Search

Objective: Recombinant human bone morphogenetic protein-2 (rhBMP-2) has been demonstrated to achieve the highest rates of arthrodesis in multilevel lumbar fusion but is also associated with possible perioperative morbidity. A novel allograft (OSTEOAMP) is a differentiated allograft that retains growth factors supporting bone healing. The authors sought to compare the clinical and radiographic outcomes of rhBMP-2 and the novel allograft in lumbar interbody arthrodesis to determine if the latter may be a safer and equally effective alternative to rhBMP-2 for single- and multilevel posterior or transforaminal lumbar interbody fusion (PLIF or TLIF)., Methods: Patients who underwent single- or multilevel TLIF or PLIF using either OSTEOAMP or rhBMP-2 at the authors' institution over a 2-year period were prospectively followed for 12 months. Healthcare utilization, safety measures, patient satisfaction, physical disability (measured on the Oswestry Disability Index [ODI]), back and leg pain (on the numeric rating scale [NRS]), quality of life (on the EQ-5D scale), and return to work (RTW) were prospectively recorded. For purposes of this study, this consecutive series was retrospectively analyzed and pseudarthrosis rates were assessed at 2 years of follow-up. All patients (100%) had both 12-month patient-reported outcome follow-up and 24-month clinical and radiographic follow-up., Results: One thousand one hundred fifty-four patients (654 treated with OSTEOAMP, 500 with rhBMP-2) were prospectively enrolled in the institutional registry. After propensity score matching, there were no significant baseline differences between 330 novel allograft and 330 rhBMP-2 cases. Perioperative morbidity and 90-day hospital readmission (3.3% vs 2.4%, p = 0.485) did not significantly differ between the novel allograft and the rhBMP-2 cases. At the 2-year follow-up, symptomatic pseudarthrosis requiring revision surgery occurred in 8 patients (2.4%) with OSTEOAMP and 6 patients (1.8%) with rhBMP-2 (p = 0.589). The overall fusion rate at 2 years was similar between groups (p = 0.213). Both groups showed significant and equivalent improvement in patient-reported outcome measures (PROMs) from baseline to 12-month follow-up, with no significant difference in 1-year mean NRS leg pain score (2.5 vs 2.7), ODI (25 vs 26), quality-adjusted life years (0.73 vs 0.73), satisfaction (83% vs 80%), or RTW (6.6 vs 7 weeks)., Conclusions: In the authors' institutional experience, OSTEOAMP is a clinically viable substitute for rhBMP-2 for single- and multilevel lumbar fusion. This novel allograft provides clinically effective arthrodesis and improvements in PROMs comparable to rhBMP-2 with a similar safety profile. Additional indications and outcome assessment in longitudinal studies are needed to further characterize this allogeneic graft.

Objective: The impact of mental health comorbidities on outcomes after lumbar spine surgery in workers' compensation (WC) patients has not been robustly explored. The goal of this study was to examine the impact of mental health comorbidities on pain, disability, quality of life, and return to work after lumbar spine surgery in WC patients., Methods: A nationwide, prospective surgical outcomes registry (National Neurosurgery Quality Outcomes Database [N2QOD]) was queried for all patients who underwent 1- to 4-level lumbar decompression and/or fusion from 2012 to 2021. Patients were stratified on the basis of compensation status into non-WC (25,507) and WC (1018) cohorts. Baseline demographic data, perioperative safety data, and patient-reported outcome measures were compared between groups. The WC cohort was further subdivided on the basis of mental health status into patients with anxiety and depression (n = 107) and those without anxiety and depression (n = 911). Propensity matching was used to generate parity between these subgroups, generating 214 patients (107 pairs) for analysis. Perioperative safety, facility utilization, 1-year patient-reported outcomes (back and leg pain, disability, and quality of life), and return to work were measured as a function of WC and mental health comorbidity status., Results: A total of 26,525 patients (25,507 non-WC and 1018 WC) who underwent 1- to 4-level lumbar spine surgery were reviewed. WC patients were younger, healthier (lower American Society of Anesthesiologists class), more likely to be minorities, less educated, and more likely to smoke and had greater baseline back pain, disability, and quality of life compared to non-WC patients. The prevalence of anxiety and depression was similar between groups (11%). WC patients had worse outcomes for all measures and lower rates of return to work compared to non-WC patients. WC patients with anxiety and depression demonstrated even greater disparities in all outcomes. After propensity matching, WC patients with anxiety and depression continued to demonstrate significantly worse outcomes in comparison to WC patients without anxiety and depression., Conclusions: Disparities in outcomes after lumbar spine surgery in WC patients are exacerbated in patients with anxiety and depression. WC patients with mental health comorbidities receive the least benefit from lumbar spine surgery and may represent the most vulnerable subset of patients with spine pathology. Addressing mental health comorbidities preoperatively may represent an opportunity for valuable resource allocation and surgical optimization in the WC population.

Objective: Patients with workers' compensation (WC) claims are reported to demonstrate poorer surgical outcomes after lumbar spine surgery. However, outcomes after anterior cervical discectomy and fusion (ACDF) in WC patients remain debatable. The authors aimed to compare outcomes between a propensity score-matched population of WC and non-WC patients who underwent ACDF., Methods: Patients who underwent 1- to 4-level ACDF were retrospectively reviewed from the prospectively maintained Quality Outcomes Database (QOD). After propensity score matching, 1-year patient satisfaction, physical disability (Neck Disability Index [NDI]), pain (visual analog scale [VAS]), EQ-5D, and return to work were compared between WC and non-WC cohorts., Results: A total of 9957 patients were included (9610 non-WC and 347 WC patients). Patients in the WC cohort were significantly younger (50 ± 9.1 vs 56 ± 11.4 years, p < 0.001), less educated, and were more frequently male, non-Caucasian, and active smokers (29.1% vs 18.1%, p < 0.001), with greater baseline VAS and NDI scores and poorer quality of life (p < 0.001). One-year postoperative improvements in VAS, NDI, EQ-5D, and return-to-work rates and satisfaction were all significantly worse for WC compared with non-WC patients. After adjusting for baseline differences via propensity score matching, WC versus non-WC patients continued to demonstrate worse 3- and 12-month VAS neck pain and NDI (p = 0.010), satisfaction (χ2 = 4.03, p = 0.045), and delayed return to work (9.3 vs 5.7 weeks, p < 0.001)., Conclusions: WC status was associated with greater 1-year residual disability and axial pain along with delayed return to work, without any difference in quality of life despite having fewer comorbidities and being a younger population. Further studies are needed to determine the societal impact that WC claims have on healthcare delivery in the setting of ACDF.

Objective: Workers' compensation (WC) and litigation have been shown to adversely impact prognoses in a vast range of health conditions. Low-back pain is currently the most frequent reason for WC claims. The objective of this study was to conduct the largest propensity-matched comparison of outcomes between patients with WC and non-WC status who underwent lumbar spinal decompression with and without fusion., Methods: Complete data sets for patients who underwent 1- to 4-level lumbar spinal fusion or decompression alone were retrospectively retrieved from the Quality Outcomes Database (QOD), which included 1-year patient-reported outcomes from more than 200 hospital systems collected from 2012 to 2021. Population demographics, perioperative safety, facility utilization, patient satisfaction, disability, pain, EQ-5D quality of life, and return to work (RTW) rates were compared between cohorts for both subgroups. Statistical significance was set at p < 0.05., Results: There were 29,652 patients included in the study. Laminectomy was performed in 16,939 with non-WC status and in 615 with WC, whereas fusion was performed in 11,767 with non-WC status and in 331 with WC. WC patients were more frequently male, a minority race, younger, less educated, more frequently a smoker, had a healthier American Society of Anesthesiologists grade, and with greater baseline visual analog scale (VAS) and Oswestry Disability Index (ODI) scores (p < 0.001). One-year postoperative improvements in VAS, ODI, quality-adjusted life years (QALYs), RTW rates, and satisfaction were all significantly worse for WC versus non-WC patients for both procedures. After adjusting for baseline differences via propensity matching, WC versus non-WC patients continued to demonstrate worse 3- and 12-month VAS and ODI scores, reduced 12-month QALY gain, and delayed RTW after both procedure types., Conclusions: WC status was associated with significantly greater residual disability and pain postoperatively, a lower quality of life, and delayed RTW. Utilizing resources to identify the negative influences on outcomes for WC patients may be valuable in preoperative optimization and could yield better outcomes in these patients.

The Quality Outcomes Database (QOD), formerly known as the National Neurosurgery Quality Outcomes Database (N2QOD), was established by the NeuroPoint Alliance (NPA) in collaboration with relevant national stakeholders and experts. The overarching goal of this project was to develop a centralized, nationally coordinated effort to allow individual surgeons and practice groups to collect, measure, and analyze practice patterns and neurosurgical outcomes. Specific objectives of this registry program were as follows: "1) to establish risk-adjusted national benchmarks for both the safety and effectiveness of neurosurgical procedures, 2) to allow practice groups and hospitals to analyze their individual morbidity and clinical outcomes in real time, 3) to generate both quality and efficiency data to support claims made to public and private payers and objectively demonstrate the value of care to other stakeholders, 4) to demonstrate the comparative effectiveness of neurosurgical and spine procedures, 5) to develop sophisticated 'risk models' to determine which subpopulations of patients are most likely to benefit from specific surgical interventions, and 6) to facilitate essential multicenter trials and other cooperative clinical studies." The NPA has launched several neurosurgical specialty modules in the QOD program in the 7 years since its inception including lumbar spine, cervical spine, and spinal deformity and cerebrovascular and intracranial tumor. The QOD Spine modules, which are the primary subject of this paper, have evolved into the largest North American spine registries yet created and have resulted in unprecedented cooperative activities within our specialty and among affiliated spine care practitioners. Herein, the authors discuss the experience of QOD Spine programs to date, with a brief description of their inception, some of the key achievements and milestones, as well as the recent transition of the spine modules to the American Spine Registry (ASR), a collaboration between the American Association of Neurological Surgeons and the American Academy of Orthopaedic Surgeons (AAOS).

