Symptomatic Disc Research Articles

11. Clinical outcome of a prospective, controlled, multicenter study evaluating two-level cervical arthroplasty with a PEEK-on-ceramic artificial disc

<h3>BACKGROUND CONTEXT</h3> Over the past two decades, there has been increasing use of cervical total disc replacement (cTDR) with designs and materials continually evolving. Nine devices have been FDA approved for 1-level use, and the current study led to the approval of a third device for two levels. <h3>PURPOSE</h3> The purpose of this study was to evaluate the safety and efficacy of a PEEK-on-ceramic artificial disc for the treatment of 2-level cervical disc disease. <h3>STUDY DESIGN/SETTING</h3> This was a prospective, non-randomized, historically controlled multicenter FDA Investigational Device Exemption (IDE) trial evaluating the Simplify®Cervical Artificial Disc (NuVasive, Inc). The anterior cervical discectomy and fusion (ACDF) control group was derived from a propensity score matched (using subclassification) cohort of patients who participated in an earlier prospective cTDR trial using similar indications. <h3>PATIENT SAMPLE</h3> The cTDR group (n=182) was compared with ACDF patients (n=170). All patients had 2-level, symptomatic cervical disc disease with radiculopathy and/or myelopathy. <h3>OUTCOME MEASURES</h3> The primary outcome measure was classification of success at 24-month follow-up based on 4 criteria (1) at least 15-point (of 100) improvement in Neck Disability Index (NDI) scores; (2) maintenance or improvement in neurological status; (3) no serious adverse event classified as implant associated or implant/surgical procedure associated; and (4) no additional index level surgery. Secondary evaluations included NDI scores, numeric rating scales assessing neck and arm pain intensity and frequency, and patient satisfaction. Safety was assessed by adverse events and subsequent surgery at an index level. <h3>METHODS</h3> Patients were evaluated preoperatively, at hospital discharge, 6 weeks, and 3, 6, 12, and 24 months after surgery. <h3>RESULTS</h3> The overall composite success rate was statistically significantly greater in the cTDR group compared with the ACDF group (86.7% vs 77.1%; p 15 points at 24-mo follow-up) occurred in 92.9% of the cTDR group and 83.5% of the ACDF group (0.05 < p < 0.10). Mean NDI scores improved significantly in both groups by 6 weeks with cTDR scores significantly lower at 6 weeks and 3 and 6 months. Mean NDI scores in the cTDR group were 58.6 preoperatively and 14.3 at 24 months. In the ACDF group, the values were 53.6 and 17.2, respectively. In both groups, neck and arm pain improved significantly (p <0.05) by 6 weeks with improvement maintained throughout follow-up. In the cTDR group, the mean preop neck pain intensity score was 7.9 and 1.8 at 24 months. In the ACDF group, the values were 7.7 and 2.5, respectively. Improvement in arm pain followed a similar pattern with a preoperative mean value of 7.5 in the cTDR group which improved to 1.8 at 24 months. In the ACDF group, the values were 7.0 and 1.6. The ACDF scores were not superior to those in the cTDR group on any of the outcome measures. There were four subsequent surgical interventions (2.2%) in the cTDR group and 15 (8.8%) in the ACDF group. <h3>CONCLUSIONS</h3> The cTDR group had a statistically significantly greater overall clinical success rate compared to ACDF as well as similar to superior scores on the NDI and pain scales at all follow-up points. These results add to the growing body of literature supporting cervical arthroplasty for treating 2-level cervical disc disease with radiculopathy and/or myelopathy. <h3>FDA DEVICE/DRUG STATUS</h3> Simplify Cervical Artificial Disc: 2-level (Approved for this indication).

