Myelopathy is associated with increased all-cause morbidity and mortality following anterior cervical discectomy and fusion: a study of 5256 patients in American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP)

Pack Years of Tobacco Cigarette Smoking as a Predictor of Bony Fusion after Anterior Cervical Discectomy and Fusion

OBJECTIVE

Smoking tobacco cigarettes negatively impacts bone healing after spinal fusion. Smoking history is often assessed based on current smoker and nonsmoker status. However, in current research, smoking history has not been quantified in terms of pack years to estimate lifetime exposure and assess its effects. Our goal was to investigate the influence of smoking history, quantified in pack years, on bony fusion after anterior cervical discectomy and fusion (ACDF).

METHODS

A retrospective chart review of consecutive patients who underwent ACDF for cervical disc degeneration between September 21, 2017 and October 17, 2018 was conducted. Patient demographics, procedural variables, and postoperative outcomes were analyzed. Multivariate logistic regression analysis was performed to identify predictive factors for bony fusion following ACDF. Receiver operating characteristic curve analysis was used to determine the optimal discrimination threshold for smoking history pack years in association with nonfusion.

RESULTS

Among 97 patients identified, 90 (93%) demonstrated bony fusion on postoperative imaging. Mean number of smoking history pack years was 6.1 ± 13 for the fusion group and 16 ± 21 for the nonfusion group. Multivariate logistic regression analysis suggested that increased pack years of tobacco cigarette smoking was a significant predictor of nonfusion (95% confidence interval, [1.0,1.1], P = 0.045). The receiver operating characteristic curve analysis revealed that 6.1 pack years best stratified the risk for nonfusion (area under the curve, 0.8).

CONCLUSIONS

Patients with a history of tobacco cigarette smoking ≥6.1 pack years may have an increased risk of nonfusion after ACDF.

Association of inpatient opioid consumption on postoperative outcomes after open posterior spinal fusion for adult spine deformity

INTRODUCTION

Opioids are the most commonly used analgesic in the postoperative setting. However, few studies have analyzed the impact of high inpatient opioid use on outcomes following surgery, with no current studies assessing its effect on patients undergoing spinal fusion for an adult spinal deformity (ASD). Thus, the aim of this study was to investigate risk factors for high inpatient opioid use, as well as to determine the impact of high opioid use on outcomes such as adverse events (AEs), hospital length of stay (LOS), cost of hospital admission, discharge disposition, and readmission rates in patients undergoing spinal fusion for ASD.

METHODS

A retrospective cohort study was performed using the Premier healthcare database from the years 2016 and 2017. All adult patients > 40 years old who underwent thoracic or thoracolumbar fusion for ASD were identified using the ICD-10-CM diagnostic and procedural coding system. Patients were then categorized into three cohorts based on inpatient opioid use: Low MME (morphine milligram equivalents), Medium MME, and High MME. Patient demographics, comorbidities, treating hospital characteristics, intraoperative variables, postoperative AEs, LOS, discharge disposition, and total cost of hospital admission were assessed in the analysis. Multivariate regression analysis was done to determine independent predictors of high inpatient MME, prolonged LOS, and increased hospital cost.

RESULTS

Of 1673 patients included, 417 (24.9%) were classified as Low MME, 840 (50.2%) as Medium MME, and 416 (24.9%) as High MME. Age significantly decreased with increasing MME (Low: 71.0% 65 + years vs Medium: 62.0% 65 + years vs High: 47.4% 65 + years, p < 0.001), while the proportions of patients presenting with three or more comorbidities were similar across the cohorts (Low: 20.1% with 3 + comorbidities vs Medium: 18.0% with 3 + comorbidities vs High: 24.3% with 3 + comorbidities, p = 0.070). With respect to postoperative outcomes, the proportion of patients who experienced any AE (Low: 60.2% vs Medium: 68.8% vs High: 70.9%, p = 0.002), extended LOS (Low: 6.7% vs Medium: 20.7% vs High: 45.4%, p < 0.001), or non-routine discharge (Low: 66.6% vs Medium: 73.5% vs High: 80.1%, p = 0.003) each increased along with total MME. In addition, rates of 30-day readmission were greatest among the High MME cohort (Low: 8.4% vs Medium: 7.9% vs High: 12.5%, p = 0.022). On multivariate analysis, medium and high MME were associated with prolonged LOS [Medium: OR 4.41, CI (2.90, 6.97); High: OR 13.99, CI (8.99, 22.51), p < 0.001] and increased hospital cost [Medium: OR 1.69, CI (1.21, 2.39), p = 0.002; High: OR 1.66, CI (1.12, 2.46), p = 0.011]. Preadmission long-term opioid use [OR 1.71, CI (1.07, 2.7), p = 0.022], a prior opioid-related disorder [OR 11.32, CI (5.92, 23.49), p < 0.001], and chronic pulmonary disease [OR 1.39, CI (1.06, 1.82), p = 0.018] were each associated with a high inpatient MME on multivariate analysis.

CONCLUSION

Our study demonstrated that increasing inpatient MME consumption was associated with extended LOS and increased hospital cost in patients undergoing spinal fusion for ASD. Further studies identifying risk factors for increased MME consumption may provide better risk stratification for postoperative opioid use and healthcare resource utilization.

Clinical Improvements in Myelopathy Result in Improved Patient-Reported Outcomes Following Anterior Cervical Discectomy and Fusion

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

To determine if myelopathy severity predicted the magnitude of improvement in health-related quality of life metrics following anterior cervical discectomy and fusion (ACDF).

SUMMARY OF BACKGROUND DATA

Surgery for myelopathy is primarily performed to halt disease progression. However, it is still controversial if these patients can expect significant health-related quality-of life improvements following ACDF. We explore the relationship between modified Japanese Orthopaedic Association (mJOA) improvements and its effect on other health-related quality-of life metrics.

MATERIALS AND METHODS

Patients undergoing ACDF for myelopathy were grouped based on preoperative mJOA scores into mild (15-17), moderate (12-14), and severe (<12) groups. Patients were subsequently categorized based on if they attained the minimum clinically detectable improvement (MCID) threshold for mJOA. Multivariate linear regression was performed to determine the magnitude of improvement in ∆patient-reported outcome measures.

RESULTS

A total of 374 patients were identified for inclusion. Of those, 169 (45.2%) had mild myelopathy, 125 (33.4%) had moderate, and 80 (21.4%) had severe myelopathy. Only the moderate and severe groups had significant improvements in mJOA following surgery (mild: P =0.073, moderate: P <0.001, severe: P <0.001). There were no significant differences in the magnitude of improvement for any patient-reported outcome measure based on myelopathy severity, except for mJOA (mild: 0.27, moderate: 1.88, severe: 3.91; P <0.001). Patients meeting the MCID for mJOA had better ∆Short-Form 12 Mental Component Score (3.29 vs. -0.21, P =0.007), ∆Short-Form 12 Physical Component Score (6.82 vs. 1.96, P <0.001), ∆Visual Analog Scale Neck (-3.11 vs. -2.17, P =0.001), ∆Visual Analog Scale Arm (-2.92 vs. -1.48, P <0.001), ∆Neck Disability Index (-18.35 vs. -7.86, P <0.001), and ∆mJOA (3.38 vs. -0.56, P <0.001) compared with patients who did not.

CONCLUSIONS

Worse baseline myelopathy severity predicts worse postoperative outcomes. However, baseline myelopathy severity is not predictive of the magnitude of postoperative improvement with the exception of mJOA. Patients who attain MCID improvement in mJOA had greater postoperative improvement for other health-related quality of life metrics.

Patients with radiculopathy have worse baseline disability and greater improvements following anterior cervical discectomy and fusion compared to patients with myelopathy

BACKGROUND CONTEXT

Anterior cervical discectomy and fusion (ACDF) is commonly performed in patients with radiculopathy and myelopathy. Although the goal of surgery in patients with radiculopathy is to improve function and reduce pain, patients with myelopathy undergo surgery to halt disease progression. Although the expectations between these preoperative diagnoses are generally understood to be disparate by spine surgeons, there is limited literature demonstrating their discordant outcomes.

PURPOSE

To compare improvements in patient reported outcome measures (PROMs) for patients undergoing ACDF for myelopathy or radiculopathy. Secondarily, we analyzed the proportion of patients who attain the minimum clinically important difference (MCID) postoperatively using thresholds derived from radiculopathy, myelopathy, and mixed cohort studies.

STUDY DESIGN/SETTING

Single institution retrospective cohort study PATIENT SAMPLE: Patients undergoing primary, elective ACDF with a preoperative diagnosis of radiculopathy or myelopathy and a complete set of preoperative and one-year postoperative PROMs.

OUTCOME MEASURES

Outcome measures included the following PROMs: Short-Form 12 Physical Component (PCS-12) and Mental Component (MCS-12) scores, the Visual Analog Scale (VAS) Arm score, and the Neck Disability Index (NDI). Hospital readmissions and revision surgery were also collected and evaluated.

METHODS

Patients undergoing an ACDF from 2014 to 2020 were identified and grouped based on preoperative diagnosis (radiculopathy or myelopathy). We utilized "general MCID" thresholds from a cohort of patients with degenerative spine conditions, and "specific MCID" thresholds generated from cohorts of patients with myelopathy or radiculopathy, respectively. Multivariate linear regressions were performed for delta (∆) PROMs and multivariate logistic regressions were performed for both general and specific MCID improvements.