OBJECTIVEBack pain and neck pain are two of the most common causes of work loss due to disability, which poses an economic burden on society. Due to recent changes in healthcare policies, patient-centered outcomes including return to work have been increasingly prioritized by physicians and hospitals to optimize healthcare delivery. In this study, the authors used a national spine registry to identify clinical factors associated with return to work at 3 months among patients undergoing a cervical spine surgery.METHODSThe authors queried the Quality Outcomes Database registry for information collected from April 2013 through March 2017 for preoperatively employed patients undergoing cervical spine surgery for degenerative spine disease. Covariates included demographic, clinical, and operative variables, and baseline patient-reported outcomes. Multiple imputations were used for missing values and multivariable logistic regression analysis was used to identify factors associated with higher odds of returning to work. Bootstrap resampling (200 iterations) was used to assess the validity of the model. A nomogram was constructed using the results of the multivariable model.RESULTSA total of 4689 patients were analyzed, of whom 82.2% (n = 3854) returned to work at 3 months postoperatively. Among previously employed and working patients, 89.3% (n = 3443) returned to work compared to 52.3% (n = 411) among those who were employed but not working (e.g., were on a leave) at the time of surgery (p < 0.001). On multivariable logistic regression the authors found that patients who were less likely to return to work were older (age > 56-65 years: OR 0.69, 95% CI 0.57-0.85, p < 0.001; age > 65 years: OR 0.65, 95% CI 0.43-0.97, p = 0.02); were employed but not working (OR 0.24, 95% CI 0.20-0.29, p < 0.001); were employed part time (OR 0.56, 95% CI 0.42-0.76, p < 0.001); had a heavy-intensity (OR 0.42, 95% CI 0.32-0.54, p < 0.001) or medium-intensity (OR 0.59, 95% CI 0.46-0.76, p < 0.001) occupation compared to a sedentary occupation type; had workers' compensation (OR 0.38, 95% CI 0.28-0.53, p < 0.001); had a higher Neck Disability Index score at baseline (OR 0.60, 95% CI 0.51-0.70, p = 0.017); were more likely to present with myelopathy (OR 0.52, 95% CI 0.42-0.63, p < 0.001); and had more levels fused (3-5 levels: OR 0.46, 95% CI 0.35-0.61, p < 0.001). Using the multivariable analysis, the authors then constructed a nomogram to predict return to work, which was found to have an area under the curve of 0.812 and good validity.CONCLUSIONSReturn to work is a crucial outcome that is being increasingly prioritized for employed patients undergoing spine surgery. The results from this study could help surgeons identify at-risk patients so that preoperative expectations could be discussed more comprehensively.

OBJECTIVE Hospital readmissions lead to a significant increase in the total cost of care in patients undergoing elective spine surgery. Understanding factors associated with an increased risk of postoperative readmission could facilitate a reduction in such occurrences. The aims of this study were to develop and validate a predictive model for 90-day hospital readmission following elective spine surgery. METHODS All patients undergoing elective spine surgery for degenerative disease were enrolled in a prospective longitudinal registry. All 90-day readmissions were prospectively recorded. For predictive modeling, all covariates were selected by choosing those variables that were significantly associated with readmission and by incorporating other relevant variables based on clinical intuition and the Akaike information criterion. Eighty percent of the sample was randomly selected for model development and 20% for model validation. Multiple logistic regression analysis was performed with Bayesian model averaging (BMA) to model the odds of 90-day readmission. Goodness of fit was assessed via the C-statistic, that is, the area under the receiver operating characteristic curve (AUC), using the training data set. Discrimination (predictive performance) was assessed using the C-statistic, as applied to the 20% validation data set. RESULTS A total of 2803 consecutive patients were enrolled in the registry, and their data were analyzed for this study. Of this cohort, 227 (8.1%) patients were readmitted to the hospital (for any cause) within 90 days postoperatively. Variables significantly associated with an increased risk of readmission were as follows (OR [95% CI]): lumbar surgery 1.8 [1.1-2.8], government-issued insurance 2.0 [1.4-3.0], hypertension 2.1 [1.4-3.3], prior myocardial infarction 2.2 [1.2-3.8], diabetes 2.5 [1.7-3.7], and coagulation disorder 3.1 [1.6-5.8]. These variables, in addition to others determined a priori to be clinically relevant, comprised 32 inputs in the predictive model constructed using BMA. The AUC value for the training data set was 0.77 for model development and 0.76 for model validation. CONCLUSIONS Identification of high-risk patients is feasible with the novel predictive model presented herein. Appropriate allocation of resources to reduce the postoperative incidence of readmission may reduce the readmission rate and the associated health care costs.

OBJECTIVE Extended hospital length of stay (LOS), unplanned hospital readmission, and need for inpatient rehabilitation after elective spine surgery contribute significantly to the variation in surgical health care costs. As novel payment models shift the risk of cost overruns from payers to providers, understanding patient-level risk of LOS, readmission, and inpatient rehabilitation is critical. The authors set out to develop a grading scale that effectively stratifies risk of these costly events after elective surgery for degenerative lumbar pathologies. METHODS The Quality and Outcomes Database (QOD) registry prospectively enrolls patients undergoing surgery for degenerative lumbar spine disease. This registry was queried for patients who had undergone elective 1- to 3-level lumbar surgery for degenerative spine pathology. The association between preoperative patient variables and extended postoperative hospital LOS (LOS ≥ 7 days), discharge status (inpatient facility vs home), and 90-day hospital readmission was assessed using stepwise multivariate logistic regression. The Carolina-Semmes grading scale was constructed using the independent predictors for LOS (0-12 points), discharge to inpatient facility (0-18 points), and 90-day readmission (0-6 points), and its performance was assessed using the QOD data set. The performance of the grading scale was then confirmed separately after using it in 2 separate neurosurgery practice sites (Carolina Neurosurgery & Spine Associates [CNSA] and Semmes Murphey Clinic). RESULTS A total of 6921 patients were analyzed. Overall, 290 (4.2%) patients required extended LOS, 654 (9.4%) required inpatient facility care/rehabilitation on hospital discharge, and 474 (6.8%) were readmitted to the hospital within 90 days postdischarge. Variables that remained as independently associated with these unplanned events in multivariate analysis included age ≥ 70 years, American Society of Anesthesiologists Physical Classification System class > III, Oswestry Disability Index score ≥ 70, diabetes, Medicare/Medicaid, nonindependent ambulation, and fusion. Increasing point totals in the Carolina-Semmes scale effectively stratified the incidence of extended LOS, discharge to facility, and readmission in a stepwise fashion in both the aggregate QOD data set and when subsequently applied to the CNSA/Semmes Murphey practice groups. CONCLUSIONS The authors introduce the Carolina-Semmes grading scale that effectively stratifies the risk of prolonged hospital stay, need for postdischarge inpatient facility care, and 90-day hospital readmission for patients undergoing first-time elective 1- to 3-level degenerative lumbar spine surgery. This grading scale may be helpful in identifying patients who may require additional resource utilization within a global period after surgery.

OBJECTIVE Quality and outcomes registry platforms lie at the center of many emerging evidence-driven reform models. Specifically, clinical registry data are progressively informing health care decision-making. In this analysis, the authors used data from a national prospective outcomes registry (the Quality Outcomes Database) to develop a predictive model for 12-month postoperative pain, disability, and quality of life (QOL) in patients undergoing elective lumbar spine surgery. METHODS Included in this analysis were 7618 patients who had completed 12 months of follow-up. The authors prospectively assessed baseline and 12-month patient-reported outcomes (PROs) via telephone interviews. The PROs assessed were those ascertained using the Oswestry Disability Index (ODI), EQ-5D, and numeric rating scale (NRS) for back pain (BP) and leg pain (LP). Variables analyzed for the predictive model included age, gender, body mass index, race, education level, history of prior surgery, smoking status, comorbid conditions, American Society of Anesthesiologists (ASA) score, symptom duration, indication for surgery, number of levels surgically treated, history of fusion surgery, surgical approach, receipt of workers' compensation, liability insurance, insurance status, and ambulatory ability. To create a predictive model, each 12-month PRO was treated as an ordinal dependent variable and a separate proportional-odds ordinal logistic regression model was fitted for each PRO. RESULTS There was a significant improvement in all PROs (p < 0.0001) at 12 months following lumbar spine surgery. The most important predictors of overall disability, QOL, and pain outcomes following lumbar spine surgery were employment status, baseline NRS-BP scores, psychological distress, baseline ODI scores, level of education, workers' compensation status, symptom duration, race, baseline NRS-LP scores, ASA score, age, predominant symptom, smoking status, and insurance status. The prediction discrimination of the 4 separate novel predictive models was good, with a c-index of 0.69 for ODI, 0.69 for EQ-5D, 0.67 for NRS-BP, and 0.64 for NRS-LP (i.e., good concordance between predicted outcomes and observed outcomes). CONCLUSIONS This study found that preoperative patient-specific factors derived from a prospective national outcomes registry significantly influence PRO measures of treatment effectiveness at 12 months after lumbar surgery. Novel predictive models constructed with these data hold the potential to improve surgical effectiveness and the overall value of spine surgery by optimizing patient selection and identifying important modifiable factors before a surgery even takes place. Furthermore, these models can advance patient-focused care when used as shared decision-making tools during preoperative patient counseling.

OBJECTIVE Current costs associated with spine care are unsustainable. Productivity loss and time away from work for patients who were once gainfully employed contributes greatly to the financial burden experienced by individuals and, more broadly, society. Therefore, it is vital to identify the factors associated with return to work (RTW) after lumbar spine surgery. In this analysis, the authors used data from a national prospective outcomes registry to create a predictive model of patients' ability to RTW after undergoing lumbar spine surgery for degenerative spine disease. METHODS Data from 4694 patients who underwent elective spine surgery for degenerative lumbar disease, who had been employed preoperatively, and who had completed a 3-month follow-up evaluation, were entered into a prospective, multicenter registry. Patient-reported outcomes-Oswestry Disability Index (ODI), numeric rating scale (NRS) for back pain (BP) and leg pain (LP), and EQ-5D scores-were recorded at baseline and at 3 months postoperatively. The time to RTW was defined as the period between operation and date of returning to work. A multivariable Cox proportional hazards regression model, including an array of preoperative factors, was fitted for RTW. The model performance was measured using the concordance index (c-index). RESULTS Eighty-two percent of patients (n = 3855) returned to work within 3 months postoperatively. The risk-adjusted predictors of a lower likelihood of RTW were being preoperatively employed but not working at the time of presentation, manual labor as an occupation, worker's compensation, liability insurance for disability, higher preoperative ODI score, higher preoperative NRS-BP score, and demographic factors such as female sex, African American race, history of diabetes, and higher American Society of Anesthesiologists score. The likelihood of a RTW within 3 months was higher in patients with higher education level than in those with less than high school-level education. The c-index of the model's performance was 0.71. CONCLUSIONS This study presents a novel predictive model for the probability of returning to work after lumbar spine surgery. Spine care providers can use this model to educate patients and encourage them in shared decision-making regarding the RTW outcome. This evidence-based decision support will result in better communication between patients and clinicians and improve postoperative recovery expectations, which will ultimately increase the likelihood of a positive RTW trajectory.

