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BackgroundGiven the increased attention to functional improvement in spine surgery as it relates to activities of daily living and cost, it is critical to fully understand the health care economic impact of enabling technologies. The use of intraoperative neuromonitoring (IOM) during spine surgery has long been controversial. Questions pertaining to utility, medico-legal considerations, and cost-effectiveness continue to be unresolved. The purpose of this study is to determine the cost-effectiveness by assessing quality-of-life due to adverse events averted, decreased postoperative pain, decreased revision rates, and improved patient reported outcomes (PROs).MethodsThe study patient population was extracted from a large multicenter database collected by a single, national IOM provider. Over 50,000 patient charts were abstracted and included in this analysis. The analysis was conducted in accordance with the second panel on cost-effectiveness health and medicine. Health-related utility was derived from questionnaire answers and expressed in quality-adjusted life years (QALYs). Both cost and QALY outcomes were discounted at a yearly rate of 3% to reflect their present value.Cost-effectiveness was calculated as the incremental cost-effectiveness ratio (ICER) for IOM. A value under the commonly accepted United States-based willingness-to-pay (WTP) threshold of $100,000 per QALY was considered cost-effective. Scenario (including litigation), probabilistic (PSA), and threshold sensitivity analyses were conducted to determine model discrimination and calibration.ResultsThe primary time horizon used to estimate cost and health utility was 2-years following index surgery. On average, indexsurgery for patients with IOM costs are approximately $1,547 greater than non-IOM cases. The base case assumed an inpatient Medicare population however multiple outpatient and payer scenarios were assessed in the sensitivity analysis.From a health system perspective IOM is cost-effective, yielding better utilities but at a higher cost than the non-IOM strategy (ICER $60,734 per QALY). From asocietal perspective the IOM strategy was dominant, suggesting that better outcomes were achieved at less cost. Except for an entirely privately insured population, alternative scenarios such as, outpatient and a 50:50 Medicare/privately insured population sample also demonstrated cost-effectiveness. Notably, IOM benefits were unable to overcome the sheer costs associated many litigation scenarios, but the data was severely limited. In the 5,000 iteration PSA, at a WTP of $100,000, 74% of simulations using IOM were cost-effective.ConclusionsThe use of IOM in spine surgery is cost-effective in most scenarios examined. In the emerging and rapidly expanding field of value-based medicine, there will be an increased demand for these analyses, ensuring surgeons are empowered to make the best, most sustainable solutions for their patients and the health care system.

STUDY DESIGN Retrospective Cohort. OBJECTIVE Identify patient variables, injury characteristics, and costs associated with operative and non-operative treatment following inter-facility transfer of patients with isolated cervical spine fractures. SUMMARY OF BACKGROUND DATA Patients with isolated cervical spine fractures are subject to inter-facility transfer for surgical assessment, yet are often treated non-operatively. The American College of Surgeons' benchmark rate of "secondary over-triage" is < 50%. Identifying patient and injury characteristics as well as costs associated with treatment following transfer of patients with isolated cervical spine fractures may help reduce rates of secondary over-triage and healthcare expenditures. METHODS Patients transferred to a Level-1 trauma center with isolated cervical spine fractures between January 2015 and September 2020 were identified. Patient demographics, comorbidities, insurance data, injury characteristics, imaging workup, treatment, and financial data were collected for all patients. Multivariable logistic regression models were constructed to identify patient and injury characteristics associated with surgical treatment. RESULTS Nearly 75% of patients were treated non-operatively. Over 97% of transfers were accepted by the general surgery trauma service. Multivariable modeling found that higher BMI, presence of any neurologic deficit including spinal cord or isolated spinal nerve root injuries, current smoking status, or cervical spine MRI obtained post-transfer, were associated with surgical treatment for isolated cervical spine fractures. Among patients with type II dens fractures, increased fracture displacement was associated with surgical treatment. Median charges to patients treated operatively and non-operatively were $380,890 and $90,734, respectively. Median hospital expenditures for patients treated operatively and non-operatively were $55,115 and $12,131, respectively. CONCLUSION A large proportion of patients with isolated cervical spine fractures are subject to over-triage. Injury characteristics are important for determining need for surgical treatment, and therefore inter-facility transfer. Improving communication with spine surgeons when deciding to transfer patients may significantly reduce healthcare costs and resource use.Level of Evidence: 4.

BackgroundBased on 6-month data from the InVivo Study of Probable Benefit of the Neuro-Spinal Scaffold for Safety and Neurological Recovery in Patients with Complete Thoracic Spinal Cord Injury (INSPIRE) study (NCT02138110), acute implantation of an investigational bioresorbable polymer device (Neuro-Spinal Scaffold [NSS]) appeared to be safe in patients with complete thoracic spinal cord injury (SCI) and was associated with an ASIA Impairment Scale (AIS) conversion rate that exceeded historical controls.ObjectiveTo evaluate outcomes through 24 months postimplantation.MethodsINSPIRE was a prospective, open-label, multicenter, single-arm study. Eligible patients had traumatic nonpenetrating SCI with a visible contusion on MRI, AIS A classification, neurological level of injury at T2-T12, and requirement for open spine surgery ≤96 hours postinjury.ResultsNineteen patients underwent NSS implantation. Three patients had early death determined by investigators to be unrelated to the NSS or its implantation procedure. Seven of 16 evaluable patients (44%) had improvement of ≥1 AIS grade at 6 months (primary end point) to AIS B (n = 5) or AIS C (n = 2). Three patients with AIS B at 6 months had further neurological improvement to AIS C by 12 (n = 2) and 24 (n = 1) months, respectively; none have deteriorated per latest available follow-up. No unanticipated or serious adverse device effects were reported.ConclusionIn this small group of patients with complete thoracic SCI, acute NSS implantation within the spinal cord appeared to be safe with no long-term neurological issues identified during the 24-month follow-up. Patients remain stable, with additional AIS conversions observed in some patients at 12 months and beyond. These data further support the safety and probable benefit of NSS implantation in this patient population.

BackgroundLaminectomy with fusion (LF) and laminoplasty (LP) are common posterior decompression procedures used to treat multilevel degenerative cervical myelopathy (DCM). There is debate on their relative efficacy and safety for treatment of DCM. The goal of this study is to examine outcomes and costs of LF and LP procedures for DCM.MethodsThis is a retrospective review of adult patients (.05). Patients were successfully weaned off opioids at similar rates (LF: 88%, LP: 86%). Fixed and variable costs respectively with LF cases hospital were higher, 15.7% and 25.7% compared to LP cases (p=.03 and p

Acute traumatic spinal cord injury (SCI) can result in severe, lifelong neurological deficits. After SCI, Rho activation contributes to collapse of axonal growth cones, failure of axonal regeneration, and neuronal loss. This randomized, double-blind, placebo-controlled phase 2b/3 study evaluated the efficacy and safety of Rho inhibitor VX-210 (9 mg) in patients after acute traumatic cervical SCI. The study enrolled patients 14-75 years of age with acute traumatic cervical SCIs, C4-C7 (motor level) on each side, and American Spinal Injury Association Impairment Scale (AIS) Grade A or B who had spinal decompression/stabilization surgery commencing within 72 h after injury. Patients were randomized 1:1 with stratification by age (

