Treatment of failed cervical total disc replacements in a series of 53 cases and description of a management strategy.

PURPOSE: 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. METHODS: 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. RESULTS: 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. CONCLUSION: 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.

Removals and Revisions of Cervical Total Disc Replacement Devices in a Consecutive Series of 1,626 Patients Beginning with the First Case Experience in 2003.

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. SUMMARY OF BACKGROUND DATA: Cervical TDR has gained acceptance as an alternative to anterior cervical discectomy and fusion (ACDF) in appropriately selected patients. There have been concerns over device safety, one measure of which is subsequent surgery related to device problems. METHODS: A consecutive series of 1,626 cervical TDR patients 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 removal/revision rate and factors possibly related to these events. RESULTS: There were 24 removals/revisions (1.48%) in the 1,626 patients. Removal was performed in 23 cases (1.41%) and revision in 1 (0.06%). Among removal cases, ACDF was performed in 18 and TDR was replaced with another TDR in 5. Removals with fusion included 5 cases of osteolysis with/without C. 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 minimum of 10year follow-up was confirmed, and none had removal/revision surgery 10 or more years after index surgery. There was no relationship between occurrence of removal/revision and age, gender, body mass index, or physician experience (learning curve). The removal/revision rate was significantly higher in FDA trials vs. post-approval (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.

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

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.

Is the Use of Intraoperative Neuromonitoring Justified During Lumbar Anterior Approach Surgery?

BACKGROUND: Intraoperative neuromonitoring (IONM) became widely used in spine surgery to reduce the risk of iatrogenic nerve injury. However, the proliferation of IONM has fallen into question based on effectiveness and costs, with a lack of evidence supporting its benefit for specific spine surgery procedures. The purpose of this study was to evaluate the use of IONM and the rate of neurological injury associated with anterior lumbar spinal surgery. METHODS: This was a retrospective study on a consecutive series of 359 patients undergoing lumbar anterior approach surgery for anterior lumbar interbody fusion (ALIF), total disc replacement (TDR), or hybrid (ALIF with TDR) for the treatment of symptomatic disc degeneration. Patients undergoing any posterior spine surgery were excluded. Operative notes were reviewed to identify any changes in IONM and the surgeon's response. Clinic notes were reviewed up to 3 months postoperatively for indications of iatrogenic nerve injury. RESULTS: There were 3 aberrant results with respect to IONM. Changes in IONM of a lower extremity occurred for 1 patient (0.3%). The surgeon evaluated the situation and there was no observable reason for the IONM change. Upon waking, the patient was found to have no neurological deficit. There were 2 cases of neurologic deficits in this population, which were classified as false-negatives of IONM (0.56%, 95% CI: 0.1% to 1.8%). In both cases, the patients were found to have a foot drop after the anterior approach surgery. CONCLUSION: In this study, there was 1 false-positive and 2 false-negative results of IONM. These data suggest that IONM is not beneficial in this population. However, many surgeons may feel obligated to use IONM for medicolegal reasons. There is a need for future studies to delineate cases in which IONM is beneficial and the type of monitoring to use, if any, for specific spine surgery types. CLINICAL RELEVANCE: This study questions the routine use of IONM in anterior lumbar approach surgery for the treatment of symptomatic disc degeneration. This has significant implications related to the cost of this practice.

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

STUDY DESIGN: This was a retrospective study with prospective patient contact attempted to collect current data. OBJECTIVE: The purpose was to investigate the incidence and reasons for lumbar total disk replacement (TDR) removal or revision. SUMMARY OF BACKGROUND DATA: 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. METHODS: 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. RESULTS: 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. CONCLUSION: 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.

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

PURPOSE: 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. METHODS: 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). RESULTS: 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. CONCLUSION: 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. LEVEL OF EVIDENCE I: Diagnostic: individual cross-sectional studies with the consistently applied reference standard and blinding.

Evaluation of Anterior Lumbar Interbody Fusion Performed Using a Stand-Alone, Integrated Fusion Cage.

