Are there differences in the reoperation rates for operative adjacent-segment disease between ALIF+PS, PLIF+PS, TLIF+PS, and LLIF+PS? An analysis of a cohort of 5291 patients.

OBJECTIVE: Biomechanical factors in lumbar fusions accelerate the development of adjacent-segment disease (ASD). Stiffness in the fused segment increases motion in the adjacent levels, resulting in ASD. The objective of this study was to determine if there are differences in the reoperation rates for symptomatic ASD (operative ASD) between anterior lumbar interbody fusion plus pedicle screws (ALIF+PS), posterior lumbar interbody fusion plus pedicle screws (PLIF+PS), transforaminal lumbar interbody fusion plus pedicle screws (TLIF+PS), and lateral lumbar interbody fusion plus pedicle screws (LLIF+PS). METHODS: A retrospective study using data from the Kaiser Permanente Spine Registry identified an adult cohort (≥ 18 years old) with degenerative disc disease who underwent primary lumbar interbody fusions with pedicle screws between L3 to S1. Demographic and operative data were obtained from the registry, and chart review was used to document operative ASD. Patients were followed until operative ASD, membership termination, the end of study (March 31, 2022), or death. Operative ASD was analyzed using Cox proportional hazards models. RESULTS: The final study population included 5291 patients with a mean ± SD age of 60.1 ± 12.1 years and a follow-up of 6.3 ± 3.8 years. There was a total of 443 operative ASD cases, with an overall incidence rate of reoperation for ASD of 8.37% (95% CI 7.6-9.2). The crude incidence of operative ASD at 5 years was the lowest in the ALIF+PS cohort (7.7%, 95% CI 6.3-9.4). In the adjusted models, the authors failed to detect a statistical difference in operative ASD between ALIF+PS (reference) versus PLIF+PS (HR 1.06 [0.79-1.44], p = 0.69) versus TLIF+PS (HR 1.03 [0.81-1.31], p = 0.83) versus LLIF+PS (HR 1.38 [0.77-2.46], p = 0.28). CONCLUSIONS: In a large cohort of over 5000 patients with an average follow-up of > 6 years, the authors found no differences in the reoperation rates for symptomatic ASD (operative ASD) between ALIF+PS and PLIF+PS, TLIF+PS, or LLIF+PS.

Postoperative Opioid Use Among Opioid-Naive Cannabis Users Following Single-Level Lumbar Fusions.

BACKGROUND: As the literature grows on opioid use, the impact of simultaneous cannabis use has hitherto been mostly unexplored. In this study, we assessed the effects of cannabis use on postoperative opioid utilization in opioid-naive patients undergoing single level fusions of the lumbar spine. METHODS: Using an all-payer claims database, the medical records of 91 million patients were analyzed to identify patients who had undergone single level lumbar fusions between January 2010 and October 2020. Rates of opioid utilization at 6 months following index procedure (morphine milligram equivalents/day), the development of opioid use disorder (OUD), and the rates of opioid overuse were assessed. RESULTS: Following examination of 87,958 patient records, 454 patients were matched and distributed equally into cannabis user and noncannabis user cohorts. At 6 months following index procedure, cannabis users were equal to nonusers in their rates of prescribed opioid utilization (49.78%, P > 0.99). Cannabis users used smaller daily dosages compared to nonusers (51.1 ± 35.05 vs. 59.72 ± 41, P = 0.003). On the other hand, the proportion of patients diagnosed with OUD was found to be significantly higher among patients using cannabis (18.94% vs. 3.96%, P < 0.0001). CONCLUSIONS: Compared to noncannabis users, opioid-naive patients who are cannabis users undergoing lumbar spinal fusions are at a higher risk of developing opioid dependence following surgery, despite having decreased daily dosages of opioids overall. Further studies should explore the factors associated with the development of OUD and the details of concurrent marijuana use to effectively treat pain while limiting the potential for abuse.

Rates and risk factors associated with 30- and 90-day readmissions and reoperations after spinal fusions for adult lumbar degenerative pathology and spinal deformity.

PURPOSE: Analyze state databases to determine variables associated with of short-term readmissions and reoperations following thoracolumbar spine fusions for degenerative pathology and spinal deformity. METHODS: Retrospective study of State Inpatient Database (2005-13, CA, NE, NY, FL, NC, UT). INCLUSION CRITERIA: age > 45 years, diagnosis of degenerative spinal deformity, ≥ 3 level posterolateral lumbar spine fusion. EXCLUSION CRITERIA: revision surgery, cervical fusions, trauma, and cancer. Univariate and step-wise multivariate logistic regression analyses were performed to identify independent variables associated with of 30- and 90-day readmissions and reoperations. RESULTS: 12,641 patients were included. All-cause 30- and 90-day readmission rates were 14.6% and 21.1%, respectively. 90-day readmissions were associated with: age > 80 (OR: 1.42), 8 + level fusions (OR: 1.19), hospital length of stay (LOS) > 7 days (OR: 1.43), obesity (OR: 1.29), morbid obesity (OR: 1.66), academic hospital (OR: 1.13), cancer history (OR:1.21), drug abuse (OR: 1.31), increased Charlson Comorbidity index (OR: 1.12), and depression (OR: 1.20). Private insurance (OR: 0.64) and lumbar-only fusions (OR: 0.87) were not associated with 90-day readmissions. All-cause 30- and 90-day reoperation rates were 1.8% and 4.2%, respectively. Variables associated with 90-day reoperations were 8 + level fusions (OR: 1.28), LOS > 7 days (OR: 1.43), drug abuse (OR: 1.68), osteoporosis (OR: 1.26), and depression (OR: 1.23). Circumferential fusion (OR: 0.58) and lumbar-only fusions (OR: 0.68) were not associated with 90-day reoperations. CONCLUSIONS: 30- and 90-day readmission and reoperation rates in thoracolumbar fusions for adult degenerative pathology and spinal deformity may have been underreported in previously published smaller studies. Identification of modifiable risk factors is important for improving quality of care through preoperative optimization.