RESULTS

A total of 798 patients met inclusion criteria. Patients with myelopathy had better baseline function and arm pain (MCS-12: 49.6 vs 47.6, p=.018; VAS Arm: 3.94 vs 6.02, p<.001; and NDI: 34.1 vs 41.9, p<.001), were older (p<.001), had more comorbidities (p=.014), more levels fused (p<.001), and had decreased improvement in PROMs following surgery compared to patients with radiculopathy (∆PCS-12: 4.76 vs 7.21, p=.006; ∆VAS Arm: -1.69 vs -3.70, p<.001; and ∆NDI: -11.94 vs -18.61, p<.001). On multivariate analysis, radiculopathy was an independent predictor of increased improvement in PCS-12 (β=2.10, p=.019), ∆NDI (β=-5.36, p<.001), and ∆VAS Arm (β=-1.93, p<.001). Radiculopathy patients were more likely to achieve general MCID improvements following surgery (NDI: Odds ratio (OR): 1.42, p=.035 and VAS Arm: OR: 2.98, p<.001), but there was no difference between patients with radiculopathy or myelopathy when using radiculopathy and myelopathy specific MCID thresholds (MCS-12: p=.113, PCS-12: p=.675, NDI: p=.108, and VAS Arm: p=.314).

CONCLUSIONS

Patients undergoing ACDF with myelopathy or radiculopathy represent two distinct patient populations with differing treatment indications and clinical outcomes. Compared to radiculopathy, patients with myelopathy have better baseline function, decreased improvement in PROMs, and are less likely to reach MCID using general threshold values, but there is no difference in the proportion reaching MCID when using specific threshold values.

LEVEL OF EVIDENCE

IRB.

Comparison of Deep Learning and Classical Machine Learning Algorithms to Predict Postoperative Outcomes for Anterior Cervical Discectomy and Fusion Procedures With State-of-the-art Performance

STUDY DESIGN

Retrospective cohort.

OBJECTIVE

Due to anterior cervical discectomy and fusion (ACDF) popularity, it is important to predict postoperative complications, unfavorable 90-day readmissions, and two-year reoperations to improve surgical decision-making, prognostication, and planning.

SUMMARY OF BACKGROUND DATA

Machine learning has been applied to predict postoperative complications for ACDF; however, studies were limited by sample size and model type. These studies achieved ≤0.70 area under the curve (AUC). Further approaches, not limited to ACDF, focused on specific complication types and resulted in AUC between 0.70 and 0.76.

MATERIALS AND METHODS

The IBM MarketScan Commercial Claims and Encounters Database and Medicare Supplement were queried from 2007 to 2016 to identify adult patients who underwent an ACDF procedure (N=176,816). Traditional machine learning algorithms, logistic regression, and support vector machines, were compared with deep neural networks to predict: 90-day postoperative complications, 90-day readmission, and two-year reoperation. We further generated random deep learning model architectures and trained them on the 90-day complication task to approximate an upper bound. Last, using deep learning, we investigated the importance of each input variable for the prediction of 90-day postoperative complications in ACDF.

RESULTS

For the prediction of 90-day complication, 90-day readmission, and two-year reoperation, the deep neural network-based models achieved AUC of 0.832, 0.713, and 0.671. Logistic regression achieved AUCs of 0.820, 0.712, and 0.671. Support vector machine approaches were significantly lower. The upper bound of deep learning performance was approximated as 0.832. Myelopathy, age, human immunodeficiency virus, previous myocardial infarctions, obesity, and documentary weakness were found to be the strongest variable to predict 90-day postoperative complications.

CONCLUSIONS

The deep neural network may be used to predict complications for clinical applications after multicenter validation. The results suggest limited added knowledge exists in interactions between the input variables used for this task. Future work should identify novel variables to increase predictive power.

Ambulatory Single-level Posterior Cervical Foraminotomy for Cervical Radiculopathy: A Propensity-matched Analysis of Complication Rates

STUDY DESIGN

Retrospective cohort comparison study.

OBJECTIVE

The aim was to compare perioperative complications and 30-day readmission between ambulatory and inpatient posterior cervical foraminotomy (PCF) in the American College of Surgeons National Surgical Quality Improvement Program (NSQIP) database.

SUMMARY OF BACKGROUND DATA

Single-level PCF for cervical radiculopathy is increasingly being performed as an ambulatory procedure. Despite this increase, there is a lack of published literature documenting the safety of ambulatory PCF.

MATERIALS AND METHODS

Patients who underwent PCF (through laminotomy or laminectomy) were identified in the 2005-2018 NSQIP database. Ambulatory procedures were defined as cases that had hospital length of stay=0 days. Inpatient procedures were defined as cases that had length of stay=1-4 days. Patient characteristics, comorbidities, and procedural variables (laminotomy or laminectomy performed) were compared between the 2 cohorts. Propensity score matched comparisons were then performed for postoperative complications and 30-day readmissions between the 2 groups.

RESULTS

In total, 795 ambulatory and 1789 inpatient single-level PCF cases were identified. After matching, there were 795 ambulatory and 795 inpatient cases. Statistical analysis after propensity score matching revealed no significant difference in individual complications including 30-day readmission, thromboembolic events, wound complications, and reoperation, or aggregated complications between ambulatory versus matched inpatient procedures. Overall 30-day readmissions after ambulatory single-level PCF were noted for 2.46% of the study population, and the most common reasons were surgical site infections (46%) and pain control (15%).

CONCLUSIONS

The perioperative outcomes assessed in this study support the conclusion that single-level PCF for cervical radiculopathy can be performed for correctly selected patients in the ambulatory setting without increased rates of 30-day perioperative complications or readmissions compared with inpatient procedures.

LEVEL OF EVIDENCE

Level III.

Patterns and outcomes of neurosurgery in England over a five-year period: A national retrospective cohort study

BACKGROUND

Neurosurgical practice has seen major changes over several decades. There are no recent evaluations of national neurosurgical practice. The aim of this observational study was to describe neurosurgical practice in England and to use outcomes to assess and benchmark the quality of care in neurosurgery.

MATERIAL AND METHODS

This national retrospective cohort study analysed Hospital Episode Statistics (HES) data from April 2013 to March 2018 for all adult admissions with a specialty code for neurosurgery. The epidemiology of patients and RCS Charlson comorbidities were derived and procedure incidence rates per 100,000 person-years calculated. Post-operative outcomes for elective and non-elective patients included: median length of stay, the proportion of patients requiring additional inpatient neurosurgical procedures, the proportion of patients discharged to their usual address, and in-hospital mortality rates.

RESULTS

During the 5-year study period, there were 371,418 admissions to neurosurgery. The proportion of admissions involving a neurosurgical procedure was 77.3% (n = 287,077). Of these, 45% were for cranial surgery and 37% for spinal. Overall, 68.3% were elective procedures. The incidence rates of most procedures were low (<20 per 100,000 person-years). Following elective neurosurgical procedures, in-hospital mortality rates for cranial and spinal surgery were 0.5% (95% CI, 0.5-0.6) and 0.1% (95% CI, 0.04-0.1), respectively. After non-elective neurosurgery, mortality rates were 7.4% (95% CI, 7.2-7.6) and 1.3% (95% CI, 1.2-1.5) for cranial and spinal surgery, respectively. Approximately 1 in 4 patients had additional procedures following non-elective cranial surgery (24%; 95% CI, 23.6-24.3). Outcomes were highly variable across different subspecialty areas.

CONCLUSIONS

The incidence rates of neurosurgical procedures are low within England, and neurosurgical units have a high volume of non-surgical admissions. In-hospital mortality rates after elective neurosurgery are low but there may be opportunities for quality improvement programmes to improve outcomes for non-elective surgery as well as ensuring equitable access to treatment.

Early Outcomes of Elective Anterior Cervical Diskectomy and Fusion for Degenerative Spine Disease Correlate With the Specialty of the Surgeon Performing the Procedure

BACKGROUND

Comparative effectiveness research has a vital role in recent health reform and policies. Specialty training is one of these provider-side variables, and surgeons who were trained in different specialties may have different outcomes on performing the same procedure.

OBJECTIVE

To investigate the impact of spine surgeon specialty (neurosurgery vs orthopedic surgery) on early perioperative outcome measures of elective anterior cervical diskectomy and fusion (ACDF) for degenerative spine diseases.

METHODS

This was a retrospective, 1:1 propensity score-matched cohort study. In total, 21 211 patients were reviewed from the American College of Surgeons National Surgical Quality Improvement Program database. Propensity score matching and subgroup analysis were performed.

RESULTS

In both groups (single-level/multilevel ACDF), patients operated on by neurosurgeons had longer operation time (133 vs 104 min/164 vs 138 min), shorter total hospital stay (24 vs 41 h/25 vs 46 h), and lower rates of return to operating room (0.7% vs 2.1%/0.6% vs 2.4%), nonhome discharge (1.2% vs 4.6%/1.0% vs 4.9%), discharge after postoperative day 1 (6.7% vs 11.9%/10.1% vs 18.9%), perioperative blood transfusion (0.4% vs 2.1%/0.6% vs 3.1%), and sepsis (0.2% vs 0.7%/0.1% vs 0.7%; P < .05). In the single-level ACDF group, patients operated on by neurosurgeons had lower readmission (1.9% vs 4.1%) and unplanned intubation rates (0.1% vs 1.1%; P < .05). Other outcome measures and mortality rates were similar among the 2 cohorts in both groups.