P64. Intradiscal injection of autologous bone marrow aspirate concentrate improves low back pain at one year

<h3>BACKGROUND CONTEXT</h3> Chronic low back pain is one of the leading causes of disability and poor quality of life in the US and worldwide. A common cause of chronic low back pain is degenerative disc disease. Current nonsurgical treatments for degenerative disc disease-associated low back pain are typically effective. However, for patients who fail these treatments, surgical fusion is often used as last line treatment. Surgical treatment is associated with higher health care expenditures and a more invasive procedure. As such, there is growing interest in the field of regenerative medicine and stem cell therapy as a less invasive treatment for low back pain. <h3>PURPOSE</h3> The purpose of this study was to investigate the effect of autologous bone marrow aspirate concentrate (BMAC) on patients with symptomatic lumbar degenereative disc disease at one year. <h3>STUDY DESIGN/SETTING</h3> Single institution prospective cohort study. <h3>PATIENT SAMPLE</h3> A total of 32 adult patients. <h3>OUTCOME MEASURES</h3> Mean ODI, EQ-5D-5L, VAS back pain, and VAS leg pain scores. <h3>METHODS</h3> A total of 32 consecutive patients over the age of 18 years diagnosed with discogenic low back pain clinically or by discography who underwent injection of autologous intradiscal BMAC at a single multi surgeon orthopedic spine center were included in this study. Active smokers and patients who had pain generators other than purely discogenic pain were excluded. For primary analysis, patients completed baseline and 1 year post-injection ODI, VAS back, VAS leg, and EQ-5D-5L questionnaires; their scores were compared over time. Preprocedural lumbar MRIs were reviewed for Modic changes and assigned a Pfirrmann grade. Thirteen postprocedural MRIs were available and reviewed using the same parameters. <h3>RESULTS</h3> Thirty-two patients (56.3% male) with a mean age of 45.9 (range 19-65) underwent BMAC injection between 1 and 6 levels completed 1 year follow up. Mean VAS back and leg scores improved from 54.0 to 30.4 (p < 0.001) and 27.9 to 13.3 (p=0.005), respectively. Mean ODI scores decreased from 33.5 to 21.1 (p < 0.001), and EQ-5D-5L scores improved from 0.69 to 0.78 (p=0.001). Using established minimum clinically important difference values, 59.4% of patients saw a clinically significant improvement in VAS back pain, 43.8% in VAS leg pain, and 56.3% in ODI scores. On pre-procedural MRIs, 62.5% of patients had a Modic score of 1 or 2 and 93.8% had a Pfirrmann grade of 3 or higher. Postprocedural MRIs were available for 13 patients, and 61.5% had no measurable change in Pfirrmann grade. Three patients worsened by one Pfirrmann grade and one improved by 1 grade. <h3>CONCLUSIONS</h3> Intradiscal injection of autologous BMAC was shown to significantly improve pain and quality of life at one year. Additionally, this study meets 88% of recently published AAOS reporting standards for studies relating to mesenchymal stem cells. The results of this study suggest that intradiscal injection of autologous BMAC has the potential to be an effective non-surgical treatment for chronic discogenic low back pain. <h3>FDA DEVICE/DRUG STATUS</h3> This abstract does not discuss or include any applicable devices or drugs.

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)