Robotic-Assisted Versus Conventional Posterior Lumbar Fusion-An Analysis of 90-Day Complications and Readmissions.

OBJECTIVE: To evaluate medical and surgical complication rates between robotic-assisted versus conventional elective posterior lumbar fusions. METHODS: The Symphony Integrated DataVerse was queried using International Classification of Diseases, 10th Edition, Clinical Modification procedure codes to identify patients undergoing elective posterior lumbar fusions for degenerative spine pathologies between 2015 and 2018. International Classification of Diseases, 10th Edition, Clinical Modification procedure codes (8E0W4CZ, 8E0W0CZ, 8E0W3CZ) were used to identify patients undergoing a robotic-assisted spinal fusion. Outcome measures were 90-day medical and surgical complications, 1-year pseudarthrosis, and 1-year revision surgery rates. Multivariate logistic regression analyses were used to assess whether undergoing a robotic-assisted fusion (vs. conventional fusion) was associated with differences in wound complications, medical complications, pseudarthrosis, revision surgery, and readmissions within 90 days of surgery. RESULTS: A total of 39,387 patients undergoing elective posterior lumbar fusions were included in the cohort-of whom 245 (0.62%) patients underwent a robotic-assisted fusion. Multivariate analysis showed that robotic-assisted fusion (vs. conventional fusion) was not associated with significant differences in 90-day rates of wound complications (P = 0.299), urinary tract infections (P = 0.648), acute myocardial infarctions (P = 0.209), acute renal failure (P = 0.461), pneumonia (P = 0.214), stroke (P = 0.917), deep venous thrombosis (P = 0.562), pulmonary embolism (P = 0.401), and readmissions (P = 0.985). In addition, there were no significant differences in the 1-year rates of revision fusions (P = 0.316) and pseudarthrosis (P = 0.695). CONCLUSIONS: Patients who underwent a robotic-assisted fusion had similar rates of surgical and medical complications compared with those who underwent a conventional fusion. Further studies are warranted to better understand the future role of robots in spine surgery.

Optimal "Low" Pedicle Screw Stimulation Threshold to Predict New Postoperative Lower-Extremity Neurologic Deficits During Lumbar Spinal Fusions.

OBJECTIVE: Previous studies have shown that pedicle screw stimulation thresholds ≤6-8 mA yield a high diagnostic accuracy of detecting misplaced screws. Our objective was to determine the optimal "low" stimulation threshold to predict new postoperative neurologic deficits and identify additional risk factors associated with deficits. METHODS: We included patients with complete pedicle screw stimulation testing who underwent posterior lumbar spinal fusion surgeries from 2010-2012. We calculated the diagnostic accuracy of pedicle screw responses of ≤4 mA, ≤6 mA, ≤8 mA, ≤10 mA, ≤12 mA, and ≤20 mA to predict new postoperative lower-extremity (LE) neurologic deficits. We used multivariate modeling to determine the best logistic regression model to predict LE deficits and identify additional risk factors. Statistics software packages used were Python3.8.5, NumPy 1.19.1, Pandas 1.1.1, and SPSS26. RESULTS: We studied 1179 patients who underwent 8584 pedicle screw stimulations with somatosensory evoked potential and free-run electromyographic monitoring for posterior lumbar spinal fusion. Twenty-five (2.1%) patients had new LE neurologic deficits. A stimulation threshold of ≤8 mA had a sensitivity/specificity of 32%/90% and a diagnostic odds ratio/area under the curve of 4.34 [95% confidence interval: 1.83, 10.27]/0.61 [0.49, 0.74] in predicting postoperative deficit. Multivariate analysis showed that patients who had pedicle screws with stimulation thresholds ≤8 mA are 3.15 [1.26, 7.83]× more likely to have postoperative LE deficits while patients who have undergone a revision lumbar spinal fusion surgery are 3.64 [1.38, 9.61]× more likely. CONCLUSIONS: Our results show that low thresholds are indicative of not only screw proximity to the nerve but also an increased likelihood of postoperative neurologic deficit. Thresholds ≤8 mA prove to be the optimal "low" threshold to help guide a correctly positioned pedicle screw placement and detect postoperative deficits.

