/or discordant pain, and/or abnormal in appearance on imaging). CONCLUSIONS The results of this study found there was no significant difference in the rates of disc-related surgery among discs that underwent discography vs those that did not, at a minimum follow-up of 10 years. The rate was greater only among discs that were abnormal on discography. These findings support that discographic injection does not injure normal discs. FDA Device/Drug Status This abstract does not discuss or include any applicable devices or drugs.

BACKGROUND CONTEXT Lumbar discography has been controversial for many years. Some of the controversy has been based on concerns about the needle causing harm to the injected, nonoperated discs. However, other studies suggest discography does not damage discs. Long-term follow-up of injected discs may be helpful to determine if discography was related to development of clinically relevant disc degeneration, evidenced by subsequent surgery. PURPOSE The purpose of this study was to compare rates of disc-related surgery during long-term follow-up in discs that underwent discography vs those that did not. STUDY DESIGN/SETTING This was a retrospective cohort study. PATIENT SAMPLE Study data were collected from 200 patients who had undergone lumbar total disc replacement with minimum 10-year follow-up data available. OUTCOME MEASURES The primary outcome measure was the occurrence of a surgery to treat discogenic pain at a level not included in the index TDR surgery. METHODS Patients were identified from a large-scale retrospective study evaluating lumbar TDR outcomes. Data collected included patient descriptives, discography information, and details of reoperations. For patients who had not been seen recently in the clinic, mailings and telephone calls were conducted attempting to collect current follow-up data, including reoperation. Only patients for whom minimum 10-year follow-up data were available were included to better assess the potential development of disc degeneration postdiscography. The mean follow-up was 156.1 months (range 120 to 254 months). Data were analyzed by individual disc level. A level was included if it was: L3-4, L4-5, L5-S1, or L2-3 that underwent discography or was adjacent to an operated disc. Discs were excluded if they underwent TDR as the index surgery or had previously undergone TDR or interbody fusion. The study included 251 discs that received discographic injection and 124 discs that did not. Rates of surgery for disc degeneration or herniation after the index surgery for these two groups were compared. RESULTS The rate of surgery for disc-related pain was not greater among discs that underwent discography vs those that were not injected (10.8% vs 8.1% p>0.40). Forward conditional binary logistic regression analysis found that the factor most strongly related to subsequent disc-related surgery was the individual lumbar level. Once in the equation the only other variable significantly related to reoperation was the result of the discogram (not simply having a discogram itself). Age, body mass index, sex, or having a discographic injection were not significantly related to subsequent disc-related surgery. Based on the results of the regression analysis, relationships between subsequent surgery and level and discography results were investigated further. Reoperation for disc-related pain was most common at L5-1 (19.6%) and L4-5 (13.6%), regardless of discography performed or not. Rates of surgery for disc-related pathology were similar for discs not receiving discography (8.1%) and those that were normal on discography (6.3%). These were both significantly less than the rate of 18.4% among discs that were not normal on discography (painful upon injection and/or discordant pain, and/or abnormal in appearance on imaging). CONCLUSIONS The results of this study found there was no significant difference in the rates of disc-related surgery among discs that underwent discography vs those that did not, at a minimum follow-up of 10 years. The rate was greater only among discs that were abnormal on discography. These findings support that discographic injection does not injure normal discs. FDA Device/Drug Status This abstract does not discuss or include any applicable devices or drugs.

STUDY DESIGN:Retrospective cohort study. OBJECTIVE:The purpose of this study was to investigate the rate of cervical total disc replacement (TDR) device removal or revision. BACKGROUND:Cervical TDR has gained acceptance as an alternative to anterior cervical discectomy and fusion in appropriately selected patients. There have been concerns over device safety, one measure of which is subsequent surgery related to device problems. PATIENTS AND METHODS:A consecutive series of 1626 patients undergoing cervical TDR from 2003 to June 2021 were included, consisting of TDRs up to 3 levels and hybrids (TDR and fusion). TDR removal or revision surgeries and reasons for these surgeries, procedures performed, and duration from index procedure were recorded. Data were analyzed to determine the removal/revision rate and factors possibly related to these events. RESULTS:There were 24 removals/revisions (1.48%) in the 1626 patients. Removal was performed in 23 cases (1.41%) and revision in 1 (0.06%). Among removal cases, anterior cervical discectomy and fusion was performed in 18 and TDR was replaced with another TDR in 5. Removals with fusion included 5 cases of osteolysis with/without Cutibacterium acnes , 4 device displacement/migration, 4 posterior spinal pathology, and one for each of the following: metal allergy, approach-related complications, malpositioning, subsidence, and hypermobility. The revision involved TDR repositioning 3 days after index surgery. There were 66 patients for whom a minimum of 10-year follow-up was confirmed, and none had removal/revision surgery 10 or more years after index surgery. There was no relationship between the occurrence of removal/revision and age, sex, body mass index, or physician experience (learning curve). The removal/revision rate was significantly higher in FDA trials versus postapproval (4.1% vs . 1.3%, P < 0.05). CONCLUSION:In this large consecutive series of patients, 1.48% of cervical TDRs were removed/revised. The low rate of removals/revisions over a long period of time provides support for the devices' safety. LEVEL OF EVIDENCE:Level IV.