BACKGROUND: Anterior lumbar interbody fusion (ALIF) has been performed for many years. Often, posterior supplemental fixation has been used to provide additional stability to the operated segment. Interbody implants have evolved to incorporate unique designs, polyetheretherketone, integrated screws, and surface texture. With these changes, the need for supplemental posterior fixation has been debated. The purpose of this study was to evaluate the clinical outcome of stand-alone ALIF. METHODS: A surgery log was reviewed to identify the consecutive series of 58 patients undergoing ALIF using a STALIF stand-alone cage from March 2011 (first case) to December 2018 (minimum 24 months postoperative) with a mean follow-up of 30.6 months. All patients were treated for symptomatic degenerative conditions. Charts were reviewed to collect general patient information, operative data, and patient-reported outcomes, including the Oswestry Disability Index (ODI), visual analog scales (VAS) separately assessing back pain and leg pain, and re-operations. For patients who were not seen recently in clinic for follow-up, current outcome data were collected through mailings. RESULTS: The mean operative blood loss was 52.1 mL. There was a statistically significant improvement in mean ODI scores from 41.7 preoperatively to 21.0 at follow-up (P < 0.01). There was also significant improvement (P < 0.01) in VAS back pain (6.0-2.5) and leg pain (4.1-1.3). Subsequent surgery was performed on 9 patients. Reasons for re-operation were pseudoarthrosis (n = 3), progressive cage subsidence (n = 1), foraminal stenosis at the index level (n = 1), metal allergy reaction (n = 2), adjacent segment degeneration (n = 1), and ongoing pain (n = 1). There were no cases of device failure, vertebral body fracture, or screws backing out of the implant. DISCUSSION: Stand-alone ALIF was associated with statistically significant improvements in ODI scores, back pain, and leg pain. The re-operation rate for clear pseudoarthrosis or cage subsidence was 6.8%. These results support that stand-alone ALIF produces good outcomes in patients treated for symptomatic disc degeneration while avoiding the use of posterior fixation and its complication risk and cost. CLINICAL RELEVANCE: The results of this study support that stand-alone ALIF is a viable procedure for the treatment of symptomatic disc degeneration unresponsive in patients who have failed nonoperative care and who do not have specific indications for supplemental posterior instrumentation.

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

PURPOSE: 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. METHODS: 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. RESULTS: 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. 41.6 years; 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). CONCLUSION: 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.

Appropriate Telemedicine Utilization in Spine Surgery: Results From a Delphi Study.

STUDY DESIGN: Delphi expert panel consensus. OBJECTIVE: To obtain expert consensus on best practices for appropriate telemedicine utilization in spine surgery. SUMMARY OF BACKGROUND DATA: Several studies have shown high patient satisfaction associated with telemedicine during the COVID-19 peak pandemic period as well as after easing of restrictions. As this technology will most likely continue to be employed, there is a need to define appropriate utilization. METHODS: An expert panel consisting of 27 spine surgeons from various countries was assembled in February 2021. A two-round consensus-based Delphi method was used to generate consensus statements on various aspects of telemedicine (separated as video visits or audio visits) including themes, such as patient location and impact of patient diagnosis, on assessment of new patients. Topics with ≥75% agreement were categorized as having achieved a consensus. RESULTS: The expert panel reviewed a total of 59 statements. Of these, 32 achieved consensus. The panel had consensus that video visits could be utilized regardless of patient location and that video visits are appropriate for evaluating as well as indicating for surgery multiple common spine pathologies, such as lumbar stenosis, lumbar radiculopathy, and cervical radiculopathy. Finally, the panel had consensus that video visits could be appropriate for a variety of visit types including early, midterm, longer term postoperative follow-up, follow-up for imaging review, and follow-up after an intervention (i.e., physical therapy, injection). CONCLUSION: Although telemedicine was initially introduced out of necessity, this technology most likely will remain due to evidence of high patient satisfaction and significant cost savings. This study was able to provide a framework for appropriate telemedicine utilization in spine surgery from a panel of experts. However, several questions remain for future research, such as whether or not an in-person consultation is necessary prior to surgery and which physical exam maneuvers are appropriate for telemedicine.Level of Evidence: 4.

