Preoperative predictors of increased hospital costs in elective anterior cervical fusions: a single-institution analysis of 1,082 patients

Adverse events after surgery for injuries to the subaxial cervical spine: analysis of incidence and risk factors

PURPOSE

To determine the incidence of severe surgical adverse events (sSAE) after surgery of patients with subaxial cervical spine injury (sCS-Fx) and to identify patient, treatment, and injury-related risk factors.

METHODS

Retrospective analysis of clinical and radiological data of sCS-Fx patients treated surgically between 2010 and 2020 at a single national trauma center. Baseline characteristics of demographic data, preexisting conditions, treatment, and injury morphology were extracted. Incidences of sSAEs within 60 days after surgery were analyzed. Univariate analysis and binary logistic regression for the occurrence of one or more sSAEs were performed to identify risk factors. P-values < .05 were considered statistically significant.

RESULTS

Two hundred and ninety-two patients were included. At least one sSAE occurred in 49 patients (16.8%). Most frequent were sSAEs of the surgical site (wound healing disorder, infection, etc.) affecting 29 patients (9.9%). Independent potential risk factors in logistic regression were higher age (OR 1.02 [1.003-1.04], p = .022), the presence of one or more modifiers in the AO Spine Subaxial Injury Classification (OR 2.02 [1.03-3.96], p = .041), and potentially unstable or unstable facet injury (OR 2.49 [1.24-4.99], p = .010). Other suspected risk factors were not statistically significant, among these Injury Severity Score, the need for surgery for concomitant injuries, the primary injury type according to AO Spine, and preexisting medical conditions.

CONCLUSION

sSAE rates after treatment of sCS-Fx are high. The identified risk factors are not perioperatively modifiable, but their knowledge should guide intra and postoperative care and surgical technique.

Spine Instrumented Surgery on a Budget-Tools for Lowering Cost Without Changing Outcome

STUDY DESIGN

Review article.

OBJECTIVES

There have been substantial increases in the utilization of complex spinal surgery in the last 20 years. Spinal instrumented surgery is associated with high costs as well as significant variation in approach and care. The objective of this manuscript is to identify and review drivers of instrumented spine surgery cost and explain how surgeons can reduce costs without compromising outcome.

METHODS

A literature search was conducted using PubMed. The literature review returned 217 citations. 27 publications were found to meet the inclusion criteria. The relevant literature on drivers of spine instrumented surgery cost is reviewed.

RESULTS

The drivers of cost in instrumented spine surgery are varied and include implant costs, complications, readmissions, facility-based costs, surgeon-driven preferences, and patient comorbidities. Each major cost driver represents an opportunity for potential reductions in cost. With high resource utilization and often uncertain outcomes, spinal surgery has been heavily scrutinized by payers and hospital systems, with efforts to reduce costs and standardize surgical approach and care pathways.

CONCLUSIONS

Education about cost and commitment to standardization would be useful strategies to reduce cost without compromising patient-reported outcomes after instrumented spinal fusion.

Radiological evaluation of the localization of sympathetic ganglia in the cervical region

PURPOSE

To determine local variations of cervical sympathetic ganglia (CSG) according to vertebral levels on preoperative neck magnetic resonance imaging (MRI) by designating carotid artery (CA) as the standard landmark at the center, in attempts to prevent injury to CSG in the anterior-anterolateral approaches performed in the cervical spinal region.

MATERIALS AND METHODS

The retrospective study reviewed neck MRI images of 281 patients, of which the images of 231 patients were excluded from the study based on the exclusion criteria. As a result, the MRI images of the remaining 50 patients were included in the study. The circumference of carotid artery (CA) was divided into eight equal zones with CA defined as the standard landmark at the center. High-risk zones were determined based on the anterior-anterolateral approaches.

RESULTS

At C1 level, a superior ganglion was located on the right side in 32 (64%) and on the left side in 30 (60%) patients. At this level, it was most commonly located in Zone 6. Middle ganglion was observed most frequently at C3 level, which was detected on the right side in 17 (34%) and on the left side in 17 (34%) patients. At this level, it was most commonly located in Zone 2.