Summary Background Degenerative cervical myelopathy represents the most common form of non-traumatic spinal cord injury. This trial investigated whether riluzole enhances outcomes in patients undergoing decompression surgery for degenerative cervical myelopathy. Methods This multicentre, double-blind, placebo-controlled, randomised, phase 3 trial was done at 16 university-affiliated centres in Canada and the USA. Patients with moderate-to-severe degenerative cervical myelopathy aged 18–80 years, who had a modified Japanese Orthopaedic Association (mJOA) score of 8–14, were eligible. Patients were randomly assigned (1:1) to receive either oral riluzole (50 mg twice a day for 14 days before surgery and then for 28 days after surgery) or placebo. Randomisation was done using permuted blocks stratified by study site. Patients, physicians, and outcome assessors remained masked to treatment group allocation. The primary endpoint was change in mJOA score from baseline to 6 months in the intention-to-treat (ITT) population, defined as all individuals who underwent randomisation and surgical decompression. Adverse events were analysed in the modified intention-to-treat (mITT) population, defined as all patients who underwent randomisation, including those who did not ultimately undergo surgical decompression. This study is registered with ClinicalTrials.gov , NCT01257828 . Findings From Jan 31, 2012, to May 16, 2017, 408 patients were screened. Of those screened, 300 were eligible (mITT population); 290 patients underwent decompression surgery (ITT population) and received either riluzole (n=141) or placebo (n=149). There was no difference between the riluzole and placebo groups in the primary endpoint of change in mJOA score at 6-month follow-up: 2·45 points (95% CI 2·08 to 2·82 points) versus 2·83 points (2·47 to 3·19), difference −0·38 points (−0·90 to 0·13; p=0·14). The most common adverse events were neck or arm or shoulder pain, arm paraesthesia, dysphagia, and worsening of myelopathy. There were 43 serious adverse events in 33 (22%) of 147 patients in the riluzole group and 34 serious adverse events in 29 (19%) of 153 patients in the placebo group. The most frequent severe adverse events were osteoarthrosis of non-spinal joints, worsening of myelopathy, and wound complications. Interpretation In this trial, adjuvant treatment for 6 weeks perioperatively with riluzole did not improve functional recovery beyond decompressive surgery in patients with moderate-to-severe degenerative cervical myelopathy. Whether riluzole has other benefits in this patient population merits further study. Funding AOSpine North America.

Objective Percutaneous vertebroplasty (VP) and medial branch block (MBB) are used to treat osteoporotic vertebral compression fractures (VCF). We compared the clinical outcomes, radiologic changes, and economic results of MBB with those of VP in treating osteoporotic VCFs. Methods A total of 164 patients with 1-level osteoporotic VCF were reviewed retrospectively. The clinical outcomes were measured with a visual analogue scale (VAS) and the Oswestry Disability Index (ODI). To compare economic costs between groups, total hospital costs at the last follow-up day were calculated. Results The patients were divided into 2 groups: 72 patients in the conservative group treated by MBB (MBB group) and 92 patients in the group who underwent VP (VP group). The VAS and ODI scores improved significantly within postoperative week 1 in the VP group compared with the MBB group. However, the VAS and ODI scores did not differ between the groups after 1 postoperative year. After 2 years of follow-up, 14 new fractures occurred in the VP group and 3 in the MBB group. The improvement in compression ratio was statistically greater in the VP group than in the MBB group. However, after 2 years the radiologic changes between groups did not differ statistically. After the final follow-up visits, the hospital costs were significantly lower in the MBB group. Conclusions After 2 years of follow-up, VP and MBB both had similar efficacy in terms of pain relief and radiologic changes. MBB was more cost effective than VP. Thus, MBB alone can be a possible alternative to VP in patients with 1-level osteoporotic VCFs.

STUDY DESIGN Cost-utility analysis of an annular closure device (ACD) based on data from a prospective, multicenter randomized controlled trial (RCT) OBJECTIVE.: The aim of this study was to determine the cost-effectiveness of a novel ACD in a patient population at high risk for recurrent herniation following discectomy. SUMMARY OF BACKGROUND DATA Lumbar disc herniation patients with annular defect widths ≥6 mm are at high risk for recurrent herniation following limited discectomy. Recurrent herniation is associated with worse clinical outcomes and greater healthcare costs. A novel ACD may reduce the incidence of recurrent herniation and the associated burdens. METHODS A decision analytical modeling approach with a Markov method was used to evaluate the cost-effectiveness of the ACD versus conventional discectomy. Health states were created by projecting visual analogue scale (VAS) onto Oswestry Disability Index (ODI). Direct costs were calculated based on Humana and Medicare 2014 claims to represent private and public payer data, respectively. Indirect costs were calculated for lost work days using 2016 US average annual wages. The incremental cost-effectiveness ratio (ICER) in dollars per quality-adjusted life year (QALY) was compared to willingness-to-pay thresholds. Sensitivity analyses were also conducted. RESULTS Patients with the ACD had less symptomatic reherniations, reoperations, and complications and gained 0.0328 QALYs within the first 2 years. Total direct medical costs for the ACD group were similar to control. When productivity loss was considered, using the ACD became $2076 cheaper, per patient, than conventional discectomy. Based on direct costs alone, the ICER comparing ACD to control equaled $6030 per QALY. When indirect costs are included, the ICER became negative, which indicates that superior quality of life was attained at less cost. CONCLUSION For lumbar disc herniations patients with annular defects ≥6 mm, the ACD was, at 2 years, a highly cost-effective surgical modality compared to conventional lumbar discectomy. LEVEL OF EVIDENCE 1.

Study Design: A nonrandomized, two-armed prospective study. Objective: Water-tight dural closure is paramount to the prevention of cerebrospinal fluid (CSF) leakage and associated complications. Synthetic polyethylene glycol (PEG) hydrogel has been used as an adjunct to sutured dural repair; however, its expansion postoperatively is a concern for neurological complications. A low-swell formulation of PEG sealant was introduced as DuraSeal Exact Spine Sealant System (DESS). A Post-Approval Study was performed primarily to evaluate the safety and efficacy of DESS for spinal dural repair compared to current alternatives, in a large patient population, reflecting a real-world practice. Methods: A total of 36 sites in the United States enrolled 429 patients treated with DESS as an adjunct to dural repair in the spinal sealant group and 406 patients treated with all other modalities in the control arm, from October 2011 to June 2016. The primary endpoint was the incidence of CSF leak within 90 days of operation. The secondary endpoints evaluated were deep surgical site infection and neurological serious adverse events. Results: The CSF leakage in the DESS group (6.6%) was not significantly different from the control group (6.5%) ( p = .83), and there was no significant difference in the time to first leak. The two groups had no significant differences in deep surgical site infection (1.6% versus control 2.1%, p = .61) or proportion of subjects with neurological serious adverse events (2.9% versus control 1.6%, p = .516). Conclusions: DuraSeal Exact Spinal Sealant is safe when compared to current alternatives for spinal dural repair.

Background Short- and mid-term studies have shown the effectiveness of cervical disc arthroplasty (CDA) to treat cervical disc degeneration. Objective To report the 10-yr outcomes of a multicenter experience with cervical arthroplasty for 1- and 2-level pathology. Methods This was a prospective study of patients treated with CDA at 1 or 2 contiguous levels using the Mobi-C® Cervical Disc (Zimmer Biomet). Following completion of the 7-yr Food and Drug Administration postapproval study, follow-up continued to 10 yr for consenting patients at 9 high-enrolling centers. Clinical and radiographic endpoints were collected out to 10 yr. Results At 10 yr, patients continued to have significant improvement over baseline Neck Disability Index (NDI), neck and arm pain, neurologic function, and segmental range of motion (ROM). NDI and pain outcomes at 10 yr were significantly improved from 7 yr. Segmental and global ROM and sagittal alignment also were maintained from 7 to 10 yr. Clinically relevant adjacent segment pathology was not significantly different between 7 and 10 yr. The incidence of motion restricting heterotopic ossification at 10 yr was not significantly different from 7 yr for 1-level (30.7% vs 29.6%) or 2-level (41.7% vs 39.2%) patients. Only 2 subsequent surgeries were reported after 7 yr. Conclusion Our results through 10 yr were comparable to 7-yr outcomes, demonstrating that CDA with Mobi-C continues to be a safe and effective surgical treatment for patients with 1- or 2-level cervical degenerative disc disease.

