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Surgical management of degenerative lumbar spine disorders is effective at improving patient pain, disability, and quality of life; however, obtaining a durable posterolateral fusion after decompression remains a challenge. Interbody fusion technologies are viable means of improving fusion rates in the lumbar spine, specifically various graft materials including autograft, structural allograft, titanium, and polyether ether ketone. This study assesses the effectiveness of Tritanium posterolateral cage in the treatment of degenerative disk disease.Nearest-neighbor 1:1 matched control transforaminal lumbar interbody fusion with PEEK vs. Tritanium posterior lumbar (PL) cage interbody fusion patients were identified using propensity scoring from patients that underwent elective surgery for degenerative disk diseases. Line graphs were generated to compare the trajectories of improvement in patient-reported outcomes (PROs) from baseline to 3 and 12 months postoperatively. The nominal data were compared via the χThe two groups had no difference regarding either the 3- or 12-month Euro-Qol-5D (EQ-5D), numeric rating scale (NRS) leg pain, and NRS back pain; however, the Tritanium interbody cage group had better Oswestry Disability Index (ODI) scores compared to the control group of the PEEK interbody cage at both 3 and 12 months (p=0.013 and 0.048).Our results indicate the Tritanium cage is an effective alternative to the previously used PEEK cage in terms of PROs, surgical safety, and radiological parameters of surgical success. The Tritanium cohort showed better ODI scores, higher fusion rates, lower subsidence, and lower indirect costs associated with surgical management, when compared to the propensity-matched PEEK cohort.

Procyon lotor (Raccoon) are a dominant predator on eggs of Malaclemys terrapin (Diamondback Terrapin), an estuarine specialist turtle endemic to saltmarshes of the eastern and gulf coasts of the United States. The purpose of this study was to determine if broadcast predator vocalizations could potentially deter Raccoons from foraging on Diamondback Terrapin eggs. We used artificial nests arrays to test 2 hypotheses: (1) predator vocalization playbacks (barking Canis lupus familiaris [Domestic Dog]) reduce number of artificial nests depredated by Raccoons compared to non-predator vocalization playbacks (Urocyon cinereoargenteus [Gray Fox]) or control treatments (no playbacks), and (2) predator vocalization playbacks reduce frequency of visits by Raccoons and overall foraging time compared to non-predator playbacks and control treatments. We randomly assigned sound treatments to each night of a 3-day trial, with 3 trials conducted at 4 experimental sites. We counted the number of depredated artificial nests and used trail cameras to document number of Raccoon visits and Raccoon foraging time following each sound treatment. On average, 51% of artificial nests were depredated in the predator vocalization treatments, 66% in the non-predator–vocalization treatments, and 81% of nests in the control treatments. Average number of Raccoon visits was about 3 times higher in the control treatment compared to the predator treatment but auditory treatment did not affect time spent foraging. Response to predator vocalization was attenuated by repeated exposure to recorded predator playbacks. Variation in type of predator vocalization, length, and frequency of playbacks may increase effectiveness of auditory deterrents on predators of Diamondback Terrapin nests.

Objective: Review the clinical presentation and management of meningeal hemangiopericytomas of the lateral skull base and cerebellopontine angle (CPA), and describe a case of anaplastic hemangiopericytoma of the CPA presenting as a middle ear mass. Study design: Case report and literature review. Case description: A 51-year-old male presented with a one year history of hearing loss, pulsatile tinnitus, and disequilibrium. Physical examination demonstrated a mass in the left middle ear. Magnetic resonance imaging revealed a 4 cm, T1-/T2-isointense, contrast-enhancing mass in the middle cranial fossa. The erosive mass extended into the middle ear and surrounding temporal lobe. A trans-zygomatic approach with a pterional craniotomy exposed a well-encapsulated, highly vascular mass. Manipulation of the tumor resulted in significant hemorrhage. Following removal from the temporal lobe and middle ear, an anterior petrosectomy was performed to remove tumor from the internal auditory canal (IAC) and carotid artery. The facial nerve near the IAC was encased in tumor, and all but a small amount of tumor adherent to the nerve was successfully removed. The final pathologic diagnosis was anaplastic hemangiopericytoma (WHO Grade III). Metastatic workup revealed no extracranial disease, and the patient underwent adjuvant radiation therapy. He continues to do well with only mild disequilibrium at one year follow-up. Conclusions: Hemangiopericytomas are rare, malignant neoplasms that are aggressive and highly vascular. Current management recommendations include excision followed by radiotherapy. Close surveillance is required for patients with anaplastic hemangiopericytoma due to the aggressive nature of this tumor and its propensity for recurrence or metastasis. Keywords: Hemangiopericytoma, Transzygomatic, Skull base, Middle ear mass, Middle cranial fossa, Tumor

BACKGROUND Considerable variability exists in the cost of surgery following spine surgery for common degenerative spine diseases. This variation in the cost of surgery can affect the payment bundling during the postoperative 90 d. OBJECTIVE To determine the drivers of variability in total 90-d cost for laminectomy and fusion surgery. METHODS A total of 752 patients who underwent elective laminectomy and fusion for degenerative lumbar conditions and were enrolled into a prospective longitudinal registry were included in the study. Total cost during the 90-d global period was derived as sum of cost of surgery, cost associated with postdischarge utilization. Multivariable regression models were built for total 90-d cost. RESULTS The mean 90-d direct cost was $29 295 (range, $28 612-$29 973). Based on our regression tree analysis, the following variables were found to drive the 90-d cost: age, BMI, gender, diagnosis, postop imaging, number of operated levels, ASA grade, hypertension, arthritis, preop and postop opioid use, length of hospital stay, duration of surgery, 90-d readmission, outpatient physical/occupational therapy, inpatient rehab, postop healthcare visits, postop nonopioid pain medication use nonsteroidal antiinflammatory drug (NSAIDs), and muscle relaxant use. The R2 for tree model was 0.64. CONCLUSION Utilizing prospectively collected data, we demonstrate that considerable variation exists in total 90-d cost, nearly 70% of which can be explained by those factors included in our modeling. Risk-adjusted payment schemes can be crafted utilizing the significant drivers presented here. Focused interventions to target some of the modifiable factors have potential to reduce cost and increase the value of care.

Background Value-based episode of care reimbursement models is being investigated to curb unsustainable health care costs. Any variation in the cost of index spine surgery can affect the payment bundling during the 90-d global period. Objective To determine the drivers of variability in cost for patients undergoing elective anterior cervical discectomy and fusion (ACDF) for degenerative cervical spine disease. Methods Four hundred forty-five patients undergoing elective ACDF for cervical spine degenerative diagnoses were included in the study. The direct 90-d cost was derived as sum of cost of surgery, cost associated with postdischarge utilization. Multiple variable linear regression models were built for total 90-d cost. Results The mean 90-d direct cost was $17685 ± $5731. In a multiple variable linear regression model, the length of surgery, number of levels involved, length of hospital stay, preoperative history of anticoagulation medication, health-care resource utilization including number of imaging, any complications and readmission encounter were the significant contributor to the 90-d cost. The model performance as measured by R2 was 0.616. Conclusion There was considerable variation in total 90-d cost for elective ACDF surgery. Our model can explain about 62% of these variations in 90-d cost. The episode of care reimbursement models needs to take into account these variations and be inclusive of the factors that drive the variation in cost to develop a sustainable payment model. The generalized applicability should take in to account the differences in patient population, surgeons' and institution-specific differences.

Background Numerous studies have demonstrated the benefits of early decompression and stabilization in unstable spine injuries with incomplete neurological deficits. However, a clear consensus on timing to operative intervention still does not exist in those with a normal neurological exam and unstable spine. Objective To determine the optimal timing of operative intervention in traumatic spine injuries without neurological deficit. Methods Retrospective chart review at a single institution was performed including patients with traumatic spine injuries without neurological deficit admitted from December 2001 to August 2012. Estimated intraoperative blood loss (EBL), in-hospital complications, postoperative hospital length of stay (HLOS), intensive care unit length of stay (ICULOS), and ventilator days were recorded. Delayed surgery was defined as surgery 72 h after admission. Results A total of 456 patients were included for analysis. There was a trend towards statistical significance between the time to operative intervention and EBL in bivariate analysis (P = .07). In the risk-adjusted multivariable analysis delayed vs early surgery was not associated with increased EBL or complications. Delayed surgery was associated with increased ICULOS (odds ratio [OR] = 2.19; 95% confidence interval [CI]: 1.38-3.51; P = .001), ventilator days (OR = 2.09; 95% CI: 1.28-3.43; P = .004), and increased postoperative HLOS (OR = 1.84; 95% CI: 1.22-2.76; P = .004). Conclusion Earlier operative intervention was associated with decreased ICULOS, ventilator days, and postoperative HLOS and did not show a statistically significant increase in EBL or complications. Earlier operative intervention for traumatic spine injuries without neurological deficit provides better outcomes compared to delayed surgery.