Analysis of re-operations after cervical total disc replacement in a consecutive series of 535 patients receiving the ProDisc-C device.

INTRODUCTION: One important factor in evaluating the safety of an implant is the rate of subsequent surgery and the reasons for surgery, particularly those that are related to possible problems with the implant. The purpose of this study was to determine the overall re-operation rate (including revisions, removals, device-related, procedure-related, adjacent segment, and others) for a large consecutive series of cervical TDR patients beginning with the first case experience, using a single device at a single institution. METHODS: Surgery records were reviewed to identify cervical TDR patients and those who underwent subsequent surgery. Cervical TDR cases involving ProDisc-C were identified, beginning with the first case performed in 2003 at a multisite spine specialty centre. Only patients who were at least 2 years post-operative were included, producing a consecutive series of 535 patients. There were 115 hybrids in the series (TDR at one level and fusion at an adjacent segment). Data collected included general demographics and level(s) operated. A surgery log through 12-31-18 was reviewed to identify re-operations occurring in the TDR patients. For each re-operation, the reason, duration from index surgery, and procedure were recorded. The mean duration from the index surgery to the search of the surgery log for re-operations was 78.3 months, range 24 to 181 months. RESULTS: Re-operation occurred in 30 patients (5.6%). These included: 3 TDR removals and revision to anterior discectomy and fusion (1 for migration, 1 for subsidence, and 1 for spondylosis), 1 TDR repositioning, 21 secondary surgeries for adjacent segment degeneration (5 of which were adjacent to fusion levels in hybrid procedures), 1 wound infection, 1 hematoma, and 2 received stimulators for pain control. There were no re- operations for device failure. In cases of re-operation for adjacent segment degeneration, the mean duration between the index surgery and re-operation was 47.3 months. CONCLUSION: The re-operation rate was 5.6%. No surgeries were performed for device failure. These results support the safety of the TDR device.

In which cases do surgeons specializing in total disc replacement perform fusion in patients with cervical spine symptoms?

PURPOSE: The purpose was to investigate reasons and their frequency for why total disc replacement (TDR) specialty surgeons performed anterior cervical discectomy and fusion (ACDF) rather than TDR. METHODS: A consecutive series of 464 patients undergoing cervical spine surgery during a 5-year period by three TDR specialty surgeons was reviewed. For each ACDF, the reason for not performing TDR was recorded. RESULTS: TDR was performed in 76.7% of patients (n = 356) and ACDF in 23.3% (n = 108). The most common reason for ACDF versus TDR was anatomical (conditions that may not be adequately addressed with TDR and/or may interfere with device function), which occurred in 64 of 464 patients (13.79%). The second most common reason was insurance (denial/lack of coverage n = 17, 3.23%), and deformity/kyphosis not addressable with TDR was noted in 13 (2.80%). Pseudoarthrosis repair led to ACDF in three patients (0.65%), two did not receive TDR due to osteoporosis (0.43%), and in two others (0.43%) ACDF was undertaken due to high risk of heterotopic ossification. There was one case (0.22%) each of: nickel allergy, trauma with posterior element fracture, TDR removal, multiple prior cervical spine surgeries, concern about artifact on future imaging studies, benign osteoblastic bone, and limitation to adequate surgical approach for TDR. ACDF patients' mean age was significantly greater than TDR patients' (55.3 vs. 46.7 years; p < 0.01). TDR group had significantly more single-level procedures than ACDF (60.8% vs. 43.5%; p < 0.05). CONCLUSION: The most common reason for ACDF versus TDR was anatomy that may compromise segmental stability and/or TDR functionality. Older age and greater number of operated levels may be related to anatomical factors, primarily significant osteophytes and severely degenerated facets. These factors, as well as deformity/kyphosis, are more common in older patients and require multi-level treatment. This study found that many patients are good cervical TDR candidates; however, even among TDR specialists, ACDF may be preferred where it is prudent to not take undue risks. These slides can be retrieved under Electronic Supplementary Material.