Mild and Severe Obesity Reduce the Effectiveness of Lumbar Fusions: 1-Year Patient-Reported Outcomes in 8171 Patients.

BACKGROUND: Elevated body mass index (BMI) is a well-known risk factor for surgical complications in lumbar surgery. However, its effect on surgical effectiveness independent of surgical complications is unclear. OBJECTIVE: To determine increasing BMI's effect on functional outcomes following lumbar fusion surgery, independent of surgical complications. METHODS: We retrospectively analyzed a prospectively built, patient-reported, quality of life registry representing 75 hospital systems. We evaluated 1- to 3-level elective lumbar fusions. Patients who experienced surgical complications were excluded. A stepwise multivariate regression model assessed factors independently associated with 1-yr Oswestry Disability Index (ODI), preop to 1-yr ODI change, and achievement of minimal clinically important difference (MCID). RESULTS: A total of 8171 patients met inclusion criteria: 2435 with class I obesity (BMI 30-35 kg/m2), 1328 with class II (35-40 kg/m2), and 760 with class III (≥40 kg/m2). Increasing BMI was independently associated with worse 12-mo ODI (t = 8.005, P < .001) and decreased likelihood of achieving MCID (odds ratio [OR] = 0.977, P < .001). One year after surgery, mean ODI, ODI change, and percentage achieving MCID worsened with class I, class II, and class III vs nonobese cohorts (P < .001) in stepwise fashion. CONCLUSION: Increasing BMI is associated with decreased effectiveness of 1- to 3-level elective lumbar fusion, despite absence of surgical complications. BMI ≥ 30 kg/m2 is, therefore, a risk factor for both surgical complication and reduced benefit from lumbar fusion.

Certificate-of-Need State Laws and Elective Posterior Lumbar Fusions: Is It Time to Repeal the Mandate?

OBJECTIVES: Our study aimed to assess whether elective posterior lumbar fusions (PLFs) performed in states with Certificate-of-Need (CON) laws versus states without CON laws had lower utilization rates, lower costs, and better quality of care. METHODS: The 2005-2014 100% Medicare Standard Analytical File was queried to identify patients undergoing elective 1- to 3-level PLF. Differences in per-capita utilization, 90-day reimbursements, and proportion of high-volume between CON and No-CON states were reported. Multivariate analyses were used to analyze 90-day complications and readmissions. RESULTS: A total of 188,687 patients underwent an elective 1- to 3-level PLF in a CON state and 167,642 patients in a No-CON state during 2005-2014. The average per capita utilization of PLFs was lower in CON states as compared with No-CON states (14.5 vs. 15.4 per 10,000 population; P < 0.001). Average 90-day reimbursements between CON and No-CON states differed by a small amount ($22,115 vs. $21,802). CON states had a higher proportion of high-volume facilities (CON vs. No CON-40.9% vs. 29.9%; P < 0.05) and lower proportion of low-volume facilities (CON vs. No-CON-37.2% vs. 45.0%; P < 0.05). PLFs performed in CON states had slightly lower odds of 90-day complications (odds ratio 0.97 [95% confidence interval 0.96-0.99]; P < 0.001) and readmissions (odds ratio 0.95 [95% confidence interval 0.93-0.97]; P < 0.001). CONCLUSIONS: The presence of CON laws was associated with lower utilization of elective 1- to 3-level PLFs and a greater number of high-volume facilities. However, their effect on quality of care, via reduction of 90-day readmissions and 90-day complications, is minimally significant.

Hospital network participation and outcomes following elective posterior lumbar fusions - are mergers effective?

BACKGROUND CONTEXT: Due to financial pressures associated with healthcare reforms, an increasing number of hospitals are now merging (or consolidating) into networks (or systems). However, it remains unclear how these mergers or network participations affect quality of care and/or costs. PURPOSE: The current study aims to evaluate the impact of hospital network participation on 90-day complications, charges, and costs following elective posterior lumbar fusions (PLFs). STUDY DESIGN: Retrospective review of a 100% national sample of Medicare claims from 2010 to 2014 (SAF100). STUDY SAMPLE: All Medicare-eligible patients undergoing elective 1-to-3 level PLFs for degenerative lumbar pathology from 2010 to 2014. OUTCOME MEASURES: Ninety-day complications, charges, and costs. METHODS: The 2010 to 2014 100% Medicare Standard Analytical Files (SAF100) was used to identify patients undergoing elective 1- to 3-level PLFs for degenerative lumbar pathology. The Dartmouth Atlas for Healthcare hospital-level data, which uses a combination of American Hospital Association and additional source data, was used to identify hospitals that were part of a network (or system) between 2010 and 2014. The study sample was divided into 2 cohorts (network hospitals and non-network hospitals) for analyses. Multivariate logistic regression models were used to compare differences in 90-day complications between network and non-network hospitals, while controlling for baseline demographics (age, gender, region, year of surgery, median household income, co-morbidity burden) and hospital-level characteristics (case volume, teaching status, urban/rural location, and hospital ownership). Generalized linear regression modeling was used to assess for differences in 90-day charges and costs. RESULTS: A total of 145,141 patients undergoing surgery in 2,186 hospitals were included in the study, out of which 107,919 (74.4%) underwent surgery in a network hospital (N=1,526). Network hospitals were more prevalent in the South or West regions of the United States. Patients in network hospitals had a median household income less than the 5th quintile. Network hospitals were also more likely to have a higher annual case volume of elective 1- to 3-level PLFs, greater number of beds, be located in an urban location, and have a voluntary/nonprofit or proprietary/profit ownership model. Multivariate analyses showed that even though patients undergoing surgery at network hospitals (vs non-network hospitals) had a slightly increased odds of 90-day cardiac complications (7.9% vs 7.4%, odds ratio [OR] 1.07 [95% confidence interval {CI} 1.02-1.12]; p=.010), thromboembolic complications (2.4% vs 2.2%, OR 1.12 [95% CI 1.01-1.20]; p=.025) and emergency department visits (16.4% vs 16.0%, OR 1.06 [95% CI 1.02-1.09]; p=.002), the differences would not be considered clinically significant. Despite a slight decrease in risk-adjusted 90-day reimbursements (-$272), the risk-adjusted 90-day charges were actually significantly higher (+$9,959; p<.001) at network hospitals. CONCLUSIONS: Even though hospitals that are part of a network do not appear to have significantly different complication rates following elective PLFs, they do have significantly higher risk-adjusted charges as compared to non-network hospitals. Further research is required to understand market-level changes induced by hospital mergers into networks.