OBJECTIVE:To evaluate whether anterior cervical spine surgery offers sustained (7 years) relief in patients with cervicogenic headaches (CGHs), and evaluate the difference between cervical disc arthroplasty (CDA) and anterior cervical discectomy and fusion (ACDF) for 1 and 2-level surgeries from a multicenter randomized clinical trial. METHODS:A post hoc analysis was performed of 575 patients who underwent one or 2-level CDA or ACDF for symptomatic cervical spondylosis as part of a prospective randomized clinical trial. Assessment of pain and functional outcome was done with the Neck Disability Index (NDI) in the trial. We used the NDI headache component to assess headache outcome. RESULTS:For both 1- and 2-level CDA and ACDF groups, there was significant headache improvement from preoperative baseline out to 7 years (p < 0.0001). For 1-level surgeries, headache improvement was similar for both groups at the 7-year point. For 2-level treatment, CDA patients had significantly improved headache scores versus ACDF patients at the 7-year point (p = 0.016). CONCLUSION:The headache improvement noted at early follow-up was sustained over the long-term period with ACDF and CDA populations. In the case of 2-level operations, CDA patients demonstrated significantly greater benefit compared to ACDF patients over the long-term. Sinuvertebral nerve irritation at the unco-vasculo-radicular junction and anterior dura may be the cause of CGH. Therefore, it is possible that improved cervical kinematics and preservation of range of motion at adjacent uncovertebral joints in CDA may contribute to the observed difference between the groups.

BACKGROUND CONTEXT PURPOSE Evaluate the safety and efficacy of a single intradiscal injection of STRO-3+ adult allogeneic mesenchymal precursor cells (MPCs) combined with hyaluronic acid (HA) in subjects with chronic low back pain (CLBP) associated with degenerative disc disease (DDD) through 36-month follow-up. STUDY DESIGN/SETTING A multicenter, randomized, controlled study conducted at 13 clinical sites (12 in the United States and 1 in Australia). SUBJECT SAMPLE A total of 100 subjects with chronic low back pain associated with moderate DDD (modified Pfirrmann score of 3–6) at one level from L1 to S1 for at least 6 months and failing 3 months of conservative treatment, including physical therapy were randomized in a 3:3:2:2 ratio to receive 6 million MPCs with HA, 18 million MPCs with HA, HA vehicle control, or saline control (placebo) treatment. OUTCOME MEASURES Subjects were clinically and radiographically evaluated at 1, 3, 6, 12, 24, and 36 months postinjection. Subject-reported outcomes including adverse events, LBP on a Visual Analog Scale (VAS), Oswestry Disability Index (ODI), SF-36 and Work Productivity and Activity Index were collected. METHODS Clinical and radiographic measures were collected at each visit. All randomized subjects were included in the safety assessments and analyzed based on the treatment received. Safety assessments included assessments of AEs, physical and radiographic examinations and laboratory testing. Efficacy assessments evaluated changes in VAS, ODI, and modified Pfirrmann (MP) scores between all active and control groups, respectively. Assessments included least squares mean (Mean), LS mean change from baseline (Mean Change) and responder analyses in order to assess the clinical significance of observed changes from baseline. The population for efficacy assessments was adjusted for the confounding effects of post-treatment interventions (PTIs). This study was conducted under an FDA Investigational New Drug application sponsored and funded by Mesoblast. RESULTS There were significant differences between the control and MPC groups for improvement in VAS and ODI. The PTI-corrected VAS and ODI Means and Mean Change analyses; the proportion of subjects with VAS ≥30% and ≥50% improvement from baseline; absolute VAS score ≤20; and ODI reduction ≥10 and ≥15 points from baseline showed MPC therapy superior to controls at various time points through 36 months. Additionally, the proportion of subjects achieving the minimally important change and clinically significant change composite endpoints for the MPC groups was also superior compared with controls at various time points from baseline to 36 months. There were no significant differences in change in MP score from baseline across the groups. There were also no statistically significant differences in change in modified MP score at the level above or below the level treated between study arms. Both the procedure and treatment were well tolerated and there were no clinical symptoms of immune reaction to allogeneic MPCs. There was a low rate of Treatment Emergent Adverse Events (TEAEs) and Serious Adverse Events, and the rates of these events in the MPC groups were not significantly different from the control groups. One TEAE of severe back pain was possibly related to study agent and one TEAE of implantation site infection was considered to be related to the study procedure. CONCLUSIONS Results provide evidence that intradiscal injection of MPCs could be a safe, effective, durable, and minimally invasive therapy for subjects who have CLBP associated with moderate DDD.

OBJECTIVE:To study risk factors of secondary lumbar discectomy (LD) for recurrent herniated lumbar disc (HLD) and identify methods to lower the rate of recurrence. METHODS:Data from 160 patients who underwent primary LD were collected retrospectively. Demographic features, radiologic findings including Pfirrmann disc degeneration, and surgical information were analyzed to compare risks between revision and non-revision patients. RESULTS:The revision rate was 15% (24 patients), and the mean follow-up was 28.3 months. HLD recurrence was not related to any demographic characteristics. Primary and secondary LD were most common at the L4-5 level, but the level of operation was not significantly associated with revision. Primary LD most commonly had a Pfirrmann disc degeneration grade of 3, followed by 4. For recurrent HLD, Pfirrmann grade 4 was most common and was statistically significant (p

Supplemental Digital Content is Available in the Text., BACKGROUND: The cervical total disc replacement (cTDR) was developed to treat cervical degenerative disc disease while preserving motion. OBJECTIVE: Cost-effectiveness of this intervention was established by looking at 2-year follow-up, and this update reevaluates our analysis over 5 years. METHODS: Data were derived from a randomized trial of 330 patients. Data from the 12-Item Short Form Health Survey were transformed into utilities by using the SF-6D algorithm. Costs were calculated by extracting diagnosis-related group codes and then applying 2014 Medicare reimbursement rates. A Markov model evaluated quality-adjusted life years (QALYs) for both treatment groups. Univariate and multivariate sensitivity analyses were conducted to test the stability of the model. The model adopted both societal and health system perspectives and applied a 3% annual discount rate. RESULTS: The cTDR costs $1687 more than anterior cervical discectomy and fusion (ACDF) over 5 years. In contrast, cTDR had $34 377 less productivity loss compared with ACDF. There was a significant difference in the return-to-work rate (81.6% compared with 65.4% for cTDR and ACDF, respectively; P = .029). From a societal perspective, the incremental cost-effective ratio (ICER) for cTDR was −$165 103 per QALY. From a health system perspective, the ICER for cTDR was $8518 per QALY. In the sensitivity analysis, the ICER for cTDR remained below the US willingness-to-pay threshold of $50 000 per QALY in all scenarios (−$225 816 per QALY to $22 071 per QALY). CONCLUSION: This study is the first to report the comparative cost-effectiveness of cTDR vs ACDF for 2-level degenerative disc disease at 5 years. The authors conclude that, because of the negative ICER, cTDR is the dominant modality. ABBREVIATIONS: ACDF, anterior cervical discectomy and fusion AWP, average wholesale price CE, cost-effectiveness CEA, cost-effectiveness analysis CPT, Current Procedural Terminology cTDR, cervical total disc replacement CUA, cost-utility analysis DDD, degenerative disc disease DRG, diagnosis-related group FDA, US Food and Drug Administration ICER, incremental cost-effectiveness ratio IDE, Investigational Device Exemption NDI, neck disability index QALY, quality-adjusted life years RCT, randomized controlled trial RTW, return-to-work SF-12, 12-Item Short Form Health Survey VAS, visual analog scale WTP, willingness-to-pay