CONCLUSION

Variations in the localizations of superior and middle cervical ganglia should be taken into consideration prior to surgical procedures planned for this region. This study sheds light on high-risk zones in the surgical site and could guide surgeons to better understand the location of cervical sympathetic ganglia before surgical planning.

Underweight patients are an often under looked “At risk” population after undergoing posterior cervical spine surgery

Background

Body Mass Index (BMI) is a weight-for-height metric that is used to quantify tissue mass and weight levels. Past studies have mainly focused on the association of high BMI on spine surgery outcomes and shown variable conclusions. Prior results may have varied due to insufficient power or inconsistent categorical separation of BMI groups (e.g. underweight, overweight, or obese). Additionally, few studies have considered outcomes of patients with low BMI. The aim of the current study was to analyze patients along the entirety of the BMI spectrum and to establish specific granular BMI categories for which patients become at risk for complication and mortality following posterior cervical spine surgery.

Methods

Patients undergoing elective posterior cervical spine surgery were abstracted from the 2005–2016 National Surgical Quality Improvement Program (NSQIP) databases. Patients were aggregated into pre-established WHO BMI categories and adverse outcomes were normalized to average risk of normal-weight subjects (BMI 18.5–24.9 kg/m²). Risk-adjusted multivariate regressions were performed controlling for patient demographics and overall health.

Results

A total of 16,806 patients met inclusion criteria. Odds for adverse events for underweight patients (BMI < 18.5 kg/m²) were the highest among any category of patients along the BMI spectrum. These patients experienced increased odds of any adverse event (Odds Ratio (OR) = 1.67, p = 0.008, major adverse events (OR=2.08, p = 0.001), post-operative infection (OR = 1.95, p = 0.002), and reoperation (OR = 1.84, p = 0.020). Interestingly, none of the overweight or obese categories were found to be correlated with increased risk of adverse event categories other than super-morbidly obese patients (BMI>50.0 kg/m²) for post-operative infection (OR = 1.54, p = 0.041).

Conclusions

The current study found underweight patients to have the highest risk of adverse events after posterior cervical spine surgery. Increased pre-surgical planning and resource allocation for this population should be considered by physicians and healthcare systems, as is often already done for patients on the other end of the BMI spectrum.

The Effect of Body Mass Index on Long-Term Patient-Reported Outcome Scores after Anterior Cervical Discectomy and Fusion in an Asian Population: A 2-Year Study

Study Design

Retrospective cohort study.

Purpose

This study aims to analyze the relationship between body mass index (BMI) subjective patient-reported outcomes (PRO) after 1- and 2-level anterior cervical discectomy and fusion (ACDF).

Overview of Literature

The prevalence of cervical spondylosis and ACDF in expected to continue rising among the aging population of Asia. Moreover, the prevalence of obesity is also increasing. However, limited information is available about the mechanism by which BMI affects PRO after ACDF.

Methods

Total 878 patients underwent ACDF between 2000 and 2015. After excluding patients with previous cervical instrumentation, >2 levels fused, missing BMI measurement, or neoplastic/trauma indication for surgery, 535 patients were included. The PRO measures of the Neck Disability Index, Numerical Pain Rating Scale (NPRS) for Neck Pain, NPRS for Limb Pain, American Academy of Orthopaedic Surgeons–Neurogenic Symptom Score, and Japanese Orthopaedic Association myelopathy score were used. Patients were grouped based on their preoperative BMI, as per the World Health Organization guidelines for Asian populations. PRO scores were collected preoperatively, at 6 months postoperatively, and 2 years postoperatively. A generalized linear model was used to analyze the relationship of BMI category with the individual score, accounting for several factors that are likely to affect the outcomes.