47. Economic consequences of waiting for lumbar disc herniation surgery

<h3>BACKGROUND CONTEXT</h3> Despite the well-established benefits of lumbar discectomy, many patients wait for their surgery which delays their return to work and potentially increases health care costs. The economic repercussions of such delays have not been well studied. <h3>PURPOSE</h3> This study aims to provide meaningful comparisons of costs to decisions-makers who plan health care services. The main goal of this study was to quantify the cost differences in terms of direct and indirect costs of early surgery for symptomatic disc herniation compared to late surgery. In other words, this study aimed to unveil what is the cost of being on a surgical waitlist for a lumbar discectomy. Secondarily, we report PROS and compared the proportions of patients reaching meaningful patient reported outcomes (PROs) between early and late surgery. <h3>STUDY DESIGN/SETTING</h3> This is a retrospective analysis of prospectively collected data from the CSORN registry. <h3>PATIENT SAMPLE</h3> Comparisons were made between patients receiving surgery less than 60 days after consent (short wait) and 60 days or more after consent (long wait). <h3>OUTCOME MEASURES</h3> The Ontario Health Insurance Plan (OHIP) claims history database was used for direct costs estimates. Canada Income Statistics and the human capital method were used to calculate indirect costs. The primary outcome was defined as the cost difference between short wait and long wait groups to determine the overall cost of waiting for surgery. <h3>METHODS</h3> Continuous data are summarized using means and standard deviations, compared using Student's t-tests. Categorical data are expressed as numbers and percentages, compared using chi-square tests. The minimum clinically important difference (MCID) was defined as 30% improvement in NRS leg and NRS back from baseline to 3 months. The proportion of patients reaching MCID was compared between patients who returned to work at 3 months or not and between short- and long-wait groups. PROs at 3 months were adjusted for baseline score. A p-value <0.05 was considered statistically significant. Analyses were performed with IBM SPSS for Windows release 28. <h3>RESULTS</h3> A total of 493 patients were included in this study with 272 patients (55.2%) in the short-wait group and 221 patients (44.8%) in the long-wait group. Demographics were similar between the two groups. The proportions of patients who returned to work at 3 months and 12 months postoperatively were similar (p <0.596; p <0.798). Time from surgery to return to work was similar between both groups (34.0 vs 34.9 days, p<0.804). Inherently, the longer wait group had significantly longer time from consent to return to work. This extended wait corresponded to an additional $11,753.10 indirect cost due to productivity loss while waiting for surgery. The short-wait group showed increased health care usage with patients more commonly visiting the emergency department (52.6% vs 25.0%, p <0.032), using physiotherapy (84.6% vs 72.0%, p <0.001) and receiving MRI (65.2% vs 41.4%, p <0.043). This corresponded to an additional direct cost of $518.21 per patient. The short wait group had higher baseline NPR leg, ODI, EQ5D, PCS and MCS. A higher proportion of patients reached MCID in terms of NRS leg pain at 3-month follow-up in the short wait group (84.0% vs 75.9%, p <0.040). <h3>CONCLUSIONS</h3> Early surgery is associated with cost saving of $11,234.89 per patient when compared to late surgery for lumbar disc herniation. The higher health care utilization in patients receiving early surgery is counterbalanced by the additional productivity loss of the long waiters. From a societal economic perspective, early surgery seems beneficial and should be promoted. <h3>FDA DEVICE/DRUG STATUS</h3> This abstract does not discuss or include any applicable devices or drugs.

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)

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

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

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

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. 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. 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. 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. 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.

Prospective Multicenter Trial of Cervical Arthroplasty with the ROTAIO® Cervical Disc Prosthesis.

Clinical observational study. The ROTAIO® cervical disc prosthesis is a novel unconstrained implant with a variable center of rotation aiming at physiological motion. The objective of this multicenter prospective trial was to evaluate clinical outcome and complications within 2years. 120 patients (72 females and 48 males with median age of 43.0years [23-60yrs] underwent ACDA (ROTAIO®, SIGNUS Medical, Alzenau, Germany) and were prospectively followed for 24 months. Preoperative complaints were mainly associated with radiculopathy (n = 104) or myelopathy (n=16). There were 108 monosegmental and 12 bisegmental procedures including 6 hybrid constructs. Clinical outcome was evaluated at 3, 12 and 24months in 100%, 96% and 77% of the cohort by VAS, NDI, WL-26, Patient`s Satisfaction Index (PSI), SF-36, Nurick Score, mJOA, Composite Success Rate, complications, patient`s overall satisfaction and analgesics use. Highly significant clinical improvements were observed according to NDI and VAS (P < .0001 (arm); P < .001 (neck); P = .002 (head)) at all time points. Analgetic use could be reduced in 87.1 to 95.2%. Doctor`s visits have been reduced in 93.8% after 24months. Patient`s overall satisfaction was high with 78.4 to 83.5% of patients. The composite success rate was 77.5% after 12months and 76.9% after 24months. There were no major complications in this series. Slight subsidence of the prosthesis was observed in 2 patients and 3 patients demonstrated fusion after 24months. 2 patients developed symptomatic foraminal stenosis, so that implant removal and fusion was performed resulting in a revision rate of 1.7% in 2years. The ROTAIO® cervical disc prosthesis is a safe and efficient treatment option for symptomatic degenerative disc disease demonstrating highly significant clinical improvement and high patient`s overall satisfaction with very low revision rates at 2years.

Full Endoscopic Thoracic Discectomy: Is the Interlaminar Approach an Alternative to the Transforaminal Approach? A Technical Note.