CONCLUSION

Our analysis found significant differences in early perioperative outcomes of patients undergoing ACDF by neurosurgeons and orthopedic surgeons. These differences might have significant clinical and cost implications for patients, physicians, program directors, payers, and health systems.

Effects of preoperative nutritional status on complications and readmissions after posterior lumbar decompression and fusion for spondylolisthesis: A propensity-score analysis

INTRODUCTION

Malnutrition, common in the elderly, may adversely affect healthcare outcomes. In spine surgery, malnutrition is associated with higher rates of perioperative complications, unplanned readmission, and prolonged length of stay (LOS). The aim of this study was to determine the effect of malnutrition on adverse events (AEs), unplanned readmission, and LOS in patients undergoing spine surgery for spondylolisthesis.

METHODS

A retrospective cohort study was performed using the American College of Surgeons National Surgical Quality Improvement Program database from 2010 to 2016. Adult patients who underwent posterior decompression or fusion for spondylolisthesis were identified using the ICD-9-CM coding systems. Patients were divided into two cohorts based on preoperative serum albumin levels. propensity-score (PS) matching was used to create an age- and sex-matched Nourished cohort. Patient demographics, comorbidities, LOS, and postoperative complications were collected. Multivariate logistic regression analysis was performed to identify predictors of prolonged LOS, unplanned readmission, and AEs.

RESULTS

Of the 2196 patients identified, 4.5% were malnourished. Patients in the Malnourished cohort were found to have significantly longer average LOS (Malnourished: 4.51 ± 3.1 days vs PS-Matched Not Nourished: 3.7 ± 3.7, p = 0.002), higher rates of AEs (Malnourished: 14.3% vs PS-Matched Nourished: 5.8%, p = 0.007), reoperation (Malnourished: 8.4% vs PS-Matched Nourished: 3.2%, p = 0.026), and unplanned readmission (Malnourished: 15.3% vs PS-Matched Nourished: 6.1%, p = 0.003). On multivariate analysis considering only preoperative data, malnutrition was a significant independent predictor of AEs [OR: 2.13, CI (1.02, 4.46), p = 0.045]. However, after correcting for the occurrence of AEs, malnutrition was not associated with total LOS [aRR: 0.29, CI (-0.37, 0.95), p = 0.392] or 30-day unplanned readmissions [aOR: 2.24, CI (0.89, 5.60), p = 0.086].

CONCLUSION

Our study found that malnourished patients undergoing lumbar fusion for spondylolisthesis have significantly higher rates of AEs, unplanned readmission, and prolonged LOS than nourished patients. Further studies are necessary to corroborate our findings.

Effect of patient's sex on early perioperative outcomes following anterior cervical discectomy and fusion

OBJECTIVE

Differences in morbidity and mortality measures between males and females have been demonstrated for a variety of spinal surgeries, however, studies of anterior cervical discectomy and fusion (ACDF) are limited. To investigate the impact ofsexon 30-day perioperative outcomes of ACDF.

METHODS

Retrospective 1:1 propensity score-matched cohort study. Patients who underwent ACDF between 2016 and 2018 were reviewed from the ACS-NSQIP database.Propensity score matchingand subgroup analysis were used.

RESULTS

21,180 patients met inclusion criteria. 11,194 patients underwent single-level ACDF and 9986 patients underwent multi-level ACDF. In the single-level group, there were 6168 (55.1%) males and 5026 (44.9%) females. In the multi-level group, there were 5033 (50.4%) males and 4953 (49.6%) females. In both single/multi-level groups, females were more likely to be of older age, be functionally dependent, and have higher BMI and lower preoperative hematocrit level. Males were more likely to be Caucasian, smokers, have myelopathy, diabetes mellitus, hypertension and bleeding disorders. In both single/multi-level groups, except for the higher incidence of urinary tract infection (UTI) in females and myocardial infarction (MI) in males, there were no significant differences in morbidity and mortality between males and females.

CONCLUSIONS

Several differences in demographics and baseline health status exist between males and females undergoing ACDF. When attempting to control for comorbid conditions, we found that sex by itself is not an independent risk factor for higher perioperative morbidity or mortality in patients undergoing ACDF, except for the higher incidence of UTI in females and MI in males. These results are important findings for clinicians and spine surgeons while counseling patients undergoing this type of procedure.

Are spine metastasis survival scoring systems outdated and do they underestimate life expectancy? Caution in surgical recommendation guidance

OBJECTIVE

Survival scoring systems for spine metastasis (SPM) were designed to help surgical practice. The authors sought to validate the prognostic accuracy of the main preoperative scoring systems for SPM.

METHODS

It was hypothesized that true patient survival in SPM was better than that predicted using prognosis scores. To investigate this hypothesis, the authors designed a French national retrospective study of a prospectively collected multicenter database involving 739 patients treated for SPM between 2014 and 2017.

RESULTS

In this series, the median survival time for all patients from an SPM diagnosis was 17.03 ± 1.5 months. Sensitivity and specificity were estimated using the area under the curve (AUC). The AUC of Tomita's prognosis score was the lowest and poorest (0.4 ± 0.023, range 0.35-0.44), whereas the AUC of the Tokuhashi score was the highest (0.825). The Lei score presented an AUC of 0.686 ± 0.022 (range 0.64-0.7), and the Rades score showed a weaker AUC (0.583 ± 0.020, range 0.54-0.63). Differences among AUCs were all statistically significant (p < 0.001). The modified Bauer score and the Rades score had the highest rate of agreement in predicting survival, with a weighted Cohen's kappa of 0.54 and 0.41, respectively, indicating a moderate agreement. The revised Tokuhashi and Lei scores had a fair rate of agreement (weighted Cohen's kappa = 0.24 and 0.22, respectively). The van der Linden and Tomita scores demonstrated the worst performance, with only a "slight" rate of agreement (weighted Cohen's kappa = 0.19 and 0.16, respectively) between what was predicted and the actual survival.

CONCLUSIONS

The use of prognostic scoring systems in the estimation of survival in patients with SPM has become obsolete and therefore underestimates survival. Surgical treatment decisions should no longer be based on survival estimations alone but must also take into account patient symptoms, spinal instability, and quality of life.

Perioperative major neurologic deficits as a complication of spine surgery

STUDY DESIGN

Retrospective review of spine surgery patients with new major neurologic complication.

OBJECTIVE

To define the causes and severity of new neurologic damage to the spinal cord or cauda equina caused by spinal surgery.

MATERIALS AND METHODS

Consult records were reviewed for all postoperative spine surgery patients referred to a tertiary spinal cord injury rehabilitation center over a 12-year period. Any patients with a new perioperative surgery-related decrement in American Spinal Injury Association (ASIA) Impairment Scale (AIS), loss of bowel or bladder function, or loss of ability to ambulate were examined and final 1-year gaps for neurologic loss reported.

RESULTS

64 patients had a new perioperative major neurologic event with: 41% thoracic, 39% cervical, and 20% lumbar; 61% intraoperative, 31% in the immediate 2-week postoperative period, 8% unknown. Chronic myelopathy (44%) was the most common indication. The causes of neurologic injury were postoperative fluid collection (25%), malposition of instrumentation (14%), traumatic decompression (14%), cord infarct (11%), deformity correction (2%), and unknown (34%). Overall, 87% lost the ability to ambulate and 66% lost volitional bowel-bladder control. AIS decrement and loss of ambulation and bowel-bladder function did not differ statistically significantly by surgical indication. However, among the main root causes, traumatic decompressions and cord infarcts had significantly worse neurologic deterioration than fluid collections or malposition of instrumentation.

CONCLUSION

The relative rate of major neurologic injury in spine surgery is higher in thoracic and cervical cases at spinal cord levels, especially when done for myelopathy, even though lumbar surgeries are most common. The most common causes of neurologic injury were potentially avoidable postoperative fluid collections, malposition of instrumentation, and traumatic decompression.

Does the Specialty of the Surgeon Performing Elective Anterior/Lateral Lumbar Interbody Fusion for Degenerative Spine Disease Correlate with Early Perioperative Outcomes?

BACKGROUND

Comparative effectiveness research has a vital role in health reform and policies. Specialty training is one of these provider-side variables, and surgeons performing the same procedure who were trained in different specialties may have different outcomes. The objective of this study was to investigate the impact of spine surgeon specialty (neurosurgery vs. orthopedic surgery) on early perioperative outcome measures of elective anterior/lateral lumbar interbody fusion (ALIF/LLIF) for degenerative disc diseases.

METHODS

In a retrospective, 1:1 propensity score-matched cohort study, 9070 patients were reviewed from the American College of Surgeons National Surgical Quality Improvement Program database. Propensity score matching and subgroup analysis were used.

RESULTS

In both groups (single-level and multilevel ALIF/LLIF), patients operated on by neurosurgeons had longer operative time (188 minutes vs. 172 minutes/239 minutes vs. 221 minutes); shorter total hospital stay (71 hours vs. 90 hours/89 hours vs. 96 hours); and lower rates of return to the operating room (2.1% vs. 4.1%/2.4% vs. 4.2%), nonhome discharge (8.7% vs. 11.1%/10.1% vs. 14.9%), discharge after postoperative day 3 (22.0% vs. 30.0%/38.0% vs. 43.9%), and perioperative blood transfusion (2.1% vs. 5.1%/5.0% vs. 9.9%) (P < 0.05). In multilevel ALIF/LLIF, patients operated on by neurosurgeons had lower readmission rates (3.9% vs. 6.9%) (P < 0.05). Other outcome measures and mortality rates were similar between the single-level and multilevel ALIF/LLIF cohorts regardless of surgeon specialty.