BACKGROUND CONTEXT:The functional goals of cervical disc arthroplasty (CDA) are to restore enough range of motion (ROM) to reduce the risk of accelerated adjacent segment degeneration but limit excessive motion to maintain a biomechanically stable index segment. This motion-range is termed the "Physiological mobility range." Clinical studies report postoperative ROM averaged over all study subjects but they do not report what proportion of reconstructed segments yield ROM in the Physiological mobility range following CDA surgery. PURPOSE:To calculate the proportion of reconstructed segments that yield flexion-extension ROM (FE-ROM) in the Physiological mobility range (defined as 5°-16°) by analyzing the 24-month postoperative data reported by clinical trials of various cervical disc prostheses. STUDY DESIGN/SETTING:Analysis of 24-month postoperative FE-ROM data from clinical trials. PATIENT SAMPLE:Data from 1,173 patients from single-level disc replacement clinical trials of 7 cervical disc prostheses. OUTCOME MEASURES:24-month postoperative index-level FE-ROM. METHODS:The FE-ROM histograms reported in Food and Drug Administration-Investigational Device Exemption (FDA-IDE) submissions and available for this analysis were used to calculate the frequencies of implanted levels with postoperative FE-ROM in the following motion-ranges: Hypomobile (0°-4°), Physiological (5°-16°), and Hypermobile (≥17°). The ROM histograms also allowed calculation of the average ROM of implanted segments in each of the 3 motion-ranges. RESULTS:Only 762 of 1,173 patients (implanted levels) yielded 24-month postCDA FE-ROM in the physiological mobility range (5°-16°). The proportions ranged from 60% to 79% across the 7 disc-prostheses, with an average of 65.0%±6.2%. Three-hundred and two (302) of 1,173 implanted levels yielded ROM in the 0°-4° range. The proportions ranged from 15% to 38% with an average of 25.7%±8.9%. One-hundred and nine (109) of 1,173 implanted levels yielded ROM of ≥17° with a range of 2%-21% and an average proportion of 9.3%±7.9%. The prosthesis with built-in stiffness due to its nucleus-annulus design yielded the highest proportion (103/131, 79%) of implanted segments in the physiological mobility range, compared to the cohort average of 65% (p<.01). Sixty-five of the 350 (18.6%) discs implanted with the 2 mobile-core designs in this cohort yielded ROM≥17° as compared to the cohort average of 9.3% (109/1,173) (p<.05). At 2-year postCDA, the "hypomobile" segments moved on average 2.4±1.2°, those in the "physiological-mobility" group moved 9.4±3.2°, and the hypermobile segments moved 19.6±2.6°. CONCLUSIONS:Prosthesis design significantly influenced the likelihood of achieving FE-ROM in the physiological mobility range, while avoiding hypomobility or hypermobility (p<.01). Postoperative ROM averaged over all study subjects provides incomplete information about the prosthesis performance - it does not tell us how many implanted segments achieve physiological mobility and how many end up with hypomobility or hypermobility. We conclude that the proportion of index levels achieving postCDA motions in the physiological mobility range (5°-16°) is a more useful outcome measure for future clinical trials.