Using machine learning to predict 30-day readmissions after posterior lumbar fusion: an NSQIP study involving 23,264 patients.

OBJECTIVE: Unplanned preventable hospital readmissions within 30 days are a great burden to patients and the healthcare system. With an estimated $41.3 billion spent yearly, reducing such readmission rates is of the utmost importance. With the widespread adoption of big data and machine learning, clinicians can use these analytical tools to understand these complex relationships and find predictive factors that can be generalized to future patients. The object of this study was to assess the efficacy of a machine learning algorithm in the prediction of 30-day hospital readmission after posterior spinal fusion surgery. METHODS: The authors analyzed the distribution of National Surgical Quality Improvement Program (NSQIP) posterior lumbar fusions from 2011 to 2016 by using machine learning techniques to create a model predictive of hospital readmissions. A deep neural network was trained using 177 unique input variables. The model was trained and tested using cross-validation, in which the data were randomly partitioned into training (n = 17,448 [75%]) and testing (n = 5816 [25%]) data sets. In training, the 17,448 training cases were fed through a series of 7 layers, each with varying degrees of forward and backward communicating nodes (neurons). RESULTS: Mean and median positive predictive values were 78.5% and 78.0%, respectively. Mean and median negative predictive values were both 97%, respectively. Mean and median areas under the curve for the model were 0.812 and 0.810, respectively. The five most heavily weighted inputs were (in order of importance) return to the operating room, septic shock, superficial surgical site infection, sepsis, and being on a ventilator for > 48 hours. CONCLUSIONS: Machine learning and artificial intelligence are powerful tools with the ability to improve understanding of predictive metrics in clinical spine surgery. The authors' model was able to predict those patients who would not require readmission. Similarly, the majority of predicted readmissions (up to 60%) were predicted by the model while retaining a 0% false-positive rate. Such findings suggest a possible need for reevaluation of the current Hospital Readmissions Reduction Program penalties in spine surgery.

Risk factors for post-discharge complications and readmissions in home-discharges after elective posterior lumbar fusions.

OBJECTIVES: Previous literature has studied overall post-operative outcomes following lumbar fusions. We examined the rates and risk factors for adverse outcomes in patients who are being discharged home. PATIENTS AND METHODS: The 2012-2016 ACS-NSQIP database was used to query for patients undergoing 1- to 2-level posterior lumbar fusions (PLFs) for degenerative spinal pathology. Patients discharged to a destination other than home were removed from the database. RESULTS: Out of a total of 19,179 home-discharge patients, 546 (2.8%) experienced any adverse event (AAE), 276 experienced a severe adverse event (SAE) and 321 (1.7%) experienced a minor adverse event (MAE). Overall re-admission and re-operation rate in home-discharged patients was 4.4% and 2.5%. Multivariate analysis identified the following predictors for experiencing an AAE - Bleeding disorder (OR 2.25), BMI ≥ 35.0 vs. BMI < 25 (OR 1.96), chronic steroid use (OR 1.89), a LOS > 3 days (OR 1.53), insulin-dependent diabetes mellitus (OR 1.44), hypertension (OR 1.28) and female gender (OR 1.24). Patients with a pre-discharge complication (OR 2.12), bleeding disorders (OR 1.84), chronic steroid use (OR 1.55), age>75 (OR 1.49), age>65 (OR 1.26), history of severe COPD (OR 1.43), total operative time >210 min. (OR 1.26), ASA > II (OR 1.26) and undergoing a 2-level fusion (OR 1.21) were likely to be re-admitted from home. CONCLUSIONS: Providers should utilize the data to risk-stratify and better understand the need of provision of supplemental health-care services, in home-discharged patients, and/or regular clinic follow-up to minimize the rate of adverse events and reduce costs in a bundled-payment environment.