Progression of Adjacent-level Degeneration After Lumbar Total Disc Replacement: Results of a Post-hoc Analysis of Patients With Available Radiographs From a Prospective Study With 5-year Follow-up.

STUDY DESIGN: Post-hoc analysis of 5-year follow-up data from a randomized, multicenter trial. OBJECTIVE: The aim of this study was to investigate the incidence of progression in radiographic adjacent-level degeneration (ΔALD) from preoperative assessment to 5 years after total disc replacement (TDR) and the relationship of these changes with range of motion and clinical adjacent-level disease. A secondary objective was to compare adjacent-level degeneration (ALD) outcomes between TDR and fusion. SUMMARY OF BACKGROUND DATA: Fusion is associated with high rates of ALD in symptomatic lumbar disc degeneration. TDR may reduce this risk. METHODS: In total, 175 patients with single-level, symptomatic, lumbar disc degeneration who had received activL or ProDisc-L and had a preoperative and 5-year postoperative radiograph available were included. Over 5-year follow-up, ΔALD was defined as an increase in ALD of ≥1 grade and clinical ALD was defined as surgical treatment at the level adjacent to an index TDR. Matching-adjusted indirect comparisons were conducted to compare ALD outcomes after TDR (current trial) with those after fusion (published trial). RESULTS: At 5-year follow-up, 9.7% (17/175) of TDR patients had ΔALD at the superior level. In patients with preoperative ALD at the superior level, most (88% [23/26]) showed no radiographic progression over 5 years. The rate of clinical ALD was 2.3% (4/175) and none of these patients had ALD at baseline. For each degree of range of motion gained at the TDR level, there was a consistent decrease in the percentage of patients with ΔALD. After matching and adjustment of baseline characteristics, TDR had a significantly lower likelihood of ΔALD than fusion (odds ratio 0.32; 95% confidence interval 0.13, 0.76). CONCLUSION: The rates of ΔALD and clinical ALD in this TDR population were similar to those previously reported in the literature for TDR at 5-year follow-up. TDR had a significantly lower rate of ΔALD than fusion. LEVEL OF EVIDENCE: 3.

Interspinous Process Decompression: Expanding Treatment Options for Lumbar Spinal Stenosis.

Interspinous process decompression is a minimally invasive implantation procedure employing a stand-alone interspinous spacer that functions as an extension blocker to prevent compression of neural elements without direct surgical removal of tissue adjacent to the nerves. The Superion® spacer is the only FDA approved stand-alone device available in the US. It is also the only spacer approved by the CMS to be implanted in an ambulatory surgery center. We computed the within-group effect sizes from the Superion IDE trial and compared them to results extrapolated from two randomized trials of decompressive laminectomy. For the ODI, effect sizes were all very large (>1.0) for Superion and laminectomy at 2, 3, and 4 years. For ZCQ, the 2-year Superion symptom severity (1.26) and physical function (1.29) domains were very large; laminectomy effect sizes were very large (1.07) for symptom severity and large for physical function (0.80). Current projections indicate a marked increase in the number of patients with spinal stenosis. Consequently, there remains a keen interest in minimally invasive treatment options that delay or obviate the need for invasive surgical procedures, such as decompressive laminectomy or fusion. Stand-alone interspinous spacers may fill a currently unmet treatment gap in the continuum of care and help to reduce the burden of this chronic degenerative condition on the health care system.

Reoperations in cervical total disc replacement compared with anterior cervical fusion: results compiled from multiple prospective food and drug administration investigational device exemption trials conducted at a single site.