BACKGROUND CONTEXT The first lumbar total disc replacement (TDR) was the Charite. There was much enthusiasm for the potential to restore/maintain motion with these devices. In 2010, the Charite was no longer available on the market with speculation this was due to poor outcomes. This later led to suspicion that TDRs were inherently related to poor safety and/or clinical outcomes. PURPOSE The purpose of this study was to investigate the long-term outcome of patients undergoing TDR using the Charite disc. STUDY DESIGN/SETTING This was a retrospective cohort study. PATIENT SAMPLE The study was based on the consecutive series of 556 patients receiving the Charite TDR beginning with the first case experience in 2000. Patients were treated for symptomatic disc degeneration after failure of nonoperative care. OUTCOME MEASURES Outcome measures used were visual analog scales (VAS) separately assessing back and leg pain, Oswestry Disability Index (ODI), and reoperations. METHODS Data were collected from existing records and chart review. For patients not recently seen in clinic, mailings and/or telephone calls were made attempting to collect current outcome data. RESULTS The mean follow-up duration was 108.3 months (median 112.5 months). Current data was collected for 238 patients (mean follow-up 182.2 months), 29 patients were deceased (mean follow-up available from chart review 41.2 months), and 289 were lost to follow-up after multiple attempts to find current contact information and mailings/calls were made for contact or opted not to participate (mean follow-up available from chart review 54.0 months). There was statistically significant improvement from preoperative to the most recent follow-up in VAS back pain scores (7.1 to 3.8; p<0.001), VAS leg pain scores (4.3 to 2.7; p<0.001), and ODI scores (49.0 to 29.9; p<0.001). Mean improvements in these outcome measures were not significantly different when comparing subgroups based on the patients being in the original FDA trial who received the TDR as an investigational device, those who received it serving as a control patient in subsequent TDR trials, or who received the TDR postapproval at one level, two levels, or as part of a hybrid combined with fusion at an adjacent level. The reoperation rate involving the TDR level was 7.6% (involved 42 patients). The mean duration from TDR implantation to reoperation was 46.6 months, with the longest duration of 165 months. Reoperation procedures included 8 cases of TDR removal with fusion performed (1.4%), 22 patients underwent posterior fusion and/or posterior supplemental fixation (4.0%), 8 cases of decompression at the TDR level (1.4%), 1 case of cyst removal (0.2%), and in the remaining 3 patients (0.5%) not enough detail was available to determine reoperation details. Removals/revisions were accomplished without excessive blood loss or complication. CONCLUSIONS This study found that lumbar TDR with the Charite disc produced good outcomes in the long term. The reoperation rate at the TDR implanted level was 7.6%. Although there have been comments made about Charite being removed from the market for a high failure rate, this has not been supported in the current study or others. The device was no longer marketed after the manufacturer was purchased by a company that already had a TDR on the market. FDA Device/Drug Status Charite (Approved for this indication).

Background Context There is little information available on the use of lumbar total disc replacement (TDR) in patients more than 60 years of age. Traditionally there had been concern of the safety of the anterior approach in older patients. Another age-related concern was the safety of these motion preserving devices as patients age versus stabilizing the spine with fusion. Purpose The purpose of this study was to investigate the clinical outcome in patients aged 60 years or older at the time of lumbar TDR surgery and also of those who became over 60 years of age in long-term follow-up. Study Design/Setting This was a retrospective cohort study. Patient Sample Records were reviewed to identify two subsets of patients: 1) those who were ≥60 years of age at the time of TDR surgery, and 2) those who became more than >60 years of age during long-term follow-up. The patients included a consecutive series beginning with the first case experience. Outcome Measures The outcomes measures included visual analog scales (VAS) separately assessing back and leg pain, Oswestry Disability Index (ODI), and reoperation for TDR revision or removal. Methods Charts from a multisite spine specialty clinic were reviewed to collect general descriptive information, surgical data, and outcome data. To collect long-term follow-up for patients who had not been seen recently in the clinic, collection of follow-up data was attempted through mailings and/or telephone calls. Results There were 36 patients who underwent TDR at age 60 or older. An additional 127 patients were younger at the time of TDR and became >60 years of age during long-term follow-up (Table 1). There were statistically significant improvements (all p<.01) in VAS back pain scores and ODI scores in both groups. Mean leg pain scores improved in both groups, but statistically significantly so in the group >60 years of age at long-term follow-up. In the group of patients more than 60 years of age at the time of TDR surgery, there were no cases of TDR removal or revision. In the group of patients who became >60 during long-term follow-up, there were 3 (2.4%) re-operations involving anterior removal or revision surgery. Of note, there were no reoperations performed for fracture of vertebral bodies occurring during long-term follow-up. Conclusions The results of this study found that patients more than 60 years of age had statistically significant improvement in VAS and ODI scores. These results support that TDR can produce good outcomes in older patients without diminution of results with aging. Of note, there were no fractures occurring in long-term follow-up, which was originally a potential concern with these motion preserving implants. Older patients merit more detailed evaluation of possible calcification of vessels anterior to the spine and facet joints. If patients meet indications, they should not be excluded from TDR based only on age. FDA Device/Drug Status This abstract does not discuss or include any applicable devices or drugs.