Various approaches are used for decompressive surgeries in the thoracic spine depending on the location and consistency of the pathology, always avoiding manipulation of the thoracic spinal cord. Recently, there has been an effort to achieve adequate results and reduce morbidity with minimally invasive surgeries. Good outcomes and the advantages of full endoscopic spine surgery (FESS) have been proven for surgerical correction of herniated discs and stenoses in the lumbar and cervical spine. Similar evidence has recently been described for the thoracic spine, but it has not previously been reported in Brazil. Although the transforaminal approach is already established for the thoracic spine, the newly described interlaminar approach is equally efficient, and both techniques must be considered when treating thoracic spine diseases. The objective of the present article was to present the full endoscopic interlaminar and transforaminal techniques in patients with symptomatic disc herniation of the thoracic spine, discuss the rationality for implementing FESS in thoracic spine, and discuss the rationality in choosing between both approaches. Two patients were submitted to thoracic FESS. A transforaminal approach was chosen for a T10-T11 foraminal disc herniation; an interlaminar approach was selected for a paramedian T7-T8 disc extrusion. Data regarding operating time, intraoperative images, hospital stay, visual analog scales before and after FESS, course of recovery, and surgery satisfaction were evaluated. The patients had eventless surgeries, improved from preoperative pain without morbidity. Both were satisfied and recovered well. Hospital stay was less than 6 hours after surgery. Transforaminal and interlaminar FESS for thoracic disc herniation are safe, efficient, and minimally invasive alternatives. Despite being an innovative technique with evident advantages, it should be carefully considered along with conventional technique for the treatment of thoracic spine diseases, since its clinical relevance is yet to be determined.

Patient with Lumbar Spondylosis and Diskogenic Pain

Diskogenic low back pain (LBP), defined as pain that originates from a damaged vertebral disk, is a common cause of LBP. It is characterized by a three-phase cascade of degeneration marked by dysfunction, instability, and stabilization. A distinct pathologic characteristic of the disks from patients with diskogenic LBP has been found to be the formation of the zones of vascularized granulation tissue, with extensive innervation extending from the outer layer of the annulus fibrosus into the nucleus pulposus along a torn fissure. In addition, there appears to be an association between microbial infection and symptomatic disk degeneration. Low-virulence microorganisms, in particular Propionibacterium acnes, might be causing a chronic low-grade infection in the lower intervertebral disks in some patients. The diagnosis of diskogenic pain is primarily based on clinical manifestations, physical examinations, imaging studies, and provocative diskography. Diskogenic pain should be differentiated from other axial back pain conditions, such as facet arthropathy, sacroiliac joint pain, myofascial strain and pain, vertebral compression fracture, and other, less common conditions. Treatment options should be tailored to individual needs. Early and gradual physical and behavioral therapies are encouraged. Pharmacologic therapy, composed primarily of analgesics, nonsteroidal antiinflammatory drugs, muscle relaxants, and antidepressants, may have modest positive effects. A subset of patients with Modic type I changes in magnetic resonance imaging may benefit antibiotic therapy directed at the infected disks by P. acnes and other low-virulence microorganisms. There is evidence that supports the use of epidural steroid injections and intradiskal injections (methylene blue, ozone, steroids) for diskogenic pain. Additional options include intradiskal biacuplasty, gray ramus communicans nerve blocks/radiofrequency ablation, and intradiskal stem cell injections for disk repair/regeneration, all of which have gained support in clinical trials. These treatment modalities have shown promise to provide equal or even better outcomes compared with surgical spinal fusion or total disk replacement with an artificial disk. This review contains 2 figures and 149 references. Keywords: collagen, diskogenic low back pain (LBP), herniation, intervertebral disk, spondylosis

Provocative Discography: Diagnostic Efficacy and Safety in Symptomatic Degenerative Disk Disease.