STUDY DESIGN: This study is based on a post hoc analysis of data collected from multiple prospective, randomized studies conducted at the same site. OBJECTIVE: The purpose of this study was to compare the reoperation rates in patients with cervical total disc replacement (TDR) versus patients with anterior cervical fusion (ACF). SUMMARY OF BACKGROUND DATA: One important evaluation of any new technology is the safety, including the need for future surgery. One of the potential benefits of cervical TDR compared with ACF, is the possibility of reducing or eliminating degeneration of the adjacent segment. It is also important to determine if the new technology introduces new problems, not seen with the current standard of care. METHODS: Data were collected prospectively for patients enrolled in 1 of 6 Food and Drug Administration regulated investigational device exemption trials conducted at a single site. Results are based on 136 patients (84 TDR, 52 ACF) with mean follow-up of 55.1 months (range, 24-98 mo). Data collected included general demographics, operative details, length of follow-up, the occurrence of a reoperation, the reason for the reoperation, length of time between the index study procedure and reoperation. For this study, reoperation was defined as any surgical procedure involving the cervical spine. The reoperation rates as well as the length of time after the index surgery the reoperation occurred were compared for the TDR and ACF groups. RESULTS: The reoperation rate in the TDR group was significantly less than in the ACF group (8.3% vs. 21.2%; P < 0.05). There was a trend for the reoperation rate attributed to adjacent segment degeneration to be significantly less in the TDR group than in the ACF group (4.8% vs. 13.5%; 0.05

Analysis of adjacent segment reoperation after lumbar total disc replacement.

BACKGROUND: Fusion has long been used for treating chronic back pain unresponsive to nonoperative care. However, potential development of adjacent segment degeneration resulting in reoperation is a concern. Total disc replacement (TDR) has been proposed as a method for addressing back pain and preventing or reducing adjacent segment degeneration. The purpose of the study was to determine the reoperation rate at the segment adjacent to a level implanted with a lumbar TDR and to analyze the pre-TDR condition of the adjacent segment. METHODS: This study was based on a retrospective review of charts and radiographs from a consecutive series of 1000 TDR patients to identify those who underwent reoperation because of adjacent segment degeneration. Some of the patients were part of randomized studies comparing TDR with fusion. Adjacent segment reoperation data were also collected from 67 patients who were randomized to fusion in those studies. The condition of the adjacent segment before the index surgery was compared with its condition before reoperation based on radiographs, magnetic resonance imaging (MRI), and computed tomography. RESULTS: Of the 1000 TDR patients, 20 (2.0%) underwent reoperation. The mean length of time from arthroplasty to reoperation was 28.3 months (range, 0.5-85 months). Of the adjacent segments evaluated on preoperative MRI, 38.8% were normal, 38.8% were moderately diseased, and 22.2% were classified as having severe degeneration. None of these levels had a different grading at the time of reoperation compared with the pre-TDR MRI study. Reoperation for adjacent segment degeneration was performed in 4.5% of the fusion patients. CONCLUSIONS: The 2.0% rate of adjacent segment degeneration resulting in reoperation in this study is similar to the 2.0% to 2.8% range in other studies and lower than the published rates of 7% to 18% after lumbar fusion. By carefully assessing the presence of pre-existing degenerative changes before performing arthroplasty, this rate may be reduced even more.

Oxiplex reduces leg pain, back pain, and associated symptoms after lumbar discectomy.