OBJECTIVECurrent 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.METHODSData 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).RESULTSEighty-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.CONCLUSIONSThis 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.

BACKGROUND Healthcare resource utilization and patient-reported outcomes (PROs) for intradural extramedullary (IDEM) spine tumors are not well reported. OBJECTIVE To analyze the PROs, costs, and resource utilization 1 year following surgical resection of IDEM tumors. METHODS Patients undergoing elective spine surgery for IDEM tumors and enrolled in a single-center, prospective, longitudinal registry were analyzed. Baseline and postoperative 1-year PROs were recorded. One-year spine-related direct and indirect healthcare resource utilization was assessed. One-year resource use was multiplied by unit costs based on Medicare national payment amounts (direct cost). Patient and caregiver workday losses were multiplied by the self-reported gross-of-tax wage rate (indirect cost). RESULTS A total of 38 IDEM tumor patients were included in this analysis. There was significant improvement in quality of life (EuroQol-5D), disability (Oswestry and Neck Disability Indices), pain (Numeric rating scale pain scores for back/neck pain and leg/arm pain), and general physical and mental health (Short-form-12 health survey, physical and mental component scores) in both groups 1 year after surgery (P < .0001). Eighty-seven percent (n = 33) of patients were satisfied with surgery. The 1-year postdischarge resource utilization including healthcare visits, medication, and diagnostic cost was $4111 ± $3596. The mean total direct cost was $23 717 ± $7412 and indirect cost was $5544 ± $4336, resulting in total 1-year cost $29 177 ± $9314. CONCLUSION Surgical resection of the IDEM provides improvement in patient-reported quality of life, disability, pain, general health, and satisfaction at 1 year following surgery. Furthermore, we report the granular costs of surgical resection and healthcare resource utilization in this population.

BACKGROUND As publically promoted by all stakeholders in health care reform, prospective outcomes registry platforms lie at the center of all current evidence-driven value-based models. OBJECTIVE To demonstrate the variability in outcomes and cost at population level and individual patient level for patients undergoing spine surgery for degenerative diseases. METHODS Retrospective analysis of prospective longitudinal spine registry data was conducted. Baseline and postoperative 1-year patient-reported outcomes were recorded. Previously published minimal clinically important difference for Oswestry Disability Index (14.9) was used. Back-related resource utilization and quality-adjusted life years (QALYs) were assessed. Variations in outcomes and cost were analyzed at population level and at the individual patient level. RESULTS A total of 1454 patients were analyzed. There was significant improvement in patient-reported outcomes at postoperative 1 year ( P < .0001). For patients demonstrating health benefit at population level, 12.5%, n = 182 of patients experienced no gain from surgery and 38%, n = 554 failed to achieve minimal clinically important difference. Mean 1-year QALY-gained was 0.29; 18% of patients failed to report gain in QALY. For patients with 2-year follow-up, surgery resulted in 0.62 QALY-gained at average direct cost of $28 953. A wide variation in both QALY-gained and cost was observed. CONCLUSION Spine treatments that on average are cost-effective may have wide variability in value at the individual patient level. The variability demonstrated here represents an opportunity, through registries, to identify specific care that may be less effective, and refine patient-specific care delivery and indications to drive overall group-level treatment value. Understanding value of spine care at an individualized as well as population level will allow clinicians, and eventually payers, to better target resources for improving care for nonresponders, ultimately driving up the average health for the whole population.

Background Chronic subdural hematoma evacuation can be achieved in select patients through bedside placement of the Subdural Evacuation Port System (SEPS; Medtronic, Inc., Dublin, Ireland). This procedure involves drilling a burr hole at the thickest part of the hematoma. Identifying this location is often difficult, given the variable tilt of available imaging and distant anatomic landmarks. This paper evaluates the feasibility and accuracy of a bedside navigation system that relies on visible light-based 3-dimensional (3D) scanning and image registration to a pre-procedure computed tomography scan. The information provided by this system may increase accuracy of the burr hole location. Methods In Part 1, the accuracy of this system was evaluated using a rigid 3D printed phantom head with implanted fiducials. In Part 2, the navigation system was tested on 3 patients who underwent SEPS placement. Results The error in registration of this system was less than 2.5 mm when tested on a rigid 3D printed phantom head. Fiducials located in the posterior aspect of the head were difficult to reliably capture. For the 3 patients who underwent 5 SEPS placements, the distance between anticipated SEPS burr hole location based on registration and actual burr hole location was less than 1cm. Conclusions A bedside cranial navigation system based on 3D scanning and image registration has been introduced. Such a system may increase the success rate of bedside procedures, such as SEPS placement. However, technical challenges such as the ability to scan hair and practical challenges such as minimization of patient movement during scans must be overcome.

Discovery of an unusual rectal gland in the Atlantic sixgill shark Hexanchus vitulus led us to examine the rectal glands of 31 species of sharks to study diversity in rectal-gland morphology. Twenty-four of 31 species of sharks had digitiform glands (mean width-length ratio ± SD = 0.17 ± 0.04) previously assumed to be characteristic of all elasmobranchs regardless of habitat depth or phylogenetic age. Rectal glands from the family Somniosidae were kidney bean-shaped (mean width: length ± SD = 0.46 ± 0.05); whereas those from families Echinorhinidae and Hexanchidae were lobulate (mean width: length ± SD = 0.55 ± 0.06). Rectal gland width: length were different among species with digitiform morphology and lobulate morphology (ANOVA; R2 = 0.9; df = 15, 386; 401, F = 219.24; P

Obese patients have greater comorbidities along with higher risk of complications and greater costs after spine surgery, which may result in increased cost and lower quality of life compared with their non-obese counterparts.The aim of the present study was to determine cost-utility following anterior cervical discectomy and fusion (ACDF) in obese patients.This study analyzed prospectively collected data.Patients undergoing elective ACDF for degenerative cervical pathology at a single academic institution were included in the study.Cost and quality-adjusted life years (QALYs) were the outcome measures.One- and two-year medical resource utilization, missed work, and health state values (QALYs) were assessed. Two-year resource use was multiplied by unit costs based on Medicare national payment amounts (direct cost). Patient and caregiver workday losses were multiplied by the self-reported gross-of-tax wage rate (indirect cost). Total cost (direct+indirect) was used to compute cost per QALY gained. Patients were defined as obese for body mass index (BMI) ≥35 based on the WHO definition of class II obesity. A subgroup analysis was conducted in morbidly obese patients (BMI≥40).There were significant improvements in pain (neck pain or arm pain), disability (Neck Disability Index), and quality of life (EuroQol-5D and Short Form-12) at 2 years after surgery (p.001). There was no significant difference in post-discharge health-care resource utilization, direct cost, indirect cost, and total cost between obese and non-obese patients at postoperative 1-year and 2-year follow-up. Mean 2-year direct cost for obese patients was $19,225±$8,065 and $17,635±$6,413 for non-obese patients (p=.14). There was no significant difference in the mean total 2-year cost between obese ($23,144±$9,216) and non-obese ($22,183±$10,564) patients (p=.48). Obese patients had a lower mean cumulative gain in QALYs versus non-obese patients at 2-years (0.34 vs. 0.42, p=.32). Two-year cost-utility in obese ($68,070/QALY) versus non-obese patients ($52,816/QALY) was not significantly different (p=.11). Morbidly obese patients had lower QALYs gained (0.17) and higher cost per QALYs gained ($138,094/QALY) at 2 years.Anterior cervical discectomy and fusion provided a significant gain in health state utility in obese patients, with a mean 2-year cost-utility of $68,070 per QALYs gained, which can be considered moderately cost-effective. Morbidly obese patients had lower cost-effectiveness; however, surgery does provide a significant improvement in outcomes. Obesity, and specifically morbid obesity, should to be taken into consideration as physician and hospital reimbursements move toward a bundled model.

