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Background: The goal of this study was to identify predictors of prolonged operative time (OT) in patients receiving posterior/transforaminal lumbar interbody fusion (P/TLIF) and examine the relationship between prolonged OT and perioperative outcomes in this population., Methods: The American College of Surgeons National Surgical Quality Improvement Program database was queried for patients undergoing single-level P/TLIF (Common Procedural Terminology code) between 2012 and 2018. Multivariable linear regression models were constructed to identify factors independently associated with changes in OT and examine the relationship between prolonged OT and perioperative outcomes (overall complications, surgical complications, medical complications, 30-day readmission, 30-day reoperation, and length of stay). All models were adjusted for sociodemographic variables, comorbidities, and procedure-specific variables., Results: Our cohort included 6260 patients. After adjusting for baseline covariates, age between 19 and 39 years increased OT by 15.14 minutes, male sex increased OT by 12.91 minutes, African American race increased OT by 17.82 minutes, other race increased OT by 18.13 minutes, obesity class III increased OT by 27.80 minutes, and the use of navigation increased OT by 10.83 minutes. Our multivariate logistic regression also found that after 2 hours, each additional hour of OT was associated with an increased risk of any complication (3-3.99 hours, odds ratio [OR], 1.68; 4-4.99 hours, OR, 2.33; and >5 hours, OR, 4.65). Incremental increases in OT were also associated with an increased risk of extended length of stay, readmission, and return to the operating room., Conclusions: The results of this study highlight several factors associated with prolonged OT and underscore its association with poorer perioperative outcomes. These data can be used to risk stratify patients before single-level P/TLIF., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Background Context: Preoperative TNF-AI use has been associated with increased rate of postoperative infections and complications in a variety of orthopedic procedures. However, the association between TNF-AI use and complications following spine surgery has not yet been studied., Purpose: The purpose of the present study was to assess the risk of reoperation in patients prescribed TNF-AI undergoing spinal fusion surgery., Study Design: This is a retrospective review., Patient Sample: A total of 427 patients who underwent spinal fusion surgery at a large healthcare system from 1/1/2009 to 12/31/2018., Outcome Measure: Reoperation within 1 year., Methods: We retrospectively reviewed the records of patients who underwent spinal fusion surgery at a large healthcare system from 1/1/2009 to 12/31/2018. There were three distinct cohorts of spine surgery patients under study: patients with TNF-AI use in 90 days before surgery, patients with non-TNF-AI DMARD medications use in the 90 days before surgery, and patients taking neither TNF-AI nor other DMARD medications in 90 days before surgery. The primary outcome of interest was reoperation for any reason within 1 year following surgery., Results: Our study included 90 TNF-AI, 90 DMARD, and 123 control patients. Reoperation up to 1-year postsurgery occurred in 19% (n=17) of the TNF-AI group, 11% (n=10) of the DMARD group, and 6% (n=7) of the control group. The reasons for reoperation for TNF-AI group were 47% (n=8) infection and 53% (n=9) other causes which included failure to fuse and adjacent segment disease. Reasons for reoperation at 1 year were 40% (n=4) infection and 60% (n=6) other causes for DMARD patients and 14% (n=1) infection with 86% (n=6) other causes for control patients. The cox-proportional hazard model of reoperation within 1 year indicated that the odds of reoperation were 3.1 (95% CI:1.4-7.0) and 2.2 (95% CI 0.96-5.3) times higher in the TNF-AI and DMARD groups, respectively, compared to the control group., Conclusions: Patients taking TNF-AIs before surgery were found to have a significantly higher rate of reoperation in the 1 year following surgery compared to controls. The higher rate of reoperation associated with TNF-AI use before spinal fusion surgery represents the potential for higher morbidity and costs for patient which is important to consider for both surgeon and patient in preoperative decision making., (Copyright © 2021. Published by Elsevier Inc.)

Study Design: Retrospective population database study., Objective: To investigate the relationship of preoperative hyponatremia to postoperative morbidity and mortality in lumbar interbody fusion patients., Summary of Background Data: Optimization of preoperative patient selection and perioperative management can improve patient outcomes in spinal surgery. Hyponatremia, incidentally identified in 1.7% of the US population, has previously been tied to poorer postoperative outcomes in both the general surgery and orthopedic surgery populations., Materials and Methods: Using the National Surgical Quality Improvement Program database, the authors identified all lumbar interbody fusion patients treated between 2012 and 2014. Patients were classified as hyponatremic (Na<135 mEq/L) or as having normal sodium levels (135-145 mEq/L) preoperatively. The primary outcome was major morbidity and secondary endpoints were prolonged hospitalization, 30-day readmission, and reoperation. Multivariable linear regression was used to find independent predictors of these outcomes., Results: Of 10,654 patients, 45.6% were male individuals, 5.5% were hyponatremic, and 4.2% experienced a major postoperative complication. On multivariable analysis, preoperative hyponatremia was independently associated with major morbidity (odds ratio, 1.22; 95% confidence interval, 1.03-1.44; P<0.05) and prolonged hospitalization (odds ratio, 1.14; 95% confidence interval, 1.02-1.27)., Conclusions: Here the authors provide the first evidence suggesting preoperative hyponatremia is an independent predictor of major morbidity after lumbar interbody fusion. Hyponatremia may represent a modifiable risk factor for improved patient care and preoperative risk counseling., Competing Interests: M.P.S.: consultant for Globus Medical and Intellirod; royalties from Elsevier and Zimmer Biomet; honorarium from Globus Medical and Stryker; research support from Globus Medical. T.E.M.: consultant for Globus Medical. Royalties from Stryker. The remaining authors declare no conflict of interest., (Copyright © 2020 Wolters Kluwer Health, Inc. All rights reserved.)