OBJECTIVE Prospective longitudinal outcomes registries are at the center of evidence-driven health care reform. Obtaining real-world outcomes data at 12 months can be costly and challenging. In the present study, the authors analyzed whether 3-month outcome measurements sufficiently represent 12-month outcomes for patients with degenerative lumbar disease undergoing surgery. METHODS Data from 3073 patients undergoing elective spine surgery for degenerative lumbar disease were entered into a prospective multicenter registry (N(2)QOD). Baseline, 3-month, and 12-month follow-up Oswestry Disability Index (ODI) scores were recorded. The absolute differences between actual 12- and 3-month ODI scores was evaluated. Additionally, the authors analyzed the absolute difference between actual 12-month ODI scores and a model-predicted 12-month ODI score (the model used patients' baseline characteristics and actual 3-month scores). The minimal clinically important difference (MCID) for ODI of 12.8 points and the substantial clinical benefit (SCB) for ODI of 18.8 points were used based on the previously published values. The concordance rate of achieving MCID and SCB for ODI at 3-and 12-months was computed. RESULTS The 3-month ODI scores differed from 12-month scores by an absolute difference of 11.9 ± 10.8, and predictive modeling estimations of 12-month ODI scores differed from actual 12-month scores by a mean (± SD) of 10.7 ± 9.0 points (p = 0.001). Sixty-four percent of patients (n = 1982) achieved an MCID for ODI at 3 months in comparison with 67% of patients (n = 2088) by 12 months; 51% (n = 1731) and 61% (n = 1860) of patients achieved SCB for ODI at 3 months and 12 months, respectively. Almost 20% of patients had ODI scores that varied at least 20 points (the point span of an ODI functional category) between actual 3- and 12-month values. In the aggregate analysis of achieving MCID, 77% of patients were concordant and 23% were discordant in achieving or not achieving MCID at 3 and 12 months. The discordance rates of achieving or not achieving MCID for ODI were in the range of 19% to 27% for all diagnoses and treatments (decompression with and without fusion). The positive and negative predictive value of 3-months ODI to predict 12-month ODI was 86% and 60% for MCID and 82% and 67% for SCB. CONCLUSIONS Based on their findings, the authors conclude the following: 1) Predictive methods for functional outcome based on early patient experience (i.e., baseline and/or 3-month data) should be used to help evaluate the effectiveness of procedures in patient populations, rather than serving as a proxy for long-term individual patient experience. 2) Prospective longitudinal registries need to span at least 12 months to determine the effectiveness of spine care at the individual patient and practitioner level.

OBJECTIVE In an era of escalating health care costs and pressure to improve efficiency and cost of care, ambulatory surgery centers (ASCs) have emerged as lower-cost options for many surgical therapies. Anterior cervical discectomy and fusion (ACDF) is one of the most prevalent spine surgeries performed, and the frequency of its performance is rapidly increasing as the aging population grows. Although ASCs offer significant cost advantages over hospital-based surgical centers, concern over the safety of outpatient ACDF has slowed its adoption. The authors intended to 1) determine the safety of the first 1000 consecutive ACDF surgeries performed in their outpatient ASC, and 2) compare the safety of these outpatient ACDFs with that of consecutive ACDFs performed during the same time period in the hospital setting. METHODS A total of 1000 consecutive patients who underwent ACDF in an ACS (outpatient ACDF) and 484 consecutive patients who underwent ACDF at Vanderbilt University Hospital (inpatient ACDF) from 2006 to 2013 were included in this retrospective study of patients' medical records. Data were collected on patient demographics, comorbidities, operative details, and perioperative and 90-day morbidity. Perioperative morbidity and hospital readmission were compared between the outpatient and inpatient ACDF groups. RESULTS Of the first 1000 outpatient ACDF cases performed in the authors' ASC, 629 (62.9%) were 1-level and 365 (36.5%) were 2-level ACDFs. Mean patient age was 49.5 ± 8.6, and 484 (48.4%) were males. All patients were observed postoperatively at the ASC postanesthesia care unit (PACU) for 4 hours before being discharged home. Eight patients (0.8%) were transferred from the surgery center to the hospital postoperatively (for pain control [n = 3], chest pain and electrocardiogram changes [n = 2], intraoperative CSF leak [n = 1], postoperative hematoma [n = 1], and profound postoperative weakness and surgical reexploration [n = 1]). No perioperative deaths occurred. The 30-day hospital readmission rate was 2.2%. All 90-day surgical morbidity was similar between outpatient and inpatient cohorts for both 1-level and 2-level ACDFs. CONCLUSIONS An analysis of 1000 consecutive patients who underwent ACDF in an outpatient setting demonstrates that surgical complications occur at a low rate (1%) and can be appropriately diagnosed and managed in a 4-hour ASC PACU window. Comparison with an inpatient ACDF surgery cohort demonstrated similar results, highlighting that ACDF can be safely performed in the outpatient ambulatory surgery setting without compromising surgical safety. In an effort to decrease costs of care, surgeons can safely perform 1- and 2-level ACDFs in an ASC environment.

OBJECTIVE Transforaminal lumbar interbody fusion (TLIF) has become the most commonly used fusion technique for lumbar degenerative disorders. This suggests an expectation of better clinical outcomes with this technique, but this has not been validated consistently. How surgical variables and choice of health utility measures drive the cost-effectiveness of TLIF relative to posterolateral fusion (PSF) has not been established. The authors used health utility values derived from Short Form-6D (SF-6D) and EQ-5D and different cost-effectiveness thresholds to evaluate the relative cost-effectiveness of TLIF compared with PSF. METHODS From the National Neurosurgery Quality and Outcomes Database (N(2)QOD), 101 patients with spondylolisthesis who underwent PSF were propensity matched to patients who underwent TLIF. Health-related quality of life measures and perioperative parameters were compared. Because health utility values derived from the SF-6D and EQ-5D questionnaires have been shown to vary in patients with low-back pain, quality-adjusted life years (QALYs) were derived from both measures. On the basis of these matched cases, a sensitivity analysis for the relative cost per QALY of TLIF versus PSF was performed in a series of cost-assumption models. RESULTS Operative time, blood loss, hospital stay, and 30-day and 90-day readmission rates were similar for the TLIF and PSF groups. Both TLIF and PSF significantly improved back and leg pain, Oswestry Disability Index (ODI) scores, and EQ-5D and SF-6D scores at 3 and 12 months postoperatively. At 12 months postoperatively, patients who had undergone TLIF had greater improvements in mean ODI scores (30.4 vs 21.1, p = 0.001) and mean SF-6D scores (0.16 vs 0.11, p = 0.001) but similar improvements in mean EQ-5D scores (0.25 vs 0.22, p = 0.415) as patients treated with PSF. At a cost per QALY threshold of $100,000 and using SF-6D-based QALYs, the authors found that TLIF would be cost-prohibitive compared with PSF at a surgical cost of $4830 above that of PSF. However, with EQ-5D-based QALYs, TLIF would become cost-prohibitive at an increased surgical cost of $2960 relative to that of PSF. With the 2014 US per capita gross domestic product of $53,042 as a more stringent cost-effectiveness threshold, TLIF would become cost-prohibitive at surgical costs $2562 above that of PSF with SF-6D-based QALYs or at a surgical cost exceeding that of PSF by $1570 with EQ-5D-derived QALYs. CONCLUSIONS As with all cost-effectiveness studies, cost per QALY depended on the measure of health utility selected, durability of the intervention, readmission rates, and the accuracy of the cost assumptions.

OBJECT The health care landscape is rapidly shifting to incentivize quality of care rather than quantity of care. Quality and outcomes registry platforms lie at the center of all emerging evidence-driven reform models and will be used to inform decision makers in health care delivery. Obtaining real-world registry outcomes data from patients 12 months after spine surgery remains a challenge. The authors set out to determine whether 3-month patient-reported outcomes accurately predict 12-month outcomes and, hence, whether 3-month measurement systems suffice to identify effective versus noneffective spine care. METHODS All patients undergoing lumbar spine surgery for degenerative disease at a single medical institution over a 2-year period were enrolled in a prospective longitudinal registry. Patient-reported outcome instruments (numeric rating scale [NRS], Oswestry Disability Index [ODI], 12-Item Short Form Health Survey [SF-12], EQ-5D, and the Zung Self-Rating Depression Scale) were recorded prospectively at baseline and at 3 months and 12 months after surgery. Linear regression was performed to determine the independent association of 3- and 12-month outcome. Receiver operating characteristic (ROC) curve analysis was performed to determine whether improvement in general health state (EQ-5D) and disability (ODI) at 3 months accurately predicted improvement and achievement of minimum clinical important difference (MCID) at 12 months. RESULTS A total of 593 patients undergoing elective lumbar surgery were included in the study. There was a significant correlation between 3-month and 12-month EQ-5D (r = 0.71; p < 0.0001) and ODI (r = 0.70; p < 0.0001); however, the authors observed a sizable discrepancy in achievement of a clinically significant improvement (MCID) threshold at 3 versus 12 months on an individual patient level. For postoperative disability (ODI), 11.5% of patients who achieved an MCID threshold at 3 months dropped below this threshold at 12 months; 10.5% of patients who did not meet the MCID threshold at 3 months continued to improve and ultimately surpassed the MCID threshold at 12 months. For ODI, achieving MCID at 3 months accurately predicted 12-month MCID with only 62.6% specificity and 86.8% sensitivity. For postoperative health utility (EQ-5D), 8.5% of patients lost an MCID threshold improvement from 3 months to 12 months, while 4.0% gained the MCID threshold between 3 and 12 months postoperatively. For EQ-5D (quality-adjusted life years), achieving MCID at 3 months accurately predicted 12-month MCID with only 87.7% specificity and 87.2% sensitivity. CONCLUSIONS In a prospective registry, patient-reported measures of treatment effectiveness obtained at 3 months correlated with 12-month measures overall in aggregate, but did not reliably predict 12-month outcome at the patient level. Many patients who do not benefit from surgery by 3 months do so by 12 months, and, conversely, many patients reporting meaningful improvement by 3 months report loss of benefit at 12 months. Prospective longitudinal spine outcomes registries need to span at least 12 months to identify effective versus noneffective patient care.

Quality measurement and public reporting are intended to facilitate targeted outcome improvement, practice-based learning, shared decision making, and effective resource utilization. However, regulatory implementation has created a complex network of reporting requirements for physicians and medical practices. These include Medicare's Physician Quality Reporting System, Electronic Health Records Meaningful Use, and Value-Based Payment Modifier programs. The common denominator of all these initiatives is that to avoid penalties, physicians must meet "generic" quality standards that, in the case of neurosurgery and many other specialties, are not pertinent to everyday clinical practice and hold specialists accountable for care decisions outside of their direct control. The Centers for Medicare and Medicaid Services has recently authorized alternative quality reporting mechanisms for the Physician Quality Reporting System, which allow registries to become subspecialty-reporting mechanisms under the Qualified Clinical Data Registry (QCDR) program. These programs further give subspecialties latitude to develop measures of health care quality that are relevant to the care provided. As such, these programs amplify the power of clinical registries by allowing more accurate assessment of practice patterns, patient experiences, and overall health care value. Neurosurgery has been at the forefront of these developments, leveraging the experience of the National Neurosurgery Quality and Outcomes Database to create one of the first specialty-specific QCDRs. Recent legislative reform has continued to change this landscape and has fueled optimism that registries (including QCDRs) and other specialty-driven quality measures will be a prominent feature of federal and private sector quality improvement initiatives. These physician- and patient-driven methods will allow neurosurgery to underscore the value of interventions, contribute to the development of sustainable health care solutions, and actively participate in meaningful quality initiatives for the benefit of the patients served.