Background Lumbar epidural steroid injection (LESI) is a valuable therapeutic option when administered to the appropriate patient, for the appropriate disease process, at the appropriate time. There is considerable variability in patient-reported outcomes (PROs) after LESI, creating uncertainty as to who will benefit from the therapy and who will not. Purpose We set out to identify patient attributes, which are important predictors for the achievement of a minimum clinically important difference (MCID) in the Oswestry Disability Index (ODI) after LESI. Study Design A prospective cohort study was carried out. Patient Sample A total of 239 consecutive patients undergoing LESI for back-related disability, back pain (BP), and leg pain (LP) associated with degenerative pathology comprised the patient sample. Outcome Measures Baseline and 3-month patient self-reported ODI, numeric rating scale-BP and LP, Euro-Qol-5D, and Short Form (SF)-12 scores were recorded. Methods A total of 239 consecutive patients undergoing LESI for degenerative pathology over a period of 2 years who were enrolled into a prospective web-based registry were included in the study. Using the previously reported anchor-based approach, an MCID threshold of 7.1% was established for ODI after LESI. Each enrolled patient was then dichotomized as a "responder" (achieving MCID) or a "non-responder." Multiple logistic regression analysis was then performed, with the achievement of MCID serving as the outcome of interest. Candidate variables included in the regression analyses were age, gender, employment, insurance type, smoking status, preoperative ambulation, preinjection narcotic use, comorbidities, predominant LP or BP symptoms, symptom duration, diagnosis, number of levels, prior surgery, baseline PROs, type of stenosis (central, lateral recesses, or foraminal), injection route (transforaminal, interlaminar, or caudal), and number of injections. Subsequently, we also randomly selected 80% of the patients to serve as the training data for a multiple logistic regression model. Once this predictive model was built, it was validated using the remaining 20% of patients. Results There were 124 (62%) patients who achieved MCID for ODI. The existence of central stenosis (p=.006), TF or IL injection route (p=.02) compared with caudal epidural steroid injection, higher baseline ODI (p=.00001), and a diagnosis of disc herniation (p=.02) increase the odds of achieving MCID for ODI at 3 months. Symptom duration for over a year (p=.006), prior surgery (p=.08), and preinjection anxiety (p=.001) decrease the odds of achieving MCID. The area under the curve (AUC) for our predictive model's receiver-operator characteristic was 0.81 when using the 80% training data set, and the AUC was 0.72 when using the 20% validation data. Conclusion We have identified patient attributes that are important predictors for the achievement of MCID in ODI 3 months after LESI. The use of these attributes, in the form of a predictive model for LESI efficacy, has the potential to improve decision making around LESI. Spine care providers can use the information to gain insight into the likelihood that a particular patient will experience a meaningful benefit from LESI.

We quantified and compared movement and microhabitat use of Eastern Copperheads (Agkistrodon contortrix) in fragmented and unfragmented habitats to determine the effects of fragmentation on movement and habitat use. We used thread bobbins to track movement and calculate straight-line distance (SLD) moved, total distance (TDM) moved, and occupied area for individual snakes. Microhabitat use was characterized by quantifying number of trees, woody vegetation stems, herbaceous vegetation stems, percent grass coverage, and percent canopy coverage at each location a snake was observed, and at an equal number of randomly selected locations. Neither SLD nor TDM differed between fragmented and unfragmented habitats. Overall average SLD moved was 24.1 m and TDM was 39.6 m over 48 h. Although SLD and TDM did not differ between sites, mean occupied area ± standard error was significantly greater at the unfragmented (2,310.9 ± 272.7 m) compared with the fragmented site (1,025.9 ± 314.9 m). Microhabitat features were similar between the fragmented and unfragmented sites, and herbaceous vegetation and high canopy cover were associated with locations where snakes were observed at both sites. It is likely that Eastern Copperheads can persist in a variety of habitats in the southeastern United States because their preferred microhabitat features are widely distributed and common in both fragmented and unfragmented environments, demonstrating that they retain characteristics of a habitat specialist within heterogeneous environments suitable for generalists.

Oviparous reptile embryos must tolerate fluctuations in oxygen availability and incubation temperature during development. In this study, regional hypoxia was simulated by painting eggs of Eublepharis macularius with melted paraffin wax to decrease the available surface area for gas exchange by approximately 80%. Experimental and control eggs were incubated at either 28 or 34 °C and embryo mass, stage, heart mass, relative heart mass, and oxygen consumption (VO2) were measured at 15 and 30 days of incubation. Embryo mass from the regional hypoxia treatment was reduced by about 50% at day 15 and by about 30% at day 30 of incubation, independent of incubation temperature compared to controls. Embryo stage from the regional hypoxia treatment was reduced by about 2 stages at day 15 independent of incubation temperature but there was no effect of hypoxia treatment at day 30. Absolute heart mass was reduced by about 60% in regional hypoxia embryos sampled at day 15 while relative heart mass was increased by about 30% in regional hypoxic embryos at day 30 compared to controls, suggesting that heart mass is conserved at the expense of somatic growth. Embryo VO2 was affected by incubation temperature at both 15 and 30 days of incubation but not by regional hypoxia treatment. These results indicate that embryos of E. macularius possess plasticity in their capacity to respond to reduction in oxygen availability during incubation, and are able to survive and continue developing when gas exchange surface area is severely limited.

OBJECTIVEHospital 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.METHODSAll 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.RESULTSA 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.CONCLUSIONSIdentification 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.

Three predator exclusion devices were designed and deployed with the goal of denying raccoons access to simulated turtle nests (n = 116) for 48 hrs. A novel design, a roughly conical cage constructed using wooden dowels for bars, protected nests through 3 trials at rates of 100% (n = 4), 100% (n = 8), and 70% (n = 84). This new cage design offers a portable, inexpensive, and reusable alternative for protecting nests of diamondback terrapins and potentially other emydid species.

BACKGROUND Value-based purchasing is rapidly being implemented to rein in the unsustainably rising costs of the US healthcare system. With a growing elderly population, it is vital to understand the value of spinal surgery in this group of individuals. OBJECTIVE To compare the cost-effectiveness of lumbar decompression with and without fusion for degenerative spine disease in elderly vs nonelderly patients. METHODS A total of 221 patients undergoing elective primary surgery for degenerative lumbar pathology who were enrolled in a prospective longitudinal registry were analyzed. Patient-reported outcomes of Oswestry Disability Index, numeric rating scale for back and leg pain, and quality-of-life scores (EuroQol-5D) were recorded. Two-year back-related medical resource use, missed work, and health-state values (quality-adjusted life-years [QALYs]) were assessed. Two-year resource use was multiplied by unit costs based on Medicare national allowable payment amounts (direct cost). Patient and caregiver workday losses were multiplied by gross-of-tax wage rate (indirect cost). Patients were divided into age groups

BACKGROUND Lumbar spine degenerative pathologies are prevalent in the United States. The health benefit of spine surgery in the elderly has been questioned. OBJECTIVE To compare effectiveness, morbidity, and quality of care associated with surgical management of degenerative lumbar spinal disorders in elderly vs nonelderly patients. METHODS The National Neurosurgery Quality and Outcomes Database registry prospectively collects measures of surgical safety and patient-reported outcomes for 1 year after surgery. All lumbar surgery cases were queried to compare the elderly surgical population (70 years of age and older) and associated outcomes with patients younger than 70 years of age. RESULTS A total of 4370 lumbar spine surgeries were enrolled in National Neurosurgery Quality and Outcomes Database with 1-year follow-up; 1020 (23%) were elderly patients. The elderly had an increased incidence of heart disease, osteoporosis, high-risk anesthesia grade (American Society of Anesthesiologists grade 3/4), more than 3 level surgery, ambulation assist device use, unemployment, female sex, white race, and stenosis as a diagnosis. The elderly patients had a lower body mass index, incidence of anxiety/depression, liability/workers' compensation claims, and disc herniation as a diagnosis. Length of hospitalization and postdischarge inpatient rehabilitation/nursing facility was significantly greater in the elderly. The incidence of surgical complications and 90-day hospital readmission were similar. Significant and equivalent improvements at 1 year in pain, disability, and quality of life were reported by both elderly and nonelderly patients overall and for each unique spine diagnosis. CONCLUSION For all ages, lumbar spine surgery resulted in significant improvement in pain, disability, and quality of life. Elderly patients experienced equivalent and significant health benefit in all measured health domains without an increased rate of surgical complications or hospital readmissions. Elective lumbar spine surgery in the elderly provides significant gains in health status, justifying its continued use in this growing population.