Objective: Preoperative patient optimization is increasingly recognized as key to good surgical outcomes. Preoperative hyponatremia is a modifiable risk factor linked to poorer postoperative outcomes in other surgical fields. We provide the first investigation of the association of preoperative hyponatremia with morbidity and mortality in patients undergoing cervical spine surgery., Methods: We queried the National Surgical Quality Improvement Program registry for patients who underwent cervical spine fusion. Preoperative serum sodium levels were classified as normal (135-145 mEq/L) or hyponatremic (<135 mEq/L); hypernatremic patients were excluded from the analysis. Multivariable logistic analyses using a multiple imputations methodology were performed to determine significant predictors of major morbidity and mortality (MMM)., Results: We included 20,817 patients, of whom 5.2% were hyponatremic at presentation. Preoperative hyponatremia was a significant predictor of MMM (odds ratio [OR], 1.23; 95% confidence interval [CI], 1.09-1.39), mortality (OR, 1.36; 95% CI, 1.03-1.77), major morbidity (OR, 1.24; 95% CI, 1.10-1.40), and odds of prolonged hospitalization (OR, 1.13; 95% CI, 1.04-1.23). Other significant predictors of MMM included age, undergoing an emergent versus nonemergent operation, having chronic obstructive pulmonary disease, having disseminated malignancy, being functionally dependent, presenting with sepsis or septic shock, and having an American Society of Anesthesiologists status of 3, 4, or 5. Similar results were seen in analyses using only complete cases and in sensitivity analyses., Conclusions: Using the National Surgical Quality Improvement Program database, hyponatremia is observed in approximately 1 in every 20 patients undergoing cervical spine fusion. More importantly, it is a predictor of mortality, major morbidity, and prolonged hospitalization. From a systems-level perspective, preoperative hyponatremia may therefore represent a point of intervention for preoperative patient optimization., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Background: More than 120,000 anterior cervical discectomy and fusions (ACDFs) are performed annually. Pseudarthrosis is a potential delayed adverse event that affects up to 33% of patients. The degree to which this adverse event affects both patient quality-of-life (QOL) outcomes and health care costs is poorly understood., Methods: Patients who underwent revision surgery for pseudarthrosis between 2007 and 2012 were identified and matched to controls not experiencing pseudarthrosis in a 1:2 fashion (case/control). Cases and controls were compared regarding total health care costs incurred in the year after the index ACDF and QOL outcomes on the following metrics: EuroQol Five-Dimensions Questionnaire, Patient Health Questionnaire-9, and Pain Disability Questionnaire., Results: Of 738 patients who underwent ACDF, 11 underwent surgery for pseudarthrosis. No differences were noted between cases and controls regarding any of the matched variables. Patients in the pseudarthrosis cohort had poorer postoperative scores on the EuroQol Five-Dimensions Questionnaire mobility, usual activities, pain/discomfort, and quality-adjusted life-year dimensions. In addition, 64% of patients with pseudarthrosis had worsened quality-adjusted life-year scores compared with only 9% of controls (P < 0.01). Patients with pseudarthrosis also had poorer mental health (P < 0.01) and pain disability outcomes (P < 0.01) than did controls. Pseudarthrosis was associated with significant increases in direct costs, direct postoperative costs, and total costs (all P < 0.01)., Conclusions: This is the first study to characterize the effect of surgical revision for pseudarthrosis on both QOL outcomes and care costs after ACDF. Patients requiring revision experienced significantly poorer QOL outcomes and higher care costs relative to controls., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Patients with symptomatic instability of the spine may be treated surgically with interbody fusion. Cost and complexity in this procedure arises owing to the implanted materials involved with facilitating fusion such as titanium or polyetheretherketone. Surface modifications have been developed to augment these base materials such as plasma-spraying polyetheretherketone with titanium or coating implants with hydroxyapatite. Although some evidence has been gathered on these novel materials, additional study is needed to establish the true efficacy of surface modifications for interbody fusion devices in improving long-term patient outcomes., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Surgical site infections (SSI) following spine procedures are serious and costly complications that may reduce patient quality of life (QOL). Deep SSIs may also extend hospitalizations and require surgical debridement or antibiotic therapy, increasing costs to both patients and the healthcare system. Here we sought to evaluate the effect of deep SSI on care cost and QOL outcomes in patients undergoing posterior lumbar decompression and fusion. To do so we performed a retrospective study of patients undergoing lumbar decompression and fusion between 2008 and 2012. Patients experiencing postoperative deep SSI were matched to controls not experiencing a deep SSI. Included patients had prospectively-gathered QOL outcome measures collected preoperatively and at 6 months postoperatively. Health resource utilization was recorded from patient electronic medical records over the 6-month follow-up. Direct costs were estimated using Medicare national payment amounts. Indirect costs were based on missed work days and patient income. We found both cohorts experienced significant improvements in QOL scores following surgery, and there were no significant differences between the cohorts. The average total cost was significantly higher in the infected cohort compared to controls ($37,009 vs. $16,227; p < 0.0001). Compared to controls, patients experiencing deep SSI had greater costs in each of the following categories: hospitalizations (p < 0.01), office visits (p = 0.03), imaging (p < 0.01), and medications (p < 0.01). Among those experiencing deep SSI, there are significant increases in costs, with minimal long-term impact on QOL outcomes as compared with controls at the six-month follow-up., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Background: Carotid artery injury and stroke secondary to prolonged retraction remains an extremely rare complication in anterior cervical discectomy and fusion (ACDF). However, multiple studies have demonstrated that carotid artery retraction during the surgical approach may alter the normal blood flow, leading to a significant reduction in the cross-sectional area of the vessel. Others have suggested that dislodgment of atherosclerotic plaques following manipulation of the carotid artery can be a potential risk for intracranial embolus and stroke., Purpose: We aimed to evaluate: (1) the incidence of postoperative stroke following ACDF and (2) incidence of other postoperative complications in a cohort of patients who had a diagnosis of carotid artery stenosis (CAS) versus those who did not., Patient Sample: This study utilized the Statewide Planning and Research Cooperative System database from January 1, 2009 to December 31, 2013. All patients who underwent (ACDF) and had a preoperative diagnosis of CAS were identified using the International Classification of Disease, ninth revision codes. Those who had a previous history of stroke were excluded. Patients who had CAS were propensity score matched to patients without history of CAS for demographics and Charlson/Deyo comorbidity scores., Outcome Measures: Incidence of postoperative stroke and other complications were compared between the cohorts. The threshold for statistical significance was set at a p<.05. This study received no funding. The authors report no conflict of interests relevant to this study., Results: There were 34,975 patients who underwent an ACDF in the study time period. After excluding those under the age of 18 and with history of previous stroke, there were 61 patients who had CAS that were compared with a propensity-matched cohort. The CAS cohort had a significantly higher incidence of postoperative stroke during their hospitalization (6.6% vs 0%, p<.042). The CAS cohort also had higher rates of acute renal failure (27.9% vs 4.9%, p = .01) and sepsis (18% vs 4.9%, p = .023). There were no stroke related deaths., Conclusions: Patients with CAS who underwent ACDF had a statistically significant greater incidence of developing a postoperative stroke. To the best of our knowledge, no previous study has evaluated the development of postoperative stroke in patients with CAS undergoing ACDF. Larger, multicenter studies are needed to estimate the true incidence of stroke in this specific patient population. However, our results may illustrate the importance of preoperative optimization, approach-selection, and postoperative stroke surveillance in patients with a history of CAS who undergoes ACDF., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Background Context: Degenerative changes in the cervical spine occur in an age-dependent manner. As the US population continues to age, the incidence of age-dependent, multilevel, degenerative cervical pathologies is expected to increase. Similarly, the average age of patients with cervical spondylotic myelopathy (CSM) will likely trend upward. Posterior cervical fusion (PCF) is often the treatment modality of choice in the management of multilevel cervical spine disease. Although outcomes following anterior cervical fusion for degenerative disease have been studied among older patients (aged 80 years and older), it is unknown if these results extend to octogenarian patients undergoing PCF for the surgical management of CSM., Purpose: The present study aimed to quantify surgical outcomes following PCF for the treatment of CSM among the octogenarian patient population compared with patients younger than 80 years old., Study Design/setting: This was a retrospective study that used the National Surgical Quality Improvement Program (NSQIP)., Patient Sample: The sample included patients aged 60-89 who had CSM and who underwent PCF from 2012 to 2014., Outcome Measures: The outcome measures were multimorbidity, prolonged length of stay (LOS), discharge disposition (to home or skilled nursing/rehabilitation facility), 30-day all-cause readmission, and 30-day reoperation., Methods: The NSQIP database was queried for patients with CSM (International Classification of Disease, Ninth Revision, Clinical Modification code 721.1) aged 60-89 who underwent PCF (Current Procedural Terminology code 22600) from 2012 to 2014. Cohorts were defined by age group (60-69, 70-79, 80-89). Data were collected on gender, race, elective or emergent status, inpatientor outpatient status, where patients were admitted from (home vs. skilled nursing facility), American Society of Anesthesiologists class, comorbidities, and single- or multilevel fusion. After controllingfor these variables, logistic regression analysis was used to compare outcome measures in the different age groups., Results: A total of 819 patients with CSM who underwent PCF (416 aged 60-69, 320 aged 70-79, and 83 aged 80-89) were identified from 2012 to 2014. Of the PCF procedures, 79.7% were multilevel. There were no significant differences in the odds of multimorbidity, prolonged LOS, readmission, or reoperation when comparing octogenarian patients with CSM with patients aged 60-69 or 70-79. Patients aged 60-69 and 70-79 were significantly more likely to be discharged to home than patients over 80 (odds ratio [OR] 4.3, 95% confidence interval [CI] 1.8-10.4, p<.0001, and OR 2.7, 95% CI 1.1-6.4, p=.0005, respectively)., Conclusions: Compared with patients aged 60-69 and 70-79, octogenarian patients with CSM were significantly more likely to be discharged to a location other than home following PCF. After controlling for patient comorbidities and demographics, 80- to 89-year-old patients with CSM who underwent PCF did not differ in other outcomes when compared with the other age cohorts. These results can improve preoperative risk counseling and surgical decision-making., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Background Context: There is significant variability in the materials commonly used for interbody cages in spine surgery. It is theorized that three-dimensional (3D)-printed interbody cages using porous titanium material can provide more consistent bone ingrowth and biological fixation., Purpose: The purpose of this study was to provide an evidence-based approach to decision-making regarding interbody materials for spinal fusion., Study Design: A comparative animal study was performed., Methods: A skeletally mature ovine lumbar fusion model was used for this study. Interbody fusions were performed at L2-L3 and L4-L5 in 27 mature sheep using three different interbody cages (ie, polyetheretherketone [PEEK], plasma sprayed porous titanium-coated PEEK [PSP], and 3D-printed porous titanium alloy cage [PTA]). Non-destructive kinematic testing was performed in the three primary directions of motion. The specimens were then analyzed using micro-computed tomography (µ-CT); quantitative measures of the bony fusion were performed. Histomorphometric analyses were also performed in the sagittal plane through the interbody device. Outcome parameters were compared between cage designs and time points., Results: Flexion-extension range of motion (ROM) was statistically reduced for the PTA group compared with the PEEK cages at 16 weeks (p-value=.02). Only the PTA cages demonstrated a statistically significant decrease in ROM and increase in stiffness across all three loading directions between the 8-week and 16-week sacrifice time points (p-value≤.01). Micro-CT data demonstrated significantly greater total bone volume within the graft window for the PTA cages at both 8 weeks and 16 weeks compared with the PEEK cages (p-value<.01)., Conclusions: A direct comparison of interbody implants demonstrates significant and measurable differences in biomechanical, µ-CT, and histologic performance in an ovine model. The 3D-printed porous titanium interbody cage resulted in statistically significant reductions in ROM, increases in the bone ingrowth profile, as well as average construct stiffness compared with PEEK and PSP., (Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.)