Orthopedic versus Neurosurgery-Understanding 90-Day Complications and Costs in Patients Undergoing Elective 1-Level to 2-Level Posterior Lumbar Fusions by Different Specialties.

BACKGROUND: Lumbar fusions are routinely performed by either orthopedic or neurologic spine surgeons. Controversy still exists as to whether a provider's specialty (orthopedic vs. neurosurgery) influences outcomes. METHODS: The 2007-2015Q2 Humana Commercial Database was queried using Current Procedural Terminology codes (22612, 22614, 22630, 22632, 22633 and 22634) to identify patients undergoing elective 1-to-2 level posterior lumbar fusions (PLFs) with active enrollment up to 90 days after procedure. Ninety-day complication rates were calculated for the 2 specialties. The surgical and 90-day resource utilization costs for the 2 groups were compared, by studying average reimbursements for acute-care and post-acute-care categories. Ninety-day complications and costs were compared using multivariable logistic and linear regression analyses. RESULTS: A total of 10,509 patients (5523 orthopedic and 4986 neurosurgery) underwent an elective 1-to-2 level PLF during the period. With the exception of a significantly lower odds of wound complications (odds ratio, 0.81) and a higher odds of dural tears (odds ratio, 1.29) in elective PLFs performed by orthopedic surgeons, no statistically strong differences were seen in 90-day complication rates between the 2 groups. Total 90-day costs were also similar between orthopedic surgeons and neurosurgeons, with the only exception being that surgeon reimbursement was lower for orthopedic surgery versus neurosurgery ($1202 vs. $1372; P < 0.001). CONCLUSIONS: It seems that a provider's specialty does not largely influence 90-day surgical outcomes and costs after elective PLFs. The results of the study promote the formation and acceptance of dual training pathways for entry into spine surgery.

Posterior lumbar fusions at physician-owned hospitals - is it time to reconsider the restrictions of the Affordable Care Act?

BACKGROUND CONTEXT: Caused by perceptions regarding unnecessary healthcare resource utilization, high costs of care, and financial incentives towards "cherry-picking" cases in physician owned hospitals, the Affordable Care Act (ACA) of 2010 imposed restrictions on existing physician-owned hospitals from expanding. Despite an increasing number of individuals requiring access to spine surgical care, no study has evaluated the surgical safety and costs of elective posterior lumbar fusions (PLFs) being performed in physician-owned vs. non-physician-owned hospitals. PURPOSE: We assessed differences in 90-day costs and outcomes between patients undergoing elective 1- to 3-level PLFs at physician-owned hospitals vs. nonphysician-owned hospitals. STUDY DESIGN: Retrospective cohort study of 2007 to 2014 100% Medicare claims database. PATIENT SAMPLE: The 2007 to 2014 Medicare 100% Standard Analytical Files (SAF100) was queried using International Classification of Diseases 9th Edition (ICD-9) procedure code for patients undergoing elective 1- to 3-level PLFs (81.07, 81.08, and 81.62). The Medicare Hospital Compare database was used to identify provider codes for physician-owned hospitals. These provider codes were cross-referenced to identify records of patients receiving elective PLFs at these hospitals from the SAF100 database. OUTCOME MEASURES: Ninety day complications, readmissions, emergency department (ED) visits, charges, and costs. METHODS: Multivariate logistic and linear regression analyses were used to assess significant differences in 90-day complications, readmissions, charges and costs between the two groups. RESULTS: A total of 6,679 (2.9%) patients received an elective PLF at a physician-owned hospital (N=39; 2.2%) whereas 225,090 (97.1%) received surgery at nonphysician-owned hospital (N=1,774; 97.8%). After controlling for age, gender, region, hospital factors (socio-economic status area, urban vs. rural location and volume) and Elixhauser co-morbidity index, undergoing surgery at physician-owned hospital was associated with lower odds of thromboembolic complications (OR 0.66 [95% CI 0.53-0.82]; p<.001), urinary tract infections (OR 0.87 [95% CI 0.79-0.95]; p=.002) and renal complications (OR 0.52 [95% CI 0.43-0.63]; p<.001) within 90-days following the surgery. Patients undergoing PLFs at physician-owned hospitals vs. nonphysician-owned hospitals also had lower risk-adjusted inpatient charges (-$10,218), inpatient costs (-$2,302), 90-day charges (-$9,780) and 90-day costs (-$2,324). No significant differences were noted between physician-owned and nonphysician-owned hospitals with regards to 90-day wound complications (OR 1.08 [95% CI 0.94-1.22]; p=.279), pulmonary complications (OR 1.06 [95% CI 0.97-1.17]; p=.187), cardiac complications (OR 0.92 [95% CI 0.83-1.01]; p=.089), septic complications (OR 0.77 [95% CI 0.56-1.01]; p=.073), all-cause ED visits (OR 0.96 [95% CI 0.89-1.04]; p=.311), revision surgery (OR 1.09 [95% CI 0.72-1.59]; p=.653) and readmissions (OR 0.98 [95% CI 0.89-1.08]; p=.680). CONCLUSION: Our results suggest that patients undergoing elective 1- to 3-level PLFs at physician-owned hospitals do not experience a greater number of complications and/or readmissions while having lower risk-adjusted charges and costs over the 90-day episode of care. The findings call on the need for revaluation/reconsideration of the ACAs restriction on the expansion of these physician-owned hospitals.