Background As part of the Affordable Care Act, health utility metrics are being investigated to define a cost-effective, value-based health care model. EuroQOL-5D (EQ-5D) and Short Form-6D (SF-6D) are commonly used quality-of-life instruments. Domains in the EQ-5D questionnaire are thought to be less responsive in measuring quality of life after cervical surgery. Objective To evaluate the validity and responsiveness of SF-6D and EQ-5D in determining health and quality of life after elective cervical spine surgery. Methods A total of 420 patients undergoing elective cervical spine surgery over a period of 2 years were enrolled in a prospective longitudinal registry. Patient-reported outcomes Neck Disability Index (NDI), EQ-5D, and SF-12 were recorded. Based on previously published equations, SF-6D was calculated using NDI and SF-12 scores. Patients were asked whether "surgery met their expectations" (meaningful improvement). The validity and relative responsiveness of SF-6D (NDI), SF-6D (SF-12), and EQ-5D to discriminate between meaningful and nonmeaningful improvement were calculated. Results Sixty-six percent of patients (277) reported a level of improvement after surgery that met their expectations (meaningful improvement). SF-6D (NDI) (area under the curve [AUC] = 0.69) was a more valid discriminator of meaningful improvement compared with the SF-6D (SF-12) (AUC = 0.65) and EQ-5D (AUC = 0.62). SF-6D (NDI) was also a more responsive measure compared with SF-6D (SF-12) and EQ-5D (standardized response mean difference: 0.66, 0.48, and 0.44, respectively). Conclusion SF-6D is a more valid and responsive measure of general health and quality of life compared with EQ-5D. SF-6D derived from disease-specific disability scores was more valid and responsive than that derived from the generic preference-based SF-12. Cost-effective studies should use SF-6D as a measure of QALY after cervical spine surgery.

Study design Mixed retrospective-prospective cohort study. Objective To characterize practice patterns for the use of Cell Saver at our institution, investigate its cost-effectiveness, and propose a new tool for patient selection. Summary of background data Blood loss is an exceedingly common complication of spine surgery, and Cell Saver intraoperative cell salvage has been used to decrease reliance on allogeneic blood transfusions for blood volume replacement. The cost-effectiveness of Cell Saver has not been established for lumbar spinal surgery, and no universal guidelines exist for clinicians to decide when to utilize this tool. Other authors have proposed cutoffs for anticipated blood loss volumes which indicate that Cell Saver should be used. Methods Five hundred and eight patients undergoing lumbar laminectomy in 3 or fewer levels were reviewed from our prospective spinal outcomes registry. Cost information for Cell Saver and allogeneic transfusions was collected from our institution's billing and collections department. Logistic regression was used to identify patient characteristics associated with use of Cell Saver. An incremental cost effectiveness ratio was calculated based on transfusion and cost data. A clinical prediction score was derived using logistic regression. Results Use of Cell Saver correlated with increased age, higher body mass index, diabetes, greater American Society of Anesthesiologists classification, and greater number of previous spine surgeries. Outcomes for patients who did and did not have Cell Saver set up intraoperatively were equivocal. Cell Saver was not cost effective based on current usage patterns, but may become cost effective if used for patients with high expected blood loss. A simple clinical prediction rule is proposed which may aid in selection of patients to have Cell Saver present intraoperatively. Conclusion Cell Saver is not a cost-effective intervention but may become cost effective if a threshold of expected intraoperative blood loss is used to select patients more judiciously. Level of evidence 3.

Development of reptile embryos is dependent upon adequate oxygen availability to meet embryonic metabolic demand. Metabolic rate of embryos is temperature dependent, with oxygen consumption increasing exponentially as a function of temperature. Because metabolic rate is more temperature sensitive than diffusion, developmental processes are predicted to be oxygen-limited at high temperatures. We tested the hypothesis that the amount of development lizard embryos achieve in the oviduct is dependent upon both temperature and oxygen availability. We evaluated the effect of temperature (23, 33°C) and oxygen concentration (9%, 15%, 21% O2) on survival and development of embryos of the oviparous skink Scincella lateralis. We predicted that incubation at 33°C under hypoxic conditions would result in higher embryo mortality due to mismatch between embryo oxygen demand and oxygen supply compared to eggs incubated at 23°C under hypoxic conditions. Embryo mortality was highest at 33°C/9% O2 (86%) compared to 23°C/9% O2 (14%), however, mortality did not differ among any other oxygen-temperature treatment combination. Both temperature and oxygen affected differentiation, but the interaction between temperature and oxygen was not significant. Embryo growth in mass and hatchling mass were affected by oxygen concentration independent of temperature treatment. Differing responses of growth and differentiation to temperature and oxygen treatments suggests that somatic growth may be more sensitive to oxygen availability than differentiation. Results indicate that embryo mortality can occur both via the direct effect of high temperature on cellular function as well as indirectly through thermally induced oxygen diffusion limitation. J. Exp. Zool. 323A: 445–455, 2015. © 2015 Wiley Periodicals, Inc.

The ability to understand factors associated with an increased duration of missed work postoperatively could be used to more effectively select patients with the greatest opportunity for a successful outcome. We set out to determine the effect of preoperative depression on postoperative return to work in patients undergoing transforaminal lumbar interbody fusion (TLIF) for degenerative spondylolisthesis.Fifty-eight patients undergoing TLIF for symptomatic grade I degenerative lumbar spondylolisthesis were included in this analysis. Patient demographics, clinical presentation, indications for surgery, radiologic studies, and operative variables were assessed for each case. Patient-assessed outcome measures were obtained prospectively at baseline and 2 years postoperatively. To understand the factors associated with prolonged return to work, univariate linear regression analysis and stepwise multivariate Cox proportional hazards model was used.All patient-reported outcomes assessed were significantly improved 2 years after TLIF (P0.001). Of the 32 patients working preoperatively, 26 (81%) returned to work postoperatively. Median time to return to work was 56 days (range, 10-150 days). Independent of patient age; preoperative pain, disability, and quality of life; and extent of postoperative improvement, increased preoperative Zung depression score remained associated with prolonged return to work (P = 0.02).Independent of postoperative improvement in pain, disability, and quality of life, the extent of preoperative depression was an independent predictor of time to return to work in patients undergoing TLIF for spondylolisthesis, suggesting that regardless of how successful TLIF surgery may be at improving a patient's pain, disability, or quality of life, greater depression will delay or prohibit their ability to return to work postoperatively.

Single cohort study of patients undergoing revision fusion for lumbar pseudoarthrosis.To assess the 2-year comprehensive costs of revision arthrodesis for lumbar pseudoarthrosis at our institution and determine the associated cost per quality-adjusted life year (QALY) gained in this patient population.The proportion of lumbar spine operations involving a fusion procedure has increased over the past 2 decades. Similarly, there has been a corresponding increase in the incidence and prevalence of pseudoarthrosis. However, the cost-effectiveness of revision surgery for pseudoarthrosis-associated back pain has yet to be examined.Forty-seven patients undergoing revision instrumented arthrodesis for pseudoarthrosis-associated back pain were included. Two-year total back-related medical resource utilization, missed work, and health-state values (QALYs, calculated from EuroQuol 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 care-giver work-day losses were multiplied by the self-reported gross-of-tax wage rate (indirect cost). The mean total 2-year cost per QALY gained after revision surgery was assessed.The mean (±SD) duration of time between prior fusion and development of symptomatic pseudoarthrosis was 2.69±3.09 years. None of the patients developed symptomatic pseudoarthrosis after 2 years of revision surgery. A mean cumulative 2-year gain of 0.35 QALYs was reported. The mean (±SD) total 2-year cost of revision fusion was $41,631±$9691 (surgery cost: $23,865±$270; outpatient resource utilization cost: $4885±$2301; indirect cost: $12,879±$8171). Revision instrumented arthrodesis was associated with a mean 2-year cost per QALY gained of $118,945.Revision arthrodesis was associated with improved 2-year quality of life in patients with pseudoarthrosis-related back pain. Nevertheless, in our experience revision surgery was shown to be marginally cost-effective at $118,945 per QALY gained.