Background Context: The United States Centers for Disease Control and Prevention estimates the prevalence of inflammatory bowel disease (IBD) at more than 3.1 million people. As diagnostic techniques and treatment options for IBD improve, the prevalence of IBD is expected to increase. For spine surgeons, patients with IBD have a unique complication profile because patients with IBD may present with poor nutritional status and because the medications used to manage IBD have been associated with poor vertebral bone mineralization and immunosuppression. Presently, there are very limited data regarding perioperative outcomes among patients with IBD who undergo spinal surgery. The present study begins to address this knowledge gap by describing trends in patients with IBD undergoing lumbar fusion and by quantifying the association between IBD and immediate postoperative outcomes using a large, national database., Purpose: To advance our understanding of the potential pitfalls and risks associated with lumbar fusion surgery in patients with IBD., Design/setting: Retrospective cross-sectional analysis., Patient Sample: The Nationwide Inpatient Sample (NIS) database was queried from 1998 to 2011 to identify adult patients (18+) who underwent primary lumbar fusion operations using International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) coding., Outcome Measures: Incidence of lumbar fusion procedures, prevalence of IBD, complication rates, length of stay, and total hospital charges., Methods: The annual number of primary lumbar fusion operations performed between 1998 and 2011 was obtained from the NIS database. Patients younger than 18 years of age were excluded. The prevalence of IBD in this population (both Crohn disease and ulcerative colitis) was determined using ICD-9-CM codes. Logistic regression models were estimated to determine the association between IBD and the odds of postoperative medical and surgical complications, while controlling for patient demographics, comorbidity burden, and hospital characteristics. The complex survey design of the NIS was taken into account by clustering on hospitals and assuming an exchangeable working correlation using the discharge weights supplied by the NIS. We accounted for multiple comparisons using the Bonferroni correction and an alpha level for statistical significance of . 0028., Results: The prevalence of IBD is increasing among patients undergoing lumbar fusion, from 0.21% of all patients undergoing lumbar fusion in 1998 to 0.48% of all patients undergoing lumbar fusion in 2011 (p<.001). The odds of experiencing a postoperative medical or surgical complication were not significantly different when comparing patients with IBD with control patients without IBD after controlling for patient demographics, comorbidity burden, and hospital characteristics (adjusted odds ratio=1.1, 95% confidence interval [CI] 0.99-1.3, p=.08). On multivariable analysis, the presence of IBD in patients undergoing lumbar fusion surgery was associated with longer length of stay and greater hospitalization charges., Conclusions: Among patients who underwent lumbar fusion, IBD is a rare comorbidity that is becoming increasingly more common. Importantly, patients with IBD were not at increased risk of postoperative complications. Spine surgeons should be prepared to treat more patients with IBD and should incorporate the present findings into preoperative risk counseling and patient selection., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Background Context: Lumbar fusion is an effective and durable treatment for symptomatic lumbar spondylolisthesis; however, the current literature provides insufficient evidence to recommend an optimal surgical fusion strategy., Purpose: The present study aims to compare the clinical outcomes, fusion rates, blood loss, and operative times between open posterolateral lumbar fusion (PLF) alone and open transforaminal lumbar interbody fusion (TLIF) + posterolateral fusion for spondylolisthesis., Study Design: This is a systematic literature review and meta-analysis of English language studies for the treatment of spondylolisthesis with PLF versus PLF + TLIF., Patient Sample: Data were obtained from published randomized controlled trials (RCTs) and retrospective cohort studies., Outcome Measures: Clinical outcomes included Oswestry Disability Index (ODI), back pain, leg pain, and health-related quality of life (HRQOL) scores. Fusion rate, operative time, blood loss, and infection rate were also assessed., Methods: A literature search of three electronic databases was performed to identify investigations performed comparing PLF alone with PLF + TLIF for treatment of low-grade lumbar spondylolisthesis. The summary effect size was assessed from pooling observational studies for each of the outcome variables, with odds ratios (ORs) used for fusion and infection rate, mean difference used for improvement in ODI and leg pain as well as operative time and blood loss, and standardized mean difference used for improvement in back pain and HRQOL outcomes. Studies were weighed based on the inverse of the variance and heterogeneity. Heterogeneity was assessed using the I 2 -an estimate of the error caused by between-study variation. Effect sizes from the meta-analysis were then compared with data from the RCTs to assess congruence in outcomes., Results: The initial literature search yielded 282 unique, English language studies. Seven were determined to meet our inclusion criteria and were included in our qualitative analysis. Five observational studies were included in our quantitative meta-analysis. The pooled fusion success rates were 84.7% (100/118) in the PLF group and 94.3% (116/123) in the TLIF group. Compared with TLIF patients, PLF patients had significantly lower odds of achieving solid arthrodesis (OR 0.33, 95% confidence interval [CI] 0.13-0.82, p=.02; I 2 =0%). With regard to improvement in back pain, the point estimate for the effect size was -0.27 (95% CI -0.43 to -0.10, p=.002; I 2 =0%), in favor of the TLIF group. For ODI, the pooled estimate for the effect size was -3.73 (95% CI -7.09 to -0.38, p=.03; I 2 =35%), significantly in favor of the TLIF group. Operative times were significantly shorter in the PLF group, with a summary effect size of -25.55 (95% CI -43.64 to -7.45, p<.01; I 2 =54%). No significant difference was observed in leg pain, HRQOL improvement, blood loss, or infection rate. Our meta-analysis results were consistent with RCTs, in favor of TLIF for achieving radiographic fusion and greater improvement in ODI and back pain., Conclusions: Our results demonstrate that for patients undergoing fusion for spondylolisthesis, TLIF is superior to PLF with regard to achieving radiographic fusion. However, current data only provide weak support, if any, favoring TLIF over PLF for clinical improvement in disability and back pain., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Background Context: Transforaminal lumbar interbody fusion (TLIF) or anterior lumbar interbody fusion with percutaneous pedicle screws (ALIFPS) offer significantly higher radiographic fusion rates than other fusion techniques for L5-S1 isthmic spondylolisthesis (IS). As it stands, there is a relative paucity of comparative data of the two techniques., Purpose: To define the clinical, radiographic, and financial differences between TLIF and ALIFPS for L5-S1 IS., Design/setting: A retrospective cohort study conducted at a single tertiary care center., Patient Sample: Sixty-six patients who underwent either TLIF or ALIPFS for L5-S1 IS at a single tertiary care center between 2009 and 2014., Outcome Measures: Quality of life outcome scores including the EuroQol-5 Dimensions (EQ-5D), Pain Disability Questionnaire (PDQ), and Patient Health Questionnaire-9 (PHQ-9). Sagittal balance parameters including: pelvic incidence, pelvic tilt, sacral slope, segmental lordosis, total lordosis, degree of slip, disc height, and L1-axis S1 distance (LASD). Cost measures included in-hospital charges, hospital length of stay (LOS), and post-admission costs accrued over 1 year., Methods: Quality of life (QoL) outcome scores, radiographic data, and financial data were collected with a minimum of 1-year follow-up. Clinical results were investigated using the PDQ, PHQ-9, and EQ-5D. Radiographic measurements included lumbar lordosis, segmental lordosis, pelvic tilt, pelvic incidence, height of disc, L-1 axis S-1 distance, and the degree of slip. Cost data were generated based on patient-level resource utilization. Comparative data were presented as median with interquartile range (IQR). Continuous variables were compared using either independent Student t tests assuming unequal variance or Mann-Whitney U tests for parametric and nonparametric variables, respectively. The minimally clinical important difference (MCID) used for each questionnaire was as follows: PDQ (26), PHQ-9 (5), and EQ-5D (0.4)., Results: A total of 66 patients met inclusion criteria. In the ALIFPS cohort, PDQ scores improved from 69 [47, 82] to 26 [18.2, 79.7], p=.02. In the TLIF cohort, PDQ scores improved from 73 [46, 85] to 48.5 [23, 67.5], p=.01. Both groups also showed a significant improvement in EQ-5D scores at 1 year, but the ALIFPS group showed a significantly greater improvement in EQ-5D scores at 1 year (0.1 [0,0.2] vs. 0.2 [0.1, 0.4], p=.02). Furthermore, only the ALIFPS cohort showed a significant improvement in segmental lordosis. The ALIFPS cohort showed a significantly greater improvement in disc height than did TLIF (3.5 [2, 5.5] vs. 6.7 [4.1, 10], p=.01). No significant differences were found in the direct costs of both procedures., Conclusions: Our findings suggest that anterior lumbar interbody fusion with percutaneous pedicle screws can achieve better clinical outcomes compared with TLIF for the treatment of IS. We believe the superior radiographic outcomes achieved through ALIFPS, namely a greater restoration of segmental lordosis and disc height, may have contributed to the improved clinical outcomes presented in the current study., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Study Design: A retrospective cohort study at a single tertiary care center., Objective: To determine the impact of superior segment facet joint violation (FJV) during lumbar fusion on reoperation rates and quality of life (QOL)., Summary of Background Data: Although lumbar fusion is an efficacious and durable treatment for numerous spinal pathologies, adjacent segment degeneration remains a serious complication. FJV has been suggested to alter load-bearing capability and potentially contribute to adjacent segment degeneration., Materials and Methods: Patients who underwent instrumented lumbar fusion surgery between 2009 and 2013 with postoperative computed tomography imaging were included. Patients were placed in the FJV group if either of the superior segment facet joints were compromised by the pedicle screw or rod. Patients with preserved facet joints were placed in the control group. Demographic, perioperative, QOL, and reoperation data were collected. QOL scores including the Pain Disability Questionnaire, Patient Health Questionnaire-9, and EuroQOL 5 Dimensions (EQ-5D) were acquired., Results: Of 240 patients included, 112 patients were found to have FJV and the remaining 128 patients were placed in the control group. One year following lumbar fusion, QOL outcomes and reoperation rates were similar between the FJV and control groups. At 2-year follow-up, patients in the FJV group were less likely to make a significant improvement in EQ-5D (P=0.041). Also, the reoperation rate in the FJV group was significantly higher than in the control group at 2 years (15.2% vs. 6.3%, respectively; P=0.024) and 3 years (19.6% vs. 9.4%, P=0.023). Multivariable logistic regression showed FJV to be an independent predictor of both (1) failing to make a significant improvement in EQ-5D (P=0.046) and (2) undergoing reoperation at both 2 and 3 years postoperatively (P=0.024 and 0.020, respectively)., Conclusions: FJV was independently associated with a higher reoperation rate and diminished improvement in QOL.

Study Design: Retrospective analysis of data from the Nationwide Inpatient Sample, a nationally representative, all-payer database of inpatient diagnoses and procedures in the United States., Objective: The objective of this study is to compare anterior cervical fusion (ACF) to posterior cervical fusion (PCF) in the treatment of cervical spondylotic myelopathy (CSM)., Summary of Background Data: Previous studies used retrospective single-institution level data to quantify outcomes for CSM patients fusion. It is unclear whether ACF or PCF is superior with regards to charges or outcomes for the treatment of CSM., Materials and Methods: We used Nationwide Inpatient Sample data to compare ACF to PCF in the management of CSM. All patients 18 years or older with a diagnosis of CSM between 1998 and 2011 were included. ACF patients were matched to PCF patients using propensity scores based on patient characteristics (number of levels fused, spine alignment, comorbidities), hospital characteristics, and patient demographics. Multivariable regression was used to measure the effect of treatment assignment on in-hospital charges, length of hospital stay, in-hospital mortality, discharge disposition, and dysphagia diagnosis., Results: From 1998 to 2011, we identified 109,728 hospitalizations with a CSM diagnosis. Of these patients, 45,629 (41.6%) underwent ACF and 14,439 (13.2%) underwent PCF. The PCF cohort incurred an average of $41,683 more in-hospital charges (P<0.001, inflation adjusted to 2011 dollars) and remained in hospital an average of 2.4 days longer (P<0.001) than the ACF cohort. The ACF cohort was just as likely to die in the hospital [odds ratio 0.91; 95% confidence interval (CI), 0.68-1.2], 3.0 times more likely to be discharged to home or self-care (95% CI, 2.9-3.2), and 2.5 times more likely to experience dysphagia (95% CI, 2.0-3.1) than the PCF cohort., Conclusions: In treating CSM, ACF led to lower hospital charges, shorter hospital stays, and an increased likelihood of being discharged to home relative to PCF.

OBJECTIVE Improvements in imaging technology have steadily advanced surgical approaches. Within the field of spine surgery, assistance from the O-arm Multidimensional Surgical Imaging System has been established to yield superior accuracy of pedicle screw insertion compared with freehand and fluoroscopic approaches. Despite this evidence, no studies have investigated the clinical relevance associated with increased accuracy. Accordingly, the objective of this study was to investigate the clinical outcomes following thoracolumbar spinal fusion associated with O-arm-assisted navigation. The authors hypothesized that increased accuracy achieved with O-arm-assisted navigation decreases the rate of reoperation secondary to reduced hardware failure and screw misplacement. METHODS A consecutive retrospective review of all patients who underwent open thoracolumbar spinal fusion at a single tertiary-care institution between December 2012 and December 2014 was conducted. Outcomes assessed included operative time, length of hospital stay, and rates of readmission and reoperation. Mixed-effects Cox proportional hazards modeling, with surgeon as a random effect, was used to investigate the association between O-arm-assisted navigation and postoperative outcomes. RESULTS Among 1208 procedures, 614 were performed with O-arm-assisted navigation, 356 using freehand techniques, and 238 using fluoroscopic guidance. The most common indication for surgery was spondylolisthesis (56.2%), and most patients underwent a posterolateral fusion only (59.4%). Although O-arm procedures involved more vertebral levels compared with the combined freehand/fluoroscopy cohort (4.79 vs 4.26 vertebral levels; p < 0.01), no significant differences in operative time were observed (4.40 vs 4.30 hours; p = 0.38). Patients who underwent an O-arm procedure experienced shorter hospital stays (4.72 vs 5.43 days; p < 0.01). O-arm-assisted navigation trended toward predicting decreased risk of spine-related readmission (0.8% vs 2.2%, risk ratio [RR] 0.37; p = 0.05) and overall readmissions (4.9% vs 7.4%, RR 0.66; p = 0.07). The O-arm was significantly associated with decreased risk of reoperation for hardware failure (2.9% vs 5.9%, RR 0.50; p = 0.01), screw misplacement (1.6% vs 4.2%, RR 0.39; p < 0.01), and all-cause reoperation (5.2% vs 10.9%, RR 0.48; p < 0.01). Mixed-effects Cox proportional hazards modeling revealed that O-arm-assisted navigation was a significant predictor of decreased risk of reoperation (HR 0.49; p < 0.01). The protective effect of O-arm-assisted navigation against reoperation was durable in subset analysis of procedures involving < 5 vertebral levels (HR 0.44; p = 0.01) and ≥ 5 levels (HR 0.48; p = 0.03). Further subset analysis demonstrated that O-arm-assisted navigation predicted decreased risk of reoperation among patients undergoing posterolateral fusion only (HR 0.39; p < 0.01) and anterior lumbar interbody fusion (HR 0.22; p = 0.03), but not posterior/transforaminal lumbar interbody fusion. CONCLUSIONS To the authors' knowledge, the present study is the first to investigate clinical outcomes associated with O-arm-assisted navigation following thoracolumbar spinal fusion. O-arm-assisted navigation decreased the risk of reoperation to less than half the risk associated with freehand and fluoroscopic approaches. Future randomized controlled trials to corroborate the findings of the present study are warranted.