BACKGROUND CONTEXT Degenerative spondylolisthesis (DS) with lumbar spinal stenosis (LSS) is commonly treated with decompression and fusion. The LimiFlex paraspinous tension band (PTB) is an investigational stabilization device for patients with DS and LSS. PURPOSE The purpose of this study is to assess the operative safety and short-term outcomes of decompression and PTB compared to transforaminal lumbar interbody fusion (TLIF) for patients with DS and LSS. STUDY DESIGN/SETTING Multicenter prospective concurrently controlled study. PATIENT SAMPLE Patients undergoing treatment (decompression and PTB or TLIF stabilization) of Grade I Meyerding lumbar degenerative spondylolisthesis. OUTCOME MEASURES Patient demographics, patient reported ODI, VAS leg, and VAS back, and procedural, discharge, and short-term clinical outcomes up to 12 months postoperatively. METHODS Patients with single-level Grade 1 DS with LSS were enrolled in the multicenter, FDA-IDE study comparing decompression with PTB and decompression with TLIF. Perioperative and patient-reported clinical outcomes were recorded at baseline and 6-week, 3-month, 6-month and 12-month follow-up. All patients who reached 12-month follow-up were included in this interim analysis. Summary statistics are reported, as well as paired t-tests to assess within-group changes. RESULTS A total of 93 patients (58 PTB, 35 TLIF) reached 12-month follow-up. Characteristics of PTB vs TLIF groups, respectively were: age 64.9±8.1, 64.1±7.4 yrs; BMI 28.7±4.9, 29.2±5.8; current smokers 2%, 3%. Perioperative outcomes for PTB vs TLIF were: operative time 110±29, 172±58 minutes; EBL 42±26, 241±155 mL; LOS 0.6±1.5, 3.3±1.7 nights. A significant reduction from baseline to 12 months for mean VAS-leg/hip (79.4±10.4 to 19.8±27.5), VAS-back (67.5±22.9 to 17.7±25.1) and ODI (53.1±13.1 to 12.6±16.0) was reported for PTB patients (all p CONCLUSIONS These preliminary results suggest that decompression with PTB stabilization for spondylolisthesis can be accomplished safely without a significant increase in complications during the perioperative and short-term follow-up periods. Similarly, statistically significant improvements in patient-reported outcomes were demonstrated in each group. As groups were not propensity matched, further investigation to include quantitative comparison between groups with long-term follow-up is needed to confirm these results. FDA DEVICE/DRUG STATUS LimiFlex Paraspinous Tension Band (Investigational/Not approved).

Primary spinal glioblastoma multiforme (GBM) of the conus medullaris is a rare and devastating pathologic entity. The presenting symptoms commonly include progressive neurologic deficits in the lower extremities, bowel and bladder dysfunction, and low back pain. Histologically, these tumors have high-grade features similar to their intracranial counterparts. However, recent advancements in the field of molecular oncology have been beginning to elucidate a unique molecular blueprint for these spinal gliomas. Given the lack of standardized treatment strategies, we have presented our institutional experience in treating a small series of patients with conus medullaris GBM and have reviewed the reported data on the relevant molecular markers, management strategies, and complication avoidance for this malignant pathologic entity.

Lumbar discectomy is largely successful surgical procedure; however, reherniation rates in patients with large annular defects are as high as 27%. The expense associated with a revision surgery places significant burden on the healthcare system.To compare the direct health care costs through 5 years follow-up of conventional discectomy (Control) with those of discectomy supplemented by an adjunctive annular closure device (ACD) in high-risk patients with large annular defects.This was a cost-effectiveness study.All-cause index level reoperations were reviewed from a multicenter, randomized controlled superiority trial that allocated 554 high-risk discectomy patients with large annular defects to either control or ACD. Medicare and private insurer (Humana) direct costs were derived from a commercially available payer database to estimate costs in the US healthcare system, including those associated with facility, surgeon, imaging, follow-up visits, physical therapy, and injections. A 50:50 split between Medicare and commercial insurers was assumed for the base case analysis. The analysis was also performed on a 80:20 commercial:Medicare payer basis. For the base case scenario, a 2-year time horizon and outpatient cost setting was established for the index procedure. Repeat discectomy was assumed to be performed on a 60:40 outpatient-to-inpatient basis. Complications requiring surgery, revisions, and/or fusion were assumed to be managed in the inpatient setting. Total costs of reoperation and per-patient costs of reoperation were compared between groups for both forms of insurers. One author received consulting fees of$50,000 for the completion of this study, and the other eight authors did not have any financial associations with the current work. Funding for this study was provided by Intrinsic Therapeutics, but all analyses, interpretation, and writing were performed independently by the authors.At two years follow-up, use of the ACD reduced the rate of symptomatic reherniations in a large defect population to 13% compared with 25% in the control group (p.001). This reduction in symptomatic reherniations in the ACD group translated to a savings of $2,802 per patient in direct health care costs compared with Control at 2 years and $5,315 per patient by 5 years based on 50% private and 50% public (Medicare) payer split. Under the scenario of 80:20 private:public insurance reimbursement, the estimated direct cost savings were $3,215 and $6,099 per patient at 2- and 5-years postoperatively, respectively, with the use of the ACD.Symptomatic reherniation and reoperation rates were nearly double among control patients compared with ACD-treated patients, which translated to markedly greater per-patient healthcare costs in the control group, where the ACD was not used.

Objective The purpose of this study was to determine reference values for the sagittal plane alignment of the thoracolumbar junction (TLJ) in a young adult Korean population. Methods Thoracolumbar computed tomography (CT) scans of 1000 individuals (age range, 20–39 years; 500 men and 500 women) from Hanyang University Health Care Center were reviewed. All subjects had no spinal pathology or a history of previous spinal surgery. The segmental (each level from T11 to L2) and global (T11-L1 and T11-L2) Cobb angles of the TLJ of the spine were measured in midsagittal CT scans. Moreover, comparisons between the 2 age groups (20s and 30s) and sexes were performed. Results The segmental Cobb angles of T11, T12, L1, and L2 were 6.5° ± 3.9°, 5.5° ± 4.1°, 2.2° ± 4.7°, and −3.3° ± 5.3°, respectively. The global Cobb angles of T11-L1 and T11-L2 were 6.5° ± 5.2° and 0.5° ± 6.1°, respectively. There were no differences in the sagittal alignment between the 2 age groups. Women presented less kyphotic and more lordotic alignment in the lumbar spine (L1 and L2) than men; however, the thoracic spine (T11 and T12) alignment was not different between the 2 groups. Conclusions This study provides reference values with a wide physiologic range for the sagittal alignment of the TLJ of the spine in a young adult Korean population.

Study Design Prospective study. Objective Because single-level disk arthroplasty or arthrodesis in the lower subaxial spine improves headaches after surgery, we studied whether this effect may be better appreciated after two-level arthroplasty. Methods We performed an independent post hoc analysis of two concurrent prospective randomized investigational device exemption trials for cervical spondylosis, one for single-level treatment and the other for two adjacent-level treatments. Results For the one-level study, baseline mean headache scores significantly improved at 60 months for both the cervical disk arthroplasty (CDA) and anterior cervical diskectomy and fusion (ACDF) groups ( p Conclusion Both CDA and ACDF at either one or two levels are associated with sustained headache relief from baseline. Patients undergoing two-level arthroplasty had significantly greater improvement in headache at all points except for at 18 and 60 months. This difference in improvement was not observed in patients undergoing single-level arthroplasty. The mechanism of greater headache relief after two-level arthroplasty remains unclear.

STUDY DESIGN Decision analysis from prior randomized controlled trial (RCT) data. OBJECTIVE To describe the importance of developing baseline utility indices while identifying effective treatment options for cervical spine disease. SUMMARY OF BACKGROUND DATA Cervical total disc replacement (CTDR) was developed to treat cervical spondylosis while preserving motion. Although anterior cervical discectomy and fusion (ACDF) has been the standard of care, a recent RCT suggested similar outcomes for 2-level disease. The quality-of-life benefit afforded by both CTDR and ACDF has never been fully elucidated. The purpose of our investigation was to better define the changes in utility and perceived value for patients undergoing these procedures. METHODS Data were derived from LDR's RCT comparing CTDR and ACDF for 2-level cervical disc disease. Using linear regression, we constructed health states on the basis of the stratification of clinical outcomes used in the RCT, namely, neck disability index and visual analogue scale. Data from SF-12 questionnaires, completed preoperatively and at each follow-up visit, were transformed into utilities using the SF-6D mapping algorithm. SAS v.9.3 was used for the analyses. RESULTS A strong correlation (R = 0.6864, P < 0.0001) was found between neck disability index and visual analogue scale. We constructed 5 distinct health states by projecting neck disability index intervals onto visual analogue scale. A poorer health state was associated with a lower mean utility value whereas a higher health state was associated with a higher mean utility value (P < 0.0001). The difference in preoperative utility between 2-level ACDF and CTDR was not significant (P = 0.1982), and yet, the difference in the postoperative utility between the cohorts was significant (P < 0.05) at every time point collected from 6 to 60 months. CONCLUSION This is the first instance in which distinct utility values have been derived for validated health states related to cervical spine disease. There is substantial potential for these to become baseline future indices for cost-utility analyses in similar populations. LEVEL OF EVIDENCE 1.