CONCLUSIONS

Our analysis found significant differences in early perioperative outcomes of patients undergoing ALIF/LLIF by neurosurgeons and orthopedic surgeons. These differences have significant clinical and cost implications for patients, physicians, program directors, payers, and health systems.

Spine Metastasis in Elderly: Encouraging Results for Better Survival

MINI

The incidence of spinal metastasis (SpM) is increasing, and life expectancy for patients with malignancy is also rising. The "elderly" represent a population with steady growth in SpM proportion. Bracing is associated with lower survival. We believe that surgery should be considered, regardless of the patient's age.

Evaluation of Benefit and Cost Utility of Immediate Postanesthesia Care Unit Radiographs to Predict Airway Compromise After Anterior Cervical Discectomy and Fusion

STUDY DESIGN

Retrospective review.

OBJECTIVE

Anterior cervical discectomy and fusion (ACDF) is a commonly performed procedure that may be complicated by airway compromise postoperatively. This life-threatening complication may necessitate reintubation and reoperation. We evaluated the cost utility of conventional postoperative x-ray.

SUMMARY OF BACKGROUND DATA

Studies have demonstrated minimal benefit in obtaining an x-ray on postoperative day 1, but there is some utility of postanesthesia care unit (PACU) x-rays for predicting the likelihood of reoperation.

METHODS

We retrospectively reviewed the records of consecutive patients who underwent ACDF between September 2013 and February 2017. Patients were dichotomized into those who received PACU x-rays and those who did not (control group). Primary outcomes were reoperation, reintubation, mortality, and health care costs.

RESULTS

Eight-hundred and fifteen patients were included in our analysis: 558 had PACU x-rays; 257 did not. In those who received PACU x-rays, mean age was 53.7 ± 11.3 years, mean levels operated on were 2.0 ± 0.79, and mean body mass index (BMI) was 30.3 ± 6.9. In those who did not, mean age was 51.8 ± 10.9 years, mean levels operated on were 1.48 ± 0.65, and mean BMI was 29.9 ± 6.3. Complications in the PACU x-ray group were reintubation-0.4%, reoperation-0.7%, and death-0.3% (due to prevertebral swelling causing airway compromise). Complications in the control group were reintubation-0.4%, reoperation-0.8%, and death-0. There were no differences between groups with respect to reoperation (P = 0.92), reintubation (P = 0.94), or mortality (P = 0.49). The mean per-patient cost was significantly higher (P = 0.009) in those who received PACU x-rays, $1031.76 ± 948.67, versus those in the control group, $700.26 ± 634.48. Mean length of stay was significantly longer in those who had PACU x-rays (P = 0.01).

CONCLUSION

Although there were no differences in reoperation, reintubation, or mortality, there was a significantly higher cost for care and hospitalization in those who received PACU x-rays. Further studies are warranted to validate the results of the presented study.Level of Evidence: 3.

Does Myelopathy Increase the Morbidity and Mortality of Elective Single-Level Anterior Cervical Discectomy and Fusion? An Updated Propensity-Matched Analysis of 3938 Patients From the American College of Surgeons National Surgical Quality Improvement Program Database

BACKGROUND

Myelopathy is thought to be associated with higher morbidity and mortality after anterior cervical discectomy and fusion (ACDF); however, the literature investigating this association has limitations.

OBJECTIVE

To investigate the influence of myelopathy on early perioperative complications of elective single-level ACDF.

METHODS

Patients who underwent ACDF between 2016 and 2018 were reviewed from the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database. Propensity score matching analysis was used.

RESULTS

Twenty percent of the cohort was myelopathic. These patients were significantly older, had more comorbidities, more likely to be functionally dependent, and to undergo emergency surgery when compared to the nonmyelopathic cohort. When 1969 myelopathic patients were 1:1 propensity matched with nonmyelopathic patients, there was no difference between the myelopathic and nonmyelopathic patients in incidence of postoperative intensive care unit admission or death. Patients in the myelopathic group were significantly more likely to have a nonhome discharge and less likely to be discharged on the first postoperative day. Myelopathic patients had a higher rate of return to operating room within the same admission (2.2%) as well as a higher unplanned readmission rate (4.2%). The total operation time (143 min) and average length of hospital stay (52 h) were significantly higher in the myelopathic group when compared to the nonmyelopathic group (117 min) and (33 h), respectively.

CONCLUSION

Patients with myelopathy who undergo elective single-level ACDF have higher risks of several perioperative events including longer operative time, longer hospital stay, higher return to operating room, and unplanned readmission rates, when compared to nonmyelopathic patients. On the other hand, myelopathic patients did not exhibit higher mortality rate.

Association of Race with Early Outcomes of Elective Posterior Spinal Fusion for Adolescent Idiopathic Scoliosis: Propensity-Matched and Subgroup Analysis

OBJECTIVE

To investigate the impact of race on 30-day postoperative complication rates of elective posterior spinal fusions (PSF) for adolescent idiopathic scoliosis (AIS).

METHODS

Patients who underwent PSF between 2012 and 2018 were reviewed from the American College of Surgeons National Surgical Quality Improvement Program pediatric database. Propensity score matching was utilized to evaluate whether patient race (i.e., black vs. white) was correlated with postoperative complications.

RESULTS

A total of 4051 PSF for AIS cases met criteria for inclusion. Of these, 3221 (79.5%) patients were white and 830 (20.5%) were black. Several baseline characteristics significantly differed between cohorts. Patients in the black cohort had a significantly higher body mass index, a greater proportion of female patients, higher ASA scores, preoperative diagnosis of asthma or cardiac risk factors, and prior use of steroids. The total number of vertebral segments fused was also greater in the black cohort. After controlling for differences in baseline characteristics with propensity score matching analysis, the only significant difference in morbidity and mortality identified was a higher incidence of venous thromboembolism among the black cohort (2.8% vs. 0.1%; P < 0.001).

CONCLUSIONS

In contrast to prior literature, our analysis did not identify black race as an independent risk factor for higher perioperative morbidity or mortality in patients of young age group undergoing elective PSF for AIS, except the higher incidence of venous thromboembolism. The findings of the present study suggest that previously reported perioperative morbidity and mortality outcomes in black patients may be secondary to baseline health characteristics, and not due to race itself.

Identification of Risk Factors for Readmission in Patients Undergoing Anterior Cervical Discectomy Fusion: A Predictive Risk Scale

STUDY DESIGN

This was a retrospective cohort study.

OBJECTIVE

The objective of this study was to analyze readmission rates among patients undergoing anterior cervical discectomy and fusion (ACDF), determine which factors were associated with higher readmission rates, and develop a scale for utilization during surgical planning.

SUMMARY OF BACKGROUND DATA

ACDF is the most common surgical treatment for many cervical disk pathologies. With the Centers for Medicare and Medicaid Services selecting readmissions as a measure of health care quality, there has been an increased focus on reducing readmissions.

MATERIALS AND METHODS

There were 114,174 recorded ACDF surgeries in the derivation cohort, the State Inpatient Database (SID) of New York and California between 2006 and 2014. There were 115,829 ACDF surgeries recorded in the validation cohort, the SID from Florida and Washington over the same time period. After identification of risk factors using univariate and multivariate analysis of the derivation cohort, a predictive scale was generated and tested utilizing the validation cohort.

RESULTS

Overall, readmission rates within 30 days of discharge were 5.87% and 5.52% in the derivation and validation cohorts, respectively. On multivariate analysis of the derivation cohort, age older than 80 years [odds ratio (OR), 1.67] male sex (OR, 1.16), Medicaid insurance (OR, 1.90), Medicare insurance (OR, 1.64), revision ACDF (OR, 1.43), anemia (OR, 1.45), chronic lung disease (OR, 1.23), coagulopathy (OR, 1.42), congestive heart failure (OR, 1.31), diabetes (OR, 1.23), fluid and electrolyte disorder (OR, 1.56), liver disease (OR, 1.37), renal failure (OR, 1.59), and myelopathy (OR, 1.19) were found to be statistically significant predictors for readmission. These factors were incorporated into a numeric scale that, that when tested on the validation cohort, could explain 97.1% of the variability in readmission rate.

CONCLUSIONS

Overall, 30-day readmission following ACDF surgery was 5%-6%. A novel risk scale based on factors associated with increased readmission rates may be helpful in identifying patients who require additional optimization to reduce perioperative morbidity.

LEVEL OF EVIDENCE

Level III-prognostic.