Study Design: A retrospective cohort study at a single institution., Objective: To determine the effect of preoperative depression on Hospital Consumer Assessment of Healthcare Providers and Systems (HCAHPS) survey scores in a lumbar fusion population., Summary of Background Data: HCAHPS surveys are used to assess the quality of the patient experience, and directly influences reimbursement for hospital systems and spine surgeons nationwide. Untreated depression has been linked to worse functional outcomes in spine surgery. We, however, aimed to elucidate whether HCAHPS survey responses were different in depressed patients., Methods: Prospectively collected functional outcome data including Patient Health Questionnaire 9, EuroQol five dimensions, and Pain Disability Questionnaire were analyzed preoperatively. Preoperative Patient Health Questionnaire 9 scores of greater than or equal to 10 (moderate to severe depression) defined our depressed cohort of patients. HCAHPS responses were obtained for each individual, allowing for real-world analysis of outcomes in this population., Results: In our 237 patient cohort, depressed patients were younger, female; were on full disability; and had lower scores on EuroQol five dimensions and Pain Disability Questionnaire preoperatively. Approximately 73.2% of depressed patients felt doctors treated them with respect, compared to 88.8% of patients without depression (P = 0.005). Also, depressed patients felt nurses treated them with less respect (P = 0.014) and that physicians did not listen to them as carefully (P = 0.029). Multivariate regression analysis revealed that patients with preoperative depression had higher odds of patients feeling less respected by both physicians and nurses. Multivariate analysis also revealed that depression was an independent predictor of lower patient satisfaction with nursing response to their needs., Conclusion: In patients undergoing lumbar fusion, preoperative depression was shown to have negative effect on patient experience measured by the HCAHPS survey. These results suggest that depression may be a modifiable risk factor for poor hospital experience., Level of Evidence: 3.

Background Context: Lumbar fusion is a common and costly procedure in the United States. Reimbursement for surgical procedures is increasingly tied to care quality and patient safety as part of value-based reimbursement programs. The incidence of adverse quality events among lumbar fusion patients is unknown using the definition of care quality (patient safety indicators [PSI]) used by the Centers for Medicare and Medicaid Services (CMS). The association between insurance status and the incidence of PSI is similarly unknown in lumbar fusion patients., Purpose: This study sought to determine the incidence of PSI in patients undergoing inpatient lumbar fusion and to quantify the association between primary payer status and PSI in this population., Study Design: A retrospective cohort study was carried out., Patient Sample: The sample comprised all adult patients aged 18 years and older who were included in the Nationwide Inpatient Sample (NIS) that underwent lumbar fusion from 1998 to 2011., Outcome Measure: The incidence of one or more PSI, a validated and widely used metric of inpatient health-care quality and patient safety, was the primary outcome variable., Methods: The NIS data were examined for all cases of inpatient lumbar fusion from 1998 to 2011. The incidence of adverse patient safety events (PSI) was determined using publicly available lists of the International Classification of Diseases, Ninth Revision, Clinical Modification diagnosis codes. Logistic regression models were used to determine the association between primary payer status (Medicaid and self-pay relative to private insurance) and the incidence of PSI., Results: A total of 539,172 adult lumbar fusion procedures were recorded in the NIS from 1998 to 2011. Patients were excluded from the secondary analysis if "other" or "missing" was listed for primary insurance status. The national incidence of PSI was calculated to be 2,445 per 100,000 patient years of observation, or approximately 2.5%. In a secondary analysis, after adjusting for patient demographics and hospital characteristics, Medicaid and self-pay patients had significantly greater odds of experiencing one or more PSI during the inpatient episode relative to privately insured patients (odds ratio 1.16, 95% confidence interval 1.07-1.27)., Conclusions: Among patients undergoing inpatient lumbar fusion, insurance status is associated with the adverse health-care quality events used to determine hospital reimbursement by the CMS. The source of this disparity must be studied to improve the quality of care delivered to vulnerable patient populations., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Background Context: Multiple studies have determined minimum clinically important difference (MCID) thresholds for EuroQOL-5 Dimensions (EQ-5D) scores in lumbar fusion patients. However, a comprehensive understanding of predictors for a clinically significant improvement (CSI) postoperatively does not exist., Purpose: To determine medical, radiographic, and surgical predictors for obtaining a CSI following lumbar fusion surgery., Study Design: This is a retrospective review of patients who underwent instrumented lumbar fusion., Patient Sample: We included patients who underwent lumbar fusion for any indication between 2008 and 2013., Outcome Measures: Outcome measures included preoperative and postoperative EQ-5D Index scores., Materials and Methods: The medical records of patients who received a lumbar fusion for any indication were retrospectively reviewed to identify patient medical and surgical characteristics. A blinded reviewer assessed radiographs for each patient to examine sagittal alignment following fusion. Multivariable logistic regression was used to model the achievement of a CSI based on two commonly cited MCID values., Results: A total of 231 patients fit the inclusion criteria; 58% exceeded an MCID value for an EQ-5D score of 0.100, and 16% exceeded an MCID value of 0.390. Statistically significant independent predictors of not obtaining a CSI for an MCID threshold of 0.100 included a higher preoperative EQ-5D score (odds ratio [OR]=44.8) and L5-S1 fusion (OR=3.3). For an MCID value of 0.390, a higher preoperative EQ-5D score (OR=2,080.8) and a diagnosis of depression (OR=7.1) were predictive of not achieving a CSI, whereas spondylolisthesis (OR=4.1) was predictive of obtaining a CSI postoperatively. For both MCID values, patients who achieved a CSI had better postoperative quality of life (QOL) scores for all metrics measured, despite worse QOL scores preoperatively., Conclusions: This study is the first to use a combination of medical, surgical, and postoperative sagittal balance variables as determinants for the achievement of a CSI after lumbar fusion. The awareness of these predictors may allow for better patient selection and surgical approach to decrease the probability of acquiring a poor outcome postoperatively., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Background Context: The incidence of adverse care quality events among patients undergoing cervical fusion surgery is unknown using the definition of care quality employed by the Centers for Medicare and Medicaid Services (CMS). The effect of insurance status on the incidence of these adverse quality events is also unknown., Purpose: This study determined the incidence of hospital-acquired conditions (HAC) and patient safety indicators (PSI) in patients with cervical spine fusion and analyzed the association between primary payer status and these adverse events., Study Design: This is a retrospective cohort design., Patient Sample: All patients in the Nationwide Inpatient Sample (NIS) aged 18 and older who underwent cervical spine fusion from 1998 to 2011 were included., Outcome Measures: Incidence of HAC and PSI from 1998 to 2011 served as outcome variables., Methods: We queried the NIS for all hospitalizations that included a cervical fusion during the inpatient episode from 1998 to 2011. All comparisons were made between privately insured patients and Medicaid or self-pay patients because Medicare enrollment is confounded with age. Incidence of nontraumatic HAC and PSI was determined using publicly available lists of International Classification of Disease, Ninth Revision, Clinical Modification (ICD-9-CM) diagnosis codes. We built logistic regression models to determine the effect of primary payer status on PSI and nontraumatic HAC., Results: We identified 419,424 hospitalizations with cervical fusion performed during an inpatient episode. The estimated national incidences of nontraumatic HAC and PSI were 0.35% and 1.6%, respectively. After adjusting for patient demographics and hospital characteristics, Medicaid or self-pay patients had significantly greater odds of experiencing one or more HAC (odds ratio [OR] 1.51 95% conflict of interest [CI] 1.23-1.84) or PSI (OR 1.52 95% CI 1.37-1.70) than the privately insured cohort., Conclusions: Among patients undergoing inpatient cervical fusion, primary payer status predicts PSI and HAC (both indicators of adverse health-care quality used to determine hospital reimbursement by CMS). As the US health-care system transitions to a value-based payment model, the cause of these disparities must be studied to improve the quality of care delivered to vulnerable patient populations., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Study Design: A retrospective cohort study., Objective: The objective of this study is to compare the radiographic and clinical outcomes of transforaminal lumbar interbody fusion (TLIF) with bilateral facetectomy (BF) versus unilateral facetectomy (UF)., Summary of Background Data: BF is a surgical technique utilized with the intent of creating a greater degree of segmental lordosis than UF alone. However, the clinical benefits of this technique have not been defined. We seek to determine whether a difference exists between bilateral versus UF during TLIF by utilizing both clinical and radiographic outcome measures., Methods: The electronic medical records of 57 patients who underwent single-level TLIF with either a UF (n = 28) or BF (n = 29) were reviewed. Clinical outcomes were measured through Patient Health Questionnaire-9 (PHQ-9), Pain Disability Questionnaire (PDQ), EuroQol 5 Dimensions (EQ-5D) Health State, and Quality Adjusted Life Year (QALY). Radiographic parameters including disc height and sagittal balance were measured on plain radiographs at 1 year following operation., Results: All radiographic parameters showed no significant differences between the UF and BF cohorts. Segmental lordosis increased significantly in both cohorts. However, there was no significant difference in the increase of segmental lordosis between cohorts. Overall lumbar lordosis did not increase significantly in either cohort. Perioperative complications were also similar between cohorts. PDQ and EQ-5D scores improved significantly in both cohorts at 1 year postoperatively. The BF cohort showed a significantly greater improvement in both EQ-5D (0.1 ± 0.2 vs. 0.3 ± 0.2, P = 0.01) and PHQ-9 scores (-0.8 ± 4.6 vs. 4.6 ± 5.2, P = 0.03) than the UF cohort. The PDQ score improved over the minimally clinical important difference (MCID) of 26 in only the BF cohort., Conclusion: The findings in the present study demonstrate that BF during single-level TLIF improves clinical outcomes to a greater degree than UF without any notable differences in perioperative complications or radiographic measurements., Level of Evidence: 3.

Study Design: Retrospective Review., Objective: The aim of this study was to determine medical, radiographic, and surgical risk factors for the development of adjacent segment disease (ASD) after lumbar fusion., Summary of Background Data: ASD is a recognized outcome of spinal fusion that leads to increased costs and debilitating symptoms for patients. However, a comprehensive understanding of risk factors for the development of this surgical outcome does not exist., Methods: The medical records of patients who received their first lumbar fusion for any indication were retrospectively examined for preoperative medical comorbidities and medications, as well as surgical approach and perioperative complications. A blinded reviewer assessed radiographs for each patient to examine sagittal alignment after fusion. Multivariable logistic regression was used to model the risk of developing ASD on the basis of one or more predictors., Results: A total of 137 patients fit the inclusion criteria; 9% required a follow-up operation for degeneration at segments adjacent to the fusion. The ASD group had a mean follow-up of 21.1 months prior to revision surgery and an overall follow-up of 41.0 months. The average follow-up in the control group was 14.0 months. Statistically significant independent predictors of developing ASD included antidepressant use [odds ratio (OR) = 5.4], diagnosis of degenerative scoliosis (OR = 34.2), fusion of L4-S1 (OR = 56.5), having no decompressions adjacent to the fusion, and low sacral slope (OR = 0.9). No patient who developed ASD received a decompression adjacent to the fusion such that an OR could not be generated for this independent predictor., Conclusion: This study is the first to use a combination of medical, surgical, and postoperative sagittal balance as risk factors for the development of adjacent segment disease after lumbar fusion. The awareness of these risk factors may allow for better patient selection and surgical technique to decrease the probability of acquiring this adverse outcome., Level of Evidence: 4.