Meaningful quality measurement and public reporting have the potential to facilitate targeted outcome improvement, practice-based learning, shared decision making, and effective resource utilization. Recent developments in national quality reporting programs, such as the Centers for Medicare & Medicaid Services Qualified Clinical Data Registry (QCDR) reporting option, have enhanced the ability of specialty groups to develop relevant quality measures of the care they deliver. QCDRs will complete the collection and submission of Physician Quality Reporting System (PQRS) quality measures data on behalf of individual eligible professionals. The National Neurosurgery Quality and Outcomes Database (N(2)QOD) offers 21 non-PQRS measures, initially focused on spine procedures, which are the first specialty-specific measures for neurosurgery. Securing QCDR status for N(2)QOD is a tremendously important accomplishment for our specialty. This program will ensure that data collected through our registries and used for PQRS is meaningful for neurosurgeons, related spine care practitioners, their patients, and other stakeholders. The 2015 N(2)QOD QCDR is further evidence of neurosurgery's commitment to substantively advancing the health care quality paradigm. The following manuscript outlines the measures now approved for use in the 2015 N(2)QOD QCDR. Measure specifications (measure type and descriptions, related measures, if any, as well as relevant National Quality Strategy domain[s]) along with rationale are provided for each measure.

OBJECT Lumbar spine surgery has been demonstrated to be efficacious for many degenerative spine conditions. However, there is wide variability in outcome after spine surgery at the individual patient level. All stakeholders in spine care will benefit from identification of the unique patient or disease subgroups that are least likely to benefit from surgery, are prone to costly complications, and have increased health care utilization. There remains a large demand for individual patient-level predictive analytics to guide decision support to optimize outcomes at the patient and population levels. METHODS One thousand eight hundred three consecutive patients undergoing spine surgery for various degenerative lumbar diagnoses were prospectively enrolled and followed for 1 year. A comprehensive patient interview and health assessment was performed at baseline and at 3 and 12 months after surgery. All predictive covariates were selected a priori. Eighty percent of the sample was randomly selected for model development, and 20% for model validation. Linear regression was performed with Bayesian model averaging to model 12-month ODI (Oswestry Disability Index). Logistic regression with Bayesian model averaging was used to model likelihood of complications, 30-day readmission, need for inpatient rehabilitation, and return to work. Goodness-of-fit was assessed via R(2) for 12-month ODI and via the c-statistic, area under the receiver operating characteristic curve (AUC), for the categorical endpoints. Discrimination (predictive performance) was assessed, using R(2) for the ODI model and the c-statistic for the categorical endpoint models. Calibration was assessed using a plot of predicted versus observed values for the ODI model and the Hosmer-Lemeshow test for the categorical endpoint models. RESULTS On average, all patient-reported outcomes (PROs) were improved after surgery (ODI baseline vs 12 month: 50.4 vs 29.5%, p < 0.001). Complications occurred in 121 patients (6.6%), 108 (5.9%) were readmitted within 30 days of surgery, 188 (10.3%) required discharge to inpatient rehabilitation, 1630 (88.9%) returned to work, and 449 (24.5%) experienced an unplanned outcome (no improvement in ODI, a complication, or readmission). There were 45 unique baseline variable inputs, derived from 39 clinical variables and 38 questionnaire items (ODI, SF-12, MSPQ, VAS-BP, VAS-LP, VAS-NP), included in each model. For prediction of 12-month ODI, R(2) was 0.51 for development and 0.47 for the validation study. For prediction of a complication, readmission, inpatient rehabilitation, and return to work, AUC values ranged 0.72-0.84 for development and 0.79-0.84 for validation study. CONCLUSIONS A novel prediction model utilizing both clinical data and patient interview inputs explained the majority of variation in outcome observed after lumbar spine surgery and reliably predicted 12-month improvement in physical disability, return to work, major complications, readmission, and need for inpatient rehabilitation for individual patients. Application of these models may allow clinicians to offer spine surgery specifically to those who are most likely to benefit and least likely to incur complications and excess costs.

OBJECT There is a paradigm shift toward rewarding providers for quality rather than volume. Complications appear to occur at a fairly consistent frequency in large aggregate data sets. Understanding how complications affect long-term patient-reported outcomes (PROs) following degenerative lumbar surgery is vital. The authors hypothesized that 90-day complications would adversely affect long-term PROs. METHODS Nine hundred six consecutive patients undergoing elective surgery for degenerative lumbar disease over a period of 4 years were enrolled into a prospective longitudinal registry. The following PROs were recorded at baseline and 12-month follow-up: Oswestry Disability Index (ODI) score, numeric rating scales for back and leg pain, quality of life (EQ-5D scores), general physical and mental health (SF-12 Physical Component Summary [PCS] and Mental Component Summary [MCS] scores) and responses to the North American Spine Society (NASS) satisfaction questionnaire. Previously published minimum clinically important difference (MCID) threshold were used to define meaningful improvement. Complications were divided into major (surgicalsite infection, hardware failure, new neurological deficit, pulmonary embolism, hematoma and myocardial infarction) and minor (urinary tract infection, pneumonia, and deep venous thrombosis). RESULTS Complications developed within 90 days of surgery in 13% (118) of the patients (major in 12% [108] and minor in 8% [68]). The mean improvement in ODI scores, EQ-5D scores, SF-12 PCS scores, and satisfaction at 3 months after surgery was significantly less in the patients with complications than in those who did not have major complications (ODI: 13.5 ± 21.2 vs 21.7 ± 19, < 0.0001; EQ-5D: 0.17 ± 0.25 vs 0.23 ± 0.23, p = 0.04; SF-12 PCS: 8.6 ± 13.3 vs 13.0 ± 11.9, 0.001; and satisfaction: 76% vs 90%, p = 0.002). At 12 months after surgery, the patients with major complications had higher ODI scores than those without complications (29.1 ± 17.7 vs 25.3 ± 18.3, p = 0.02). However, there was no difference in the change scores in ODI and absolute scores across all other PROs between the 2 groups. In multivariable linear regression analysis, after controlling for an array of preoperative variables, the occurrence of a major complication was not associated with worsening ODI scores 12 months after surgery. There was no difference in the percentage of patients achieving the MCID for disability (66% vs 64%), back pain (55% vs 56%), leg pain (62% vs 59%), or quality of life (19% vs 14%) or in patient satisfaction rates (82% vs 80%) between those without and with major complications. CONCLUSIONS Major complications within 90 days following lumbar spine surgery have significant impact on the short-term PROs. Patients with complications, however, do eventually achieve clinically meaningful outcomes and report satisfaction equivalent to those without major complications. This information allows a physician to counsel patients on the fact that a complication creates frustration, cost, and inconvenience; however, it does not appear to adversely affect clinically meaningful long-term outcomes and satisfaction.

OBJECT In an era of escalating health care cost and universal pressure of improving efficiency and cost of care, ambulatory surgery centers (ASCs) have emerged as lower cost options for many surgical therapies. Anterior cervical discectomy and fusion (ACDF) is one of the most prevalent spine surgeries performed and is rapidly increasing with an expanding aging population. While ASCs offer cost advantages for ACDF, there is a scarcity of evidence that ASCs allow for equivalent quality and thus superior health care value. Therefore, the authors analyzed a nationwide, prospective quality improvement registry (National Surgical Quality Improvement Program [NSQIP]) to compare the quality of ACDF surgery performed in the outpatient ASC versus the inpatient hospital setting. METHODS Patients undergoing ACDF (2005-2011) were identified from the NSQIP database based on the primary Current Procedural Terminology codes. Patients were divided into 2 cohorts (outpatient vs inpatient) based on the acute care setting documented in the NSQIP database. All 30-day surgical morbidity and mortality rates were compared between the 2 groups. Propensity score matching and multivariate logistic regression analysis were used to adjust for confounding factors and to identify the independent association of outpatient ACDF with perioperative outcomes and morbidity. RESULTS A total of 7288 ACDF cases were identified (inpatient = 6120, outpatient = 1168). Unadjusted rates of major morbidity (0.94% vs 4.5%, p < 0.001) and return to the operating room (OR) within 30 days (0.3% vs 2.0%, p < 0.001) were significantly lower in outpatient versus inpatient ACDF. After propensity matching 1442 cases (inpatient = 650, outpatient = 792) based on baseline 32 covariates, rates of major morbidity (1.4% vs 3.1%, p = 0.03), and return to the OR (0.34% vs 1.4%, p = 0.04) remained significantly lower after outpatient ACDF. Adjusted comparison using multivariate logistic regression demonstrated that ACDF performed in the outpatient setting had 58% lower odds of having a major morbidity and 80% lower odds of return to the OR within 30 days. CONCLUSIONS An analysis of a nationwide, prospective quality improvement registry representing more than 250 hospitals demonstrates that 1- to 2-level ACDF can be safely performed in the outpatient ambulatory surgery setting in patients who are appropriate candidates. In an effort to decrease cost of care, surgeons can safely consider performing ACDF in an ASC environment.

Object: Infections following spine surgery negatively affect patient quality of life (QOL) and impose a significant financial burden on the health care system. Postoperative wound infections occur at higher rates following dorsal cervical procedures than ventral procedures. Quantifying the health outcomes and costs associated with infections following dorsal cervical procedures may help to guide treatment strategies to minimize the deleterious consequences of these infections. Therefore, the goals of this study were to determine the cost and QOL outcomes affecting patients who developed deep wound infections following subaxial dorsal cervical spine fusions., Methods: The authors identified 22 (4.0%) of 551 patients undergoing dorsal cervical fusions who developed deep wound infections requiring surgical debridement. These patients were individually matched with control patients who did not develop infections. Health outcomes were assessed using the EQ-5D, Pain Disability Questionnaire (PDQ), Patient Health Questionnaire (PHQ-9), and visual analog scale (VAS). QOL outcome measures were collected preoperatively and after 6 and 12 months. Health resource utilization was recorded from patient electronic medical records over an average follow-up of 18 months. Direct costs were estimated using Medicare national payment amounts, and indirect costs were based on patients' missed workdays and income., Results: No significant differences in preoperative QOL scores were found between the 2 cohorts. At 6 months postsurgery, the noninfection cohort had significant pre- to postoperative improvement in EQ-5D (p = 0.02), whereas the infection cohort did not (p = 0.2). The noninfection cohort also had a significantly higher 6-month postoperative EQ-5D scores than the infection cohort (p = 0.04). At 1 year postsurgery, there was no significant difference in EQ-5D scores between the groups. Health care-associated costs for the infection cohort were significantly higher ($16,970 vs $7658; p < 0.0001). Indirect costs for the infection cohort and the noninfection cohort were $6495 and $2756, respectively (p = 0.03). Adjusted for inflation, the total costs for the infection cohort were $21,778 compared with $9159 for the noninfection cohort, reflecting an average cost of $12,619 associated with developing a postoperative deep wound infection (p < 0.0001)., Conclusions: Dorsal cervical infections temporarily decrease patient QOL postoperatively, but with no long-term impact; they do, however, dramatically increase the cost of care. Knowledge of the financial burden of wound infections following dorsal cervical fusion may stimulate the development and use of improved prophylactic and therapeutic techniques to manage this serious complication.