This was a prospective, randomized, controlled multicenter trial.The purpose of this study was to compare clinical outcomes at 4-year follow-up of patients receiving cervical total disk replacement (TDR) with those receiving anterior cervical discectomy and fusion (ACDF).ACDF has been the traditional treatment for symptomatic disk degeneration. Several studies found single-level TDR to be as safe and effective as ACDF at ≥2 years follow-up.Patients from 23 centers were randomized in a 2:1 ratio with 164 receiving the investigational device (Mobi-C Cervical Disc Prosthesis) and 81 receiving ACDF using an anterior plate and allograft. Patients were evaluated preoperatively and 6 weeks, 3, 6, 12, 18, 24, 36, and 48 months postoperatively. Outcome assessments included a composite success score, Neck Disability Index, visual analog scales assessing neck and arm pain, patient satisfaction, major complications, subsequent surgery, segmental range of motion, and adjacent-segment degeneration.The composite success rate was similar in the 2 groups at 48-month follow-up. Mean Neck Disability Index, visual analog scale, and SF-12 scores were significantly improved in early follow-up in both groups with improvements maintained throughout 48 months. On some measures, TDR had significantly greater improvement during early follow-up. At no follow-up were TDR scores significantly worse than ACDF scores. Subsequent surgery rate was significantly higher for ACDF compared with TDR (9.9% vs. 3.0%, P0.05). Range of motion was maintained with TDR having a mean baseline value of 8 degrees compared with 10 degrees at 48 months. The incidence of adjacent-segment degeneration was significantly higher with ACDF at inferior and superior segments compared with TDR (inferior: 50% vs. 30%, P0.025; superior: 53% vs. 34%, P0.025).Significant improvements were observed in pain and function. TDR patients maintained motion and had significantly lower rates of reoperation and adjacent-segment degeneration compared with ACDF. This study supports the safety and efficacy of TDR in appropriately selected patients.

Prospective, 3:1 randomized, single-blind, multicenter investigational study.To assess the safety and efficacy of a low-swell spinal sealant when used as an adjunct to sutured dural repair compared with standard of care methods to obtain watertight dural closure in subjects undergoing spinal surgery.Watertight dural closure is paramount in spinal surgery to avoid complications of cerebrospinal fluid leak. Prior reports have proven the efficacy of a synthetic, absorbable polyethylene glycol (PEG) hydrogel sealant in spinal surgery compared with standard of care. Given the potential concerns of swelling in spinal applications, the hydrogel was modified to a low-swell formulation.The primary endpoint was success rate in obtaining intraoperative watertight dural closure in subjects receiving PEG hydrogel sealant versus a control group of subjects receiving any standard method designed to provide intraoperative watertight closure. Subjects were evaluated at discharge and at 30 and 90 days postprocedure for cerebrospinal fluid leaks, surgical site infections, and adverse events.Between May 2007 and May 2009, 98 subjects (74 PEG hydrogel spinal sealant, 24 control) were randomized at 14 clinical sites in the United States. Patients treated with the PEG hydrogel spinal sealant had a significantly higher rate of watertight closure than the control (98.6% vs. 79.2%, P = 0.003). No statistical differences were seen in postoperative cerebrospinal fluid, infection, and wound healing. No neurological deficits were seen attributable to the sealant.The low-swell PEG hydrogel spinal sealant evaluated in this study has been proven safe and effective for providing watertight closure when used as an adjunct to sutured closure of intentional durotomies during spinal surgery. PEG hydrogel sealants have again proved superior to other standard of care technologies for safe, efficacious dural closure.2.

Background The surgical treatment of cervical radiculopathy has centered around anterior cervical discectomy and fusion (ACDF). Alternatively, the posterior cervical laminoforaminotomy/microdiscectomy (PCF/PCM), which results in comparable outcomes and is more cost-effective, has been underutilized. Methods Here, we compared the direct/indirect costs, reoperation rates, and outcome for ACDF and PCF vs. PCM using PubMed, Medline, and Embase databases. Results There were no significant differences between the re-operative rates of PCF/PCM (2% to 9.8%) versus ACDF (2% to 8%). Direct costs of ACDF were also significantly higher; the 1-year cost-utility analysis demonstrated that ACDF had $131,951/QALY while PCM had $79,856/QALY. Conclusion PCF/PCM for radiculopathy are safe and more cost-effective vs. ACDF, and have similar clinical outcomes.

Traumatic spinal cord injury (SCI) is associated with a lifetime of disability stemming from loss of motor, sensory, and autonomic functions; these losses, along with increased comorbid sequelae, negatively impact health outcomes and quality of life. Early decompression surgery post-SCI can enhance patient outcomes, but does not directly facilitate neural repair and regeneration. Currently, there are no U.S. Food and Drug Administration–approved pharmacological therapies to augment motor function and functional recovery in individuals with traumatic SCI. After an SCI, the enzyme, Rho, is activated by growth-inhibitory factors and regulates events that culminate in collapse of the neuronal growth cone, failure of axonal regeneration, and, ultimately, failure of motor and functional recovery. Inhibition of Rho activation is a potential treatment for injuries such as traumatic SCI. VX-210, an investigational agent, inhibits Rho. When administered extradurally after decompression (corpectomy or laminectomy) and stabilization surgery in a phase 1/2a study, VX-210 was well tolerated. Here, we describe the design of the SPRING trial, a multicenter, phase 2b/3, randomized, double-blind, placebo-controlled clinical trial to evaluate the efficacy and safety of VX-210 (NCT02669849). A subset of patients with acute traumatic cervical SCI is currently being enrolled in the United States and Canada. Medical, neurological, and functional changes are evaluated at 6 weeks and at 3, 6, and 12 months after VX-210 administration. Efficacy will be assessed by the primary outcome measure, change in upper extremity motor score at 6 months post-treatment, and by secondary outcomes that include question-based and task-based evaluations of functional recovery.

Background context Intraoperative imaging is essential in spinal surgery to both determine the correct level and place implants safely. Surgeons have a variety of options: C-arm fluoroscopy (C-arm), portable X-ray (XR) radiography, and portable cone-beam computed tomography (O-arm). Although these modalities have their respective advantages and disadvantages, direct comparison of radiation exposure to either the patient or the operating room (OR) staff has not been made. Purpose To determine the amount of radiation exposure to patients and OR staff during spine surgery with C-arm, XR, and O-arm. Study design An experimental model to assess radiation exposure to OR staff and phantom patient during spine surgery. Methods A plastic phantom was created to emulate patient volume and absorption scattering characteristics of a typical sized adult abdominal volume. Radiation exposure was measured with ion chamber dosimeters to determine entrance phantom and scatter exposures at common positions occupied by OR staff for C-arm, XR, and O-arm in typical image acquisition during spinal surgery. Results Single lateral (LAT)/posterior-anterior entrance patient radiation exposure for C-arm was on average 116/102 mR, single-exposure XR for LAT/anterior-posterior (AP) was 3,435/2,160 mR, and single-exposure O-arm for LAT/AP was 4,360/5,220 mR. O-arm surface exposure LAT/AP was equivalent to 38/41 C-arm and 1.5/2.4 XR exposures. The surgeon and surgeon assistant had higher levels of scatter radiation for C-arm, followed by O-arm and XR. For the LAT C-arm acquisition, a 7.7-fold increase in radiation exposure was measured on the X-ray tube side compared with the detector side. The anesthesiologist scatter radiation level for a single acquisition was highest for O-arm, followed by XR and C-arm. The radiologic technologist scatter radiation level was highest for XR, followed by O-arm and fluoroscopy. Overall radiation exposure to OR staff was less than 4.4 mR for a single acquisition in all modalities. Conclusions Assessment of radiation risk to the patient and OR staff should be part of the decision for utilization of any specific imaging modality during spinal surgery. This study provides the surgeon with information to better weigh the risks and benefits of each imaging modality.