STUDY DESIGN: Prospective, randomized, blinded clinical trial. OBJECTIVE: To evaluate effectiveness of Oxiplex gel for reduction of pain and associated symptoms after lumbar discectomy. SUMMARY OF BACKGROUND DATA: Oxiplex gel (carboxymethylcellulose, polyethylene oxide, and calcium) is used during discectomy to coat the surgical site for reduction of pain and symptoms after lumbar discectomy. METHODS: Patients undergoing single-level lumbar discectomy performed by laminectomy or laminotomy and randomized to receive either surgery plus Oxiplex gel (treatment group) or surgery alone (control group) were assessed 6 months after surgery using (1) a quality of life questionnaire (Lumbar Spine Outcomes Questionnaire [LSOQ]) and (2) clinical evaluations. RESULTS: There were no statistically significant differences in baseline demographics, surgical procedures, LSOQ scores, and clinical evaluations between treatment (N = 177) and control (N = 175) groups. More gel-treated patients were satisfied with outcome of their surgical treatment than control patients (P = 0.05). The gel-treated group showed greater reductions in pain and symptoms from baseline compared with surgery-only controls. Additional benefits of gel were consistently shown in reduction of leg and back pain at 6 months in the patient population having substantial back pain at baseline (greater than or equal to the median LSOQ pain score of 63). In that population, there was a statistically significant reduction of leg pain and back pain (P < 0.01) in the treatment group compared with controls. Fewer patients in the treatment group had abnormal musculoskeletal physical examinations at 6 months compared with controls. There were no cases of cerebrospinal fluid leaks and no differences in laboratory values or vital signs. Patients in the treatment group had less hypoesthesia, paraesthesia, sensory loss, and fewer reoperations during the 6-month follow-up than controls (1 vs. 6). CONCLUSION: These data demonstrate improvements in clinical outcomes resulting from the use of Oxiplex gel in discectomy procedures for treatment of lumbar disc herniation.

Prospective, randomized, multicenter Food and Drug Administration investigational device exemption study of lumbar total disc replacement with the CHARITE artificial disc versus lumbar fusion: five-year follow-up.

BACKGROUND CONTEXT: The CHARITE artificial disc, a lumbar spinal arthroplasty device, was approved by the United States Food and Drug Administration in 2004 based on two-year safety and effectiveness data from a multicenter, prospective, randomized investigational device exemption (IDE) study. No long-term, randomized, prospective study on the CHARITE disc or any other artificial disc has been published to date. PURPOSE: The purpose of this study was to compare the safety and effectiveness at the five-year follow-up time point of lumbar total disc replacement using the CHARITE artificial disc (DePuy Spine, Raynham, MA) with that of anterior lumbar interbody fusion (ALIF) with BAK cages and iliac crest autograft, for the treatment of single-level degenerative disc disease from L4 to S1, unresponsive to nonoperative treatment. STUDY DESIGN/SETTING: Randomized controlled trial-five-year follow-up. PATIENT SAMPLE: Ninety CHARITE patients and 43 BAK patients. OUTCOME MEASURES: Self-reported measures: visual analog scale (VAS); validated Oswestry disability index (ODI version 1.0); Short-Form 36 Questionnaire, and patient satisfaction. Physiologic measures: radiographic range of motion, disc height, and segmental translation. Functional measures: work status. METHODS: Of the 375 subjects enrolled in the CHARITE IDE trial, 277 were eligible for the five-year study and 160 patients thereof completed the five-year follow-up. The completers included 133 randomized patients. Overall success was defined as improvement> or =15 pts in ODI vs. baseline, no device failure, absence of major complications, and maintenance or improvement of neurological status. Additional clinical outcomes included an ODI questionnaire as well as VAS, SF-36, and patient satisfaction surveys. Work status was tracked for all patients. Safety assessments included occurrence and severity of adverse events and device failures. Radiographic analyses such as index- and adjacent-level range of motion, segmental translation, disc height, and longitudinal ossification were also carried out. RESULTS: Overall success was 57.8% in the CHARITE group vs. 51.2% in the BAK group (Blackwelder's test: p=0.0359, Delta=0.10). In addition, mean changes from baseline for ODI (CHARITE: -24.0 pts vs. BAK: -27.5 pts), VAS pain scores (CHARITE: -38.7 vs. BAK: -40.0), and SF-36 questionnaires (SF-36 Physical Component Scores [PCS]: CHARITE: 12.6 pts vs. BAK: 12.3 pts) were similar across groups. In patient satisfaction surveys, 78% of CHARITE patients were satisfied vs. 72% of BAK patients. A total of 65.6% patients in the CHARITE group vs. 46.5% patients in the BAK group were employed full-time. This difference was statistically significant (p=0.0403). Long-term disability was recorded for 8.0% of CHARITE patients and 20.9% of BAK patients, a difference that was also statistically significant (p=0.0441). Additional index-level surgery was performed in 7.7% of CHARITE patients and 16.3% of BAK patients. Radiographic findings included operative and adjacent-level range of motion (ROM), intervertebral disc height and segmental translation. At the five-year follow-up, the mean ROM at the index level was 6.0 degrees for CHARITE patients and 1.0 degrees for BAK patients. Changes in disc height were also similar for both CHARITE and BAK patients (0.7 mm for both groups, p=0.9827). Segmental translation was 0.4 and 0.8mm in patients implanted with CHARITE at L4-L5 vs. L5-S1, respectively, and 0.1mm in BAK patients. CONCLUSIONS: The results of this five-year, prospective, randomized multicenter study are consistent with the two-year reports of noninferiority of CHARITE artificial disc vs. ALIF with BAK and iliac crest autograft. No statistical differences were found in clinical outcomes between groups. In addition, CHARITE patients reached a statistically greater rate of part- and full-time employment and a statistically lower rate of long-term disability, compared with BAK patients. Radiographically, the ROMs at index- and adjacent levels were not statistically different from those observed at two-years postsurgery.