Object: The real-world effectiveness of antibiotic-impregnated shunt catheters to reduce the incidence of shunt infections is still debated. The literature to date consists mostly of small, single-institution studies. The aim of this study was to assess the incidence of infection for antibiotic-impregnated catheters (AICs) versus standard shunt catheters in a large nationwide administrative database., Methods: The authors retrospectively reviewed hospital discharge and billing records from the Premier Perspective Database from April 2003 to July 2009 to identify all adult and pediatric patients undergoing de novo ventricular shunt placement. The primary end point was the incidence of shunt infection within 1 year of implantation. Multivariate logistical regression was performed to determine factors associated with increased incidence of infection., Results: A total of 10,819 adult (AIC, 963; standard catheter, 9856) and 1770 pediatric (AIC, 229; standard catheter, 1541) patients underwent ventricular shunt placement in 287 US hospitals. Overall, the incidence of infection was 3.5% in adults (n=380) and 6.6% in pediatric patients (n=116). AICs were associated with significant reduction in infection for both adult (2.2% vs 3.6%, p=0.02) and pediatric (2.6% vs 7.1%, p<0.01) patients. AIC use was associated with reduced infection regardless of hospital size, annual shunt volume, hospital location, or patient risk factors and remained associated with a reduced infection in multivariate analysis for both adult (p=0.02) and pediatric (p=0.02) patients., Conclusions: The use of antibiotic-impregnated shunt catheters was associated with a reduction in shunt infections for both adult and pediatric patients. This provides further support that AICs may represent a reliable means of reducing shunt infections for both adult and pediatric patients.

Object: Despite multiple preventive strategies for reducing infection, up to 15% of patients with shunt catheters and 27% of patients with external ventricular drains (EVDs) may develop an infection. There are few data on the cost-effectiveness of measures to prevent hydrocephalus catheter infection from the hospital perspective. The objective of this study was to perform a cost-consequence analysis to assess the potential clinical and economic value of antibiotic-impregnated catheter (AIC) shunts and EVDs compared with non-AIC shunts and EVDs in the treatment of hydrocephalus from a hospital perspective., Methods: The authors used decision analytical techniques to assess the clinical and economic consequences of using antibiotic-impregnated shunts and EVDs from a hospital perspective. Model inputs were derived from the published, peer-reviewed literature. Clinical studies comparing infection rates and the clinical and economic impact of infections associated with the use of AICs and standard catheters (non-AICs) were evaluated. Outcomes assessed included infections, deaths due to infection, surgeries due to infection, and cost associated with shunt- and EVD-related infection. A subanalysis using only AIC shunt and EVD Level I evidence (randomized controlled trial results) was conducted as an alternate to the cumulative analysis of all of the AIC versus non-AIC studies (13 of the 14 shunt studies and 4 of the 6 EVD studies identified were observational). Sensitivity analyses were conducted to determine how changes in the values of uncertain parameters affected the results of the model., Results: In 100 patients requiring shunts, AICs may be associated with 0.5 fewer deaths, 71 fewer hospital days, 11 fewer surgeries, and $128,228 of net savings in hospital costs due to decreased infection. Results of the subanalysis showed that AICs may be associated with 1.9 fewer deaths, 1611 fewer hospital days, 25 fewer surgeries, and $346,616 of net savings in hospital costs due to decreased infection. The rate of decrease in infection with AIC shunts was shown to have the greatest impact on the cost savings realized with use of AIC shunts. In 100 patients requiring EVDs, AICs may be associated with 2.7 fewer deaths and 82 fewer hospital days due to infection. The relative risk of more severe neurological impairment was estimated to be 5.33 times greater with EVD infection. Decreases in infection with AIC EVDs resulted in an estimated $264,069 of net savings per 100 patients treated with AICs. Results of the subanalysis showed that AIC EVDs may be associated with 1.0 fewer deaths, 31 infection-related hospital days averted, and $74,631 saved per 100 patients treated with AIC EVDs. As was seen with AIC shunts, the rate of decrease in infection with AIC EVDs was shown to have the greatest impact on the cost savings realized with use of AIC EVDs., Conclusions: The current value analysis demonstrates that evidence supports the use of AICs as effective and potentially cost-saving treatment.

Object: Current health care reform calls for a reduction of procedures and treatments that are less effective, more costly, and of little value (high cost/low quality). The authors assessed the 2-year cost and effectiveness of comprehensive medical management for lumbar spondylolisthesis, stenosis, and herniation by utilizing a prospective single-center multidisciplinary spine center registry in a real-world practice setting., Methods: Analysis was performed on a prospective longitudinal quality of life spine registry. Patients with lumbar spondylolisthesis (n = 50), stenosis (n = 50), and disc herniation (n = 50) who had symptoms persisting after 6 weeks of medical management and who were eligible for surgical treatment were entered into a prospective registry after deciding on nonsurgical treatment. In all cases, comprehensive medical management included spinal steroid injections, physical therapy, muscle relaxants, antiinflammatory medication, and narcotic oral agents. Two-year patient-reported outcomes, back-related medical resource utilization, and occupational work-day losses were prospectively collected and used to calculate Medicare fee-based direct and indirect costs from the payer and societal perspectives. The maximum health gain associated with medical management was defined as the improvement in pain, disability, and quality of life experienced after 2 years of medical treatment or at the time a patient decided to cross over to surgery., Results: The maximum health gain in back pain, leg pain, disability, quality of life, depression, and general health state did not achieve statistical significance by 2 years of medical management, except for pain and disability in patients with disc herniation and back pain in patients with lumbar stenosis. Eighteen patients (36%) with spondylolisthesis, 11 (22%) with stenosis, and 17 (34%) with disc herniation eventually required surgical management due to lack of improvement. The 2-year improvement did not achieve a minimum clinically important difference in any outcome measure. The mean 2-year total cost (direct plus indirect) of medical management was $6606 for spondylolisthesis, $7747 for stenosis, and $7097 for herniation., Conclusions: In an institution-wide, prospective, longitudinal quality of life registry that measures cost and effectiveness of all spine care provided, comprehensive medical management did not result in sustained improvement in pain, disability, or quality of life for patients with surgically eligible degenerative lumbar spondylolisthesis, stenosis, or disc herniation. From both the societal and payer perspective, continued medical management of patients with these lumbar pathologies in whom 6 weeks of conservative therapy failed was of minimal value given its lack of health utility and effectiveness and its health care costs. The findings from this real-world practice setting may more accurately reflect the true value and effectiveness of nonoperative care in surgically eligible patient populations.

Object: Suboccipital decompression is a common procedure for patients with Chiari malformation Type I (CMI). Published studies have reported complication rates ranging from 3% to 40%, with pseudomeningocele being one of the most common complications. To date, there are no studies assessing the effect of this complication on long-term outcome. Therefore, the authors set out to assess the effect of symptomatic pseudomeningocele on patient outcomes following suboccipital decompression for CM-I., Methods: The study comprised 50 adult patients with CM-I who underwent suboccipital craniectomy and C-1 laminectomy with or without duraplasty. Clinical presentation, radiological studies, operative variables, and complications were assessed for each case. Baseline and 1-year postoperative patient-reported outcomes were assessed to determine improvement in pain, disability, and quality of life. The extent of improvement was compared for patients with and without development of a postoperative symptomatic pseudomeningocele., Results: A symptomatic pseudomeningocele developed postoperatively in 9 patients (18%). There was no difference with regard to clinical, radiological, or operative variables for patients with or without a postoperative pseudomeningocele. Patients without a pseudomeningocele had significant improvement in all 9 patient-reported outcome measures assessed. On the other hand, patients with pseudomeningocele only had significant improvement in headache (as measured on the Numeric Rating Scale) and headache-related disability (as measured on the Headache Disability Index) but no improvement in quality of life. Twenty-nine (71%) of 41 patients without a pseudomeningocele reported improvement in health status postoperatively compared with only 3 (33%) of 9 patients with a postoperative pseudomeningocele (p = 0.05)., Conclusions: Surgical management of CM-I in adults provides significant and sustained improvement in pain, disability, general health, and quality of life. Development of a postoperative symptomatic pseudomeningocele has lingering effects at 1 year, and it significantly diminishes the overall benefit of suboccipital decompression for CM-related symptoms. Further research is needed to accurately predict which patients may benefit from decompression alone without duraplasty.

Object: Surgical site infection (SSI) is a morbid complication with high cost in spine surgery. In this era of health care reforms, adjuvant therapies that not only improve quality but also decrease cost are considered of highest value. The authors introduced local application of vancomycin powder into their practice of posterior spinal fusion for spine trauma and undertook this study to determine the value and cost benefit of using vancomycin powder in surgical sites to prevent postoperative infections., Methods: A retrospective review of 110 patients with traumatic spine injuries treated with instrumented posterior spine fusions over a 2-year period at a single institution was performed. One group (control group) received standard systemic prophylaxis only, whereas another (treatment group) received 1 g of locally applied vancomycin powder (spread over the surgical wound) in addition to systemic prophylaxis. Data were collected on patient demographic characteristics, clinical variables, surgical variables, and 90-day morbidity. Incidence of infection was the primary outcome evaluated, and billing records were reviewed to determine total infection-related medical cost (cost of reoperation/wound debridement, medications, and diagnostic tests). The payer's cost was estimated to be 70% of the total billing cost., Results: A total of 110 patients were included in the study. The control (n = 54) and treatment groups (n = 56) were similar at baseline. Use of vancomycin powder led to significant reduction in infection rate (13% infection rate in the control group vs 0% in the treatment group, p = 0.02). There were no adverse effects noted from the use of vancomycin powder. The total mean cost of treating postoperative infection per patient was $33,705. Use of vancomycin powder led to a cost savings of $438,165 per 100 posterior spinal fusions performed for traumatic injuries., Conclusions: The use of adjuvant vancomycin powder was associated with a significant reduction in the incidence of postoperative infection as well as infection-related medical cost. These findings suggest that use of adjuvant vancomycin powder in high-risk patients undergoing spinal fusion is a cost-saving option for preventing postoperative infections, as it can lead to cost-savings of $438,165 per 100 spinal fusions performed.