BACKGROUND CONTEXT Short- and mid-term studies have shown the effectiveness of cervical disc arthroplasty (CDA) to treat cervical disc degeneration. Upon completion of the 7-year Mobi-C FDA study, follow-up continued on a subset of CDA patients in the FDA study. PURPOSE The purpose of this study is to report the 10-year outcomes of a multicenter experience with cervical arthroplasty for 1- and 2-level pathology. STUDY DESIGN/SETTING This was a prospective cohort study of patients treated with cervical disc replacement at one or two contiguous levels using the Mobi-C® Cervical Disc. PATIENT SAMPLE Following completion of the 7-year FDA post approval study, follow-up continued to 10 years for consenting patients at 9 high-enrolling centers. The primary inclusion criteria were cervical degenerative disc at one or two contiguous levels and no prior cervical operations. OUTCOME MEASURES Outcome measures included NDI, VAS neck and arm pain, patient satisfaction, secondary surgical procedures (removals, revisions, reoperations, or additional fixation) and adverse events. Radiographic end points included segmental and global range of motion, sagittal alignment, adjacent level degeneration (ALD) and heterotopic ossification (HO). Radiographic ALD was defined with the Kellgren-Lawrence scale. HO was classified by the system adapted from McAfee and Mehren. Independent radiologists (Medical Metrics, Inc., Houston, TX) conducted radiographic evaluations. METHODS From the original enrollment of 257 CDA patients at 9 sites, 231 patients were eligible for follow-up after 7 years. Ten-year follow-up was obtained from 187 patients (81% follow-up). The longest follow-up was 11.2 years. Radiographs were obtained from 170 patients at 10 years. There were no significant differences in preoperative characteristics between these patients and the original FDA cohort. RESULTS Ten years after CDA, patients continued to show significant improvement from baseline NDI, VAS neck and arm pain, and neurologic function. Outcomes at 10 years were improved from results at 7 years for NDI at one (14.2 vs 18.7; p=0.12) and two levels (15.6 vs 19.7; p=0.02). Comparable results were observed for neck and arm pain. These improvements were less than the MCID for NDI and pain. There were no significant differences in outcomes between 1- and 2-level CDA at 10 years. Segmental flexion-extension range of motion remained significantly higher (p 0.05). The incidence of clinically relevant HO at 10 years was not significantly different from the 7-year incidence for 1-level (30.7% vs 29.6%; p=0.88) or 2-level (41.7% vs 39.2%; p=0.70) CDA patients. Only 2 subsequent surgeries were reported after 7 years. One patient underwent supplemental fixation at the index level 9.5 years after CDA. The other case was ACDF at a nonadjacent level unrelated to the CDA. Total incidence of subsequent surgery after 10 years was 4.7% (12/257) at the index level and 3.5% (9/257) at an adjacent level. CONCLUSIONS At 10-years, both 1- and 2-level CDA demonstrate sustained improvement of NDI, pain scores, range of motion and sagittal alignment compared to baseline. Progression of ALD and HO from 7 to 10 years was minimal. Our results through 10 years demonstrate that CDA with Mobi-C continues to be a safe and effective surgical treatment for patients with 1- or 2-level cervical degenerative disc disease. FDA DEVICE/DRUG STATUS Unavailable from authors at time of publication.

Objective: To evaluate the safety and effectiveness of two-level total disc replacement (TDR) using a Mobi-C(r) Cervical Artificial Disc at the 36 month follow-up. Methods: a Prospective, randomized, controlled, multicenter clinical trial of an artificial cervical disc (Mobi-C(r) Cervical Artificial Disc) was conducted under the Investigational Device Exemptions (IDE) and the U.S. Food & Drug Administration (FDA) regulations. A total of 339 patients with degenerative disc disease were enrolled to receive either two-level treatment with TDR, or a two-level anterior cervical discectomy and fusion (ACDF) as control. The 234 TDR patients and 105 ACDF patients were followed up at regular time points for three years after surgery. Results: At 36 months, both groups demonstrated an improvement in clinical outcome measures and a comparable safety profile. NDI scores, SF-12 PCS scores, patient satisfaction, and overall success indicated greater statistically significant improvement from baseline for the TDR group, in comparison to the ACDF group. The TDR patients experienced lower subsequent surgery rates and a lower rate of adjacent segment degeneration. On average, the TDR patients maintained segmental range of motion through 36 months with no device failure. Conclusion: Results at three-years support TDR as a safe, effective and statistically superior alternative to ACDF for the treatment of degenerative disc disease at two contiguous cervical levels. Objetivo: Avaliar a segurança e a eficácia da artroplastia total de disco (ATD) em dois níveis, usando o disco cervical artificial Mobi-C(r) aos 36 meses de acompanhamento. Métodos: Realizou-se estudo clínico prospectivo, randomizado, controlado e multicêntrico de disco cervical artificial (Mobi-C(r)) regido pelas regulamentações de Investigational Device Exemptions (IDE, isenção do dispositivo em investigação) e da Food & Drug Administration (FDA) dos Estados Unidos. Um total de 339 pacientes com doença degenerativa de disco foi inscrito para receber tratamento com ATD em dois níveis ou discectomia cervical anterior e fusão em dois níveis (DCAF) que constituíram o grupo controle. Os 234 pacientes tratados com ATD e os 105 tratados com DCAF tiveram acompanhamento em pontos do tempo regulares durante três anos após a cirurgia. Resultados: Aos 36 meses, ambos os grupos apresentaram melhora das medidas de desfecho clínico e perfil de segurança comparável. Os escores NDI, SF-12 e PCS, a satisfação dos pacientes e o êxito geral indicaram melhora com maior significância estatística desde o início do estudo no grupo ATD, em comparação com o grupo DCAF. Os pacientes do grupo ATD tiveram percentuais menores de cirurgia subsequente e taxas inferiores de degeneração do segmento adjacente. Em média, os pacientes do grupo ATD mantiveram a amplitude de movimento segmentar nos 36 meses, sem falhas do dispositivo. Conclusão: Os resultados aos três anos corroboram que a ATD é uma alternativa segura, eficaz e estatisticamente superior à DCAF no tratamento de doenças degenerativas de disco em dois níveis cervicais contíguos. Objetivo: Evaluar la seguridad y la eficacia de la artroplastía total de disco (ATD) en dos niveles, usando el disco cervical artificial Mobi-C(r) a los 36 meses de acompañamiento. Métodos: Se realizó estudio clínico prospectivo, aleatorio, controlado y multicéntrico de disco cervical artificial (Mobi-C(r)) regido por las reglamentaciones de Investigational Device Exemptions (IDE, exención del dispositivo en investigación) y de la Food & Drug Administration (FDA) de los Estados Unidos. Un total de 339 pacientes con enfermedad degenerativa de disco fue inscripto para recibir tratamiento con ATD en dos niveles o discectomía cervical anterior y fusión en dos niveles (DCAF) que constituyeron el grupo control. Los 234 pacientes tratados con ATD y los 105 tratados con DCAF tuvieron acompañamiento en puntos de tiempo regulares durante tres años después de la cirugía. Resultados: A los 36 meses, ambos grupos presentaron mejora de las medidas de resultado clínico y perfil de seguridad comparable. Los registros NDI, SF-12 y PCS, la satisfacción de los pacientes y el éxito general indicaron mejora con mayor significado estadístico desde el inicio del estudio en el grupo ATD, en comparación con el grupo DCAF. Los pacientes del grupo ATD tuvieron porcentuales menores de cirugía subsiguiente y tasas inferiores de degeneración del segmento adyacente. Como promedio, los pacientes del grupo ATD mantuvieron la amplitud de movimiento segmentar en los 36 meses, sin fallas del dispositivo. Conclusión: Los resultados a los tres años corroboran que la ATD es una alternativa segura, eficaz y estadísticamente superior a DCAF en el tratamiento de enfermedades degenerativas de disco en dos niveles cervicales contiguos.