Frailty Is a Better Predictor than Age of Mortality and Perioperative Complications after Surgery for Degenerative Cervical Myelopathy: An Analysis of 41,369 Patients from the NSQIP Database 2010-2018

Background: The ability of frailty compared to age alone to predict adverse events in the surgical management of Degenerative Cervical Myelopathy (DCM) has not been defined in the literature. Methods: 41,369 patients with a diagnosis of DCM undergoing surgery were collected from the National Surgical Quality Improvement Program (NSQIP) Database 2010–2018. Univariate analysis for each measure of frailty (modified frailty index 11- and 5-point; MFI-11, MFI-5), modified Charlson Co-morbidity index and ASA grade) were calculated for the following outcomes: mortality, major complication, unplanned reoperation, unplanned readmission, length of hospital stay, and discharge to a non-home destination. Multivariable modeling of age and frailty with a base model was performed to define the discriminative ability of each measure. Results: Age and frailty have a significant effect on all outcomes, but the MFI-5 has the largest effect size. Increasing frailty correlated significantly with the risk of perioperative adverse events, longer hospital stay, and risk of a non-home discharge destination. Multivariable modeling incorporating MFI-5 with age and the base model had a robust predictive value (0.85). MFI-5 had a high categorical assessment correlation with a MFI-11 of 0.988 (p < 0.001). Conclusions and Relevance: Measures of frailty have a greater effect size and a higher discriminative value to predict adverse events than age alone. MFI-5 categorical assessment is essentially equivalent to the MFI-11 score for DCM patients. A multivariable model using MFI-5 provides an accurate predictive tool that has important clinical applications.

Have Total Hip Arthroplasty Operative Times Changed Over the Past Decade? An Analysis of 157,574 Procedures

BACKGROUND

With the recent reevaluation of surgeon reimbursement for total hip arthroplasty (THA) by the Centers for Medicare and Medicaid Services, there is increasing need for information regarding trends in operative time. While single-institutional analyses exist, there is a lack of large-scale, nationally representative, multi-institutional data. Therefore, the purpose of our study is to (1) evaluate past/present operative time trends for THA and (2) investigate factors influencing operative times from a 10-year, large multi-institutional database.

METHODS

All primary THAs conducted between 2008 and 2018 were queried using Current Procedural Terminology code 27130 from the American College of Surgeons-National Surgical Quality Improvement Program database, yielding 157,574 patients. Operative time, demographics, and comorbidity data were collected and analyzed. Multivariable linear models were created, and trend analyses were used where appropriate.

RESULTS

Median operative time was 87 minutes. Operative time was stable across included study years, with all calculated values within 5 minutes of the median (range, 86-92 minutes). Operative time was statistically stable over the last 3 years (P = .121). Age, body mass index, resident involvement, modified Charlson comorbidity index, and preoperative laboratory values influenced operative time (P < .001). Length of stay, readmission, superficial wound infection, and sepsis decreased over the study period. Nonelective procedures were statistically longer than elective (P < .0001).

CONCLUSION

While numerous factors influence the duration of THA, this study found that THA operative time has remained stable in recent years. Therefore, revaluation for THA based on intraservice time is not supported. Future analyses should continue to analyze factors that influence operative time in order to ensure patient safety and maintain positive outcomes.

Factors Associated With Extended Length of Stay and 90-Day Readmission Rates Following ACDF

STUDY DESIGN

Retrospective.

OBJECTIVE

Identify patient risk factors for extended length of stay (LOS) and 90-day hospital readmissions following elective anterior cervical discectomy and fusion (ACDF).

METHODS

Included ACDF patients from 2013 to 2017 at a single institution. Eligible patients were subset into LOS <2 and LOS ≥2 days, and no 90-day hospital readmission and yes 90-day hospital readmission. Patient and surgical factors were compared between the LOS and readmission groups. Multivariable logistic regression analysis was utilized to determine the association of independent factors with LOS and 90-day readmission rates.

RESULTS

Our sample included 1896 patients; 265 (14%) had LOS ≥2 days, and 121 (6.4%) had a readmission within 90 days of surgery. Patient and surgical factors associated with LOS included patient age ≥65 years (odds ratio [OR] 1.72, 95% confidence interval [CI] 1.15-2.56), marriage (OR 0.57, 95% CI 0.43-0.79), private health insurance (OR 0.28, 95% CI 0.15-0.50), American Society of Anesthesiologists (ASA) score (OR 1.52, 95% CI 1.12-1.86), African American race (OR 1.95, 95% CI 1.38-2.72), and harvesting iliac crest autograft (OR 4.94, 95% CI 2.31-10.8). Patient and surgical factors associated with 90-day hospital readmission included ASA score (OR 1.81, 95% CI 1.32-2.49), length of surgery (OR 1.002, 95% CI 1.001-1.004), and radiculopathy as indication for surgery (OR 0.60, 95% CI 0.39-0.96).

CONCLUSIONS

Extended LOS and 90-day hospital readmissions may lead to poorer patient outcomes and increased episode of care costs. Our study identified patient and surgical factors associated with extended LOS and 90-day readmission rates. In general, preoperative patient factors affected these outcomes more than surgical factors.

What Factors Influence Operative Time in Total Knee Arthroplasty? A 10-Year Analysis in a National Sample

BACKGROUND

Changes in reimbursement in total knee arthroplasty (TKA) by Centers for Medicare and Medicaid Services (CMS) have been tied to a perceived decrease in the total surgical time required to perform these operations. However, little information is available to CMS about recorded surgical times for TKA across the United States and the variables that drive these values. Therefore, the purpose of our study, is to evaluate (1) changes in operative time over time and (2) factors associated with variations in operative time.

METHODS

The National Surgical Quality Improvement Program database was queried to identify all primary TKAs conducted between January 1, 2008, and December 31, 2017. All TKAs conducted within our study period that had operative time data available were included. Multivariable linear models were created to assess factors that influence operative time over the study period.

RESULTS

Our final analysis included 140,890 TKAs. The mean operative time across the study period was found to be 92.60 minutes. Examining quarterly values, operative time stayed within 5 minutes of this mean (range, 89.80-97.51 minutes). Age, sex, functional status, anesthesia type, body mass index, operative year, transfusion requirements, and preoperative laboratory findings significantly influenced operative time (P < .05 for all).

CONCLUSION

Our analysis indicates that while there are numerous factors that influence procedure duration, operative times have remained stable. This information should be heavily considered in regard to physician reimbursement, because providers are maintaining operative times and work effort while mitigating factors that influence outcomes in the perioperative period.

Effect of Myelopathy on Early Clinical Improvement After Cervical Disc Replacement: A Study of a Local Patient Cohort and a Large National Cohort

Objective

Cervical disc replacement (CDR) is an effective long-term treatment for both cervical radiculopathy and myelopathy. However, there may be unique differences in the early postoperative clinical improvement for patients with and without myelopathy. In addition, previous studies using CDR to treat cervical myelopathy were underpowered to determine risk factors for relatively postoperative medical complications.

Methods

Two different cohorts were studied. A local cohort of patients undergoing CDR by a single surgeon was utilized to study the early postoperative course of clinical improvement. In addition, a national cohort of patients undergoing CDR in the 2015 and 2016 National Surgical Quality Improvement Program database was utilized to study differences in postoperative medical complications after CDR. Patients with a preoperative diagnosis of cervical myelopathy were identified in both cohorts, and perioperative outcomes and complications were compared to patients without myelopathy.

Results

A total of 43 patients undergoing CDR were included in the institutional cohort, of those 16 patients (37% of cohort) had a preoperative diagnosis of cervical myelopathy. A total of 3,023 patients undergoing CDR were included in the national cohort, of those 411 (13% of cohort) had a preoperative diagnosis of cervical myelopathy. In the institutional cohort, the nonmyelopathy group had a lower initial Neck Disability Index (NDI) and saw a faster improvement in NDI by 2 weeks postoperative. However, at 24 weeks there was no significant difference between groups in terms of NDI. Interestingly, only the nonmyelopathy cohort had a significant improvement in modified Japanese Orthopaedic Association score by 6 weeks (p<0.05). In the national cohort, myelopathy was associated with longer operative time and length of stay (p<0.05). However, there was no significant difference in perioperative complications (p>0.05) between myelopathy and nonmyelopathy patients.

Conclusion

Significant improvements in NDI, visual analogue scale (VAS)-arm pain, and VAS-neck pain are seen in both myelopathy and nonmyelopathy populations undergoing CDR by 6 weeks postoperatively. However, nonmyelopathy populations improve faster by 2 weeks postoperatively. In the national cohort analysis, medical complications were similarly low in both myelopathy and nonmyelopathy groups.

NuNec™ Cervical Disc Arthroplasty Improves Quality of Life in Cervical Radiculopathy and Myelopathy: A 2-yr Follow-up

BACKGROUND

Anterior cervical disc replacement is an alternative to fusion for the treatment of selected cases of radiculopathy and myelopathy. We report clinical and radiological outcomes after disc replacement with the NuNec™ artificial cervical disc (Pioneer® Surgical Technology, Marquette, Michigan) with subgroup analysis.

OBJECTIVE

To review clinical and radiological outcomes after anterior cervical disc replacement with the NuNec™ artificial cervical disc.

METHODS

A consecutive case series of patients undergoing cervical disc replacement with the NuNec™ artificial disc was conducted. Clinical outcomes were assessed by questionnaires preoperatively and up to 2 yr postoperatively including neck and arm pain, Neck Disability Index, Euroqol 5-dimensions, and Short Form-36; x-rays from the same period were analyzed for range of movement and presence of heterotopic ossification.

RESULTS

A total of 44 NuNec™ discs were implanted in 33 patients. Clinical improvements were seen in all outcomes; significant improvements on the Neck Disability Index, Euroqol 5-dimensions, and physical domain of the Short Form-36 were maintained at 2 yr. There was a mean of 4° range of movement at the replacement disc level at 2 yr, a significant reduction from baseline; there was also progression in levels of heterotopic ossification. Complications included temporary dysphagia (10%) and progression of disease requiring foraminotomy (6%); no surgery for adjacent level disease was required. There was no significant difference in the outcomes of the radiculopathy and myelopathy groups.