Object: Treatment effectiveness following spine surgery is usually gauged with the help of patient-reported outcome (PRO) questionnaires. Although these questionnaires assess pain, disability, and general health state, their numerical scores lack direct, clinically significant meaning. Thus, the concept of minimum clinically important difference (MCID) has been introduced, which indicates the smallest change in an outcome measure that reflects clinically meaningful improvement to patients. The authors set out to determine anterior cervical discectomy and fusion (ACDF)-specific MCID values for the visual analog scale (VAS), Neck Disability Index (NDI), 12-Item Short-Form Health Survey (SF-12), and EQ-5D (the EuroQol health survey) in patients undergoing ACDF for cervical radiculopathy., Methods: Data on 69 patients who underwent ACDF for cervical radiculopathy were collected in the authors' web-based, prospective registry during the study enrollment period. Patient-reported outcome questionnaires (VAS-neck pain [NP]), VAS-arm pain [AP], NDI, SF-12, and EQ-5D) were administered preoperatively and 3 months postoperatively, allowing 3-month change scores to be calculated. Four established calculation methods were used to calculate anchor-based MCID values using the North American Spine Society (NASS) patient satisfaction scale as the anchor: 1) average change, 2) minimum detectable change (MDC), 3) change difference, and 4) receiver operating characteristic (ROC) curve analysis., Results: Sixty-one patients (88%) were available at follow-up. At 3 months postoperatively, statistically significant improvement (p < 0.001) was observed for the following PROs assessed: VAS-NP (2.7 ± 3.3), VAS-AP (3.7 ± 3.6), NDI (23.2% ± 19.7%), SF-12 physical component score (PCS; 10.7 ± 9.7), and EQ-5D (0.20 ± 0.23 QALY). Improvement on the SF-12 mental component score (MCS) trended toward significance (3.4 ± 11.4, p = 0.07). The 4 MCID calculation methods generated a range of MCID values for each of the PROs: VAS-NP 2.6-4.0, VAS-AP 2.4-4.2, NDI 16.0%-27.6%, SF-12 PCS 7.0-12.2, SF-12 MCS 0.0-7.2, and EQ-5D 0.05-0.24 QALY. The maximum area under the curve (AUC) was observed for NDI (0.80), and the minimum AUC was observed for SF-12 MCS (0.66) and EQ-5D (0.67). Based on the MDC approach, the MCID threshold was 2.6 points for VAS-NP, 4.1 points for VAS-AP, 17.3% for NDI, 8.1 points for SF-12 PCS, 4.7 points for SF-12 MCS, and 0.24 QALY for EQ-5D. The mean improvement in patient scores at 3 months surpassed the MCID threshold for VAS-NP, NDI, and SF-12 PCS but not for VAS-AP, SF-12 MCS, and EQ-5D., Conclusions: The ACDF-specific MCID is highly variable depending on the calculation technique used. The MDC approach seems to be most appropriate for MCID calculations in the ACDF population, as it provided a threshold value above the 95% confidence interval of nonresponders (greater than the measurement error) and was closest to the average change of most PROs reported by responders. When the MDC method was applied with the NASS patient satisfaction scale as the anchor, the MCID thresholds were 2.6 points for VAS-NP, 4.1 points for VAS-AP, 17.3% for NDI, 8.1 points for SF-12 PCS, 4.7 points for SF-12 MCS, and 0.24 QALY for EQ-5D.

In terms of policy, research, quality improvement, and practice-based learning, there are essential principles--namely, quality, effectiveness, and value of care--needed to navigate changes in the current and future US health care environment. Patient-centered outcome measurement lies at the core of all 3 principles. Multiple measures of disease-specific disability, generic health-related quality of life, and preference-based health state have been introduced to quantify disease impact and define effectiveness of care. This paper reviews the basic principles of patient outcome measurement and commonly used outcome instruments. The authors provide examples of how utilization of outcome measurement tools in everyday neurosurgical practice can facilitate practice-based learning, quality improvement, and real-world comparative effectiveness research, as well as promote the value of neurosurgical care.

Given the unsustainable costs of US health care, universal agreement exists among payers, regulatory agencies, and other health care stakeholders that reform must include substantial improvements in the quality, effectiveness, and value of health care delivery. The Institute of Medicine and the American Recovery and Reinvestment Act of 2009 have called for the establishment of prospective registries to capture patient-centered data from real-world practice as a high priority to guide evidence-based reform. As a result, the American Association of Neurological Surgeons launched the National Neurosurgery Quality and Outcomes Database (N(2)QOD) and began enrolling patients in March 2012 into its initial pilot project: a web-based lumbar spine module. As a nationwide, prospective longitudinal registry utilizing patient reported outcome instruments, the N(2)QOD lumbar spine surgery pilot aims to systematically measure and aggregate surgical safety and 1-year postoperative outcome data from approximately 30 neurosurgical practices across the US with the primary aim of demonstrating the feasibility and validity of standardized 1-year outcome measurement from everyday real-world practice. At the end of the pilot year, 1) risk-adjusted modeling will be developed for the safety, quality, and effectiveness of lumbar surgical care (morbidity, readmission, improvements in pain, disability, quality of life, and return to work); 2) data integrity and validation will be demonstrated via internal quality control analyses and auditing, and 3) the feasibility of obtaining a high level of follow-up (~80%) of nationwide 1-year outcome measurement will be established. N(2)QOD will use only prospective clinical data, will avoid the use of administrative data proxies, and will rely on neurosurgically relevant risk factors for risk adjustment. Once national benchmarks of quality and effectiveness are accurately established and validated utilizing practice-based data extractors in the pilot year, N(2)QOD aims to introduce non-full-time employee (FTE)-dependent methodologies such as electronic medical record auto-extraction. N(2)QOD's non-FTE-dependent methodologies can then be validated against practice-based data extractor-derived measures of safety and effectiveness with the aim of more rapid expansion into the majority of US practice groups. The general overview, methods, and registry design of the N(2)QOD pilot year (lumbar module) are presented here.

Patient care data will soon inform all areas of health care decision making and will define clinical performance. Organized neurosurgery believes that prospective, systematic tracking of practice patterns and patient outcomes will allow neurosurgeons to improve the quality and efficiency and, ultimately, the value of care. In support of this mission, the American Association of Neurological Surgeons, in cooperation with a broad coalition of other neurosurgical societies including the Congress of Neurological Surgeons, Society of Neurological Surgeons, and American Board of Neurological Surgery, created the NeuroPoint Alliance (NPA), a not-for-profit corporation, in 2008. The NPA coordinates a variety of national projects involving the acquisition, analysis, and reporting of clinical data from neurosurgical practice using online technologies. It was designed to meet the health care quality and related research needs of individual neurosurgeons and neurosurgical practices, national organizations, health care plans, biomedical industry, and government agencies. To meet the growing need for tools to measure and promote high-quality care, NPA collaborated with several national stakeholders to create an unprecedented program: the National Neurosurgery Quality and Outcomes Database (N(2)QOD). This resource will allow any US neurosurgeon, practice group, or hospital system to contribute to and access aggregate quality and outcomes data through a centralized, nationally coordinated clinical registry. This paper describes the practical and scientific justifications for a national neurosurgical registry; the conceptualization, design, development, and implementation of the N(2)QOD; and the likely role of prospective, cooperative clinical data collection systems in evolving systems of neurosurgical training, continuing education, research, public reporting, and maintenance of certification.

Outcomes-directed approaches to quality improvement have been adopted by diverse industries and are increasingly the focus of government-mandated reforms to health care education and delivery. The authors identify and review current reform initiatives originating from agencies regulating and funding graduate medical education and health care delivery. These reforms use outcomes-based methodologies and incorporate principles of lifelong learning and patient centeredness. Important new initiatives include the Accreditation Council for Graduate Medical Education Milestones; the pending adoption by the American Board of Neurological Surgery of new requirements for Maintenance of Certification that are in part outcomes based; initiation by health care systems and consortia of public reporting of patient outcomes data; institution by the Centers for Medicare & Medicaid Services of requirements for comparative effectiveness research and the physician quality reporting system; and linking of health care reimbursement in part to patient outcomes data and quality measures. Opportunities exist to coordinate and unify patient outcomes measurement throughout neurosurgical training and practice, enabling effective patient-centered improvements in care delivery as well as efficient compliance with regulatory mandates. Coordination will likely require the development of a new science of practice based in the daily clinical environment and utilizing clinical data registries. A generation of outcomes science and quality experts within neurosurgery should be trained to facilitate attainment of these goals.

Clinical registries have emerged in the current resource-restricted environment of modern medicine as useful and logical mechanisms for providing health care stakeholders with high-quality data related to the safety, effectiveness, and value of specific interventions. Temporal and qualitative requirements for data acquisition in the context of clinical registries have rapidly expanded as clinicians and other stakeholders increasingly recognize the central importance of this information to the intelligent transformation of health care processes. Despite the potential of more robust clinical data collection efforts to advance the science of care, certain aspects of these newer systems, particularly the prospective, longitudinal acquisition of clinical data and direct patient contact, represent areas of structural overlap between emerging quality improvement efforts and traditional models of human subjects research. This overlap has profound implications for the design and implementation of modern clinical registries. In this paper, the authors describe the evolution of clinical registries as important tools for advancing the science of practice, and review the existing federal regulations that apply to these systems.

Object: Spine surgery outcome studies rely on patient-reported outcome (PRO) measurements to assess treatment effect, but the extent of improvement in the numerical scores of these questionnaires lacks a direct clinical meaning. Because of this, the concept of a minimum clinically important difference (MCID) has been used to measure the critical threshold needed to achieve clinically relevant treatment effectiveness. As utilization of spinal fusion has increased over the past decade, so has the incidence of same-level recurrent stenosis following index lumbar fusion, which commonly requires revision decompression and fusion. The MCID remains uninvestigated for any PROs in the setting of revision lumbar surgery for this pathology., Methods: In 53 consecutive patients undergoing revision surgery for same-level recurrent lumbar stenosis-associated back and leg pain, PRO measures of back and leg pain were assessed preoperatively and 2 years postoperatively, using the visual analog scale for back pain (VAS-BP) and leg pain (VAS-LP), Oswestry Disability Index (ODI), Physical and Mental Component Summary categories of the 12-Item Short Form Health Survey (SF-12 PCS and MCS) for quality of life, Zung Depression Scale (ZDS), and EuroQol-5D health survey (EQ-5D). Four established anchor-based MCID calculation methods were used to calculate MCID (average change; minimum detectable change; change difference; and receiver operating characteristic curve analysis) for 2 separate anchors (health transition index of the SF-36 and the satisfaction index)., Results: All patients were available for 2-year PRO assessment. Two years after surgery, a significant improvement was observed for all PROs assessed. The 4 MCID calculation methods generated a range of MCID values for each of the PROs (VAS-BP 2.2-6.0, VAS-LP 3.9-7.5, ODI 8.2-19.9, SF-12 PCS 2.5-12.1, SF-12 MCS 7.0-15.9, ZDS 3.0-18.6, and EQ-5D 0.29-0.52). Each patient answered synchronously for the 2 anchors, suggesting both of these anchors are equally appropriate and valid for this patient population., Conclusions: The same-level recurrent stenosis surgery-specific MCID is highly variable based on calculation technique. The "minimum detectable change" approach is the most appropriate method for calculation of MCIDs in this population because it was the only method to reliably provide a threshold above the 95% confidence interval of the unimproved cohort (greater than the measurement error). Based on this method, the MCID thresholds following neural decompression and fusion for symptomatic same-level recurrent stenosis are 2.2 points for VAS-BP, 5.0 points for VAS-LP, 8.2 points for ODI, 2.5 points for SF-12 PCS, 10.1 points for SF-12 MCS, 4.9 points for ZDS, and 0.39 QALYs for EQ-5D.