To compare radiologic and clinical outcomes, including rates of dysphagia and dysphonia, using a no-profile stand-alone intervertebral spacer with integrated screw fixation versus an anterior cervical plate and spacer construct for single-level anterior cervical discectomy and fusion (ACDF) procedures.This multicenter, randomized, prospective study included 54 patients with degenerative disc disease requiring ACDF at a single level at C3-C7. Twenty-six patients underwent single-level ACDF with stand-alone spacers, and 28 with plate fixation and spacers. Analyses were based on comparison of perioperative outcomes, radiologic and clinical metrics, and incidence of dysphagia and/or dysphonia.Mean patient age was 48.8 ± 10.1years (53.7% female). No significant differences were observed between groups in operative time (101.8 ± 34.4 minutes, 114.4 ± 31.5 minutes), estimated blood loss (44.8 ± 76.5 mL, 82.5 ± 195.1 mL), or length of hospital stay (1.2 ± 0.6 days, 1.3 ± 0.6 days). Mean visual analog scale pain scores and Neck Disability Index scores improved significantly from preoperative to last follow-up (10.8 ± 2.6 months) in both groups (P0.05). Mean Voice Handicap Index and Eating Assessment Tool scores improved significantly from discharge to last follow-up in both groups (P0.05). From discharge to 6 months, the stand-alone spacers group consistently demonstrated greater improvement in Voice Handicap Index. Preoperative intervertebral disc and neuroforaminal heights increased significantly across treatment groups (P0.01), and no cases required surgical revision at index or adjacent levels.Anterior cervical discectomy and fusion with stand-alone spacers resulted in similar clinical and radiologic outcomes as compared with plate and spacers and may help minimize postoperative dysphonia.

Introduction The US Food and Drug Administration allows a previously unapproved device to be used clinically to collect safety and effectiveness data under their Investigational Device Exemption (IDE) category. The process usually falls under 3 different trial categories: noninferiority, equivalency, and superiority. To confidently inform our patients, understanding the basic concepts of these trials is paramount. The purpose of this manuscript was to provide a comprehensive review of these topics using recently published IDE trials and economic analyses of cervical total disc replacement as illustrative examples. Case study mobi-c artificial cervical disc In 2006, an IDE was initiated to study the safety and effectiveness of total disc replacement controlled against the standard of care, anterior cervical discectomy, and fusion. Under the IDE, randomized controlled trials comparing both 1 and 2 level cervical disease were completed. The sponsor designed the initial trial as noninferiority; however, using adaptive methodology, superiority could be claimed in the 2-level investigation. Reviewing healthcare economics Healthcare economics are critical in medical decision making and reimbursement practices. Once both cost- and quality-adjusted life-year (QALY) are known for each patient, the incremental cost-effectiveness ratio is calculated. Willingness-to-pay is controversial, but a commonly cited guideline considers interventions costing below 20 000 $/QALY strongly cost effective and more than 100 000 $/QALY as not cost effective. Conclusion While large Food and Drug Administration IDE studies are often besieged by complex statistical considerations and calculations, it is fundamentally important that clinicians understand at least the terminology and basic concepts on a practical level.

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.

STUDY DESIGN: A prospective, multicenter, randomized, two-arm, single-blind, investigational device exemption pivotal study. OBJECTIVE: To assess the efficacy and the safety of a polyethylene glycol (PEG) hydrogel spinal sealant (DuraSeal Spinal Sealant) as an adjunct to sutured dural repair compared with standard of care methods (control) to obtain a watertight dural closure in patients undergoing an intentional durotomy during spinal surgery. SUMMARY OF BACKGROUND DATA: If a watertight dural closure is not achieved, cerebrospinal fluid leak with associated complications may occur. The PEG hydrogel spinal sealant is an Food and Drug Administration (FDA)-approved adjunct to sutured dural repair in spine surgery. This synthetic, absorbable hydrogel sealant works in the presence of fluid, conforms to irregular surfaces, and demonstrates strong adherence and compliance to tissue, without interfering with underlying tissue visibility. METHODS: A total of 158 patients were treated at 24 centers after they were randomized on the basis of an approximately 2:1 ratio (sealant:control); 102 received the PEG hydrogel spinal sealant and 56 received standard care. The primary end point was intraoperative watertight closure. Secondary end points included evaluations of postoperative cerebrospinal fluid leak, infection, and wound healing. RESULTS: Patients treated with the PEG hydrogel spinal sealant had a significantly higher rate of watertight closure than the control (100% vs. 64.3%, P < 0.001). No statistical differences were seen in postoperative cerebrospinal fluid leak, infection, and wound healing. No neurologic deficits were seen attributable to the sealant. CONCLUSION: The PEG hydrogel spinal sealant evaluated in this study is safe and effective for providing watertight closure when used as an adjunct to sutured dural repair during spinal surgery. This readily available tool is superior to other standard of care technologies commonly used to achieve intraoperative watertight dural closure.

Study Design. Biomechanical study and the review of literature on lumbar interbody fusion constructs. Objective. To demonstrate the comparative stabilizing effects of lateral interbody fusion with various supplemental internal fixation options. Summary of Background Data. Lumbar interbody fusion procedures are regularly performed using anterior, posterior, and more recently, lateral approaches. The biomechanical profile of each is determined by the extent of resection of local supportive structures, implant size and orientation, and the type of supplemental internal fixation used. Methods. Pure moment flexibility testing was performed using a custom-built 6 degree-of-freedom system to apply a moment of 7.5 Nm in each motion plane, while motion segment kinematics were evaluated using an optoelectronic motion system. Constructs tested included the intact spine, stand-alone extreme lateral interbody implant, interbody implant with lateral plate, unilateral and bilateral pedicle screw fixation. These results were evaluated against those from literature-reported biomechanical studies of other lumbar interbody constructs. Results. All conditions demonstrated a statistically significant reduction in range of motion (ROM) as a percentage of intact. In flexion-extension, ROM was 31.6% standalone, 32.5% lateral fixation, and 20.4% and 13.0% unilateral and bilateral pedicle screw fixation, respectively. In lateral bending, the trend was similar with greater reduction with lateral fixation than in flexion-extension; ROM was 32.5% stand-alone, 15.9% lateral fixation, and 21.6% and 14.4% unilateral and bilateral pedicle screw fixation. ROM was greatest in axial rotation; 69.4% stand-alone, 53.4% lateral fixation, and 51.3% and 41.7% unilateral and bilateral pedicle screw fixation, respectively. Conclusion. The extreme lateral interbody construct provided the largest stand-alone reduction in ROM compared with literature-reported ALIF and TLIF constructs. Supplemental bilateral pedicle screw-based fixation provided the overall greatest reduction in ROM, similar among all interbody approach techniques. Lateral fixation and unilateral pedicle screw fixation provided intermediate reductions in ROM. Clinically, surgeons may evaluate these comparative results to choose fixation options commensurate with the stability requirements of individual patients.