CONCLUSION

Clinical outcomes using the NuNec™ disc replacement are comparable with other disc replacements. Although the range of movement is reduced, the reoperation rate is very low.

Swallowing Function Following Anterior Cervical Discectomy and Fusion With and Without Anterior Plating: A SWAL-QOL (Swallowing-Quality of Life) and Radiographic Assessment

Objective

Anterior cervical plating in anterior cervical discectomy and fusion (ACDF) procedures are associated with improved outcomes compared to stand-alone cages. However, concerns exist regarding increased rates of postoperative dysphagia following an ACDF. This study aims to quantify the effect of anterior plating on swallowing-quality of life (SWAL-QOL) scores and radiographic swelling assessments following a primary, single-level ACDF.

Methods

Patients retrospectively reviewed. Patients grouped into those receiving a cage or anterior plate. SWAL-QOL scores were recorded preoperatively and 6 weeks and 12 weeks postoperatively. Lateral radiographs were used to create a swelling index with a ratio of the prevertebral swelling distance to the anterior-posterior diameter of each involved vertebral body. An air index was created using the same methodology. Statistical analysis was performed using chi-square analysis and independent t-tests for categorical and continuous variables.

Results

Sixty-eight primary, single-level ACDF patients were included. Forty-one (60.3%) received a stand-alone cage and 27 (39.7%) received a cage with anterior plating. No differences in demographics, comorbidities, operative time, estimated blood loss, or length of hospital stay were identified between Cage and Plate cohorts. Finally, no differences were observed in postoperative SWAL-QOL scores or swelling and air indices between groups.

Conclusion

The results demonstrate that patients undergoing a primary, single-level ACDF with or without anterior plating experience similar operative times and lengths of stay. Patients that receive a cage with anterior plating did not experience significant increases in dysphagia as measured by the SWAL-QOL questionnaire compared to patients that received a stand-alone cage. Furthermore, radiographic assessments of swelling are comparable.

Obesity does not impact clinical outcome but affects cervical sagittal alignment and adjacent segment degeneration in short term follow-up after an anterior cervical decompression and fusion

BACKGROUND CONTEXT

Obesity increases complications and cost following spine surgery. However, the impact on sagittal alignment and adjacent segment degeneration (ASD) after anterior cervical decompression and fusion is less understood.

PURPOSE

To compare clinical and radiographic outcomes after anterior cervical decompression and fusion between obese and nonobese patients.

STUDY DESIGN

Retrospective cohort study.

PATIENT SAMPLE

In all, 467 patients that underwent an anterior cervical decompression and fusion procedure from January 2008 through December 2015 were assessed. Surgery indications were radiculopathy, myelopathy, or myeloradiculopathy that had failed nonoperative treatments. Exclusion criteria included patients who had postoperative follow-up less than 6 months. Of 467 patients originally identified, 399 fulfilled the inclusion and exclusion criteria.

OUTCOME MEASURES

The following patient-reported outcomes were obtained: Neck Disability Index and Visual Analog Scale scores for the neck and arm pain. Radiographic assessments included: C2-C7 lordosis, T1 angle, levels fused, sagittal vertical axis (SVA), fusion mass lordosis, proximal and distal adjacent segment lordosis, ASD, and presence of fusion.

METHODS

Plain radiographs were performed preoperatively, immediately postoperatively, and final follow-up. Demographic information was collected on all patients. Baseline patient characteristics were compared using chi-squared analysis and independent sample t tests for categorical and continuous data, respectively. For analysis, patients were divided into 4 groups based on obesity stratification as defined by Center for Disease Control: body mass index (BMI) <25 kg/m² (normal weight), BMI≥25 kg/m² to <30 kg/m² (overweight), ≥30 kg/m² to <35 kg/m² (Class I obesity), BMI≥35 kg/m² to <40 kg/m² (Class II obesity), and BMI≥40 kg/m² (Class III obesity). Additionally, obese (≥30 kg/m²) and nonobese (<30 kg/m²) patients were compared in a separate analysis. Multivariate analysis was used to compare clinical and radiographic outcomes among all BMI classes, as well as between BMI≥30 kg/m² versus BMI<30 kg/m² study groups. Multivariate analyses controlled for differences in baseline patient characteristics and included age, sex, smoking, American Society of Anesthesiologists Physical Status Score, diabetes mellitus, and number of levels.

RESULTS

Of the 399 patients assessed, 97 were identified as normal weight, 157 as overweight, 81 with Class I obesity, 45 with Class II obesity, and 19 with Class III obesity. On multivariate analysis, despite having similar SVA measurements on preoperative radiographs, increase in BMI was associated with increase in postoperative SVA (p=0.041) along with significantly larger SVA in immediate postoperative (p=0.004) and final follow-up radiographs (p=0.003) for patients with BMI≥30 kg/m² versus BMI<30 kg/m². Furthermore, patients with BMI≥30 kg/m² had smaller preoperative (p=0.012), immediate postoperative (p=0.017), and final lordosis (p<0.001) in addition to smaller immediate postoperative (p=0.025) and final fusion segment lordosis (p=0.015) and smaller preoperative (p=0.024) and final distal lordosis (p=0.021) compared with patients with BMI<30 kg/m². Additionally, greater BMI was associated with lower final Visual Analog Scale neck scores (p=0.008). Radiographic early ASD rates were higher in patients BMI≥30 kg/m² versus BMI<30 kg/m² (p=0.028).

CONCLUSIONS

Overall, obese patients who underwent anterior cervical decompression and fusion had similar patient-reported outcomes compared with nonobese patients but had worse radiographic parameters and higher rates of ASD development compared with nonobese patients. This underscores the importance of patient selection and surgical approach for both patient populations.

Reporting Methodology of Neurosurgical Studies Utilizing the American College of Surgeons-National Surgical Quality Improvement Program Database: A Systematic Review and Critical Appraisal

BACKGROUND

Use of large databases such as the American College of Surgeons-National Surgical Quality Improvement Program (ACS-NSQIP) has become increasingly common in neurosurgical research.

OBJECTIVE

To perform a critical appraisal and evaluation of the methodological reporting for studies in neurosurgical literature that utilize the ACS-NSQIP database.

METHODS

We queried Ovid MEDLINE, EMBASE, and PubMed databases for all neurosurgical studies utilizing the ACS-NSQIP. We assessed each study according to number of criteria fulfilled with respect to Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) Statement, REporting of studies Conducted using Observational Routinely-collected Health Data (RECORD) Statement, and Journal of American Medical Association–Surgical Section (JAMA-Surgery) Checklist. A separate analysis was conducted among papers published in core and noncore journals in neurosurgery according to Bradford's law.

RESULTS

A total of 117 studies were included. Median (interquartile range [IQR]) scores for number of fulfilled criteria for STROBE Statement, RECORD Statement, and JAMA-Surgery Checklist were 20 (IQR:19-21), 9 (IQR:8-9), and 6 (IQR:5-6), respectively. For STROBE Statement, RECORD Statement, and JAMA-Surgery Checklist, item 9 (potential sources of bias), item 13 (supplemental information), and item 9 (missing data/sensitivity analysis) had the highest number of studies with no fulfillment among all studies (56, 68, 50%), respectively. When comparing core journals vs noncore journals, no significant difference was found (STROBE, P = .94; RECORD, P = .24; JAMA-Surgery checklist, P = .60).

CONCLUSION

While we observed an overall satisfactory reporting of methodology, most studies lacked mention of potential sources of bias, data cleaning methods, supplemental information, and external validity. Given the pervasive role of national databases and registries for research and health care policy, the surgical community needs to ensure the credibility and quality of such studies that ultimately aim to improve the value of surgical care delivery to patients.

Management of Degenerative Spondylolisthesis: Analysis of a Questionnaire Study, Correlation With a National Sample, and Perioperative Outcomes of Treatment Options

Background

Surgical treatment for lumbar degenerative spondylolisthesis has been shown to provide better long-term outcomes than conservative treatment. However, there is variation in surgical approaches employed by surgeons. This study investigates current surgical practice patterns and compares perioperative outcomes of 3 common surgical treatments for this pathology.

Methods

A survey was administered to surgeons who attended the Lumbar Spine Research Society (LSRS) meeting in 2014. Data were extracted from the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) from 2005 to 2014 to characterize the same responses. The 2 data sets were compared. Perioperative outcomes of those in the ACS-NSQIP posterior fusion subcohorts were characterized and compared.

Results

Posterior surgical approaches utilized by surgeons who responded to the LSRS survey were similar to those captured by ACS-NSQIP where 72% of those with degenerative spondylolisthesis were fused. Of those that were fused, 8% had an uninstrumented posterior fusion, 33% had an instrumented posterior fusion, and 59% had an instrumented posterior fusion with interbody. On multivariate analysis, there was no difference in risk of postoperative adverse events, readmission, or length of stay between these 3 common types of fusion.

Conclusions

Practice patterns for the posterior management of lumbar degenerative spondylolisthesis were similar between LSRS survey responses and ACS-NSQIP data. The ACS-NSQIP perioperative outcome measures assessed were similar regardless of surgical technique. These findings highlight that cost-benefit considerations and longer-term outcomes have to be the measures by which surgical technique is chosen for degenerative spondylolisthesis.