This was a retrospective cohort analysis. The objective of this study was to report the efficacy and safety profile of provocative discography. It is reported that the provocative discogram as a diagnostic test for symptomatic degenerative disk disease induces disk degeneration. Discogram cases from 1998 to 2011 were identified. A matched control group with no discogram was identified. Both had pre-magnetic resonance imaging (MRI) and post-MRI with 5 years minimum between MRI studies. Statistics were generated by group for each level and for all levels combined. The discogram cohort comprised 53 patients (193 disks). The control group had 51 subjects (255 disks). There were no significant demographic differences between the groups. Time intervals between the index and follow-up MRI were 11 and 8 years for the discogram and control groups, respectively. The most common injected level was L4-L5; the most painful level was L5-S1 (Visual Analog Scale=7.9); the most concordant level was L5-S1 (75%). The most deranged level as seen on discography was L5-S1 (98%). Degeneration from normal to abnormal MRI among discogram patients was 60%. For controls, the rate was 33%. The discogram and control cohorts were statistically different (P<0.01). Among discogram patients, 58% had a fusion surgery between MRI studies. Comparing the discogram group without interval fusion to controls, the degeneration rate was not different at a 5 years' minimum follow-up. The L5-S1 intervertebral disk level was the most painful, concordant, and deranged level as seen on discogram. Patients who underwent a provocative discogram and interval fusion had a higher rate of subsequent degeneration than similar low back pain sufferers with no discogram. Degeneration rates were comparable at 5 years' minimum follow-up between discogram patients without interval spine fusion and patients without discogram exposure. The provocative discogram did not accelerate degeneration among these patients.

ProDisc-C versus anterior cervical discectomy and fusion for the surgical treatment of symptomatic cervical disc disease: two-year outcomes of Asian prospective randomized controlled multicentre study.

Our study aimed to evaluate non-inferiority of ProDisc-C to anterior cervical discectomy and fusion (ACDF) in terms of clinical outcomes and incidence of adjacent segment disease (ASD) at 24-months post-surgery in Asian patients with symptomatic cervical disc disease (SCDD). This multicentre, prospective, randomized controlled trial was initiated after ethics committee approval at nine centres (China/Hong Kong/Korea/Singapore/Taiwan). Patients with single-level SCDD involving C3-C7-vertebral segments were randomized (2:1) into: group-A treated with ProDisc-C and group-B with ACDF. Assessments were conducted at baseline, 6-weeks, 3/6/12/18/24-months post-surgery and annually thereafter till 84-months. Primary endpoint was overall success at 24-months, defined as composite of: (1) ≥ 20% improvement in neck disability index (NDI); (2) maintained/improved neurologic parameters; (3) no implant removal/revision/re-operation at index level; and (4) no adverse/severe/life-threatening events. Of 120 patients (80ProDisc-C,40ACDF), 76 and 37 were treated as per protocol (PP). Overall success (PP) was 76.5% in group-A and 81.8% in group-B at 24-months (p = 0.12), indicating no clear non-inferiority of ProDisc-C to ACDF. Secondary outcomes improved for both groups with no significant inter-group differences. Occurrence of ASD was higher in group-B with no significant between-group differences. Range of motion (ROM) was sustained with ProDisc-C but lost with ACDF at 24-months. Cervical TDR with ProDisc-C is feasible, safe, and effective for treatment of SCDD in Asians. No clear non-inferiority was demonstrated between ProDisc-C and ACDF. However, patients treated with ProDisc-C demonstrated significant improvement in NDI, neurologic success, pain scores, and 36-item-short-form survey, along with ROM preservation at 24-months. Enrolment difficulties resulted in inability to achieve pre-planned sample size to prove non-inferiority. Future Asian-focused, large-scale studies are needed to establish unbiased efficacy of ProDisc-C to ACDF.

Catastrophic delayed cervical arthroplasty failure: illustrative case.

BACKGROUNDCervical disc replacement (CDR) is an increasingly used alternative to fusion for symptomatic cervical disc disease. While more studies have suggested favorability of CDR over fusion procedures, limited data exist regarding implant fatigability. Here, the authors present a unique and previously unreported failure of the M6-C prosthesis causing spinal cord injury.OBSERVATIONSA 49-year-old female with history of cervical degenerative disease and prior C4–7 M6-C arthroplasty presented 9 years later after a minor fall from standing. She endorsed bilateral hand numbness ascending to forearms and shoulders, with dysesthesias and weakness. Imaging showed fractured arthroplasty penetrating the spinal cord. Revision surgery found a ruptured arthroplasty annulus with metal piece piercing the spinal cord. Partial C4 and C5 corpectomy was performed to remove the integrated fins of the arthroplasty and inspect the cord and dura. This was reconstructed with a corpectomy cage and plate. The patient made an excellent recovery, with improvement in her weakness and resolution of her sensory symptoms.LESSONSPossibility of fatigue-related failures presenting years after implantation have only been infrequently reported but can be catastrophic for patients. The authors encourage further discussions in this area, increased counseling with patients, and recommend a patient registry to better document adverse events.