BackgroundCerebrospinal fluid (CSF) shunt infection is a major cause of morbidity and mortality in the treatment of hydrocephalus and is associated with significant medical cost. Several studies have demonstrated the efficacy of antibiotic-impregnated (AI) shunt catheters in reducing CSF shunt infection; however, providers remain reluctant to adopt AI catheters into practice because of the increased upfront cost. The objective of this study was to determine if the use of AI catheters provided cost savings in a large nationwide database.MethodsHospital discharge and billing records from the Premier Perspective Database from 2003–2009 were retrospectively reviewed to identify all adult and pediatric patients undergoing de novo ventricular shunt placement. The incidence of shunt infection within 1 year of implantation was determined. Shunt infection–related cost was defined as all inpatient billing costs incurred during hospitalization for treatment of shunt infection.ResultsIn 287 U.S. hospitals, 10,819 adult (AI catheters, 963; standard catheters, 9856) and 1770 pediatric (AI catheters, 229; standard catheters, 1541) patients underwent ventricular shunt placement. AI catheters 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. Total infection-related costs were $17,371,320 ($45,714 ± $49,745 per shunt infection) for adult patients and $6,508,064 ($56,104 ± $65,746 per shunt infection) for pediatric patients. Infection-related cost per 100 de novo shunts placed was $120,534 for AI catheters and $162,659 for standard catheters in adult patients and $165,087 for AI catheters and $395,477 for standard catheters in pediatric patients.ConclusionsIn analysis of this large, nationwide database, AI catheters were found to be associated with a significant reduction in infection incidence, resulting in tremendous cost savings. AI catheters were associated with a cost savings of $42,125 and $230,390 per 100 de novo shunts placed in adult and pediatric patients, respectively.

OBJECTIVEQuality 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.METHODSIncluded 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.RESULTSThere 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).CONCLUSIONSThis 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.

OBJECTIVEExtended 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.METHODSThe 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).RESULTSA 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.CONCLUSIONSThe 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.

Background The healthcare reimbursement models are rapidly transitioning to pay-per-performance episode of care payment models. These models, if designed well, must account for the variability in the cost of index surgeries during the global period. Objective To analyze the variability in 90-d cost and determine the drivers of the variability in total 90-d cost associated with single-level microdiscectomy. Methods A total of 203 patients undergoing primary microdiscectomy for degenerative lumbar conditions were included in the study. The total 90-d cost was derived as the sum of cost of surgery, cost associated with postdischarge utilization. A multivariable linear regression model for total 90-d cost was built. Results The mean total cost within 90-d after single-level primary microdiscectomy was $7962 ± $2092. In a multivariable linear regression model, obesity, history of myocardial infarction, factors that lengthen the time of surgery and hospital stay, complications and readmission within 90-d, postdischarge healthcare utilization including emergency room visits, time to opioid independence, number of days on nonopioid pain medications, diagnostic imaging, and the number of days in outpatient and inpatient rehabilitation contribute to the total 90-d cost. The model performance as measured by R2 is 0.76. Conclusion Utilizing prospectively collected data, we highlight major drivers of variation in cost following a single-level primary microdiscectomy. Our model explains about three-quarters of the variation in cost. The risk-adjusted cost estimates powered by models such as the one presented here can be used to formulate a sustainable total 90-d episode of care bundle payment.

With growing older population and increasing rates of cervical spinal surgery, it is vital to understand the value of cervical surgery in this population. We set forth to determine the cost utility following anterior cervical decompression and fusion (ACDF) for degenerative disease in older patients. Patients undergoing ACDF for degenerative diseases were enrolled into prospective longitudinal registry. Patient-reported outcomes (PROs) were recorded at baseline, 1-year, and 2-year postoperatively. Two-year medical resource utilization, missed work, and health-state values [quality-adjusted life years (QALYs)] were assessed to compute cost per QALY gained. Patients were dichotomized based on age

Prospective registries have emerged as a feasible way to capture real-world care across large patient populations. However, the proven validity of more robust and cumbersome patient-reported outcomes instruments (PROis) must be balanced with what is feasible to apply in large-scale registry efforts.To determine the relative validity and responsiveness of common PROis in accurately determining effectiveness of lumbar fusion for degenerative lumbar spondylolisthesis in registry efforts.Prospective cohort study.Fifty-eight patients undergoing transforaminal lumbar interbody fusion (TLIF) for degenerative lumbar spondylolisthesisPatient-reported outcome measures for pain (numeric rating scale for back and leg pain [NRS-BP, NRS-LP]), disability (Oswestry Disability Index [ODI]), general health (Short Form [SF]-12), quality of life (QOL) (EuroQol five dimensions [EQ-5D]), and depression (Zung depression scale [ZDS]) were assessed.Fifty-eight patients undergoing primary TLIF for lumbar spondylolisthesis were entered into an institutional registry and prospectively followed for 2 years. Baseline and 2-year patient-reported outcomes were assessed. To assess the validity of PROis to discriminate between effective and noneffective improvements, receiver operating characteristic curves were generated for each outcomes instrument. An area under the curve (AUC) of ≥0.80 was considered an accurate discriminator. The difference between standardized response means (SRMs) in patients reporting meaningful improvement versus not was calculated to determine the relative responsiveness of each instrument.For pain and disability, ODI had AUC=0.94, suggesting it as an accurate discriminator of meaningful improvement. Oswestry Disability Index was most responsive to postoperative improvement (SRM difference: 2.18), followed by NRS-BP and NRS-LP. For general health and QOL, SF-12 physical component score (AUC: 0.90), ZDS (AUC: 0.89), and SF-12 mental component score (AUC: 0.85) were all accurate discriminators of meaningful improvement, however, EQ-5D was most accurate (AUC: 0.97). EuroQol five dimensions was also most responsive (SRM difference: 2.83).For pain and disability, ODI was the most valid and responsive measure of effectiveness of lumbar fusion. Numeric rating scale-BP and NRS-LP should not be used as substitutes for ODI in measuring effectiveness of care in registry efforts. For health-related QOL, EQ-5D was the most valid and responsive measure of improvement, however, SF-12 and ZDS are valid alternatives with less responsiveness.

STUDY DESIGN Literature review and case example. OBJECTIVE Describe methodological considerations of spine surgery registries. Review existing spine surgery registries. Describe the Vanderbilt Prospective Spine Registry (VPSR) as a case example and demonstrate its impact on comparative effectiveness research, value analysis, quality improvement, and practice-based learning. SUMMARY OF BACKGROUND DATA To bend the cost curve and ultimately achieve sustainability in health care, medical providers and surgical treatments of the highest quality and effectiveness must be preferentially used and purchased. As the current US health care environment continues to evolve, it will be essential for all spine clinicians to understand and be facile with the principles of evidence-based health care reform. METHODS We describe the methodological considerations of spine surgery registries, review the literature to describe existing spine surgery registries, and discuss the VPSR as a case example. RESULTS We were able to obtain detailed information on 13 existing spine surgery registries through various internet-based resources. Of the 13, 2 registries had start dates before 2000, 3 between 2001 and 2005, 5 starting in 2006, and 3 were indeterminate. Follow-up rates were in the range from 22% to 79%, with longer follow-up times consistently producing lower follow-up rates. CONCLUSION Prospective, longitudinal, patient-reported outcomes registries are powerful tools that allow measurement of cost, safety, effectiveness, and health care value across clinically meaningful episodes of care. Registries entirely based on claims or billing data, safety measures alone, process measures, or other proxies of outcome offer valuable insights, but do not provide comprehensive data to drive patient-centered value-based reform. As more spine-focused registries emerge and their integration into the US health care delivery evolve, the evidence to power value-based reform will be enabled.

Study design National Prospective Observational Registry. Objective Describe our preliminary experience with the National Neurosurgery Quality and Outcomes Database (NQOD), a national collaborative registry of quality and outcomes reporting after low back surgery. Summary of background data All major health care stakeholders are now requiring objective data regarding the value of medical services. Surgical therapies for spinal disorders have faced particular scrutiny in recent value-based discussions, in large part due to the dramatic growth in the cost and application of these procedures. Reliable data are fundamental to understanding the value of delivered health care. Clinical registries are increasingly used to provide such data. Methods The NQOD is a prospective observational registry designed to establish risk-adjusted expected morbidity and 1-year outcomes for the most common lumbar surgical procedures performed by spine surgeons; provide practice groups and hospitals immediate infrastructure for analyzing their 30-day morbidity and mortality and 3- and 12-month quality data in real-time; generate surgeon-, practice-, and specialty-specific quality and efficacy data; and generate nationwide quality and effectiveness data on specific surgical treatments. Results In its first 2 years of operation, the NQOD has proven to be a robust data collection platform that has helped demonstrate the objective quality of surgical interventions for medically refractory disorders of the lumbar spine. Lumbar spine surgery was found to be safe and effective at the group mean level in routine practice. Subgroups of patients did not report improvement using validated outcome measures. Substantial variation in treatment response was observed among individual patients. Conclusion The NQOD is now positioned to determine the combined contribution of patient variables to specific clinical and patient-reported outcomes. These analyses will ultimately facilitate shared decision making and encourage efficient allocation of health care resources, thus significantly advancing the value paradigm in spine care. Level of evidence 3.