Results

Total 19 (3.4%) were underweight, 155 (28.0%) were normal weight, 112 (20.3%) were overweight, and 267 (48.3%) were obese. Patients across all BMI categories experienced significant and similar improvements in their postoperative PRO scores. There were no significant differences in the preoperative, 6-month postoperative, and 2-year postoperative PRO scores of the groups. Rate of reoperation was highest in patients with grade II obesity at 8.07%; however, the difference was not statistically significant.

Conclusions

Irrespective of the BMI, all patients exhibited similar satisfactory outcomes following ACDF. The results support surgery in all subgroups of patients with symptomatic nerve compression in the cervical spine.

Later Surgical Start Time Is Associated With Longer Length of Stay and Higher Cost in Cervical Spine Surgery

STUDY DESIGN

Retrospective study of a surgical cohort from a single, large academic institution.

OBJECTIVE

The aim of this study was to investigate associations between surgical start time, length of stay, cost, perioperative outcomes, and readmission.

SUMMARY OF BACKGROUND DATA

One retrospective study with a smaller cohort investigated associations between surgical start time and outcomes in spine surgery and found that early start times were correlated with shorter length of stay. No examinations of perioperative outcomes or cost have been performed.

METHODS

All patients undergoing anterior cervical discectomy and fusion (ACDF) and posterior cervical decompression and fusion (PCDF) were queried from a single institution from January 1, 2008 to November 30, 2016. Patients undergoing surgery that started between 12:00 AM and 6:00 AM were excluded due to their likely emergent nature. Cases starting before and after 2:00 PM were compared on the basis of length of stay and cost as the primary outcomes using multivariable logistic regression.

RESULT

The patients undergoing ACDF and PCDF were both similar on the basis of comorbidity burden, preoperative diagnosis, and number of segments fused. The patients undergoing ACDF starting after 2 PM had longer LOS values (adjusted difference of 0.65 days; 95% confidence interval [CI]: 0.28-1.03; P = 0.0006) and higher costs of hospitalization (adjusted difference of $1177; 95% CI: $549-$1806; P = 0.0002). Patients undergoing PCDF starting after 2 PM also had longer LOS values (adjusted difference of 1.19 days; 95% CI: 0.46-1.91; P = 0.001) and higher costs of hospitalization (adjusted difference of $2305; 95% CI: $826-$3785; P = 0.002).

CONCLUSION

Later surgical start time is associated with longer LOS and higher cost. These findings should be further confirmed in the spine surgical literature to investigate surgical start time as a potential cost-saving measure.

LEVEL OF EVIDENCE

3.

Underweight patients are at just as much risk as super morbidly obese patients when undergoing anterior cervical spine surgery

BACKGROUND CONTEXT

Past studies have focused on the association of high body mass index (BMI) on spine surgery outcomes. These investigations have reported mixed conclusions, possible due to insufficient power, poor controlling of confounding variables, and inconsistent definitions of BMI categories (e.g. underweight, overweight, and obese). Few studies have considered outcomes of patients with low BMI.

PURPOSE

To analyze how anterior cervical spine surgery outcomes track with World Health Organization categories of BMI to better assess where along the BMI spectrum patients are at risk for adverse perioperative outcomes.

DESIGN/SETTING

Retrospective cohort study.

PATIENT SAMPLE

Patients undergoing elective anterior cervical spine surgery were abstracted from the 2005 to 2016 American College of Surgeons National Surgical Quality Improvement Program database.

OUTCOME MEASURES

Thirty-day adverse events, hospital readmissions, postoperative infections, and mortality.

METHODS

Patients undergoing anterior cervical spine procedures (anterior cervical discectomy and fusion, anterior cervical corpectomy, cervical arthroplasty) were identified in the 2005 to 2016 National Surgical Quality Improvement Program database. Patients were then aggregated into modified World Health Organization categories of BMI. Odds ratios of adverse outcomes, normalized to average risk of normal weight subjects (BMI 18.5-24.9 kg/m²), were calculated. Multivariate analyses were then performed on aggregated adverse outcome categories controlling for demographics (age, sex, functional status) and overall health as measured by the American Society of Anesthesiologists classification.