Relationship between the length of time off work preoperatively and clinical outcome at 24-month follow-up in patients undergoing total disc replacement or fusion.

BACKGROUND CONTEXT: A recent study involving interbody fusion patients found that preoperative work status was significantly related to clinical outcome. In another study comparing the best and worst outcomes of total disc replacement, among a battery of variables analyzed, the only one that differentiated the best and worst outcome groups was the length of time off work before total disc replacement. PURPOSE: The purpose of this study was to determine if there was a relationship between the length of time off work and treatment outcome at 24-month follow-up. If such a relationship existed, a secondary study objective would be to determine if a duration of work could be identified beyond which would be associated with compromised clinical outcome. STUDY DESIGN AND SETTING: Data were collected prospectively from randomized clinical trials comparing total disc replacement with lumbar fusion conducted at a single site. PATIENT SAMPLE: A database of 232 patients enrolled in one of two Food and Drug Administration-regulated trials comparing total disc replacement with fusion for the treatment of symptomatic disc degeneration was the basis of the study group. Only patients who had reached 24-month follow-up were included. The 28 patients who were not employed by choice preoperatively were not included in the analysis. OUTCOME MEASURES: Primary outcome measures used were visual analog scales (VAS) assessing pain and Oswestry disability index. METHODS: The length of time off work before surgery was recorded in weeks. The mean percentage improvement between preoperative and 24-month follow-up scores were analyzed. RESULTS: There was a significant relationship between duration off work preoperatively and clinical outcome (p<.05). The length of time off work preoperatively was more strongly related to outcome than was surgery type, insurance type, job demand, or preoperative VAS and Oswestry scores. Further analysis of the data identified a window of approximately 0 to 13 weeks off work preoperatively that was related to significantly greater improvements on visual analog scales (VAS) and Oswestry scores after surgery compared with patients who were off work for more than 13 weeks preoperatively. Although the subgroup off work for more than 13 weeks improved significantly from their preoperative status, the improvement was not as great as in the subgroup off work for a shorter duration. CONCLUSIONS: The results of this study found that patients off work for a longer duration before surgery improved significantly postoperatively, but had less favorable clinical outcomes than patients off work for a lesser duration. This study suggests a window of approximately 13 weeks off work before surgery after which clinical improvement is reduced. Implications of this finding may be that once a patient becomes unable to work for an extended period, more rigorous psychological screening may be in order as well as perhaps engaging in more rigorous rehabilitation after surgery. Further investigation is needed to determine if the 13 weeks identified in this study is applicable to other populations.