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

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

448 Revision Rate and Long-Term Outcome After Minimally Invasive Surgical Treatment of Lumbar Adjacent Segment Disease: A Retrospective Review of 176 Adjacent Level Reoperations

INTRODUCTION: The concept of accelerated degeneration at the level adjacent to a fused spinal segment is a well-known and studied phenomenon. Most current surgical paradigms address this with extension of fusion. However, decompression with laminectomy and/or discectomy, particularly with MIS approaches, are viable options. METHODS: A single-center retrospective review of consecutive cases from 2013-2020 was performed. All patients who underwent lumbar surgery for ASD were included. The primary outcome was need for revision surgery following either a decompression, microdiscectomy, or instrumented fusion for lumbar ASD. Multivariable regression analysis (chi-square and ANOVA) was performed on demographic, operative, and follow-up data. RESULTS: We identified 176 patients who underwent surgery for lumbar ASD with mean follow-up of 9.3 years. 129 patients were treated with fusion, 37 with laminectomy, and 10 with microdiscectomy. In total, 41 patients required revision surgery following their ASD operation: 28 (21.7%) after fusion, 10 (27%) after laminectomy, and 3 (30%) after microdiscectomy (p = 0.697). Symptomatic disc herniation manifested sooner requiring reoperation -- on average 43.8 months (p = 0.006) after index procedure. CONCLUSION: There was no significant difference in revision rate among patients undergoing extension of fusion, laminectomy, or discectomy in the treatment of lumbar ASD. Focal adjacent stenosis or disc herniation can be durably treated with MIS laminectomy or discectomy, respectively. Accelerated disc degeneration after discectomy for lumbar ASD may require a subsequent fusion. Lumbar ASD associated with mobile spondylolisthesis should be treated by extension of fusion.

Single-stage C6-7 ACDF with T1-2 Oblique Keyhole Transcorporeal Disectomy to Treat Cervico-thoracic Tandem Disc Herniation: A Case Report

Symptomatic cervico-thoracic tandem disc herniation occurs very rarely. On the other hand, cervical disc herniations are common and may be treated via a variety of surgical procedures. Symptomatic upper thoracic disc herniations are extremely rare, and use of a surgical approach in their treatment is controversial due to the narrow operative space within which surgical procedures must be performed. We report an extremely rare case of symptomatic tandem C6-7 and T1-2 disc herniation successfully treated via single-stage, single-incision, C6-7 anterior cervical decompression and fusion, and T1-2 oblique keyhole transcorporeal discectomy. This is the first symptomatic cervico-thoracic tandem disc herniation with its treatment.

Current Knowledge and Future Therapeutic Prospects in Symptomatic Intervertebral Disc Degeneration.

Intervertebral disc (IVD) degeneration is the main source of intractable lower back pain, and symptomatic IVD degeneration could be due to different degeneration mechanisms. In this article, we describe the molecular basis of symptomatic IVD degenerative disc diseases (DDDs), emphasizing the role of degeneration, inflammation, angiogenesis, and extracellular matrix (ECM) regulation during this process. In symptomatic DDD, pro-inflammatory mediators modulate catabolic reactions, resulting in changes in ECM homeostasis and, finally, neural/vascular ingrowth-related chronic intractable discogenic pain. In ECM homeostasis, anabolic protein-regulating genes show reduced expression and changes in ECM production, while matrix metalloproteinase gene expression increases and results in aggressive ECM degradation. The resultant loss of normal IVD viscoelasticity and a concomitant change in ECM composition are key mechanisms in DDDs. During inflammation, a macrophage-related cascade is represented by the secretion of high levels of pro-inflammatory cytokines, which induce inflammation. Aberrant angiogenesis is considered a key initiative pathologic step in symptomatic DDD. In reflection of angiogenesis, vascular endothelial growth factor expression is regulated by hypoxia-inducible factor-1 in the hypoxic conditions of IVDs. Furthermore, IVD cells undergoing degeneration potentially enhance neovascularization by secreting large amounts of angiogenic cytokines, which penetrate the IVD from the outer annulus fibrosus, extending deep into the outer part of the nucleus pulposus. Based on current knowledge, a multi-disciplinary approach is needed in all aspects of spinal research, starting from basic research to clinical applications, as this will provide information regarding treatments for DDDs and discogenic pain.