Background Minimally invasive transforaminal lumbar interbody fusion (MIS TLIF) for lumbar spondylolisthesis allows for the surgical treatment of back/leg pain while minimizing tissue injury and accelerating the patient's recovery. Although previous results have shown shorter hospital stays and decreased intraoperative blood loss for MIS versus open TLIF, short- and long-term outcomes have been similar. Therefore, we performed comparative effectiveness and cost-utility analysis for MIS versus open TLIF. Methods A total of 100 patients (50 MIS, 50 open) undergoing TLIF for lumbar spondylolisthesis were prospectively studied. Back-related medical resource use, missed work, and quality-adjusted life years were assessed. Cost of in-patient care, direct cost (2-year resource use × unit costs based on Medicare national allowable payment amounts), and indirect cost (work-day losses × self-reported gross-of-tax wage rate) were recorded, and the incremental cost-effectiveness ratio was calculated. Results Length of hospitalization and time to return to work were less for MIS versus open TLIF ( P = 0.006 and P = 0.03, respectively). MIS versus open TLIF demonstrated similar improvement in patient-reported outcomes assessed. MIS versus open TLIF was associated with a reduction in mean hospital cost of $1758, indirect cost of $8474, and total 2-year societal cost of $9295 ( P = 0.03) but similar 2-year direct health care cost and quality-adjusted life years gained. Conclusions MIS TLIF resulted in reduced operative blood loss, hospital stay and 2-year cost, and accelerated return to work. Surgical morbidity, hospital readmission, and short- and long-term clinical effectiveness were similar between MIS and open TLIF. MIS TLIF may represent a valuable and cost-saving advancement from a societal and hospital perspective.

Objective Adjacent segment disease (ASD) may occur as a long-term consequence of spinal fusion and is associated with significant back and leg pain. Surgical management of symptomatic ASD consists of neural decompression and extension of fusion. However, conflicting results have been reported with respect to the long-term clinical effectiveness of revision surgery in this setting. We set out to comprehensively assess the long-term clinical outcome after revision surgery and determine its effectiveness in the treatment of adjacent segment disease. Methods Fifty patients undergoing revision surgery for ASD-associated back and leg pain were included in this study. Baseline and 2-year Visual Analog Scale–Back Pain (VAS-BP), Visual Analog Scale–Leg Pain (VAS-LP), Oswestry Disability Index, physical and mental quality of life (Short Form–12 [SF-12] physical and mental component score [PCS and MCS]) and health-state utility (EuroQol [EQ-5D]) were assessed. Results A sustained improvement in VAS-BP (8.72 ± 1.85 vs. 3.92 ± 2.84, P = 0.001), VAS-LP (6.30 ± 3.90 vs. 3.02 ± 3.03, P = 0.001), Oswestry Disability Index (28.72 ± 9.64 vs. 18.48 ± 11.31, P = 0.001), SF-12 PCS (26.89 ± 8.85 vs. 35.58 ± 11.97, P = 0.001) and SF-12 MCS (44.66 ± 12.85 vs. 53.16 ± 9.46, P = 0.001) was observed 2 years after revision surgery, with a cumulative mean 2-year gain of 0.76 quality-adjusted life-years (EQ-5D). Median (interquartile range) time to narcotic independence and return to work was 1.7 (1.0–8.0) months and 2.0 (1.0–4.75) months, respectively. Conclusions Patients undergoing decompression and extension of fusion for adjacent segment disease–associated back and leg pain reported long-term improvement in pain, disability, and both physical and mental quality of life, suggesting that revision surgery is a highly effective treatment strategy in this patient population.

Background context Given the unsustainable costs of the US health-care system, health-care purchasers, payers, and hospital systems are adopting the concept of value-based purchasing by shifting care away from low-quality providers or hospitals. Legislation now allows public reporting of these quality rankings. True measures of quality, such as surgical morbidity and validated questionnaires of effectiveness, are burdensome and costly to collect. Hence, patients' satisfaction with care has emerged as a commonly used metric as a proxy for quality because of its feasibility of collection. However, patient satisfaction metrics have yet to be validated as a measure of overall quality of surgical spine care. Purpose We set out to determine whether patient satisfaction is a valid measure of safety and effectiveness of care in a prospective longitudinal spine registry. Study design Prospective longitudinal cohort study. Patient population All patients undergoing elective spine surgery for degenerative conditions over a 6-month period at a single medical center. Outcome measures Patient-reported outcome instruments (numeric rating scale [NRS], Oswestry disability index [ODI], neck disability index [NDI], short-form 12-item survey [SF-12], Euro-Qol-5D [EQ-5D], Zung depression scale, and Modified Somatic Perception Questionnaire [MSPQ] anxiety scale), return to work, patient satisfaction with outcome, and patient satisfaction with provider care. Methods All patients undergoing elective spine surgery for degenerative conditions over a 6-month period at a single medical center were enrolled into a prospective longitudinal registry. Data collected on all patients included demographics, disease characteristics, treatment variables, readmissions/reoperations, and all 90-day surgical morbidity. Patient-reported outcome instruments (NRS, ODI, NDI, SF-12, EQ-5D, Zung depression scale, and MSPQ anxiety scale), return to work, patient satisfaction with outcome, and patient satisfaction with provider care were recorded at baseline and 3 months after treatment. Receiver-operating characteristic (ROC) curve analysis was performed to determine whether extent of improvement in quality of life (SF-12 physical component summary [PCS]) and disability (ODI/NDI) accurately predicted patient satisfaction versus dissatisfaction. Standard interpretation of area under the curve (AUC) was used: less than 0.7, poor; 0.7 to 0.8, fair; and greater than 0.8, good accuracy. Multivariate logistic regression analysis was performed to determine if surgical morbidity (quality) or improvement in disability and quality of life (effectiveness of care) were independently associated with patient satisfaction. Results Four hundred twenty-two (84%) patients completed all questionnaires 3 months after surgery during the reviewed time period (mean age 55±14 years). Lumbar surgery was performed in 287 (68%) and cervical surgery in 135 (32%) patients. There were 51 (12.1%) 90-day complications, including 21 (5.0%) readmissions and 12 (2.8%) return to operating room. Three hundred fifty-eight (84.8%) patients were satisfied with provider care and 288 (68.2%) with their outcome. Satisfaction with provider care: In ROC analyses, extent of improvement in quality of life (SF-12) and disability (ODI/NDI) differentiated satisfaction versus dissatisfaction with care with very poor accuracy (AUC 0.49–0.69). In regression analysis, 3-month morbidity (odds ratio [95% confidence interval]: 1.45 [0.79–2.66]), readmission (0.66 [0.24–1.80]), improvement in quality of life (SF-12 PCS), or improvement in general health (health transition index) were not associated with satisfaction with care. Satisfaction with outcome: In ROC analyses, improvement in quality of life (SF-12) and disability (ODI/NDI) failed to differentiate satisfaction with good accuracy (AUC 0.76). Neither 90-day morbidity (1.05 [0.46–2.34]) nor 90-day readmission (0.27 [0.04–2.04]) was associated with satisfaction with outcome in regression analysis. Conclusions Patient satisfaction is not a valid measure of overall quality or effectiveness of surgical spine care. Patient satisfaction metrics likely represent the patient's subjective contentment with health-care service, a distinct aspect of care. Satisfaction metrics are important patient-centered measures of health-care service but should not be used as a proxy for overall quality, safety, or effectiveness of surgical spine care.

ObjectSurgical 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.MethodsA 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.ResultsA 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.ConclusionsThe 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.