RESULTS

In total, 51,149 anterior cervical surgery patients met inclusion criteria. Multivariate analyses revealed the odds of any adverse event to be significantly elevated for underweight and super morbidly obese patients (Odds Ratios [OR] of 1.62 and 1.55, respectively). Additionally, underweight patients had elevated odds of serious adverse events (OR=1.74) and postoperative infections (OR=1.75) and super morbidly obese patients had elevated odds of minor adverse events (OR=1.72). Relative to normal BMI patients, there was no significant elevation for any adverse outcomes for any of the other overweight/obese categories, in fact some had reduced odds of various adverse outcomes.

CONCLUSIONS

Underweight and super morbidly obese patients have the greatest odds of adverse outcomes after anterior cervical spine surgery. The current study identifies underweight patients as an at-risk population that has previously not received significant focus. Physicians and healthcare systems should give additional consideration to this population, as they often already do for those at the other end of the BMI spectrum.

Chronic Obstructive Pulmonary Disease Is an Independent Predictor for 30-Day Complications and Readmissions Following 1- to 2-Level Anterior Cervical Discectomy and Fusion

STUDY DESIGN

Retrospective cohort.

OBJECTIVES

To study evidence to assess the impact of chronic obstructive pulmonary disease (COPD) on 30-day outcomes following 1- to 2-level anterior cervical discectomy and fusion (ACDF).

METHODS

The 2015-2016 American College of Surgeons-National Surgical Quality Improvement Program (ACS-NSQIP) database was queried using Current Procedural Terminology (CPT) codes 22 551 (single-level) and 22 552 (additional level). Patients undergoing disc arthroplasty, multilevel (>2) fusion, posterior cervical spine surgery, and patients with fracture, tumor, and/or infection were excluded.

RESULTS

Out of 14 835 patients undergoing an elective 1- to 2-level ACDF, 649 (4.4%) had a diagnosis of COPD at the time of the surgery. Following adjusted logistic regression analysis, prior history of COPD was significantly associated with a longer length of stay (odds ratio [OR] 1.25 [95% confidence interval (CI0 1.04-1.52]; P = .019), superficial surgical site infection (OR 2.68 [95% CI 1.06-6.80]; P = .038), discharge destination other than home (OR 1.49 [95% CI 1.05-2.12]; P = .026), pneumonia (OR 4.37 [95% CI 2.42-7.88]; P < .001), ventilator use >48 hours (OR 5.34 [95% CI 1.88-15.15]; P = .002), unplanned reintubation (OR 3.36 [1.48-7.62]; P = .004), and 30-day readmissions (OR 1.69 [95% CI 1.20-2.38]; P = .003).

CONCLUSIONS

The findings of this study show that COPD patients are more likely to have postoperative complications and 30-day readmissions, despite elective ACDF itself being a low-risk surgery in general. Results show that majority of the complications were pulmonary in nature, further stressing the need for accurate medical optimization following surgery in these patients.

Ninety-Day Bundled Payment Reimbursement for Patients Undergoing Anterior and Posterior Procedures for Degenerative Cervical Radiculopathy

BACKGROUND

Anterior cervical discectomy with fusion (ACDF) or posterior cervical foraminotomy (PCF) are the mainstay surgical treatment options for patients with degenerative cervical radiculopathy (DCR).

OBJECTIVE

To compare 90-d bundled payments between ACDF and PCF for DCR in a cohort study.

METHODS

Data were extracted from MarketScan database (2000-2016) using ICD-9, ICD-10, and CPT-4 codes. The bundle payments were calculated as the payments accumulated from the index hospitalization admission to 90 d postsurgery. We also analyzed the index hospitalization (physician, hospital, and total) and the postdischarge payments (hospital readmission, outpatient services, medications, and total). Surgical groups were matched based on baseline characteristics (age, sex, insurance type, and Elixhauser score).