The Modified 5-Item Frailty Index: A Concise and Useful Tool for Assessing the Impact of Frailty on Postoperative Morbidity Following Elective Posterior Lumbar Fusions.

BACKGROUND: The modified 5-item frailty index (mFI-5) is a concise comorbidity-based risk stratification tool that has been shown to predict the occurrence of adverse outcomes following various orthopedic surgeries. METHODS: The 2012-2016 American College of Surgeons - National Surgical Quality Improvement Program (ACS-NSQIP) dataset was used to identify patients undergoing an elective 1- to 2-level posterior lumbar fusion for degenerative lumbar pathology. The mFI-5 score was calculated based on the presence of the 5 co-morbidities: congestive heart failure within 30 days prior to surgery, insulin-dependent or noninsulin-dependent diabetes mellitus, chronic obstructive pulmonary disease or pneumonia, partially dependent or totally dependent functional health status at time of surgery, and hypertension requiring medication. Multivariate analysis was used to assess the independent impact of increasing mFI-5 score on postoperative morbidity while controlling for baseline clinical characteristics. RESULTS: Increasing mFI-5 score versus mFI-5 = 0 was associated with higher odds of any complication (mFI-5 ≥2: odds ratio [OR] 1.45; mFI-5 = 1: OR 1.22), 30-day readmissions (mFI-5 ≥2: OR 1.46; mFI-5 = 1: OR 1.18), and nonhome discharge (mFI-5 ≥2: OR 1.80; mFI-5 = 1: OR 1.16). Higher mFI-5 score was significantly associated with increased risks of superficial surgical site infection, deep surgical site infection, unplanned reoperation, any medical complication, pneumonia, unplanned intubation, postoperative ventilator use, progressive renal insufficiency, acute renal failure, urinary tract infection, stroke, myocardial infarction, bleeding requiring transfusion, sepsis, and septic shock. CONCLUSIONS: Higher mFI-5 scores were associated with increased postoperative morbidity following elective 1- to 2-level posterior lumbar fusions.

Discharge to Inpatient Care Facility Following Revision Posterior Lumbar Fusions-Risk Factors and Postdischarge Outcomes.

BACKGROUND: Recent literature has denoted care in an inpatient facility after discharge to be linked with worse outcomes after elective primary lumbar and cervical fusions. No study has explored the risk factors and associated postdischarge outcomes after discharge to inpatient facility after revision posterior lumbar fusion. METHODS: The 2012-2016 American College of Surgeons-National Surgical Quality Improvement Program were queried using Current Procedural Terminology codes for posterior lumbar fusions (22630, 22633, 22614) combined with Current Procedural Terminology codes for revision-22830 (exploration of spinal fusion), 22849 (reinsertion of spinal fixation device), 22850 (removal of posterior nonsegmental instrumentation), and 22852 (removal of posterior segmental instrumentation). RESULTS: Of 1170 patients who underwent revision posterior lumbar fusion, 253 (21.6%) were discharged to an inpatient care facility and 917 (78.4%) were discharged to home. Significant risk factors associated with discharge to inpatient care facility were age 60-69 years (odds ratio [OR] 3.62), age ≥70 years (OR 7.46), female gender (OR 1.61), partially dependent functional health status before surgery (OR 2.94), history of chronic obstructive pulmonary disease (OR 1.92), a length of stay >3 days (OR 3.13), and the occurrence of any predischarge complication (OR 4.10). Discharge to inpatient care facilities versus home was associated with a higher risk of experiencing any postdischarge complication (8.3% vs. 3.2%; OR 2.2). CONCLUSIONS: Providers should understand the need of construction of care pathways and reducing discharge to inpatient facilities to mitigate the risks of experiencing adverse outcomes and consequently reduce the financial burden on the health care system.

Is There a "Sex Effect" in 30-Day Outcomes After Elective Posterior Lumbar Fusions?

BACKGROUND: Sex has been known to significantly affect postoperative complications and length of stay after elective anterior cervical fusions. Current evidence on lumbar spine surgery is limited. METHODS: The 2012-2016 American College of Surgeons National Surgical Quality Improvement Program database was queried using Current Procedural Terminology codes 22612, 22630, and 22633 to identify patients undergoing posterior lumbar fusions. A total of 23,615 patients were included in the final cohort. RESULTS: Out of 23,615 patients, 10,810 (45.8%) were men and 12,805 (54.2%) were women. After controlling for demographic, comorbidities-specific, preoperative, and operative differences between the 2 groups, female sex was found to be an independent risk factor significantly associated with a length of stay longer than 3 days (odds ratio [OR], 1.43; 95% confidence interval [CI], 1.35-1.51; P < 0.001), occurrence of any complication within 30 days (OR, 1.31; 95% CI, 1.16-1.47; P < 0.001), wound complications (OR, 1.43; 95% CI, 1.18-1.74; P < 0.001), urinary tract infections (OR, 2.25; 95% CI, 1.79-2.83; P < 0.001), 30-day reoperations (OR, 1.19; 95% CI, 1.02-1.39; P = 0.025), 30-day readmissions (OR, 1.16; 95% CI, 1.03-1.31; P = 0.015), and nonhome discharge (OR, 1.83; 95% CI, 1.69-1.98; P < 0.001). Interestingly, the only adverse outcome associated with male sex was renal complication (OR, 2.28; 95% CI, 1.43-3.65; P = 0.001). CONCLUSIONS: Contrary to literature on cervical fusions, we found that female sex was independently tied to an increased risk of adverse outcomes after elective posterior lumbar fusion. The results from the study suggest that women may benefit from close surveillance during the postoperative period to minimize risk of complications and subsequent resource utilization in this group.