BACKGROUND CONTEXT Short- and mid-term studies have demonstrated that cervical disc arthroplasty (CDA) can maintain or restore range of motion and sagittal alignment in select patients with cervical disc degeneration. Upon completion of the 7-year Mobi-C FDA study, follow-up continued out to 10 years on a subset of CDA patients from high-enrolling centers in the FDA study. This is an analysis of the radiographic outcomes of the first 98 CDA patients with 10-years follow-up. PURPOSE The purpose of this study is to present preliminary radiographic outcomes of the first 98 (approximately 50%) patients followed for 10-years in a multicenter study of cervical arthroplasty for one- and two-level pathology. STUDY DESIGN/SETTING This was a prospective cohort study of patients treated with cervical disc replacement at one or two contiguous levels using the Mobi-C Cervical Disc. Following completion of the 7-year FDA post approval study, follow-up was extended to 10 years for consenting patients at seven high-enrolling centers. PATIENT SAMPLE The inclusion criteria for this study was adult patients (>18 years) with radiculopathy or myelopathy and cervical spondylosis at one or two contiguous levels and no prior cervical operations. OUTCOME MEASURES All radiographic evaluations were conducted by independent radiologists (Medical Metrics, Inc., Houston, TX, USA). Radiographic endpoints included segmental and global range of motion, sagittal alignment, adjacent level degeneration (ALD) and heterotopic ossification (HO). The Kellgren-Lawrence scale of disc degeneration was used to define radiographic ALD. HO was classified using the system adapted from McAfee and Mehren. HO grades 3 and 4 were classified as clinically relevant due to restricted ROM. METHODS Ten-year radiographic follow-up was obtained from 98 CDA patients (53 2-level; 45 1-level) at seven centers. All radiological endpoints for the study cohort including HO were evaluated at 10 years, and were compared to the 7-year data for the group using statistical tests that were 2-sided, with p values RESULTS There were no significant differences in demographic factors or preoperative patient-reported outcomes between these patients and the original FDA cohort. Both segmental flexion-extension (FE) and lateral bending (LB) range of motion remained significantly greater (p .05). Global (C2-C6) flexion-extension and sagittal alignment also were maintained from 7 to 10 years (p>.05). Clinically relevant ALD (Grades III-IV) at 10 years was not significantly different from the 7-year incidence for one-level (25.0% vs. 26.2%; p=.47) or 2-level (17.0% vs. 13.7%; p=.16) CDA patients. The incidence of clinically relevant HO at 10 years was not significantly different from the 5-year incidence for one-level (28.9% vs. 33.3%; p=.88) or 2-level (35.8% vs. 26.9%; p=.21) CDA patients. From 7 to 10 years, 94% of patients had no progression of HO. Although patients with Grade 3/4 HO had diminished ROM, range of motion at the affected level(s) remained stable in these patients from 7 years (FE 3.7°; LB 2.7°) to 10 years (FE 3.5°; LB 2.6°). CONCLUSIONS We demonstrate continued maintenance of radiographic performance of cervical arthroplasty out to 10 years. At 10-year follow-up, both one- and two-level arthroplasty demonstrate sustained range of motion and sagittal alignment in comparison to baseline values. Progression of ALD and HO was limited from 7 to 10 years in these patients. Our preliminary results through 10 years demonstrate that total disc arthroplasty with Mobi-C continues to be an effective surgical treatment for patients with one- or two-level cervical degenerative disc disease. FDA DEVICE/DRUG STATUS The Mobi-C is approved for this indication.

Study design Case presentation and literature review. Objective To review the safety of using INFUSE bone graft (recombinant human bone morphogenetic protein-2 applied to an absorbable collagen sponge) in occipitocervical (OC) fusion. Summary of background data Although INFUSE bone graft is currently approved for use in certain tibial fractures, oral maxillary procedures, and anterior lumbar interbody fusion, it has been extensively used "off-label" in posterolateral lumbar and anterior cervical fusions. INFUSE is highly effective in promoting cervical spine fusion via an anterior approach, but its potential role in promoting bony fusion in posterior cervical or OC fixation has not been studied. Methods A 53-year-old woman with basilar invagination underwent OC fixation using INFUSE bone graft. Three days after surgery she experienced neurologic decline associated with significant tissue swelling and a large postoperative seroma under significant pressure. She made excellent recovery after reoperation and drainage. An extensive review of the literature was performed to propose a modified approach to the use of INFUSE in OC fixation. Results Proper dosing and delivery of INFUSE for posterior cervical/OC fixation is not currently known. Previously published experience with anterior cervical fusion suggests that INFUSE can have potent inflammatory effects on paraspinal soft tissue. Conclusion INFUSE should only be used for OC fixation in patients at elevated risk of nonunion. To prevent complications due to soft tissue swelling, consideration should be given to preventing direct exposure of INFUSE to paraspinal musculature, prolonged soft tissue drainage, and prophylactic treatment with perioperative steroid therapy.

Bullet injuries to the spine may cause injury to the anatomical structures with or without neurologic deterioration. Most bullet injuries are acute, resulting from direct injury. However, in rare cases, delayed injury may occur, resulting in claudication. We report a case of intradural bullet at the L3-4 level with radiculopathy in a 30-year-old male. After surgical removal, radicular and claudicating pain were improved significantly, and motor power of the right leg also improved. We report the case of intradural bullet, which resulted in delayed radiculopathy.

Percutaneous epidural neuroplasty (PEN) is a known interventional technique for the management of spinal pain. As with any procedures, PEN is associated with complications ranging from mild to more serious ones. We present a case of intracranial subdural hematoma after PEN requiring surgical evacuation. We review the relevant literature and discuss possible complications of PEN and patholophysiology of intracranial subdural hematoma after PEN.

Background In North America, the largest number of neurosurgical cases stemming from parasitic infections involves the larval form of Taenia solium, the infectious organism causing neurocysticercosis. This infection of the central nervous system (CNS) is most commonly seen in areas with significant immigrant populations and can often present particular challenges to treating physicians. Methods A review of the literature was performed, highlighting the epidemiology, parasitology, and clinical manifestations of neurocysticercosis. Particular attention was paid to 4 locations of neurocysticercosis lesions: parenchymal, subarachnoid/cisternal, intraventricular, and spinal. Results Both medical and surgical interventions may be necessary for adequate treatment of neurocysticercosis, depending on various factors, including location of lesion. Conclusions A review of neurocysticercosis, with particular attention paid to location of disease involvement in the CNS, provides important information to the clinical management of this disease.

Object Although good surgical technique is effective in reducing postoperative epidural fibrosis, compression or tethering of the nerve root may cause recurrent radicular pain and physical impairment. The implantation of a bioresorbable gel on the dura may further decrease the amount of scar formation after surgery and thus improve the patient's ability to perform activities of daily living (ADL). This study is a 12-month evaluation of the safety and effectiveness of Oxiplex/SP Gel (FzioMed, Inc., San Luis Obispo, CA) in the reduction of pain and radiculopathy after lumbar discectomy. Methods A pilot randomized single-blind multicenter clinical trial was conducted to evaluate the performance of Oxiplex/SP Gel in patients who underwent surgery for unilateral herniation of the lumbar disc at L4–5 or L5–S1. Eighteen patients with severe leg pain and lower-extremity weakness (11 women and seven men) were randomly assigned intraoperatively to receive the gel at the conclusion of surgery (treatment group) or to undergo surgery alone (control group). Self-assessment questionnaires (Lumbar Spine Outcomes Questionnaire) to assess pain, symptoms, and ADL were completed preoperatively and at scheduled postoperative intervals (30 days, 90 days, 6 months, and 12 months). The authors examined the spine and lower extremities of patients scheduled for discectomy to assess neurological function and pain. Treated patients received sufficient Oxiplex/SP Gel (1–3 ml) to coat the nerve root and fill the epidural space. Postoperative clinical evaluations were performed at 30 and 90 days. Patients completed the self-assessment questionnaires at baseline and were contacted by telephone or mail for the completion of the postoperative self-assessment questionnaires. Surgical procedures were well tolerated; no device-related adverse events and no clinically significant laboratory results were reported. The 11 patients with severe leg pain and lower-extremity weakness who were treated with Oxiplex/SP Gel had a reduction in those symptoms at 30 days, 90 days, 6 months, and 12 months after discectomy, compared with the seven control patients who underwent surgery only. Conclusions Oxiplex/SP Gel was easy to use and safe in patients who underwent unilateral discectomy. A greater benefit in clinical outcome measures was seen over the 12-month follow-up period in gel-treated patients.

Numerous health care resources are utilized to treat low back pain (LBP) resulting from degenerative disc disease (DDD). Most patients with disc degeneration remain asymptomatic, and the degree of disc degeneration does not correlate with pain severity, making diagnosis and effective treatment challenging.