OBJECTIVE Ossification of the posterior longitudinal ligament (OPLL) is a pathological calcification or ossification of the PLL, predominantly occurring in the cervical spine. Although surgery is often necessary for patients with symptomatic neurological deterioration, there remains controversy with regard to the optimal surgical treatment. In this systematic review and meta-analysis, the authors identified differences in complications and outcomes after anterior or posterior decompression and fusion versus after decompression alone for the treatment of cervical myelopathy due to OPLL. METHODS A MEDLINE, SCOPUS, and Web of Science search was performed for studies reporting complications and outcomes after decompression and fusion or after decompression alone for patients with OPLL. A meta-analysis was performed to calculate effect summary mean values, 95% CIs, Q statistics, and I(2) values. Forest plots were constructed for each analysis group. RESULTS Of the 2630 retrieved articles, 32 met the inclusion criteria. There was no statistically significant difference in the incidence of excellent and good outcomes and of fair and poor outcomes between the decompression and fusion and the decompression-only cohorts. However, the decompression and fusion cohort had a statistically significantly higher recovery rate (63.2% vs 53.9%; p < 0.0001), a higher final Japanese Orthopaedic Association score (14.0 vs 13.5; p < 0.0001), and a lower incidence of OPLL progression (< 1% vs 6.3%; p < 0.0001) compared with the decompression-only cohort. There was no statistically significant difference in the incidence of complications between the 2 cohorts. CONCLUSIONS This study represents the only comprehensive review of outcomes and complications after decompression and fusion or after decompression alone for OPLL across a heterogeneous group of surgeons and patients. Based on these results, decompression and fusion is a superior surgical technique compared with posterior decompression alone in patients with OPLL. These results indicate that surgical decompression and fusion lead to a faster recovery, improved postoperative neurological functioning, and a lower incidence of OPLL progression compared with posterior decompression only. Furthermore, decompression and fusion did not lead to a greater incidence of complications compared with posterior decompression only.

OBJECTIVE Pedicle and lateral mass screw placement is technically demanding due to complex 3D spinal anatomy that is not easily visualized. Neurosurgical and orthopedic surgery residents must be properly trained in such procedures, which can be associated with significant complications and associated morbidity. Current training in pedicle and lateral mass screw placement involves didactic teaching and supervised placement in the operating room. The objective of this study was to assess whether teaching residents to place pedicle and lateral mass screws using navigation software, combined with practice using cadaveric specimens and Sawbones models, would improve screw placement accuracy. METHODS This was a single-blinded, prospective, randomized pilot study with 8 junior neurosurgical residents and 2 senior medical students with prior neurosurgery exposure. Both the study group and the level of training-matched control group (each group with 4 level of training-matched residents and 1 senior medical student) were exposed to a standardized didactic education regarding spinal anatomy and screw placement techniques. The study group was exposed to an additional pilot program that included a training session using navigation software combined with cadaveric specimens and accessibility to Sawbones models. RESULTS A statistically significant reduction in overall surgical error was observed in the study group compared with the control group (p = 0.04). Analysis by spinal region demonstrated a significant reduction in surgical error in the thoracic and lumbar regions in the study group compared with controls (p = 0.02 and p = 0.04, respectively). The study group also was observed to place screws more optimally in the cervical, thoracic, and lumbar regions (p = 0.02, p = 0.04, and p = 0.04, respectively). CONCLUSIONS Surgical resident education in pedicle and lateral mass screw placement is a priority for training programs. This study demonstrated that compared with a didactic-only training model, using navigation simulation with cadavers and Sawbones models significantly reduced the number of screw placement errors in a laboratory setting.

Study Design: Retrospective 1-year cost-utility analysis., Objective: To determine the cost-effectiveness of decompression with and without instrumented fusion for patients with grade I degenerative L4-L5 spondylolisthesis at 1-year follow-up., Summary of Background Data: Despite its benefits to health outcomes, lumbar fusion is associated with substantial costs. This study analyzed the cost-effectiveness of instrumented fusion for grade I L4-L5 spondylolisthesis at 1-year follow-up., Materials and Methods: Four cohorts of 25 patients with grade I L4-L5 degenerative spondylolisthesis were analyzed: cohort 1 (decompression), cohort 2 (decompression with instrumented posterolateral fusion (PLF), cohort 3 (decompression with instrumented posterior lumbar interbody fusion/transforaminal lumbar interbody fusion), and cohort 4 (decompression with instrumented PLF and posterior lumbar interbody fusion/transforaminal lumbar interbody fusion). One-year postoperative health outcomes were assessed based on Visual Analogue Scale, Pain Disability Questionnaire, and EuroQol 5 Dimensions questionnaires. Direct medical costs were estimated using Medicare national payment amounts and indirect costs were based on patient missed work days. Postoperative 1-year cost/utility ratios and incremental cost-effectiveness ratios (ICERs) were calculated. Cost-effectiveness was assessed using a threshold of $100,000/QALY gained., Results: Compared with preoperative health states, EuroQol 5 Dimensions QALY scores improved for all cohorts (P<0.01). The 1-year cost-utility ratio for cohort 1 was significantly lower ($56,610/QALY gained; P<0.01) than that for cohorts 2 ($116,991/QALY gained), 3 ($109,740/QALY gained), and 4 ($107,546/QALY gained). The 1-year ICERs relative to cohort 1 were: cohort 2 (dominated), cohort 3 ($1,060,549/QALY gained), and cohort 4 ($830,047/QALY gained)., Conclusions: Decompression without fusion is cost-effective for patients with grade I L4-L5 spondylolisthesis. Decompression with fusion is not cost effective in a 1-year timeframe for these patients based on the threshold. Accordingly, although fusion is beneficial for improving health outcomes in patients with spondylolisthesis, it is not cost-effective when analyzing a 1-year timeframe based on the threshold. The durability of these results must be analyzed with longer term cost-utility analysis studies.

Study Design: A retrospective 1-year cost-utility analysis., Objective: To determine the cost-effectiveness of anterior cervical discectomy and fusion with plating (ACDFP) in comparison with posterior cervical foraminotomy (PCF) for patients with single-level cervical radiculopathy., Summary of Background Data: Cervical radiculopathy due to cervical spondylosis is commonly treated by either PCF or ACDFP for patients who are refractory to nonsurgical treatment. Although some have suggested superior outcomes with ACDFP as compared with PCF, the former is also associated with greater costs. The present study analyzes the cost-effectiveness of ACDFP versus PCF for patients with single-level cervical radiculopathy., Methods: Forty-five patients who underwent ACDFP and 25 patients who underwent PCF for single-level cervical radiculopathy were analyzed. One-year postoperative health outcomes were assessed based on Visual Analogue Scale, Pain Disability Questionnaire, Patient Health Questionnaire, and EuroQOL-5 Dimensions questionnaires to analyze the comparative effectiveness of each procedure. Direct medical costs were estimated using Medicare national payment amounts and indirect costs were based on patient missed work days and patient income. Postoperative 1-year cost/utility ratios and the incremental cost-effectiveness ratio (ICER) were calculated to assess for cost-effectiveness using a threshold of $100,000/QALY gained., Results: The 1-year cost-utility ratio for the PCF cohort was significantly lower ($79,856/QALY gained) than that for the ACDFP cohort ($131,951/QALY gained) (P<0.01). In calculating the 1-year ICER, as the ACDFP cohort showed lower QALY gained than the PCF cohort, the ICER was negative and is not reported, meaning that ACDFP was dominated by PCF., Conclusions: Statistically significant and clinically relevant improvements (through minimum clinically important differences) were seen in both cohorts. Although both cohorts showed improved health outcomes, ACDFP was not cost-effective relative to the threshold of $100,000/QALY gained at 1-year postoperatively, whereas PCF was. The durability of these results must be analyzed with long-term cost-utility analysis studies.

Background Context: Cervical arthroplasty is an increasingly popular alternative for the treatment of cervical radiculopathy and myelopathy. This technique preserves motion at the index and adjacent disc levels, avoiding the restraints of fusion and potentially minimizing adjacent segment pathology onset during the postoperative period., Purpose: This study aimed to identify all prospective studies reporting adjacent segment pathology rates for cervical arthroplasty., Study Design/setting: Systematic review and meta-analysis were carried out., Patient Sample: Studies reporting adjacent segment degeneration (ASDegeneration) and adjacent segment disease (ASDisease) rates in patients who underwent cervical arthroplasty comprised the patient sample., Outcome Measures: Outcomes of interest included reported ASDegeneration and ASDisease events after cervical arthroplasty., Methods: We conducted a MEDLINE, SCOPUS, and Web of Science search for studies reporting ASDegeneration or ASDisease following cervical arthroplasty. A meta-analysis was performed to calculate effect summary values, 95% confidence intervals (CIs), Q values, and I(2) values. Forest plots were constructed for each analysis group., Results: Of the 1,891 retrieved articles, 32 met inclusion criteria. The patient incidence of ASDegeneration and ASDisease was 8.3% (95% CI 3.8%-12.7%) and 0.9% (95% CI 0.1%-1.7%), respectively. The rate of ASDegeneration and ASDisease at individual levels was 10.5% (95% CI 6.1%-14.9%) and 0.2% (95% CI -0.1% to 0.5%), respectively. Studies following patients for 12-24 months reported a 5.1% (95% CI 2.1%-8.1%) incidence of ASDegeneration and 0.2% (95% CI 0.1%-0.2%) incidence of ASDisease. Conversely, studies following patients for greater than 24 months reported a 16.6% (5.8%-27.4%) incidence of ASDegeneration and 2.6% (95% CI 1.0%-4.2%) of ASDisease. This identified a statistically significant increase in ASDisease diagnosis with lengthier follow-up. Additionally, 1- and 2-level procedures resulted in a 7.4% (95% CI 3.3%-11.4%) and15.6% (95 CI-9.2% to 40.4%) incidence of ASDegeneration, respectively. Although there was an 8.2% increase in ASDegeneration following 2-level operations (relative to 1-level), it did not reach statistical significance. We were unable to analyze ASDisease incidence following 2-level arthroplasty (too few cases), but 1-level operations resulted in an ASDisease incidence of 0.8% (95% CI 0.1%-1.5%)., Conclusions: This review represents a comprehensive estimation of the actual incidence of ASDegeneration and ASDisease across a heterogeneous group of surgeons, patients, and arthroplasty techniques. Our investigation should serve as a framework for individual surgeons to understand the impact of various cervical arthroplasty techniques, follow-up duration, and surgical levels on the incidence of ASDegeneration and ASDisease during the postoperative period., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Study Design: A retrospective 1-year cost-utility analysis., Objective: To determine the cost-effectiveness of using recombinant human bone morphogenic protein (rhBMP-2) in addition to autograft for 1- and 2-level lumbar fusions., Summary of Background Data: rhBMP-2 has been studied extensively to identify its benefits, risks, patient outcomes, and costs relative to autograft [local bone or iliac crest bone graft (ICBG)]. This study seeks to analyze the cost-effectiveness of adding rhBMP-2 to autograft versus without rhBMP-2 in lumbar fusions., Methods: Thirty-three patients receiving rhBMP-2 in addition to either local bone autograft or ICBG (rhBMP-2 cohort) and 42 patients receiving only local bone autograft or ICBG (control cohort) for 1- or 2-level dorsal lumbar fusion were analyzed. This included posterolateral fusion, posterior lumbar interbody fusion, and transforaminal lumbar interbody fusion. One-year postoperative health outcomes were assessed based on Visual Analogue Scale, Pain Disability Questionnaire, Patient Health Questionnaire, and EuroQol-5 Dimensions questionnaires. Direct medical costs were estimated using Medicare national payment amounts and indirect costs were based on patient missed work days and patient income. Postoperative 1-year cost-utility ratios and the incremental cost-effectiveness ratio (ICER) were calculated to assess for cost-effectiveness using a threshold of $100,000/QALY gained., Results: The 1-year cost-utility ratio (total cost/ΔQALY) for the control cohort was significantly lower ($143,251/QALY gained) than that of the rhBMP-2 cohort ($272,414/QALY gained) (P<0.01). At 1-year follow-up, the control group dominated the ICER compared with the rhBMP-2 group., Conclusions: Statistically significant and clinically relevant improvements (through minimum clinically important differences) were seen for both cohorts. In the ICER analysis, the control cohort dominated the rhBMP-2 group. Assuming durable per year gains in QALY, by 2 years fusion with autograft but without rhBMP-2 would be considered cost-effective ($71,625/QALY gained), whereas fusion with both autograft and rhBMP-2 would not be cost-effective ($136,207/QALY gained).