Pregabalin Did Not Improve Pain Management After Spinal Fusions.

BACKGROUND: The treatment of postoperative pain is a challenge after posterior spinal fusions. Pain management using predominantly opioids is often associated with multiple adverse effects, while multimodal postoperative analgesia may provide adequate pain relief with fewer opioid side effects. QUESTIONS/PURPOSES: The purpose of this review is to determine whether addition of 150 mg pregabalin daily would reduce narcotic requirements and improve outcomes after posterior lumbar fusion (PLF). METHODS: The method used is a randomized, controlled trial of elective PLF patients who received pregabalin or placebo. With institutional review board (IRB) approval, 86 patients undergoing elective posterior lumbar fusion, ASA I-III, were randomized to receive either a placebo or pregabalin after obtaining written informed consent. Both arms, i.e., placebo and pregabalin, consisted of 43 patients each.The 86 patients for elective PLF were randomly assigned to receive 150 mg of pregabalin 1 h before surgery and then 150 mg daily, or a placebo tablet. All patients received a similar general anesthetic and in the post-anesthesia care unit (PACU), started on intravenous (IV) patient-controlled analgesia (PCA) of hydromorphone (0.2 mg/ml). Postoperative pain was assessed daily until discharge using a Numerical Rating Scale (NRS) at rest and with physical therapy (PT). Patients were also assessed twice daily for level of sedation and nausea and/or vomiting and expected PT milestones. All narcotics (IV, oral) were documented. RESULTS: Demographics and operative time between groups were similar. PCA hydromorphone administration and oral narcotic intake were not statistically different between the two groups. However, an increased incidence of nausea and vomiting in the placebo group reached statistical significance (p < 0.05). In addition, there was no statistical difference between groups with respect to achieving PT milestones and hospital discharge day. CONCLUSION: After PLF, patients receiving pregabalin 150 mg/day did not have reduced IV narcotic usage, improved PT milestones, or reduced length of hospital stay. We were unable to demonstrate an analgesic advantage to prescribing pregabalin to patients undergoing lumbar spinal fusions.

Older literature review of increased risk of adjacent segment degeneration with instrumented lumbar fusions.

BACKGROUND: Adjacent segment degeneration (ASD) following lumbar spine surgery occurs in up to 30% of cases, and descriptions of such changes are not new. Here, we review some of the older literature concerning the rate of ASD, typically more severe cephalad than caudad, and highly correlated with instrumented fusions. Therefore, for degenerative lumbar disease without frank instability, ASD would be markedly reduced by avoiding instrumented fusions. METHODS: In a prior review, the newer literature regarding the frequency of ASD following lumbar instrumented fusions (e.g., transforaminal or posterior lumbar interbody fusions [TLIF/PLIF] fusions or occasionally, posterolateral fusions [PLFs]) was presented. Some studies cited an up to an 18.5% incidence of ASD following instrumented versus noninstrumented fusions/decompressions alone (5.6%). A review of the older literature similarly documents a higher rate of ASD following instrumented fusions performed for degenerative lumbar disease alone. RESULTS: More frequent and more severe ASD follows instrumented lumbar fusions performed for degenerative lumbar disease without instability. Alternatively, this entity should be treated with decompressions alone or with noninstrumented fusions, without the addition of instrumentation. CONCLUSIONS: Too many studies assume that TLIF, PLIF, and even PLF instrumented fusions are the "gold standard of care" for dealing with degenerative disease of the lumbar spine without documented instability. It is time to correct that assumption, and reassess the older literature along with the new to confirm that decompression alone and noninstrumented fusion avoid significant morbidity and even potentially mortality attributed to unnecessary instrumentation.

Adjacent level disease following lumbar spine surgery: A review.