Patient satisfaction ratings are increasingly being used in health care as a proxy for quality and are becoming the focal point for several quality improvement initiatives. Affective disorders, such as depression, have been shown to influence patient-reported outcomes and self-interpretation of health status. We hypothesize that patient psychiatric profiles influence reported satisfaction with care, independent of surgical effectiveness.To assess the predictive value of preoperative depression on patient satisfaction after revision surgery for same-level recurrent stenosis.Retrospective cohort study.Fifty-three patients undergoing a revision surgery for symptomatic same-level recurrent stenosis.Patient-reported outcome measures were assessed using an outcomes questionnaire that included questions on health state values (EuroQol-5D [EQ-5D]), disability (Oswestry Disability Index [ODI]), pain (visual analog scale [VAS]), depression (Zung self-rating depression scale), and Short Form 12 (SF-12) physical and mental component scores (PCS and MCS). Patient satisfaction was dichotomized as either "YES" or "NO" on whether they were satisfied with their surgical outcome 2 years after the surgery.A total of fifty-three patients undergoing revision neural decompression and instrumented fusion for same-level recurrent stenosis-associated back and leg pain were included in this study. Preoperative Zung self-rating depression score (ZDS), education status, comorbidities, and postoperative satisfaction with surgical care and outcome was assessed for all patients. Baseline and 2-year VAS for leg pain (VAS-LP), VAS for low back pain (VAS-BP), ODI, SF-12 PCS and MCS, and health-state utility (EQ-5D) were assessed. Factors associated with patient satisfaction after surgery were assessed via multivariate logistic regression analysis.Two years after surgery, a significant improvement was reported in all outcome measures: VAS-BP (5±2.94 vs. 9.28±1, p.001), VAS-LP (3.43±2.95 vs. 9.5±0.93, p.001), ODI (21.75±12.07 vs. 36.01±6, p.001), SF-12 PCS (32.30±11.01 vs. 25.13±5.84, p.001), SF-12 MCS (47.48±10.96 vs. 34.91±12.77, p.001), EQ-5D (0.60±0.31 vs. 0.18±0.22, p.001), and ZDS (37.52±11.98 vs. 49.90±10.88, p.001). Independent of postoperative improvement in pain and disability (surgical effectiveness), increasing preoperative Zung depression score was significantly associated with patient dissatisfaction 2 years after revision lumbar surgery (Odds ratio=0.67 [confidence interval: 0.38, 0.87], p.001).Our study suggests that independent of the surgical effectiveness, the extent of preoperative depression influences the reported patient satisfaction after revision lumbar surgery. Quality improvement initiatives using patient satisfaction as a proxy for quality should account for the patients' baseline depression as potential confounders.

BACKGROUND There has been a transition to using patient-reported outcome instruments (PROi) to assess surgical effectiveness. However, none of these instruments have been validated for outcomes of adult Chiari I malformation (CMI). OBJECTIVE The aim of this study was to determine the relative validity and responsiveness of various PROi in measuring outcomes after surgery for CMI. METHODS Fifty patients undergoing suboccipital craniotomy for adult CMI were prospectively followed for 1 year. Baseline and 1-year patient-reported outcomes (visual analog scale for head pain and visual analog scale for neck pain, Neck Disability Index [NDI], Headache Disability Index, SF-12, Zung Self-Rating Depression Scale, and EuroQol-5D [EQ-5D]) were assessed. A level of improvement in general health after surgery was defined as meaningful improvement. Receiver-operating characteristic curves were generated to assess the validity of PROi to discriminate between meaningful improvement and not. The difference between standardized response means (SRMs) in patients reporting meaningful improvement vs not as calculated to determine the relative responsiveness of each outcome instrument. RESULTS For pain and disability, the NDI was the most accurate discriminator of meaningful effectiveness (area under the curve: 0.90) and also most responsive to postoperative improvement (standardized response means difference: 1.87). For general health and quality of life, the SF-12 PCS, EQ-5D, and Zung Self-Rating Depression Scale were all accurate discriminators; however, SF-12 Physical Component Scale (SF-12 PCS) and EQ-5D were most accurate. SF-12 PCS was also most responsive. CONCLUSION For pain and disability, NDI is the most valid and responsive measure of improvement after surgery for CMI. For health-related quality of life, SF-12 PCS and EQ-5D are the most valid and responsive measures. NDI with SF-12 or EQ-5D is the most valid in patients with CMI and should be considered in cost-effectiveness studies.

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.

A prospective cohort study.To evaluate whether an annular closure device could be implanted safely to reduce same-level recurrent disk herniation, or attenuate disk height loss and improve the outcome after lumbar discectomy.Same-level recurrent disk herniation, disk height loss, and progressive degeneration are common complications and sequelae after lumbar discectomy. Techniques to reduce these consequences may improve outcomes.Forty-six consecutive patients undergoing lumbar discectomy for single-level herniated disk at 2 institutions were followed prospectively with clinical and radiographic evaluations at 6 weeks and 3, 6, 12, and 24 months (control cohort). A second consecutive cohort of 30 patients undergoing 31 lumbar discectomies with implantation of an annular closure device was followed similarly. Incidence of recurrent disk herniation, disk height loss, the leg and back pain visual analog scale (VAS), and the Oswestry Disability Index were assessed at each follow-up.Cohorts were well matched at baseline. By 2 years of follow-up, symptomatic recurrent same-level disk herniation occurred in 3 (6.5%) patients in the control cohort versus 0 (0%) patients in the annular repair cohort (P=0.27). A trend of greater preservation of disk height was observed in the annular repair versus the control cohort 3 months (7.9 vs. 7.27 mm, P=0.08), 6 months (7.81 vs. 7.18 mm, P=0.09), and 12 months (7.63 vs. 6.9 mm, P=0.06) postoperatively. The annular closure cohort reported less leg pain (VAS-LP: 5 vs. 16, P0.01), back pain (VAS-BP: 13 vs. 22, P0.05), and disability (Oswestry Disability Index: 16 vs. 22, P0.05) 1 year postoperatively.Implantation of a novel annular repair device was associated with greater maintenance of disk height and improved 1-year leg pain, back pain, and low-back disability. Recurrent disk herniation did not occur in any patient after annular repair. Closure of annular defect after lumbar discectomy may help preserve the physiological disk function and prevent long-term disk height loss and associated back and leg pain.

Study design Analysis of prospectively collected longitudinal web-based registry data. Objective To determine relative validity, responsiveness, and minimum clinically important difference (MCID) thresholds in patients undergoing surgery for intradural extramedullary (IDEM) spinal tumors. Summary of background data Patient-reported outcomes (PROs) are vital in establishing the value of care in spinal pathology. There is limited availability of prospective, quality studies reporting PROs for IDEM spine tumors. Methods . A total of 40 patients were analyzed. Baseline, postoperative 3-month, and 12-month PROs were recorded: Oswestry Disability Index or Neck disability Index (ODI/NDI), Quality of life EuroQol-5D (EQ-5D), Short Form-12 (SF-12), Numeric Rating Scale (NRS)-pain scores. Responders were defined as those who achieved a level of improvement one or two, after surgery, on health transition index (HTI) of SF-36. Receiver-operating characteristic curves were generated to assess the validity of PROs, and the difference between standardized response means (SRMs) in responders versus nonresponders was utilized to determine the relative responsiveness of each PRO measure. MCID thresholds were derived using previously reported minimal detectable change approach. Results A significant improvement across all PROs at 3-months and 12-months follow up was noted. The derived MCID thresholds were 13.9 points: ODI/NDI, 0.14 quality adjusted life years: EQ-5D, 2.8 points: SF-12PCS and 10.7 points: SF-12MCS, 1.9 points: NRS-back/neck pain, and 1.8 points: NRS-leg/arm pain. SF-12PCS was most accurate discriminator of meaningful improvement (area under the curve, AUC-0.83) and most responsive (SRM-1.36) to postoperative improvement. EQ-5D, ODI/NDI, NRS-pain scores were all accurate discriminator (AUC-0.7-0.8) and responsive measures (0.97-0.67) of meaningful postoperative improvement. SF-12MCS was neither a valid discriminator (AUC-0.48) nor a responsive measure (SRM: -1.5) of outcome. Conclusion Surgical resection of IDEM spinal tumors provides significant and sustained improvement in quality of life, general health, disability, and pain at 12-month after surgery. The surgically resected IDEM-specific clinically meaningful thresholds are reported. All the PROs reported in this study can accurately discriminate responders and nonresponder based on SF-36 HTI index except for SF-12 MCS. Level of evidence 3.