RESULTS

A total of 100 041 patients met the inclusion criteria. 94.9% of patients (n = 95 031). Patients underwent ACDF with 5.1% (n = 5 010) treated via PCF. Overall, median 90-d costs were significantly higher for ACDF than for PCF ($31567 vs $18412; P < .0001). The median total index hospitalization ($27841 vs $15043), physician ($4572 vs $1920), and hospital payments ($14540 vs $7404) were higher for ACDF compared to PCF for both single- and multiple-level cohorts (P < .0001). There was no difference in overall 90-d postdischarge payments. Factors associated with higher 90-d payments for both cohorts included age and comorbidity scores.

CONCLUSION

ACDF is associated with greater bundle payments in patients diagnosed with DCR. No difference was noted for the total postdischarge payments. PCF may be a cost-effective surgical option in appropriately selected patients with unilateral, paracentral, and foraminal soft herniated discs.

Determinants and Variations of Hospital Costs in Patients With Lumbar Radiculopathy Hospitalized for Spinal Surgery

STUDY DESIGN

A retrospective study.

OBJECTIVE

The aim of this study was to determine hospital costs related to surgery for lumbar radiculopathy and identify determinants of intramural costs based on minimal hospital and claims data.

SUMMARY OF BACKGROUND DATA

Costs related to the initial hospitalization of patients undergoing surgery for lumbar radiculopathy make up the major part of direct health care expenditure in this population. Identifying factors influencing intramural costs can be beneficial for health care policy makers, and clinicians working with patients with lumbar radiculopathy.

METHODS

The following data were collected from the University Hospital Brussels data warehouse for all patients undergoing surgery for lumbar radiculopathy in 2016 (n = 141): age, sex, primary diagnosis, secondary diagnoses, type of surgery, severity of illness (SOI), admission and discharge date, type of hospital admission, and all claims incurred for the particular hospital stay. Descriptive statistics for total hospital costs were performed. Univariate analyses were executed to explore associations between hospital costs and all other variables. Those showing a significant association (P < 0.05) were included in the multivariate general linear model analysis.

RESULTS

Mean total hospital costs were &OV0556; 5016 ± 188 per patient. Costs related to the actual residence (i.e., "hotel costs") comprised 53% of the total hospital costs, whereas 18% of the costs were claimed for the surgical procedure. Patients with moderate/major SOI had 44% higher hospital costs than minor SOI (P = 0.01). Presence of preadmission comorbidities incurred 46% higher costs (P = 0.03). Emergency procedures led to 72% higher costs than elective surgery (P < 0.001). Patients receiving spinal fusion had 211% higher hospital costs than patients not receiving this intervention (P < 0.001).

CONCLUSION

Hospital costs in patients receiving surgery for lumbar radiculopathy are influenced by SOI, the presence of preadmission comorbidities, type of hospital admission (emergency vs. elective), and type of surgical procedure.

LEVEL OF EVIDENCE

3.

Hospital length of stay and healthcare costs among African American women due to obesity and diabetic conditions in United States: A model for correlation studies comparing ethnicity, co-morbidities and hospital resources

Objective

To examine obesity and diabetes associations with United States hospital use and healthcare costs for African American women, to explore the relationship between co-morbidities of interest (obesity and diabetes) and hospital resources [length of stay (LOS) and costs].

Methods

A retrospective, correlation, quantitative analysis for lengths of hospital stay and cost among adult African American women categorized according to their weight status with type 2 diabetes. Healthcare Cost and Utilization Project (HCUP) data which contains the Nationwide Inpatient Sample was used. Focused on 803,163 African American, female inpatients between the ages of 21 and 55 in the United States from 2008 to 2010. Researcher explored the relationship between individual health factors of interest (obesity and diabetes) and the effects on hospital LOS and healthcare costs. All statistical analysis will be performed using Stata v12. All inferential tests will be two-sided and will utilize a 95% significance level. Two separate multiple regressions will be used.