Association between vitamin D receptor gene polymorphism (rs731236) and aggrecan gene VNTR polymorphism with the risk of lumbar intervertebral disc degeneration.

Background:Low back pain is one of the most common causes of referral to physicians. Lumbar disc degeneration (LDD) is the main cause of back pain in different countries. It seems that genetic factors are more effective than environmental factors in the developing of degenerative phenomena. The aim of this investigation, therefore, was to study the association of the aggrecan gene (ACAN) variable number tandem repeat (VNTR) and the vitamin D receptor (VDR) rs731236 (TaqI) polymorphisms, with lumbar intervertebral disc degeneration in a population in the North of Iran.Methods:In this study, 55 patients with symptomatic intervertebral disk degeneration and 55 control subjects were included. VDR gene polymorphism was genotyped by PCR-based RFLP. The isolated DNA was used to genotype the VNTR of ACAN gene via conventional PCR.Results:For VDR gene polymorphism, the CC genotype (OR=5.337, P=0.019) was significantly higher among the patients compared with the controls, revealing a higher frequency of the C allele in patients compared with controls (OR=2.707, P=0.005). The lower number of frequent repetitions in the VNTR aggrecan gene was associated with a six-time increase of lumbar disc degeneration. Also, high BMI can be considered as an independent factor in the incidence of this disease.Conclusion:Aggrecan gene VNTR polymorphism had an association with degeneration of lumbar intervertebral discs that the shorter VNTR repeats increasing the chance of the disc degeneration in this population in the North of Iran. Moreover, an association between the mutant allele (C) of VDR gene TaqI polymorphism and disc degeneration is found.

Surgical treatment of herniated thoracic discs using transthoracic extrapleural approach

To analyze the results of herniated thoracic disc resection via transthoracic extrapleural approach. The study included 16 patients with 18 symptomatic herniated thoracic discs wo underwent transthoracic extrapleural surgery. In 11 cases, clinical pattern of disease was represented by myelopathy with radicular or axial pain syndrome. Five patients had radiculopathy alone. Median localization of hernias was observed in 8 (44.4%) cases, paramedian hernias - in 10 (55.6%) cases. There were 10 (55.6%) ossified hernias, 5 (27.7%) giant, 10 (55.5%) large and 3 (16.6%) medium hernias. In most patients, VAS score of pain syndrome decreased by 2-6 points (mean 3.6). In 4 patients, this value remained the same. Among 11 patients with myelopathy, regression of conduction disorders in 1 year after surgery was achieved in 9 (82%) cases including complete recovery in 6 (55%) patients (Frankel E, Nurick - 0-I). In 2 patients, neurological status was equal to preoperative one. In all cases, the follow-up examination confirmed total removal of compressive substrate and found no signs of spine instability. Surgery time varied from 80 to 210 min (mean 161), blood loss - from 300 to 800 ml (mean 378 ml). Two patients had transient neurological deterioration. There was damage to dura mater in 4 cases. Intercostal neuralgia was observed in 3 patients. While retaining the advantages of open thoracotomy, transthoracic extrapleural approach is less traumatic, allows complete spinal cord decompression, minimizes the risk of iatrogenic spinal cord injury and avoids certain postoperative complications.

A prospective randomized controlled multicentre study of prodisc- C versus anterior cervical discectomy and fusion for the surgical treatment of symptomatic cervical disc disease in Asian population: A four-year outcome

A prospective randomized controlled multicentre study of prodisc- C versus anterior cervical discectomy and fusion for the surgical treatment of symptomatic cervical disc disease in Asian population: A four-year outcome