With growing older population and increasing rates of cervical spinal surgery, it is vital to understand the value of cervical surgery in this population. We set forth to determine the cost utility following anterior cervical decompression and fusion (ACDF) for degenerative disease in older patients.Patients undergoing ACDF for degenerative diseases were enrolled into prospective longitudinal registry. Patient-reported outcomes (PROs) were recorded at baseline, 1-year, and 2-year postoperatively. Two-year medical resource utilization, missed work, and health-state values [quality-adjusted life years (QALYs)] were assessed to compute cost per QALY gained. Patients were dichotomized based on age: 65 years (younger) and ≥65 years (older) to compare the cost utility in these age groups.Total 218 (87%) younger patients and 33 (13%) older patients who underwent ACDF were analyzed. Both the groups demonstrated a significant improvement in PROs 2-year following surgery. The older patients had a lower mean cumulative gain in QALYs compared to younger patients at 1 year (0.141 vs. 0.28, P = 0.05) and 2 years (0.211 vs. 0.424, P = 0.04). There was no significant difference in the mean total 2-year cost between older [$21,041 (95% CI $18,466-$23,616)] and younger [$22,669 (95% CI $$21,259-$24,079)] patients (P = 0.27). Two-year cost per QALY gained in older vs. younger patients was ($99,720/QALYs gained vs. ($53,464/QALYs gained, P = 0.68).ACDF surgery provided a significant gain in health-state utility in older patients with degenerative cervical pathology, with a mean cumulative 2-year cost per QALY gained of $99,720/QALY. While older patients have a slightly higher cost utility compared to their younger counterparts, surgery in the older cohort does provide a significant improvement in pain, disability, and quality-of-life outcomes.

Background Context Over the last decade, clinical investigators and biomedical industry groups have used significant resources to develop advanced technologies that enable less invasive spine fusions. These minimally invasive surgery (MIS) technologies often require increased expenditures by hospitals and payers. Although several small single center studies have suggested MIS technologies decrease surgical morbidity and reduce hospital stay, evidence documenting benefit from a patient perspective remains limited. Furthermore, MIS outcomes have yet to be evaluated from the perspective of multiple practice types representing the broad spectrum of US spine surgery. Purpose This study aimed to examine a population of patients who underwent one- or two-level interbody lumbar fusion diagnosed with lumbar stenosis or Grade 1 spondylolisthesis in an observational, prospective national registry for the purposes of determining how MIS and traditional open technologies affect postsurgical and patient-reported outcomes (PROs). Study Design/Setting This study used observational analysis of prospectively collected data. Patient Sample The sample consisted of cases from the National Neurosurgery Quality and Outcomes Database (N 2 QOD). Outcome Measures Numeric rating scale for back and leg pain, Oswestry Disability Index, EuroQol-5D, return to work, and perioperative morbidity were the outcome measures. Methods The N 2 QOD is a prospective PROs registry enrolling patients undergoing elective spine surgery from 60 hospitals in 27 US states via representative sampling. We analyzed the N 2 QOD aggregate dataset (2010–2014) to identify one- and two-level lumbar interbody fusion procedures performed for lumbar stenosis or Grade 1 spondylolisthesis with 12 months' follow-up where surgical instrumentation and implant types were clearly identified. Perioperative and 1-year outcomes were compared between cases performed with MIS enabling technologies versus traditional open technologies before and after propensity matching. Results There were 467 (24%) patients who underwent elective interbody lumbar fusion using MIS enabling technologies whereas 1,480 (76%) underwent the procedure using traditional open technologies. The MIS patients were slightly healthier (American Society of Anesthesiologists grade), had private insurance more frequently, and underwent two-level fusion less frequently. Unmatched, the MIS cohort was associated with reduced blood loss, a 0.7-day reduction in mean length of hospital stay, and 5% reduced need for post-discharge inpatient rehabilitation, but equivalent 90-day safety measures. After propensity matching, the MIS cohort remained associated with reduced blood loss and a shorter length of stay for one-level fusion (p Conclusions In a representative sampling registry of elective interbody lumbar spine fusion procedures spanning 27 US states, nearly a quarter of procedures performed from 2010 to 2014 used minimally invasive enabling technologies. Regardless of approach, interbody lumbar fusion was associated with significant and sustained improvements in all measured health domains. When used in everyday care by a wide spectrum of spine surgeons in non-research settings, the use of MIS technologies was associated with reduced intraoperative blood loss but only a half-day reduction in mean length of hospital stay for one-level fusions. Minimally invasive surgery was not associated with any improved perioperative safety measures or 12-month outcomes. Although MIS enabling technologies may increase some in-hospital care efficiencies, MIS clinical outcomes are similar to open surgery for patients undergoing one- and two-level interbody lumbar fusions.

Purpose of study Low back pain is one of the most prevalent and disabling musculoskeletal conditions affecting the working population in the United States. Informed, shared decision making among patients, clinicians, and case managers about treatment options for chronic low back pain-including the role of spinal fusion where medically necessary-can have a meaningful impact on return to work, normal function, and economic outcomes. Minimally invasive techniques for lumbar spinal fusion, including transforaminal lumbar interbody fusion (MIS TLIF) have recently been introduced with the goal of smaller operative wounds, less tissue trauma, and faster postoperative recovery when compared with open fusion. Although similar long-term clinical outcomes have been reported for MIS TLIF and open TLIF, the relative merits with respect to workplace productivity have not been comprehensively investigated. Time to return to work and narcotic independence after MIS TLIF and open TLIF are important parameters that may affect overall workplace productivity, and as such are the focus of this study. Primary practice setting(s) This study was performed via a review of the literature. Methodology and sample We performed a systematic literature review to identify all published articles that reported on the postoperative outcomes of patients, as assessed by return to work or narcotic independence status or both, following MIS TLIF or open TLIF. A cumulative comparison was made for all included MIS TLIF versus open TLIF surgeries. Results Seventy-four published studies reported postoperative outcomes following MIS TLIF or open TLIF; only five (6.8%) studies directly described time to return to work or duration of narcotic use postoperatively or both, and were therefore included into the analysis of this review. Four studies in the published literature describe time to return to work following MIS TLIF or open TLIF, and two studies describe time to narcotic independence. Overall, the reviewed literature suggests that MIS TLIF may be associated with an accelerated time to narcotic independence and return to work versus open TLIF. Implications for case management practice There are limited data regarding time to return to work and duration of postoperative narcotic use following TLIF for low back pain. The available data appear to suggest that MIS TLIF may be associated with accelerated return to work and narcotic independence compared with open TLIF. Further analysis will be necessary to quantify the impact of MIS TLIF on workplace productivity and the indirect costs borne by patients and employers. Such information will be of value to case managers, disability managers, employers, patients, and clinicians aligned on reducing morbidity and hastening return to normal function.

Objective Minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) for lumbar spondylolisthesis allows for surgical treatment of back and leg pain while theoretically minimizing tissue injury and accelerating overall recovery. Although the authors of previous studies have demonstrated shorter length of hospital stay and reduced blood loss with MIS versus open-TLIF, short- and long-term outcomes have been similar. No studies to date have evaluated the comprehensive health care costs associated with TLIF procedures or assessed the cost-utility of MIS- versus open-TLIF. As such, we set out to assess previously unstudied end points of health care cost and cost-utility associated with MIS- versus open-TLIF. Methods Thirty patients undergoing MIS-TLIF (n = 15) or open-TLIF (n = 15) for grade I degenerative spondylolisthesis associated back and leg pain were prospectively studied. Total back-related medical resource use, missed work, and health-state values (quality-adjusted life years [QALYs], calculated from EQ-5D with U.S. valuation) were assessed after two-year follow-up. Two-year resource use was multiplied by unit costs on the basis of Medicare national allowable payment amounts (direct cost) and work-day losses were multiplied by the self-reported gross-of-tax wage rate (indirect cost). Difference in mean total cost per QALY gained for MIS- versus open-TLIF was assessed as incremental cost-effectiveness ratio (ICER: COSTmis – COSTopen/QALYmis – QALYopen). Results MIS versus open-TLIF cohorts were similar at baseline. By two years postoperatively, patients undergoing MIS- versus open-TLIF reported similar mean QALYs gained (0.50 vs. 0.41, P = 0.17). Mean total two-year cost of MIS- and open-TLIF was $35,996 and $44,727, respectively. The $8,731 two-year cost savings of MIS- versus open-TLIF did not reach statistical significance ( P = 0.18) for this sample size. Conclusions Although our limited sample size prevented statistical significance, MIS- versus open-TLIF was associated with reduced costs over two years while providing equivalent improvement in QALYs. MIS-TLIF allows patients to leave the hospital sooner, achieve narcotic independence sooner, and return to work sooner than open-TLIF. In our experience, MIS- versus open-TLIF is a cost reducing technology in the surgical treatment of medically refractory low-back and leg pain from grade I lumbar spondylolisthesis.