Results

A total of 758,874 records were retained for analysis. The patients in the weighted population ranged in age from 21 to 55 years. The patient LOS ranged from 0 to 333 days. The patients had approximately 2 procedures on average, and presented with approximately 3 chronic conditions on average. The total charges (Cost) ranged from 106 to over 1 million US dollars. The size and direction of the relationship between LOS, healthcare costs and the independent variables of diabetes and obesity suggests that both LOS and health care cost decreased for African American female patients with diabetes or obesity. There is a statistically significant relationship between at least one of the individual health factors of interest (obesity and diabetes) and hospital LOS (F = 13,394.00, P < 0.0005, R ²  = 0.440) and hospital costs (F = 10,171.23, P < 0.0005, R ²  = 0.502).

Conclusions

There is evidence of racial and ethnic disparities in health care quality in hospital treatment of African American patients. After accounting for social determinants and insurance statuses, African Americans may receive lower-quality care than the population at large. African Americans are admitted to the hospital, but services and LOS are shorter than the general population partially due to disparities in evaluating and offering treatment.

Impact of body mass index on surgical outcomes, narcotics consumption, and hospital costs following anterior cervical discectomy and fusion

OBJECTIVE Given the increasing prevalence of obesity, more patients with a high body mass index (BMI) will require surgical treatment for degenerative spinal disease. In previous investigations of lumbar spine pathology, obesity has been associated with worsened postoperative outcomes and increased costs. However, few studies have examined the association between BMI and postoperative outcomes following anterior cervical discectomy and fusion (ACDF) procedures. Thus, the purpose of this study was to compare surgical outcomes, postoperative narcotics consumption, complications, and hospital costs among BMI stratifications for patients who have undergone primary 1- to 2-level ACDF procedures. METHODS The authors retrospectively reviewed a prospectively maintained surgical database of patients who had undergone primary 1- to 2-level ACDF for degenerative spinal pathology between 2008 and 2015. Patients were stratified by BMI as follows: normal weight (< 25.0 kg/m²), overweight (25.0-29.9 kg/m²), obese I (30.0-34.9 kg/m²), or obese II-III (≥ 35.0 kg/m²). Differences in patient demographics and preoperative characteristics were compared across the BMI cohorts using 1-way ANOVA or chi-square analysis. Multivariate linear or Poisson regression with robust error variance was used to determine the presence of an association between BMI category and narcotics utilization, improvement in visual analog scale (VAS) scores, incidence of complications, arthrodesis rates, reoperation rates, and hospital costs. Regression analyses were controlled for preoperative demographic and procedural characteristics. RESULTS Two hundred seventy-seven patients were included in the analysis, of whom 20.9% (n = 58) were normal weight, 37.5% (n = 104) were overweight, 24.9% (n = 69) were obese I, and 16.6% (n = 46) were obese II-III. A higher BMI was associated with an older age (p = 0.049) and increased comorbidity burden (p = 0.001). No differences in sex, smoking status, insurance type, diagnosis, presence of neuropathy, or preoperative VAS pain scores were found among the BMI cohorts (p > 0.05). No significant differences were found among these cohorts as regards operative time, intraoperative blood loss, length of hospital stay, and number of operative levels (p > 0.05). Additionally, no significant differences in postoperative narcotics consumption, VAS score improvement, complication rates, arthrodesis rates, reoperation rates, or total direct costs existed across BMI stratifications (p > 0.05). CONCLUSIONS Patients with a higher BMI demonstrated surgical outcomes, narcotics consumption, and hospital costs comparable to those of patients with a lower BMI. Thus, ACDF procedures are both safe and effective for all patients across the entire BMI spectrum. Patients should be counseled to expect similar rates of postoperative complications and eventual clinical improvement regardless of their BMI.

High-Risk Subgroup Membership Is a Predictor of 30-Day Morbidity Following Anterior Lumbar Fusion

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

To determine if membership in a high-risk subgroup is predictive of morbidity and mortality following anterior lumbar fusion (ALF).

METHODS

The American College of Surgeons National Surgical Quality Improvement Program database was utilized to identify patients undergoing ALF between 2010 and 2014. Multivariate analysis was utilized to identify high-risk subgroup membership as an independent predictor of postoperative complications.