Short-term outcomes following posterior cervical fusion among octogenarians with cervical spondylotic myelopathy: a NSQIP database analysis

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.

Sex Differences for Anterior Cervical Fusion: Complications and Length of Stay

STUDY DESIGN

Retrospective cohort.

OBJECTIVE

To assess differences in baseline characteristics between sexes of patients undergoing anterior cervical discectomy and fusion (ACDF) and risk factors for adverse outcomes according to sex.

SUMMARY OF BACKGROUND DATA

ACDF is a common treatment for cervical spine disease. To reduce the rate of complications, risk factors associated with adverse events have been identified. However, few studies have examined the risk for inferior outcomes or complications after ACDF by sex.

METHODS

The American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database was used to identify patients who underwent ACDF from 2005 through 2014. Data collected included demographics, comorbidities, operative characteristics, and postoperative adverse events. Demographic and comorbidity variables were compared between men and women using chi-squared analysis. Perioperative outcomes were compared between groups using multivariate linear regression or Poisson regression with robust error variance controlling for preoperative characteristics.

RESULTS

In the 20,383 patients who met inclusion criteria, the male cohort was slightly older, less likely to be normal weight or morbidly obese, and had a higher incidence of diabetes and hypertension (P < 0.001 for each). Male sex was associated with a greater risk of any adverse event (relative risk = 1.2; P = 0.043), as well as any severe adverse event (relative risk  = 1.4; P = 0.001). Moreover, male sex exhibited longer operative times compared to the female group (127 vs. 117 min; β = 10; P < 0.001).

CONCLUSION

The results of the current study suggest male sex is associated with an increased risk of adverse events following ACDF. Male sex has previously been demonstrated to correlate with medical comorbidities, which may be partly responsible for the increased morbidity. Because of the contrasting evidence throughout the literature, further studies are required to better elucidate this effect.

LEVEL OF EVIDENCE

3.

General Health Adverse Events Within 30 Days Following Anterior Cervical Discectomy and Fusion in US Patients: A Comparison of Spine Surgeons' Perceptions and Reported Data for Rates and Risk Factors

STUDY DESIGN

Survey study and retrospective review of prospective data.

OBJECTIVES

To contrast surgeons' perceptions and reported national data regarding the rates of postoperative adverse events following anterior cervical discectomy and fusion (ACDF) and to assess the accuracy of surgeons in predicting the impact of patient factors on such outcomes.

METHODS

A survey investigating perceived rates of perioperative complications and the perceived effect of patient risk factors on the occurrence of complications following ACDF was distributed to spine surgeons at the Cervical Spine Research Society (CSRS) 2015 Annual Meeting. The equivalent reported rates of adverse events and impacts of patient risk factors on such complications were assessed in patients undergoing elective ACDF from the National Surgical Quality Improvement Program (NSQIP).

RESULTS

There were 110 completed surveys from attending physicians at CSRS (response rate = 44%). There were 18 019 patients who met inclusion criteria in NSQIP years 2011 to 2014. The rates of 11 out of 17 (65%) postoperative adverse events were mildly overestimated by surgeons responding to the CSRS questionnaire in comparison to reported NSQIP data (overestimates ranged from 0.24% to 1.50%). The rates of 2 out of 17 (12%) postoperative adverse events were mildly underestimated by surgeons (range = 0.08% to 1.2%). The impacts of 5 out of 10 (50%) patient factors were overestimated by surgeons (range relative risk = 0.56 to 1.48).

CONCLUSIONS

Surgeon estimates of risk factors for and rates of adverse events following ACDF procedures were reasonably nearer to national data. Despite an overall tendency toward overestimation, surgeons' assessments are roughly appropriate for surgical planning, expectation setting, and quality improvement initiatives.

Poorer Fusion Outcomes in Diabetic Cervical Spondylotic Myelopathy Patients Undergoing Single-level Anterior Cervical Discectomy and Fusion Does Not Compromise Functional Outcomes and Quality of Life

STUDY DESIGN

Retrospective matched pair cohort study using prospectively collected registry data.

OBJECTIVES

The aim of this study was to determine whether patients with DM have poorer patient-reported outcomes and poorer fusion rates after undergoing a single-level anterior cervical discectomy and fusion (ACDF) for cervical myelopathy.

SUMMARY OF BACKGROUND DATA

ACDF remains the most common procedure in the treatment of cervical spondylotic myelopathy (CSM); however, there is a paucity of literature with regards to patient-reported outcome measures (PROMs), health-related quality-of-life (HRQOL) scores, and fusion rates post-ACDF in diabetic patients with CSM.

METHODS

From 2002 to 2012, 29 diabetic patients were matched with 29 nondiabetic controls. Patient demographics, perioperative data, and validated spine-specific scores including the Numerical Pain Rating Scale on Neck Pain and Upper Limb Pain, American Academy of Orthopaedic Surgeons (AAOS) neck pain and disability scores, AAOS Neurogenic Symptoms Score, Neck Disability Index, Japanese Orthopaedic Association Cervical Myelopathy Score, and Short Form 36 Physical/Mental Component Summaries were recorded. Fusion rates based on Bridwell grading were assessed at 2 years.

RESULTS

After matching, there were no significant preoperative differences in patient demographics, clinical outcomes, PROMs or HRQoL measures between the DM and control group (P > 0.05). There was no difference in either length of hospital stay (P = 0.92) or length of surgery (P = 0.92) between the two groups. At 2 years postoperatively, there were no significant differences between validated spine-specific scores, PROMs, HRQoL scores, satisfaction rates, or fulfilment of expectations between the two groups. Significant poorer Bridwell fusion grades were noted in the DM group at 2 years postoperatively (P < 0.05). Subgroup analysis within the DM group demonstrated that glycated hemoglobin levels had no impact on functional outcomes, fulfilment of expectations, or patient satisfaction at 2 years (P > 0.05).

CONCLUSION

Despite poorer fusion outcomes following single-level ACDF for symptomatic CSM, there was no significant difference in validated spine outcome scores, PROMs, HRQoL measures, or satisfaction levels when compared to nondiabetic controls at short-term follow-up.

LEVEL OF EVIDENCE

3.

Performance Indicators in Spine Surgery

STUDY DESIGN

Systematic review.

OBJECTIVE

To elucidate how performance indicators are currently used in spine surgery.

SUMMARY OF BACKGROUND DATA

The Patient Protection and Affordable Care Act has given significant traction to the idea that healthcare must provide value to the patient through the introduction of hospital value-based purchasing. The key to implementing this new paradigm is to measure this value notably through performance indicators.

METHODS

MEDLINE, CINAHL Plus, EMBASE, and Google Scholar were searched for studies reporting the use of performance indicators specific to spine surgery. We followed the Prisma-P methodology for a systematic review for entries from January 1980 to July 2016. All full text articles were then reviewed to identify any measure of performance published within the article. This measure was then examined as per the three criteria of established standard, exclusion/risk adjustment, and benchmarking to determine if it constituted a performance indicator.

RESULTS

The initial search yielded 85 results among which two relevant studies were identified. The extended search gave a total of 865 citations across databases among which 15 new articles were identified. The grey literature search provided five additional reports which in turn led to six additional articles. A total of 27 full text articles and reports were retrieved and reviewed. We were unable to identify performance indicators. The articles presenting a measure of performance were organized based on how many criteria they lacked. We further examined the next steps to be taken to craft the first performance indicator in spine surgery.

CONCLUSION

The science of performance measurement applied to spine surgery is still in its infancy. Current outcome metrics used in clinical settings require refinement to become performance indicators. Current registry work is providing the necessary foundation, but requires benchmarking to truly measure performance.

LEVEL OF EVIDENCE

1.

Definitional Differences of 'Outpatient' Versus 'Inpatient' THA and TKA Can Affect Study Outcomes

BACKGROUND

There has been great interest in performing outpatient THA and TKA. Studies have compared such procedures done as outpatients versus inpatients. However, stated "outpatient" status as defined by large national databases such as the National Surgical Quality Improvement Program (NSQIP) may not be a consistent entity, and the actual lengths of stay of those patients categorized as outpatients in NSQIP have not been specifically ascertained and may in fact include some patients who are "observed" for one or more nights. Current regulations in the United States allow these "observed" patients to stay more than one night at the hospital under observation status despite being coded as outpatients. Determining the degree to which this is the case, and what, exactly, "outpatient" means in the NSQIP, may influence the way clinicians read studies from that source and the way hospital systems and policymakers use those data.

QUESTIONS/PURPOSES

The purposes of this study were (1) to utilize the NSQIP database to characterize the differences in definition of "inpatient" and "outpatient" (stated status versus actual length of stay [LOS], measured in days) for THA and TKA; and (2) to study the effect of defining populations using different definitions.

METHODS

Patients who underwent THA and TKA in the 2005 to 2014 NSQIP database were identified. Outpatient procedures were defined as either hospital LOS = 0 days in NSQIP or being termed "outpatient" by the hospital. The actual hospital LOS of "outpatients" was characterized. "Outpatients" were considered to have stayed overnight if they had a LOS of 1 day or longer. The effects of the different definitions on 30-day outcomes were evaluated using multivariate analysis while controlling for potential confounding factors.