BACKGROUND: Instrumented lumbar spine surgery is associated with an increased risk of adjacent segment disease (ASD). Multiple studies have explored the various risk factors contributing to ASD that include; fusion length (especially, three or more levels), sagittal malalignment, facet injury, advanced age, and prior cephalad degenerative disease. METHODS: In this selective review of ASD, following predominantly instrumented fusions for lumbar degenerative disease, patients typically underwent open versus minimally invasive surgery (MIS), transforaminal lumbar interbody fusions (TLIFs), posterior lumbar interbody fusions (PLIFs), or rarely posterolateral lumbar instrumented or noninstrumented fusions (posterolateral lumbar fusion). RESULTS: The incidence of ASD, following open or MI lumbar instrumented fusions, ranged up to 30%; notably, the addition of instrumentation in different series did not correlate with improved outcomes. Alternatively, in one series, at 164 postoperative months, noninstrumented lumbar fusions reduced the incidence of ASD to 5.6% versus 18.5% for ASD performed with instrumentation. Of interest, dynamic instrumented/stabilization techniques did not protect patients from ASD. Furthermore, in a series of 513 MIS TLIF, there was a 15.6% incidence of perioperative complications that included; a 5.1% frequency of durotomy and a 2.3% instrumentation failure rate. CONCLUSIONS: The incidence of postoperative ASD (up to 30%) is greater following either open or MIS instrumented lumbar fusions (e.g., TLIF/PLIF), while decompressions with noninstrumented fusions led to a much smaller 5.6% risk of ASD. Other findings included: MIS instrumented fusions contributed to higher perioperative complication rates, and dynamic stabilization did not protect against ASD.

Adverse Event Recording and Reporting in Clinical Trials Comparing Lumbar Disk Replacement with Lumbar Fusion: A Systematic Review.

Study Design Systematic review. Objectives (1) To compare the quality of adverse event (AE) methodology and reporting among randomized trials comparing lumbar fusion with lumbar total disk replacement (TDR) using established AE reporting systems; (2) to compare the AEs and reoperations of lumbar spinal fusion with those from lumbar TDR; (3) to make recommendations on how to report AEs in randomized controlled trials (RCTs) so that surgeons and patients have more-detailed and comprehensive information when making treatment decisions. Methods A systematic search of PubMed, the Cochrane collaboration database, and the National Guideline Clearinghouse through May 2015 was conducted. Randomized controlled trials with at least 2 years of follow-up comparing lumbar artificial disk replacement with lumbar fusion were included. Patients were required to have axial or mechanical low back pain of ≥3 months' duration due to degenerative joint disease defined as degenerative disk disease, facet joint disease, or spondylosis. Outcomes included the quality of AE acquisition methodology and results reporting, and AEs were defined as those secondary to the procedure and reoperations. Individual and pooled relative risks and their 95% confidence intervals comparing lumbar TDR with fusion were calculated. Results RCTs demonstrated a generally poor description of methods for assessing AEs. There was a consistent lack of clear definition or grading for these events. Furthermore, there was a high degree of variation in reporting of surgery-related AEs. Most studies lacked adequate reporting of the timing of AEs, and there were no clear distinctions between acute or chronic AEs. Meta-analysis of the pooled data demonstrated a twofold increased risk of AEs in patients having lumbar fusion compared with patients having lumbar TDR at 2-year follow-up, and this relative risk was maintained at 5 years. Furthermore, the pooled data demonstrated a 1.7 times greater relative risk of reoperation in the fusion group compared with lumbar TDR, although this risk decreased to 1.1 at 5-year follow-up. However, given the lack of quality and consistency in the methods of recording and reporting of AEs, we are unable to make a clear recommendation of one treatment over the other. Conclusions Based on the currently available literature, lumbar TDR appears to be comparable in safety to lumbar fusion. However, due to lack of consistency in reporting of AEs, it is difficult to make conclusions regarding the true safety profile of lumbar TDR. Standardization in AE reporting will significantly improve the reliability of the current literature.

The Incidence of Potential Candidates for Total Disc Replacement among Lumbar and Cervical Fusion Patient Populations.

STUDY DESIGN: Retrospective chart review. PURPOSE: To evaluate the incidence of potential total disc replacement (TDR) candidates among cervical and lumbar fusion patient populations using strict Food and Drug Administration (FDA) criteria and with relative exclusion criteria removed. OVERVIEW OF LITERATURE: Recent studies suggest that the potential percentage of patients that are candidates for TDR ranges from 0-5% in lumbar fusions and 43% in cervical fusions. METHODS: We performed a retrospective chart review of 280 consecutive patients who had lumbar (n = 174) and cervical (n = 106) fusion or TDR performed by one of four independent adult orthopaedic spine surgeons. Charts were screened for investigational device exemption (IDE) inclusion/exclusion criteria and later reanalyzed excluding relative exclusion criteria, such as history of chronic medical illness, twolevel disease (cervical cases), and history of prior fusion surgery in the anatomic region. RESULTS: Of the 174 lumbar surgeries, 10 were TDR with Prodisc-L and 164 were lumbar fusions. The most common TDR exclusion criteria were lytic spondylolisthesis or spinal stenosis (47.7% of patients) and more than 2 level degenerative disc disease (37.9%). 14.9% had no IDE exclusion criteria and would be considered candidates for TDR. After excluding the relative lumbar exclusion criteria, this percentage increased to 25.8%. Of the 106 cervical cases, 3 had a TDR with Prodisc-C and 103 had a cervical fusion. Twenty eight percent had no IDE exclusion criteria and would be considered candidates for cervical TDR. CONCLUSIONS: A larger percentage of cervical fusion candidates are potential candidates for TDR (28%) than lumbar fusion candidates (14.9%) based on the strict IDE criteria.