Object: Revision lumbar fusion procedures are technically challenging and can be associated with tremendous health care resource utilization and cost. There is a paucity of data regarding specific factors that significantly contribute to increased cost of care. In light of this, the authors set out to identify independent risk factors predictive of increasing 2-year direct health care costs after revision lumbar fusion., Methods: One hundred fifty patients undergoing revision instrument-assisted fusion for adjacent-segment disease (50 cases), pseudarthrosis (47 cases), or same-level stenosis (53 cases) were included in this study. Patient demographics, comorbidities, preoperative health states as assessed by patient-reported outcome questionnaires and perioperative complications were collected and analyzed. Two-year back-related medical resource utilization and direct health care costs were assessed. The independent association of all variables to increasing cost was assessed using multivariate linear regression analysis., Results: There was a wide range ($24,935-$63,769) in overall 2-year direct costs for patients undergoing revision lumbar fusion (mean $32,915 ± $8344 [± SD]). Preoperative variables independently associated with 2-year direct health care costs included diagnosis of congestive heart failure, more severe leg pain (visual analog scale), greater back-related disability (Oswestry Disability Index), and worse mental health (12-Item Short Form Health Survey Mental Component Summary score). There was a 1.1- to 1.2-fold increase in cost for patients in the greatest quartiles compared with those in the lowest quartiles for these variables. Surgical site infection, return to the operating room, and spine-related hospital readmission during the 90-day global health period were postoperative variables independently associated with 2-year cost. Patients in the greatest versus lowest quartiles had a 1.7- to 1.9-fold increase in cost for these variables., Conclusions: Revision lumbar fusion can be associated with considerable 2-year health care costs. These costs can also vary widely among patients, as evidenced by the 2.6-fold overall cost range in this series. Although comorbidities and preoperative severity of disease states contribute to cost of care, the primary drivers of increased cost include perioperative complications such as surgical site infection, return to the operating room, and readmission during the global health period. Measures focused on health service improvement will be most successful in reducing the cost of care for patients undergoing revision lumbar fusion.

Object: Despite advances in technology and understanding in spinal physiology, reoperation for symptomatic same-level recurrent stenosis continues to occur. Although revision lumbar surgery is effective, attention has turned to the question of the utility and value of revision decompression and fusion procedures. To date, an analysis of cost and heath state gain associated with revision lumbar surgery for recurrent same-level lumbar stenosis has yet to be described. The authors set out to assess the 2-year comprehensive cost of revision surgery and determine its value in the treatment of same-level recurrent stenosis., Methods: Forty-two patients undergoing revision decompression and instrumented fusion for same-level recurrent stenosis-associated leg and back pain were included in this study. Two-year total back-related medical resource utilization, missed work, and health state values (quality-adjusted life years [QALYs], calculated from the EQ-5D with US valuation) were assessed. Two-year resource use was multiplied by unit costs based on Medicare national allowable payment amounts (direct cost), and patient and caregiver workday losses were multiplied by the self-reported gross-of-tax wage rate (indirect cost). Mean total 2-year cost per QALY gained after revision surgery was assessed., Results: The mean (± SD) interval between prior and revision surgery was 4.16 ± 4.64 years. Bone morphogenetic protein was used in 7 cases of revision arthrodesis (16.7%). A mean cumulative 2-year gain of 0.84 QALY was observed after revision surgery. The mean total 2-year cost of revision fusion was $49,431 ± $7583 (surgery cost $21,060 ± $4459; outpatient resource utilization cost $9748 ± $5292; indirect cost $18,623 ± $9098). Revision decompression and extension of fusion was associated with a mean 2-year cost per QALY gained of $58,846., Conclusions: In the authors' practice, revision decompression and fusion provided a significant gain in health state utility for patients with symptomatic same-level recurrent stenosis, with a 2-year cost per QALY gained of $58,846. When indicated, revision surgery for same-level recurrent stenosis is a valuable treatment option for patients experiencing back and leg pain secondary to this disease. The authors' findings provide a value measure of surgery that can be compared with the results of future cost-per-QALY-gained studies of medical management or alternative surgical approaches.

Object: Over the past decade, there has been a dramatic increase in the number of spinal fusions performed in the US and a corresponding increase in the incidence of adjacent-segment disease (ASD). Surgical management of symptomatic ASD consists of decompression of neural elements and extension of fusion. It has been shown to have favorable long-term outcomes, but the cost-effectiveness remains unclear. In this study, the authors set out to assess the cost-effectiveness of revision surgery in the treatment of ASD over a 2-year period., Methods: Fifty patients undergoing neural decompression and extension of fusion construct for ASD-associated back and leg pain were included in the study. Two-year total back-related medical resource utilization, missed work, and health state values (quality-adjusted life years [QALYs], calculated from the EQ-5D with US valuation) were assessed. Two-year resource use was multiplied by unit costs based on Medicare national allowable payment amounts (direct cost), and patient and caregiver workday losses were multiplied by the self-reported gross-of-tax wage rate (indirect cost). Mean total 2-year cost per QALY gained after revision surgery was assessed., Results: The mean (± SD) interval between prior fusion and revision surgery for ASD was 3.07 ± 2.02 years. A mean cumulative 2-year gain of 0.76 QALYs was observed after revision surgery. The mean total 2-year cost of extension of fusion constructs was $47,846 ± $32,712 (surgery cost: $24,063 ± $300; outpatient resource utilization cost: $4175 ± $3368; indirect cost: $19,607 ± $32,187). Revision decompression and extension of fusion was associated with a mean 2-year cost per QALY gained of $62,955., Conclusions: In the authors' practice, revision decompression and extension of fusion provided a significant gain in health state utility for patients with symptomatic ASD, with a 2-year cost per QALY gained of $62,995. When indicated, revision surgery for ASD is a valuable treatment option for patients experiencing back and leg pain secondary to ASD. The findings provide a value measure of surgery that can be compared with future cost-per-QALY-gained studies of medical management or alternative surgical approaches.

Object: Spinal surgical outcome studies rely on patient-reported outcome (PRO) measurements to assess treatment effect. A shortcoming of these questionnaires is that the extent of improvement in their numerical scores lack a direct clinical meaning. As a result, the concept of minimum clinical important difference (MCID) has been used to measure the critical threshold needed to achieve clinically relevant treatment effectiveness. As utilization of spinal fusion has increased over the past decade, so has the incidence of adjacent-segment degeneration following index lumbar fusion, which commonly requires revision laminectomy and extension of fusion. The MCID remains uninvestigated for any PROs in the setting of revision lumbar surgery for adjacent-segment disease (ASD)., Methods: In 50 consecutive patients undergoing revision surgery for ASD-associated back and leg pain, PRO measures of back and leg pain on a visual analog scale (BP-VAS and LP-VAS, respectively), Oswestry Disability Index (ODI), 12-Item Short Form Health Survey Physical and Mental Component Summaries (SF-12 PCS and MCS, respectively), and EuroQol-5D health survey (EQ-5D) were assessed preoperatively and 2 years postoperatively. The following 4 well-established anchor-based MCID calculation methods were used to calculate MCID: average change; minimum detectable change (MDC); change difference; and receiver operating characteristic curve (ROC) analysis for the following 2 separate anchors: health transition item (HTI) of the SF-36 and satisfaction index., Results: All patients were available for 2-year PRO assessment. Two years after surgery, a statistically significant improvement was observed for all PROs (mean changes: BP-VAS score [4.80 ± 3.25], LP-VAS score [3.28 ± 3.25], ODI [10.24 ± 13.49], SF-12 PCS [8.69 ± 12.55] and MCS [8.49 ± 11.45] scores, and EQ-5D [0.38 ± 0.45]; all p < 0.001). The 4 MCID calculation methods generated a range of MCID values for each of the PROs (BP-VAS score, 2.3-6.5; LP-VAS score, 1.7-4.3; ODI, 6.8-16.9; SF-12 PCS, 6.1-12.6; SF-12 MCS, 2.4-10.8; and EQ-5D, 0.27-0.54). The area under the ROC curve was consistently greater for the HTI anchor than the satisfaction anchor, suggesting this as a more accurate anchor for MCID., Conclusions: Adjacent-segment disease revision surgery-specific MCID is highly variable based on calculation technique. The MDC approach with HTI anchor appears to be most appropriate for calculation of MCID after revision lumbar fusion for ASD because it provided a threshold above the 95% CI of the unimproved cohort (greater than the measurement error), was closest to the mean change score reported by improved and satisfied patients, and was not significantly affected by choice of anchor. Based on this method, MCID following ASD revision lumbar surgery is 3.8 points for BP-VAS score, 2.4 points for LP-VAS score, 6.8 points for ODI, 8.8 points for SF-12 PCS, 9.3 points for SF-12 MCS, and 0.35 quality-adjusted life-years for EQ-5D.

Object: The number of low-back fusion procedures for the treatment of spine disorders has increased steadily over the past 10 years. Lumbar pseudarthrosis is a potential complication of lumbar arthrodesis and can be associated with significant pain and disability. The aim of this study was to assess, using validated patient-reported outcomes measures, the long-term effectiveness of revision arthrodesis in the treatment of symptomatic pseudarthrosis., Methods: This is a retrospective study of 47 patients who underwent revision lumbar arthrodesis for pseudarthrosis-associated back pain. Baseline 2-year outcomes were assessed using the following: visual analog scale (VAS) for back pain, Oswestry Disability Index (ODI), Zung Self-Rating Depression Scale, time to narcotic independence, time to return to work, EuroQol health-state utility, and physical and mental quality of life (Short Form [SF]-12 Physical and Mental Component Summary scores)., Results: The mean duration of time between prior fusion and development of symptomatic pseudarthrosis was 2.69 years. Bone morphogenetic protein was used in 4 cases (8.5%) of revision arthrodesis. A significant improvement in VAS back pain (7.31 ± 0.81 vs 5.06 ± 2.64, p = 0.001), ODI (29.74 ± 5.35 vs 25.42 ± 6.0, p = 0.001), and physical health SF-12 (23.83 ± 6.89 vs 27.85 ± 8.90, p = 0.001) scores was observed when comparing baseline and 2-year post-revision arthrodesis scores, respectively, with a mean cumulative 2-year gain of 0.35 quality-adjusted life years. The median time to narcotics independence was 12.16 (interquartile range 1.5-24.0) months and the median time to return to work was 4 months (interquartile range 3-5 months). By 2 years after revision surgery, no patients had experienced pseudarthrosis. The SF-12 Mental Component Summary (44.72 ± 7.90 vs 43.46 ± 7.51, p = 0.43) and Zung Self-Rating Depression Scale scores (39.36 ± 7.48 vs 41.39 ± 10.72, p = 0.37) were not significantly improved by 2 years., Conclusions: The authors' study suggests that revision lumbar arthrodesis for symptomatic pseudarthrosis provides improvement in low-back pain, disability, and quality of life. Revision lumbar arthrodesis should be considered a viable treatment option for patients with pseudarthrosis-related back pain. Mental health symptoms from pseudarthrosis-associated back pain may be more refractory to revision surgery.