Management of spine surgery patients with osteoporosis is challenging because of the difficulty of instrumenting and the potential complications, including nonunion and adjacent level fractures. Treatment of this patient population should involve a multidisciplinary approach including the spine surgeon, primary care physician, endocrinologist, and physical therapist. Indication for preoperative treatment before spinal fusion surgery is unclear. All patients should receive calcium and vitamin D. Hormone replacement therapy, including estrogen or selective estrogen receptor modulators, should be considered for elderly female patients with decreased bone mass. Bisphosphonates or intermittent parathyroid hormone are reserved for those with significant bone loss in the spine. Pretreatment with antiresorption medications affect bone remodeling, which is a vital part of graft incorporation and fusion. Although there have been numerous animal studies, there is limited clinical evidence. Accordingly, surgery should be delayed, if possible, to treat the osteoporosis before the intervention. Treatment may include bisphosphonates, as well as newer agents, such as recombinant parathyroid hormone. Further clinical data are needed to understand the relative advantages/disadvantage of antiresorptive vs anabolic agents, as well as the impact of administration of these medications before vs after fusion surgery. Future clinical studies will enable better understanding of the impact of current therapies on biomechanics and fusion outcomes in this unique and increasingly prevalent patient population.

Background Context: Anterior cervical discectomy and fusion (ACDF) is a commonly performed procedure for patients presenting with cervical radiculopathy, myelopathy, or deformity. A systematic literature review and meta-analysis of pseudoarthrosis rates associated with ACDF with plate fixation have not been previously performed., Purpose: The purpose of this study was to identify all prospective studies reporting pseudoarthrosis rates for ACDF with plate fixation., Study Design/setting: This study is based on a systematic review and meta-analysis., Patient Sample: Studies reporting pseudoarthrosis rates in patients who received one-, two-, or three-level ACDF surgeries were included., Outcome Measures: Outcomes of interest included reported pseudoarthrosis events after ACDF with plate fixation., Methods: We conducted a MEDLINE, SCOPUS, Web of Science, and EMBASE search for studies reporting complications for ACDF with plate fixation. We recorded pseudoarthrosis events from all included studies. A meta-analysis was performed to calculate effect summary mean values, 95% confidence intervals (CIs), Q statistics, and I(2) values. Forest plots were constructed for each analysis group., Results: Of the 7,130 retrieved articles, 17 met the inclusion criteria. The overall pseudoarthrosis rate was 2.6% (95% CI: 1.3-3.9). Use of autograft fusion (0.9%, 95% CI: -0.4 to 2.1) resulted in a reduced pseudoarthrosis rate compared with allograft fusion procedures (4.8%, 95% CI: 1.7-7.9). Studies were separated based on the length of follow-up: 12 to 24 and greater than 24 months. These groups reported rates of 3.1% (95% CI: 1.2-5.0) and 2.3% (95% CI: 0.1-4.4), respectively. Studies performing single-level ACDF yielded a rate of 3.7% (95% CI: 1.6-5.7). Additionally, there was a large difference in the rate of pseudoarthrosis in randomized controlled trials (4.8%, 95% CI: 2.6-7.0) versus prospective cohort studies (0.2%, 95% CI: -0.1 to 0.5), indicating that the extent of follow-up criteria affects the rate of pseudoarthrosis., Conclusions: This review represents a comprehensive estimation of the actual incidence of pseudoarthrosis across a heterogeneous group of surgeons, patients, and ACDF techniques. The definition of pseudoarthrosis varied significantly within the literature. To ensure its diagnosis and prevent sequelae, standardized criteria need to be established. This investigation sets the framework for surgeons to understand the impact of surgical techniques on the rate of pseudoarthrosis., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Study Design: Systematic review., Objective: To evaluate literature comparing fusion rates in anterior lumbar interbody fusion (ALIF), posterior lumbar interbody/transforaminal lumbar interbody fusion (PLIF/TLIF), and posterolateral lumbar fusion (PLF) with and without recombinant human bone morphogenetic protein-2 (rhBMP-2)., Summary of Background Data: rhBMP-2 is used for the FDA-approved indication of single-level ALIF with LT-Cage and off-label for PLIF/TLIF, and PLF. Due to recent controversies, it is essential to evaluate the literature for its effects on fusion rates to evaluate whether benefits outweigh potential complications., Methods: A Medline search was performed of clinical studies published between May 2000 and May 2012 comparing fusion rates after ALIF, PLIF/TLIF, and PLF surgery with versus without rhBMP-2. Only studies with a control arm were reviewed., Results: 16 studies were reviewed (1794 patients, 995 treated with rhBMP-2 and 799 without). 5 of 5 studies for PLIF/TLIF (including 301 of 301 patients), 1 of 4 for ALIF (including 279 of 589 patients), and 3 of 7 for PLF (including 272 of 904 patients) reported no significant improvement in fusion rates with rhBMP-2 compared with those without rhBMP-2 at longest follow-up investigated. Average fusion rate 24 months after surgery was 97.8% for ALIF (n = 316), 95.7% for PLIF/TLIF (n = 141), and 93.6% for PLF (n = 422) with rhBMP-2 and 88.2% (n = 228), 89.5% (n = 86), and 83.1% (n = 372) without rhBMP-2, for ALIF, PLIF/TLIF, and PLF, respectively. Odds ratio of fusion were calculated as 7.08 (95% CI: 1.54-32.7) in ALIF, 1.98 (95% CI: 0.39-10.1) in PLIF/TLIF, and 3.06 (95% CI: 1.61-5.80) in PLF with rhBMP-2 as compared with without rhBMP-2., Conclusion: Although numerous studies did not show statistically significant improvement in fusion rates with rhBMP-2 use, analysis of combined studies revealed significant improvement in fusion rate with rhBMP-2 in ALIF and PLF patients. Notably, even when pooling data from several studies, rhBMP-2 did not result in statistically significantly improved fusion rates in PLIF/TLIF. However, heterogeneity of rhBMP-2 dosing, surgical techniques, and quality of papers reviewed may limit the validity of conclusions drawn., Level of Evidence: 4.

Background Context: Anterior cervical discectomy and fusion (ACDF) and posterior cervical foraminotomy (PCF) are both used to surgically treat patients with cervical radiculopathy and have been shown to have similar outcomes. Nonetheless, ACDF has become increasingly more commonplace compared with PCF, in part because of a pervasive belief that PCF has a higher incidence of required reoperations., Purpose: To determine the reoperation rate at the index level of ACDF versus PCF 2 years postoperatively., Study Design: A retrospective case-control., Patient Sample: All patients that underwent ACDF and PCF for radiculopathy (excluding myelopathy indications) between January 2005 and December 2011., Outcome Measures: Revision surgery within 2 years, at the index level, was recorded., Methods: Propensity score analysis between the ACDF and PCF groups was done, matching for age, gender, race, body mass index, tobacco use, median income and insurance status, primary surgeon, level of surgery, surgery duration, and length of hospital stay., Results: Seven hundred ninety patients met the inclusion/exclusion criteria, including 627 ACDF and 163 PCF. Before propensity matching, the PCF group was found to be significantly older and more likely to be male. After matching, there were no significant differences between groups for any baseline characteristics. Reoperation rate at the index level was 4.8% for the ACDF group and 6.4% for the PCF group (p=.7) within 2 years of the initial surgery. Using equivalence testing, based on an a priori null hypothesis that a clinically meaningful difference between the two groups would be ≥5%, we found that the absolute difference of 1.6% was significantly (p=.01) less than our hypothesized difference., Conclusions: This study demonstrates that even after accounting for patient demographics, operative characteristics, and primary surgeon, there are no significant differences in 2-year reoperation rates at the index level between ACDF and PCF. The reoperation rates are statistically equivalent. Thus, spine surgeons can operate via the posterior approach without putting patients at increased risk for revision surgery at the index level., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Study Design: Retrospective chart review., Objective: To describe the adverse outcomes associated with the use of rhBMP-2 in thoracolumbar and lumbar fusions., Summary of Background Data: rhBMP-2 has been increasingly used in spinal fusions over the past decade. Early studies reported that the use of rhBMP-2 is associated with decreased operative time, blood loss, and pain scores, as well as improved fusion rates. Recent investigations have shown rhBMP-2 to be associated with various complications occurring at incidences ranging from 0% to 100%., Methods: Using the institutional electronic medical records, we retrospectively reviewed all patients between January 2002 and September 2010 that underwent thoracolumbar and lumbar spine fusion with BMP. Patient demographics, operative, and outcome/complication information was collected., Results: A total of 547 patient charts were reviewed with a mean follow-up time of 17 months. Mean age was 58 years. Forty-one percent of patients had undergone previous spine surgery. Thirty-nine percent of patients had a PLIF/TLIF, 29% underwent a PLF, and 20% an ALIF. No relevant differences in the patient characteristics and complications were identified between the various surgical approaches. For all approaches, having undergone a previous spine surgery was associated with increased incidence of radiculitis, reoperation, and pseudoarthrosis (P=0.005, 0.0008, 0.05, respectively) as compared with those without previous spine surgery. Being a current smoker at the time of operation was associated with increased rate of radiculitis (P=0.03) as compared with nonsmokers., Conclusions: The use of rhBMP-2, in this study, had an incidence of radiculitis, pseudoarthrosis, and reoperation that was similar to the rates in historical controls without rhBMP-2. Complications do not differ by surgical approach, but are more likely in current smokers and those undergoing revision surgery. A prospective study is warranted to further delineate the adverse event profile of rhBMP-2 and the variables that are likely to affect it (ie, type of surgery, carrier, and dose).