RESULTS

Of 72,651 patients undergoing THA, 529 were identified as "outpatients" but only 63 of these (12%) had a LOS = 0. Of 117,454 patients undergoing TKA, 890 were identified as "outpatients" but only 95 of these (11%) had a LOS = 0. After controlling for potential confounding factors such as gender, body mass index, functional status before surgery, comorbidities, and smoking status, we found "inpatient" THA to be associated with increased risk of any adverse event (relative risk, 2.643, p = 0.002), serious adverse event (relative risk, 2.455, p = 0.011), and readmission (relative risk, 2.775, p = 0.010) compared with "outpatient" THA. However, for the same procedure and controlling for the same factors, patients who had LOS > 0 were not associated with any increased risk compared with patients who had LOS = 0. A similar trend was also found in the TKA cohort.

CONCLUSIONS

Future THA, TKA, or other investigations on this topic should consistently quantify the term "outpatient" because different definitions, stated status or actual LOS, may lead to different assignments of risk factors for postoperative complications. Accurate data regarding risk factors for complications after total joint arthroplasty are crucial for efforts to reduce length of hospital stay and minimize complications.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Use of Computer Assistance in Lumbar Fusion Surgery: Analysis of 15 222 Patients in the ACS-NSQIP Database

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

Several studies have shown that the accuracy of pedicle screw placement significantly improves with use of computer-assisted surgery (CAS). Yet few studies have compared the incidence of postoperative complications between CAS and conventional techniques. The objective of this study is to determine the difference in postoperative complication rates between CAS and conventional techniques in spine surgery.

METHODS

The American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database was used to identify patients who underwent posterior lumbar fusion from 2011 to 2013. Multivariate analysis was conducted to demonstrate the difference in postoperative complication rates between CAS and conventional techniques in spine surgery.

RESULTS

Out of 15 222 patients, 14 382 (95.1%) were operated with conventional techniques and 740 (4.90%) were operated with CAS. Multivariate analysis showed that patients in the CAS group had fewer odds to experience adverse events postoperatively (odds ratio [OR] = 0.57, P < .001). Minor adverse events occurred in 2905 (20.2%) patients in the conventional group and in 98 (13.2%) patients in the CAS group (OR = 0.57, P < .001). Blood transfusion was present in 2488 (17.3%) of the patients in the conventional group compared to 81 (11.0%) of the patients in the CAS group (OR = 0.56, P < .001). The mean operative time in the conventional group was 205.2 ± 106.1 minutes, and it was 227.0 ± 111.9 minutes in the CAS group. This difference was statistically significant (r = 20.14, P < .001).

CONCLUSION

This article examined the complications in lumbar spinal surgery with or without the use of CAS. These results suggest that CAS may provide a safer technique for implant placement in lumbar fusion surgeries.

Thirty-Day Readmission Risk Factors Following Single-Level Transforaminal Lumbar Interbody Fusion (TLIF) for 4992 Patients From the ACS-NSQIP Database

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

To describe the readmission rate and identify risk factors associated with 30-day readmission after transforaminal lumbar interbody fusion (TLIF) surgery.

METHODS

Patients who underwent elective single level TLIF surgery from 2011 to 2013 were identified in the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database. Emergency or trauma cases were excluded. Preoperative, intraoperative, and postoperative variables were extracted. A multivariate binary regression identified predictors correlated with 30-day readmission.

RESULTS

A total of 4992 patients were included in the analysis. The overall 30-day readmission rate was 5.51% (275/4992) for readmissions reported between 2011 to 2013. The mean age of patients readmitted was 62.40 years (standard error [SE] = 0.78) and 60.92 years (SE = 0.20) among those whom were not readmitted (P = .05). The top three causes for readmission included postoperative pain control, deep or superficial surgical site infections. Predictors associated with 30-day readmission in a multivariate analysis included female gender (odds ratio [OR] = 1.27, 95% CI = 0.97-1.65), history of severe chronic obstructive pulmonary disease (OR = 1.81, 95% CI = 1.11-2.96), and in the postoperative period, American Society of Anesthesiologists class (OR = 1.30, 95% CI = 1.04-1.63), presence of superficial surgical site infection (OR= 18.23, 95% CI = 10.36-32.08), or urinary tract infection (OR = 4.93, 95% CI = 2.84-8.58).

CONCLUSIONS

The readmission rate, risk factors, and causes following TLIF surgery are comparable to other lumbar spinal procedures reported from the ACS-NSQIP database.

Higher Modified Charlson Index Scores Are Associated With Increased Incidence of Complications, Transfusion Events, and Length of Stay Following Revision Hip Arthroplasty

BACKGROUND

Revision total hip arthroplasty (RHA) has been associated with greater morbidity and length of stay (LOS) compared to primary total hip arthroplasty. Despite this, few validated metrics exist for risk stratification in RHA cohorts. The Charlson Comorbidity Index (CCI) has been associated with complications in total hip arthroplasty, but its utility in revision surgery remains unexplored. The purpose of this study was to examine the relationship between preoperative CCI and a variety of outcome metrics following RHA.

METHODS

The National Surgical Quality Improvement Program database was used to identify all patients undergoing aseptic RHA between 2006 and 2013. A variety of demographics and perioperative variables were collected. Modified CCI scores were computed for each patient based on a validated formula incorporating comorbidities found in the National Surgical Quality Improvement Program database. Outcome variables of interest included mortality, major postoperative complications, minor adverse events, incidence of transfusion, and prolonged LOS. Perioperative factors were tested for association with these outcomes using bivariate analysis and significant variables were then incorporated into a logistic regression model to explore the relationship between preoperative CCI scores and postoperative events.

RESULTS

In a multivariable regression model controlling for the significant perioperative variables, operative time, and American Society of Anesthesiologists classification, higher CCI scores were significantly associated with mortality (odds ratio [OR] 1.89, 95% confidence interval [CI] 1.64-2.18, P < .001), major complications (OR 1.12, 95% CI 1.05-1.20, P = .001), minor complications (OR 1.53, 95% CI 1.39-1.69, P < .001), transfusions (OR 1.14, 95% CI 1.09-1.20, P < .001), and prolonged LOS (OR 1.32, 95% CI 1.26-1.39, P < .001).

CONCLUSION

Higher preoperative CCI scores were independent risk factors for numerous complications. This highlights the potential utility of the CCI in risk stratification for RHA populations.

Most 30-day Readmissions After Anterior Cervical Discectomy and Fusion Are Not Due to Surgical Site-Related Issues: An Analysis of 17,088 Patients

STUDY DESIGN

A retrospective study of patients undergoing anterior cervical discectomy and fusion (ACDF) in the prospective National Surgical Quality Improvement Program (NSQIP) database.

OBJECTIVE

To determine the most common reasons for readmission within 30 days after elective ACDF.

SUMMARY OF BACKGROUND DATA

ACDF is a commonly performed surgery that is safe and effective for treating a variety of cervical spine pathologies. With new quality-based reimbursements tied to readmissions within 30 days of discharge, better understanding of the causes of readmissions is, however, needed.

METHODS

Patients undergoing ACDF in the NSQIP database from 2012 to 2014 were reviewed. The overall rate of readmission and documented reasons for readmission were collected. Multivariate regression was then used to determine risk factors for readmissions.

RESULTS

A total of 17,088 patients undergoing elective ACDF were identified. There were 545 (3.2%) readmissions within 30 postoperative days. Of the readmitted patients, 293 (53.8%) were readmitted for nonsurgical site-related reasons, with neuropsychiatric (n = 44), cardiovascular (n = 39), and pneumonia (n = 37) being the most common reasons. A total of 184 patients (33.8%) were readmitted for surgical site-related reasons, with surgical site infection (n = 42), hemorrhage/hematoma (n = 42), and dysphagia (n = 32) being the most common reasons. A total of 84 patients (15.6%) had undocumented reasons for readmission. In multivariate analysis, only older age and higher American Society of Anesthesiologists class were independently associated with readmissions.

CONCLUSION

Most readmissions after ACDF were due to nonsurgical site-related reasons, suggesting the importance of careful patient selection, aggressive preoperative medical optimization, and adequate postoperative management.

LEVEL OF EVIDENCE

3.

Systemic inaccuracies in the National Surgical Quality Improvement Program database: Implications for accuracy and validity for neurosurgery outcomes research

The American College of Surgeons (ACS) National Surgical Quality Improvement Program (NSQIP) provides a rich database of North American surgical procedures and their complications. Yet no external source has validated the accuracy of the information within this database. Using records from the 2006 to 2013 NSQIP database, we used two methods to identify errors: (1) mismatches between the Current Procedural Terminology (CPT) code that was used to identify the surgical procedure, and the International Classification of Diseases (ICD-9) post-operative diagnosis: i.e., a diagnosis that is incompatible with a certain procedure. (2) Primary anesthetic and CPT code mismatching: i.e., anesthesia not indicated for a particular procedure. Analyzing data for movement disorders, epilepsy, and tumor resection, we found evidence of CPT code and postoperative diagnosis mismatches in 0.4-100% of cases, depending on the CPT code examined. When analyzing anesthetic data from brain tumor, epilepsy, trauma, and spine surgery, we found evidence of miscoded anesthesia in 0.1-0.8% of cases. National databases like NSQIP are an important tool for quality improvement. Yet all databases are subject to errors, and measures of internal consistency show that errors affect up to 100% of case records for certain procedures in NSQIP. Steps should be taken to improve data collection on the frontend of NSQIP, and also to ensure that future studies with NSQIP take steps to exclude erroneous cases from analysis.