RESULTS

Members of the elderly (≥65 years) (OR = 1.3, P = .02) and non-Caucasian (black, Hispanic, other) (OR = 1.7, P < .0001) subgroups were at greater risk for a LOS ≥5 days. Obese patients (≥30 kg/m² ) were at greater risk for an operative time ≥4 hours (OR = 1.3, P = .005), and wound complications (OR = 1.8, P = .024) compared with nonobese patients. Emergent procedures had a significantly increased risk for LOS ≥5 days (OR = 4.9, P = .021), sepsis (OR = 14.8, P = .018), and reoperation (OR = 13.4, P < .0001) compared with nonemergent procedures. Disseminated cancer was an independent risk factor for operative time ≥4 hours (OR = 8.4, P < .0001), LOS ≥5 days (OR = 15.2, P < .0001), pulmonary complications (OR = 7.4, P = .019), and postoperative blood transfusion (OR = 3.1, P = .040).

CONCLUSIONS

High-risk subgroup membership is an independent risk factor for morbidity following ALF. These groups should be targets for aggressive preoperative optimization, and quality improvement initiatives.

Does Obesity Correlate With Worse Patient-Reported Outcomes Following Elective Anterior Cervical Discectomy and Fusion?

BACKGROUND

Studies have investigated the impact of obesity in thoracolumbar surgery; however, the effect of obesity on patient-reported outcomes (PROs) following anterior cervical discectomy and fusion (ACDF) is unknown.

OBJECTIVE

To examine the relationship between obesity and PROs following elective ACDF.

METHODS

Consecutive patients undergoing ACDF for degenerative conditions were evaluated. Patients were divided into groups with a body mass index ≥35. The EuroQol-5D, Short-Form 12 (SF-12), modified Japanese Orthopaedic Association score, and Neck Disability Index were used. Correlations between PROs and obesity were calculated at baseline and 1 year.

RESULTS

A total of 299 patients were included, with 80 obese (27%) and 219 nonobese (73%). patients At baseline, obesity was associated with worse myelopathy (modified Japanese Orthopaedic Association score: 10.7 vs 12.2, P = .01), general physical health (SF-12 physical component scale score: 28.7 vs 31.8, P = .02), and general mental health (SF-12 mental component scale score: 38.9 vs 42.3, P = .04). All PROs improved significantly following surgery in both groups. There was no difference in absolute scores and change scores for any PRO at 12 months following surgery. Furthermore, there was no difference in the percentage of patients achieving a minimal clinically important difference for the Neck Disability Index (52% vs 56%, P = .51) and no difference in patient satisfaction (85% vs 85%, P = .85) between groups.

CONCLUSION

Obesity was not associated with less improvement in PROs following ACDF. There was no difference in the proportion of patients satisfied with surgery and those achieving a minimal clinically important difference across all PROs. Obese patients may therefore achieve meaningful improvement following elective ACDF.

ABBREVIATIONS

ACDF, anterior cervical discectomy and fusionBMI, body mass indexEQ-5D, EuroQol-5DMCID, minimal clinically important differenceMCS, mental component scalemJOA, modified Japanese Orthopaedic AssociationNDI, Neck Disability IndexNRS, Numerical Rating ScalePCS, physical component scalePROs, patient-reported outcomesSF-12, Short Form 12.

Cost Variation of Anterior Cervical Fusions in Elderly Medicare Beneficiaries

STUDY DESIGN

Retrospective database review.

OBJECTIVE

To determine how demographics and comorbid diagnoses influence hospital costs during admission for anterior cervical fusions (ACFs) in the elderly Medicare population.

SUMMARY OF BACKGROUND DATA

Elective ACFs to treat degenerative cervical pathology are extremely common within the elderly population. Although it is well known that every patient has a significantly different medical profile that guides treatment and postoperative care, little information is available regarding how hospital costs vary from patient to patient.