Object: Cerebrospinal fluid shunt infections are associated with significant morbidity and mortality in the treatment of adult and pediatric hydrocephalus. Antibiotic-impregnated shunt (AIS) catheters have been used with the aim of reducing shunt infection. While many studies have demonstrated a reduction in shunt infection with AIS, this reported efficacy has varied within the literature., Methods: The authors performed a systematic literature review to identify all published articles comparing the incidence of CSF shunt infection in AIS versus non-AIS catheters. The incidence of infection for AIS versus non-AIS catheters was calculated using the Mantel-Haenszel common odds ratio, and baseline demographics were compared between AIS and non-AIS cohorts., Results: Twelve AIS versus non-AIS cohort comparisons were identified in the literature (5 pediatric hydrocephalus, 3 adult hydrocephalus, and 4 mixed populations). In a total of 5613 reported shunt procedures (2664 AISs vs 2949 non-AISs), AISs were associated with a reduction in shunt infection (3.3% vs 7.2%; OR 0.439, p < 0.0001). In 787 shunt procedures for adult hydrocephalus (427 AIS vs 360 non-AIS), AISs were associated with reduction in shunt infection (0.9% vs 5.8%; OR 0.153, p < 0.0001). In 1649 shunt procedures for pediatric hydrocephalus (854 AIS vs 795 non-AIS), AISs were associated with reduction in shunt infection (5.0% vs 11.2%; OR 0.421, p < 0.0001)., Conclusions: The authors' systematic review of the literature demonstrates that AIS catheters are associated with a significant reduction over non-AIS catheters in the reported incidence of CSF shunt infection in adult and pediatric populations. The AIS catheters do not appear to be associated with an increased incidence of antibiotic-resistant microorganisms. Prospective, randomized trials are needed to firmly assess and confirm this apparent difference in infection incidence.

Object: Transforaminal lumbar interbody fusion (TLIF) for spondylolisthesis-associated back and leg pain is associated with improvement in pain, disability, and quality of life. However, given the rising health care costs associated with spinal fusion procedures and varying results of recent cost-utility studies, the cost-effectiveness of TLIF remains unclear. The authors set out to assess the comprehensive costs of TLIF at their institution and to determine its cost-effectiveness in the treatment of degenerative spondylolisthesis., Methods: Forty-five patients undergoing TLIF for Grade I degenerative spondylolisthesis-associated back and leg pain after 6-12 months of conservative therapy were included. The authors assessed the 2-year back pain visual analog scale (VAS) score, leg pain VAS score, Oswestry Disability Index, and total back-related medical resource utilization, missed work, and health-state values (quality-adjusted life years [QALYs], calculated from EQ-5D with US valuation). Two-year resource use was multiplied by unit costs based on Medicare national allowable payment amounts (direct cost), and patient and caregiver workday losses were multiplied by the self-reported gross-of-tax wage rate (indirect cost). The mean total 2-year cost per QALY gained after TLIF was assessed., Results: Compared with preoperative health states reported after at least 6 months of medical management, a significant improvement in back pain VAS score, leg pain VAS score, and Oswestry Disability Index was observed 2 years after TLIF, with a mean 2-year gain of 0.86 QALYs. The mean ± SD total 2-year cost of TLIF was $36,836 ± $11,800 (surgery cost, $21,311 ± $2800; outpatient resource utilization cost, $3940 ± $2720; indirect cost, $11,584 ± $11,363). Transforaminal lumbar interbody fusion was associated with a mean 2-year cost per QALY gained of $42,854., Conclusions: Transforaminal lumbar interbody fusion improved pain, disability, and quality of life in patients with degenerative spondylolisthesis-associated back and leg pain. The total cost per QALY gained for TLIF was $42,854 when evaluated 2 years after surgery with Medicare fees, suggesting that TLIF is a cost-effective treatment of lumbar spondylolisthesis.

Object: Pedicle screws provide efficient stabilization along all 3 columns of the spine, but they can be technically demanding to place, with malposition rates ranging from 5% to 10%. Intraoperative electromyographic (EMG) monitoring has the capacity to objectively identify a screw breaching the medial pedicle cortex that is in proximity to a nerve root. The purpose of this study is to describe and evaluate the authors' 7-year institutional experience with intraoperative EMG monitoring during placement of lumbar pedicle screws and to determine the clinical utility of intraoperative EMG monitoring., Methods: The authors retrospectively studied 2450 consecutive lumbar pedicle screws placed in 418 patients from June 2002 through June 2009. All screws were inserted using a free-hand technique and anatomical landmarks, stimulated at 10.0 mA, and evaluated with CT scanning within 48 hours postoperatively. Medial pedicle screw breach was defined as having greater than 25% of the screw diameter extend outside of the pedicle, as confirmed on CT scanning or intraoperatively by a positive EMG response indicating a medial breach. The sensitivity and specificity of intraoperative EMG monitoring in detecting the presence of a medial screw breach was evaluated based on the following definitions: 1) true positive (a positive response to EMG stimulation confirmed as a breach intraoperatively or on postoperative CT scans); 2) false positive (positive response to EMG stimulation confirmed as a correctly positioned screw on postoperative CT scans); 3) true negative (no response to EMG stimulation confirmed as a correctly positioned screw on postoperative CT scans); or 4) false negative (no response to EMG stimulation but confirmed as a breach on postoperative CT scans)., Results: One hundred fifteen pedicle screws (4.7%) showed positive stimulation during intraoperative EMG monitoring. At stimulation thresholds less than 5.0, 5.0-8.0, and > 8.0 mA, the specificity of a positive response was 99.9%, 97.9%, and 95.9%, respectively. The sensitivity of a positive response at these thresholds was only 43.4%, 69.6%, and 69.6%, respectively. At a threshold less than 5.0 mA, 91% of screws with a positive EMG response were confirmed as true medial breaches. However, at thresholds of 5.0-8.0 mA or greater than 8.0 mA, a positive EMG response was associated with 89% and 100% false positives (no breaches), respectively., Conclusions: When using intraoperative EMG monitoring, a positive response at screw stimulation thresholds less than 5.0 mA was highly specific for a medial pedicle screw breach but was poorly sensitive. A positive response to stimulation thresholds greater 5.0 mA was associated with a very high rate of false positives. The authors' experience suggests that pedicle screws showing positive stimulation below 5.0 mA warrants intraoperative investigation for malpositioning while responses at higher thresholds are less reliable at accurately representing a medial breach.

Object: Surgical site infection (SSI) after lumbar fusion results in significant patient morbidity and associated medical resource utilization. Minimally invasive (MI) techniques for posterior/transforaminal lumbar interbody fusion (P/TLIF) were introduced with the goals of smaller wounds, less tissue trauma, reduced blood loss, and quicker postoperative recovery, while maintaining comparable surgical results. Studies with sufficient power to directly compare the incidence of SSI following MI versus open P/TLIF procedures have been lacking. Furthermore, the direct medical cost associated with the treatment of SSI following the P/TLIF procedure is poorly understood and has not been adequately assessed. Thus, the aim in the present study was to determine the incidence of perioperative SSI in patients undergoing MI versus open P/TLIF and the direct hospital cost associated with the diagnosis and management of SSI after P/TLIF as reported in a large administrative database., Methods: The authors retrospectively reviewed hospital discharge and billing records from the Premier Perspective Database for 2003 to 2009 to identify patients undergoing 1- or 2-level MI or open P/TLIF for lumbar spondylotic disease, disc degeneration, or spondylolisthesis. The ICD-9-CM procedure codes were used to identify patients undergoing P/TLIF and those experiencing SSI. Infection-related costs were obtained from the total costs incurred by the hospital for SSI-related care provided during inpatient or hospital outpatient encounters., Results: Five thousand one hundred seventy patients undergoing P/TLIF were identified. Demographic profiles, including the Charlson Comorbidity Index, were similar between MI and open cohorts. Overall, 292 patients (5.6%) experienced an SSI with a mean direct cost of $15,817 per SSI. For 1-level MI versus open P/TLIF, the incidence of SSI (38 [4.5%] vs 77 [4.8%], p = 0.77) and the mean SSI-associated cost per P/TLIF ($684 vs $724, p = 0.680) were similar. For 2-level MI versus open P/TLIF, the incidence of SSI (27 [4.6%] vs 150 [7.0%], p = 0.037) and mean SSI-associated cost per P/TLIF ($756 vs $1140, p = 0.030) were both significantly lower among MI-treated patients. In a multivariate model that accounted for differences in demographics and patient severity, open fusion was associated with a strong trend of increased incidence of SSI as compared with MI fusion (OR 1.469, 95% CI 0.959-2.250)., Conclusions: In this multihospital study, the MI technique was associated with a decreased incidence of perioperative SSI and a direct cost savings of $38,400 per 100 P/TLIF procedure when used in 2-level fusion. There was no significant difference in the incidence of SSIs between the open and MI cohorts for 1-level fusion procedures. The results of this study provide further evidence of the reduced patient morbidity and health care costs associated with MI P/TLIF.

Object: Outcome studies for spine surgery rely on patient-reported outcomes (PROs) to assess treatment effects. Commonly used health-related quality-of-life questionnaires include the following scales: back pain and leg pain visual analog scale (BP-VAS and LP-VAS); the Oswestry Disability Index (ODI); and the EuroQol-5D health survey (EQ-5D). A shortcoming of these questionnaires is that their numerical scores lack a direct meaning or clinical significance. Because of this, the concept of the minimum clinically important difference (MCID) has been put forth as a measure for the critical threshold needed to achieve treatment effectiveness. By this measure, treatment effects reaching the MCID threshold value imply clinical significance and justification for implementation into clinical practice., Methods: In 45 consecutive patients undergoing transforaminal lumbar interbody fusion (TLIF) for low-grade degenerative lumbar spondylolisthesis-associated back and leg pain, PRO questionnaires measuring BP-VAS, LPVAS, ODI, and EQ-5D were administered preoperatively and at 2 years postoperatively, and 2-year change scores were calculated. Four established anchor-based MCID calculation methods were used to calculate MCID, as follows: 1) average change; 2) minimum detectable change (MDC); 3) change difference; and 4) receiver operating characteristic curve analysis for two separate anchors (the health transition index [HTI] of the 36-Item Short Form Health Survey [SF-36], and the satisfaction index)., Results: All patients were available at the 2-year follow-up. The 2-year improvements in BP-VAS, LP-VAS, ODI, and EQ-5D scores were 4.3 ± 2.9, 3.8 ± 3.4, 19.5 ± 11.3, and 0.43 ± 0.44, respectively (mean ± SD). The 4 MCID calculation methods generated a range of MCID values for each of the PROs (BP-VAS, 2.1-5.3; LP-VAS, 2.1-4.7; ODI, 11-22.9; and EQ-5D, 0.15-0.54). The mean area under the curve (AUC) for the receiver operating characteristic curve from the 4 PRO-specific calculations was greater for the HTI versus satisfaction anchor (HTI [AUC 0.73] vs satisfaction [AUC 0.69]), suggesting HTI as a more accurate anchor., Conclusions: The TLIF-specific MCID is highly variable based on calculation technique. The MDC approach with the SF-36 HTI anchor appears to be most appropriate for calculating MCID because it provided a threshold above the 95% CI of the unimproved cohort (greater than the measurement error), was closest to the mean change score reported by improved and satisfied patients, and was least affected by the choice of anchor. Based on the MDC method with HTI anchor, MCID scores following TLIF are 2.1 points for BP-VAS, 2.8 points for LP-VAS, 14.9 points for ODI, and 0.46 quality-adjusted life years for EQ-5D.