Background Context: In select patients, posterior cervical foraminotomy (PCF) and anterior cervical discectomy and fusion (ACDF) result in similar clinical outcomes when used to treat cervical radiculopathy. Nonetheless, ACDF is performed more frequently, in part because of surgeon perception that PCF requires operative revisions more frequently. The present study investigates the rate of ACDF reoperation at the index level after initial PCF., Purpose: To determine the rate of ACDF after initial PCF and to further describe any patient characteristics or preoperative or operative data that increase the rate of reoperation after PCF., Study Design: Retrospective chart review., Methods: Demographic, operative, and reoperation information was collected from the electronic medical records for all patients who underwent PCF at one institution between 2004 and 2011. All patients were subsequently contacted by telephone to identify postoperative complications and more conclusively determine whether any revision operation was performed at the index level., Results: One hundred seventy-eight patients who underwent a PCF were reviewed, with an average follow-up of 31.7 months. Nine (5%) patients underwent an ACDF revision operation at the index level. The reason for reoperation in these patients included cervical radiculopathy, foraminal stenosis, disc herniation, and cervical spondylosis. Patients who subsequently underwent ACDF at the index level were significantly younger (25 vs. 35 years, p=.03), had lower body mass index (25 vs. 29, p=.01), and more likely to take anxiolytic (56% vs. 22%, p=.04) or antidepressant medication (67% vs. 27%, p=.02), compared with those that did not have a revision operation., Conclusions: This is the first study to determine conversion to ACDF after PCF. The present study demonstrates that PCF is associated with a low reoperation rate, similar to the historical reoperation for ACDF. Accordingly, spine surgeons can operate via a PCF approach without a significant increased risk for ACDF revision surgery at the index level., (Published by Elsevier Inc.)

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

Background Context: Some, smaller studies have investigated the effect of preoperative depression on postoperative improvement in quality of life (QOL). However, they have not used the Patient Health Questionnaire 9 (PHQ-9) in self-reported depression., Purpose: To assess the effect of preoperative depression as measured by the PHQ-9 on postoperative improvement in QOL., Study Design: A retrospective review at a single tertiary-care referral center., Patient Sample: Patients who underwent lumbar decompression or fusion between 2008 and 2012., Outcomes Measures: A self-reported EuroQol five-dimensions (EQ-5D) quality-adjusted life-years Index., Methods: Quality of life data were collected using the institutional prospectively collected database of patient-reported health status measures. The EQ-5D questionnare, PDQ, and PHQ-9 were used. Linear and logistic regression analyses were performed to assess the impact of preoperative depression on QOL improvement., Results: Elevated preoperative pain (PDQ, β=-0.0017, p=.0009) and worsened depression (PHQ-9, β=-0.0044, p=.0359) were significantly associated with diminished postoperative improvement in QOL, as measured by the EQ-5D. Furthermore, greater depression (PHQ-9, odds ratio [OR] 0.93, p<.0001) and pain (PDQ, OR 0.99, p=.02) were associated with significantly diminished postoperative improvement exceeding the minimum clinically important difference., Conclusions: Increased preoperative pain and depression were shown to be associated with significantly reduced improvement in postoperative QOL, as measured by the EQ-5D., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Background Context: Posterior cervical fusion (PCF) has been shown to be an effective treatment for cervical spondylosis, but is associated with a 9% complication rate and high costs. To limit such complications and costs, it is imperative that proper selection of surgical candidates occur for those most likely to do well with the surgery. Affective disorders, such as depression, are associated with worsened outcomes after lumbar surgery; however, this effect has not been evaluated in patients undergoing cervical spine surgery., Purpose: To assess the predictive value of preoperative depression and the health state on 1-year quality of life (QOL) outcomes after PCF., Study Design: A retrospective cohort analysis., Patient Sample: Eighty-eight patients who underwent PCF for cervical spondylosis were reviewed., Outcome Measures: Preoperative and 1-year postoperative health outcomes were assessed based on the Pain Disability Questionnaire (PDQ), the Patient Health Questionnaire-9 (PHQ-9), and the EuroQol five-dimensions (EQ-5D) questionnaire., Methods: Univariable and multivariable regression analyses were performed to assess for preoperative predictors of 1-year change in health status., Results: Compared with preoperative health states, the PCF cohort showed statistically significant improved PDQ (87.8 vs. 73.6), PHQ-9 (7.7 vs. 6.6), and EQ-5D (0.50 vs. 0.60) scores at 1 year postoperatively. Only 10/88 (11%) patients achieved or surpassed the minimum clinically important difference for the PHQ-9 (5). Multiple linear and logistic regression analyses showed that increasing PHQ-9 and EQ-5D preoperative scores were associated with reduced 1-year postoperative improvement in health status (EQ-5D index)., Conclusions: Of patients who undergo PCF, those with a greater degree of preoperative depression have lower improvements in postoperative QOL compared with those with less depression. Additionally, patients with better preoperative health states also attain lower 1-year QOL improvements., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Background Context: C5 palsy is a debilitating postoperative complication of cervical decompression surgery. Although the prognosis is typically good, patients may be unable to perform basic activities of daily living, resulting in a decreased quality of life. No studies have investigated the quality-of-life and financial implications., Purpose: The aim of the study was to determine the impact on quality-of-life and costs of C5 palsy after posterior cervical decompression and fusion (PCDF)., Study Design/setting: A 2:1 matched retrospective cohort study was conducted at a single tertiary-care institution between 2007 and 2012., Patient Sample: Individuals who had undergone PCDF were included., Outcome Measures: Self-reported: Euroqol-5 Dimensions quality-of-life survey. Physiologic: postoperative change in deltoid and biceps strength via manual muscle testing. Functional: cost of interventions and missed workdays postoperatively., Methods: Individuals with postoperative C5 palsy were matched to controls based on age, gender, body mass index, and diagnosis. Demographic, operative, postoperative, quality-of-life, and cost data were collected for both the C5 palsy and control groups, with 1-year follow-up., Results: We reviewed 245 patients who underwent PCDF and 17 were identified (6.9%) with C5 palsy and matched to 34 controls. No significant differences in demographic or operative characteristics were observed between groups. The C5 palsy group had a significantly reduced capacity for self-care in the immediate postoperative (2.0±0.71 vs. 1.2±0.4, p<.001) and long-term (1.6±0.6 vs. 1.2±0.4, p=.004) periods and a significantly reduced capacity for completion of usual activities (2.4±0.7 vs. 1.9±0.6, p=.014) compared with controls. Furthermore, the C5 group had a significantly greater cost of physical/occupational therapy, an increase of $2,078 ($4,386±$2,801 vs. $2,307±$1,907, p=.013). There were no significant differences between groups in the cost of hospital stay, surgery, or other direct or indirect costs. Overall, there was a significantly greater cost ($1,918) for the C5 palsy group compared with the control group ($7,584±$3,992 vs. $5,666±$2,359, respectively, p=.038)., Conclusions: This study represents the first quantification of the impact of C5 palsy on patients' quality of life and the associated costs for care. We found that C5 palsy adds a significant burden on patients' quality of life and presents a financial burden to the health-care system., (Copyright © 2014 Elsevier Inc. All rights reserved.)

Object: Single-level anterior cervical discectomy and fusion (ACDF) is an established surgical treatment for cervical myelopathy. Within 10 years of undergoing ACDF, 19.2% of patients develop symptomatic adjacent-level degeneration. Performing ACDF adjacent to prior fusion requires exposure and removal of previously placed hardware, which may increase the risk of adverse outcomes. Zero-profile cervical implants combine an interbody spacer with an anterior plate into a single device that does not extend beyond the intervertebral disc space, potentially obviating the need to remove prior hardware. This study compared the biomechanical stability and adjacent-level range of motion (ROM) following placement of a zero-profile device (ZPD) adjacent to a single-level ACDF against a standard 2-level ACDF., Methods: In this in vitro biomechanical cadaveric study, multidirectional flexibility testing was performed by a robotic spine system that simulates flexion-extension, lateral bending, and axial rotation by applying a continuous pure moment load. Testing conditions were as follows: 1) intact, 2) C5-6 ACDF, 3) C4-5 ZPD supraadjacent to simulated fusion at C5-6, and 4) 2-level ACDF (C4-6). The sequence of the latter 2 test conditions was randomized. An unconstrained pure moment of 1.5 Nm with a 40-N simulated head weight load was applied to the intact condition first in all 3 planes of motion and then using the hybrid test protocol, overall intact kinematics were replicated subsequently for each surgical test condition. Intersegmental rotations were measured optoelectronically. Mean segmental ROM for operated levels and adjacent levels was recorded and normalized to the intact condition and expressed as a percent change from intact. A repeated-measures ANOVA was used to analyze the ROM between test conditions with a 95% level of significance., Results: No statistically significant differences in immediate construct stability were found between construct Patterns 3 and 4, in all planes of motion (p > 0.05). At the operated level, C4-5, the zero-profile construct showed greater decreases in axial rotation (-45% vs -36%) and lateral bending (-55% vs -38%), whereas the 2-level ACDF showed greater decreases in flexion-extension (-40% vs -34%). These differences were marginal and not statistically significant. Adjacent-level motion was nearly equivalent, with minor differences in flexion-extension., Conclusions: When treating degeneration adjacent to a single-level ACDF, a zero-profile implant showed stabilizing potential at the operated level statistically similar to that of the standard revision with a 2-level plate. Revision for adjacent-level disease is common, and using a ZPD in this setting should be investigated clinically because it may be a faster, safer alternative.

Background: Pedicle fractures in the cervical spine are common. They may occur in isolation or in combination with other concomitant fractures. Multiple classification systems have been introduced to provide a clinical framework when approaching these types of fractures; however, these systems do not provide guidelines for optimal treatment. Data regarding decision making are limited. Conservative treatment with orthoses may result in subluxation and instability requiring further treatment. Surgery may not be required in all instances because many of these injuries may heal without surgical intervention., Methods: All cases of cervical fractures treated at a single institution over a 5-year period were retrospectively reviewed. Cases with pedicle fractures were further evaluated, and 40 cases managed either with or without surgery were identified. Data on presenting history, neurologic examination, imaging findings, comorbidity, method of treatment, complication rate, and length of hospital stay were collected. Fractures were classified based on computed tomography scans. Data on associated injuries were also collected. Fusion rate and fracture displacement were assessed by plain radiographs and computed tomography scans at follow-up. Follow-up time points included 2, 6, and 12 weeks and 6 months after injury. Primary outcome was fracture healing regardless of modality in the absence of progressive deformity (i.e., listhesis, kyphosis) and need for further surgery., Results: Conservative therapy was administered to 26 patients, and 14 patients underwent surgery. There were no statistically significant differences between the 2 groups in terms of total levels injured (P = 0.9) or injury severity score (P = 0.5). Patients who presented with intact neurologic status were more likely to be treated conservatively (88% vs. 29%; P = 0.0004), whereas patients presenting with spinal cord injuries were more likely to undergo surgical fixation (35% vs. 0%; P = 0.0004). Length of hospital stay trended toward being significantly greater in patients who underwent surgery (10.6 days vs. 5.5 days; P = 0.07). According to our classification system, the most common fracture type was single line horizontal fracture occurring in 68% (27 of 40 cases). Vertical split pedicle fracture occurred in 28% (11 of 40 cases), and double line horizontal fracture occurred in 5% (2 of 40 cases). Posttreatment progressive listhesis was significantly higher in patients who were treated conservatively (31% vs. 0%; P = 0.03), especially when associated with comminuted lateral mass or subluxation or both., Conclusions: This study describes and classifies unique cervical pedicle fractures and associated injuries. Our findings suggest that surgical treatment results in definitive stability for these injuries compared with conservative therapy, particularly for pedicle fractures associated with comminuted lateral mass or initially displaced fractures. However, nondisplaced vertical split pedicle fractures and isolated single line horizontal fractures may be treated nonsurgically without occurrence of further instability. A larger prospective study is required to confirm these findings., (Copyright © 2014 Elsevier Inc. All rights reserved.)

Background Context: Few studies have evaluated the extent of biomechanical destabilization of thoracic decompression on the upper and lower thoracic spine. The present study evaluates lower thoracic spinal stability after laminectomy, unilateral facetectomy, and unilateral costotransversectomy in thoracic spines with intact sternocostovertebral articulations., Purpose: To assess the biomechanical impact of decompression and fixation procedures on lower thoracic spine stability., Study Design: Biomechanical cadaveric study., Methods: Sequential surgical decompression (laminectomy, unilateral facetectomy, unilateral costotransversectomy) and dorsal fixation were performed on the lower thoracic spine (T8-T9) of human cadaveric spine specimens with intact rib cages (n=10). An industrial robot was used to apply pure moments to simulate flexion-extension (FE), lateral bending (LB), and axial rotation (AR) in the intact specimens and after decompression and fixation. Global range of motion (ROM) between T1-T12 and intrinsic ROM between T7-T11 were measured for each specimen., Results: The decompression procedures caused no statistically significant change in either global or intrinsic ROM compared with the intact state. Instrumentation, however, reduced global motion for AR (45° vs. 30°, p=.0001), FE (24° vs. 19°, p=.02), and LB (47° vs. 36°, p=.0001) and for intrinsic motion for AR (17° vs. 4°, p=.0001), FE (8° vs. 1°, p=.0001), and LB (12° vs. 1°, p=.0001). No significant differences were identified between decompression of the upper versus lower thoracic spine, with trends toward significantly greater ROM for AR and lower ROM for LB in the lower thoracic spine., Conclusions: The lower thoracic spine was not destabilized by sequential unilateral decompression procedures. Addition of dorsal fixation increased segment rigidity at intrinsic levels and also reduced overall ROM of the lower thoracic spine to a greater extent than did fusing the upper thoracic spine (level of the true ribs). Despite the lack of true ribs, the lower thoracic spine was not significantly different compared with the upper thoracic spine in FE and LB after decompression, although there were trends toward significance for greater AR after decompression. In certain patients, instrumentation may not be needed after unilateral decompression of the lower thoracic spine; further validation and additional clinical studies are warranted., (Copyright © 2014 Elsevier Inc. All rights reserved.)

Object: Cost-effectiveness research in spine surgery has been a prominent focus over the last decade. However, there has yet to be a standardized method developed for calculation of costs in such studies. This lack of a standardized costing methodology may lead to conflicting conclusions on the cost-effectiveness of an intervention for a specific diagnosis. The primary objective of this study was to systematically review all cost-effectiveness studies published on spine surgery and compare and contrast various costing methodologies used., Methods: The authors performed a systematic review of the cost-effectiveness literature related to spine surgery. All cost-effectiveness analyses pertaining to spine surgery were identified using the cost-effectiveness analysis registry database of the Tufts Medical Center Institute for Clinical Research and Health Policy, and the MEDLINE database. Each article was reviewed to determine the study subject, methodology, and results. Data were collected from each study, including costs, interventions, cost calculation method, perspective of cost calculation, and definitions of direct and indirect costs if available., Results: Thirty-seven cost-effectiveness studies on spine surgery were included in the present study. Twenty-seven (73%) of the studies involved the lumbar spine and the remaining 10 (27%) involved the cervical spine. Of the 37 studies, 13 (35%) used Medicare reimbursements, 12 (32%) used a case-costing database, 3 (8%) used cost-to-charge ratios (CCRs), 2 (5%) used a combination of Medicare reimbursements and CCRs, 3 (8%) used the United Kingdom National Health Service reimbursement system, 2 (5%) used a Dutch reimbursement system, 1 (3%) used the United Kingdom Department of Health data, and 1 (3%) used the Tricare Military Reimbursement system. Nineteen (51%) studies completed their cost analysis from the societal perspective, 11 (30%) from the hospital perspective, and 7 (19%) from the payer perspective. Of those studies with a societal perspective, 14 (38%) reported actual indirect costs., Conclusions: Changes in cost have a direct impact on the value equation for concluding whether an intervention is cost-effective. It is essential to develop a standardized, accurate means of calculating costs. Comparability and transparency are essential, such that studies can be compared properly and policy makers can be appropriately informed when making decisions for our health care system based on the results of these studies.

Background Context: Decompressive procedures such as laminectomy, facetectomy, and costotransversectomy are routinely performed for various pathologies in the thoracic spine. The thoracic spine is unique, in part, because of the sternocostovertebral articulations that provide additional strength to the region relative to the cervical and lumbar spines. During decompressive surgeries, stability is compromised at a presently unknown point., Purpose: To evaluate thoracic spinal stability after common surgical decompressive procedures in thoracic spines with intact sternocostovertebral articulations., Study Design: Biomechanical cadaveric study., Methods: Fresh-frozen human cadaveric spine specimens with intact rib cages, C7-L1 (n=9), were used. An industrial robot tested all spines in axial rotation (AR), lateral bending (LB), and flexion-extension (FE) by applying pure moments (±5 Nm). The specimens were first tested in their intact state and then tested after each of the following sequential surgical decompressive procedures at T4-T5 consisting of laminectomy; unilateral facetectomy; unilateral costotransversectomy, and subsequently instrumented fusion from T3-T7., Results: We found that in all three planes of motion, the sequential decompressive procedures caused no statistically significant change in motion between T3-T7 or T1-T12 when compared with intact. In comparing between intact and instrumented specimens, our study found that instrumentation reduced global range of motion (ROM) between T1-T12 by 16.3% (p=.001), 12% (p=.002), and 18.4% (p=.0004) for AR, FE, and LB, respectively. Age showed a negative correlation with motion in FE (r = -0.78, p=.01) and AR (r=-0.7, p=.04)., Conclusions: Thoracic spine stability was not significantly affected by sequential decompressive procedures in thoracic segments at the level of the true ribs in all three planes of motion in intact thoracic specimens. Age appeared to negatively correlate with ROM of the specimen. Our study suggests that thoracic spinal stability is maintained immediately after unilateral decompression at the level of the true ribs. These preliminary observations, however, do not depict the long-term sequelae of such procedures and warrant further investigation., (Copyright © 2014 Elsevier Inc. All rights reserved.)

Cervical spondylotic myelopathy (CSM) often can be surgically treated by either ventral or dorsal decompression and fusion. However, there is a lack of high-level evidence on the relative advantages and disadvantages for these treatments of CSM. The authors' goal was to provide a comprehensive review of the relative benefits of ventral versus dorsal fusion in terms of quality of life (QOL) outcomes, complications, and costs. They reviewed 7 studies on CSM published between 2003 and 2013 and summarized the findings for each category. Both procedures have been shown to lead to statistically significant improvement in clinical outcomes for patients. Ventral fusion surgery has been shown to yield better QOL outcomes than dorsal fusion surgery. Complication rates for ventral fusion surgery range from 11% to 13.6%, whereas those for dorsal fusion surgery range from 16.4% to 19%. Larger randomized controlled trials are needed, with particular emphasis on QOL and minimum clinically important differences.

Object: The goal of this study was to compare the urological complications in patients after anterior lumbar interbody fusion (ALIF) with and without the use of recombinant human bone morphogenetic protein-2 (rhBMP-2)., Methods: The authors retrospectively reviewed the medical records of all patients who underwent ALIF with and without rhBMP-2 between January 2002 and August 2010. Patient demographic, operative, and complication information was analyzed. Male patients who underwent ALIF between L-4 and S-1 were contacted to assess postoperative urological complications., Results: Of the 110 male patients who underwent ALIF and were included in this study, 59 were treated with rhBMP-2 and 51 did not receive rhBMP-2. The mean follow-up duration was 17.5 months for the rhBMP-2 group and 30.8 months for the control group. No difference was found regarding the total number of urological complications in the rhBMP-2 group versus the control group (22% vs 20%, respectively; p = 1.0) or for retrograde ejaculation specifically (8% vs 8%, respectively; p = 1.0)., Conclusions: In this study, the use of rhBMP-2 with ALIF surgery was not associated with an increased incidence of urological complications and retrograde ejaculation when compared with control ALIF without rhBMP-2. Further prospective analyses that specifically look at these complications are warranted.

Study Design: A prospective clinical research article., Objective: The primary goals were to determine (1) radiation exposure to the spine surgeon with the use of an intraoperative 3-dimensional imaging system and (2) to define the safe distance from the computed tomographic scanner., Summary of Background: Intraoperative radiation exposure to the spinal surgeon has been assessed during 2-dimensional fluoroscopy but has not been investigated during intraoperative 3-dimensional imaging., Methods: Ten patients undergoing lumbar or thoracolumbar fusion were enrolled in a prospective trial to determine the radiation exposure to a spine surgeon standing in the substerile room, with the use of the O-ARM Imaging System (Medtronic, Memphis, TN). A thermolucent digital dosimeter was worn at chest level without a lead apron. Dosimeter readings and distance from the spine surgeon were recorded. RESULTS.: Average surgeon exposure was 44.22 ± 17.4 μrem (range: 17.71-70.76 μrem). The mean distance from the O-ARM was 4.56 ± .32 m, and the surgeon was exposed for an average of 19.6 ± 5.7 seconds (range: 8.05-28.7 s). The annual number of necessary procedures required to surpass the exposure limit, according to the data presented here, would be 113,071 operations using O-ARM. Hence, the number of necessary procedures for O-ARM use is predicted to be 1,130,710 annual procedures to reach the occupational exposure limits for extremity, skin, and all other organs and 339,213 procedures to reach the limits for the lens of eye., Conclusion: Radiation exposure is minimal to the surgical team during routine use of the O-ARM imaging system. The number of procedures required to surpass occupational exposure limits is high if using appropriate distance from the O-ARM.