METHODS

Medicare records from the PearlDiver database (2011-2012) were retrospectively queried to select all 65- to 84-year-old patients who underwent primary, 1 to 2 level ACF (International Classification of Diseases, Ninth Revision, Clinical Modification: 81.02) for either cervical spondylosis or cervical disc disease. All patients with corpectomies, posterior cervical fusions, and all other same-day spine fusion surgeries were excluded. The primary outcome of this study was Medicare reimbursement from the full inpatient stay as associated with the selected International Classification of Diseases, Ninth Revision procedure code. The relative contributions of year, age, sex, region, myelopathy diagnosis, and various comorbidities to the total cost were determined with both univariate statistics and multivariate analysis. For all analyses, P < 0.001 was determined to be significant.

RESULTS

In total, 21,853 patients were selected for analysis. The average reimbursement for the full cohort was $13,648 ± $7306. On multivariate analysis, advanced age ($1083), diagnosis of myelopathy ($2150), diabetes mellitus ($1019), obesity ($651), congestive heart failure ($1523), chronic kidney disease ($1962), and chronic pulmonary disease ($489) were all factors that increased costs. Of note, sex, smoking history, and prior liver disease were not associated with changes in cost.

CONCLUSION

Medicare reimbursements provide a value means by which determinants of cost can be elucidated. Although multiple comorbidities, older age, and myelopathy diagnosis could be theorized to contribute to increased costs, there is still some uncertainty regarding their relative costs. These data are informative to practicing physicians as health care as a whole transitions to a more value-based approach.

LEVEL OF EVIDENCE

4.

Patterns of healthcare resource utilization prior to anterior cervical decompression and fusion in patients with radiculopathy

Objective

To assess patterns of healthcare resource utilization prior to anterior cervical decompression and fusion (ACDF) in patients diagnosed with radiculopathy with a retrospective cohort study design.

Background

ACDF is associated with improvement in quality of life among patients with cervical radiculopathy. However, little is known regarding utilization of healthcare services and total cost of care before ACDF surgery in the United States.

Methods

We analyzed a group of patients who received ACDF for radiculopathy during 2009-2011 using a healthcare database of over 20 million patients of all ages. Patients with fewer than two years of data prior to ACDF procedure were excluded. Inclusion criteria included patients with a diagnosis of disc displacement/degeneration and radiculopathy. All charges related to healthcare administration within two years prior to surgery were recorded and analyzed.

Results

Sixteen hundred seventy six patients met the inclusion criteria. Seventy-three percent of patients were in the 40-59 year age range; 55% were women and 45% were men. In the two years preceding the surgery, 34% of patients received prescription NSAIDs, and 98% received prescription narcotics for total charges of $101,188 ($174.46/patient) and $222,860 ($134.82/patient) respectively. Total pain-related interventions over two years (oral pharmacotherapy and injections) were charged at $4,368,900 at an average of $2,606/treatment. Total outpatient charges including physician office visits, other outpatient visits and emergency room visits amounted to $25,450,012. Mean total outpatient charges over the two years preceding ACDF was $15,556 per patient for 26,397 episodes of care. Injectable corticosteroids were provided for 84.7% of patients and charges related to this treatment totaled $1,137 per patient.

Conclusions

In the two years prior to ACDF, healthcare resource utilization is extremely high. Given that these patients ultimately undergo surgical intervention, opportunities to reduce charges of conservative care exist.

Effect of obesity on cost per quality-adjusted life years gained following anterior cervical discectomy and fusion in elective degenerative pathology

BACKGROUND

Obese patients have greater comorbidities along with higher risk of complications and greater costs after spine surgery, which may result in increased cost and lower quality of life compared with their non-obese counterparts.

PURPOSE

The aim of the present study was to determine cost-utility following anterior cervical discectomy and fusion (ACDF) in obese patients.

STUDY DESIGN

This study analyzed prospectively collected data.

PATIENT SAMPLE

Patients undergoing elective ACDF for degenerative cervical pathology at a single academic institution were included in the study.

OUTCOME MEASURES

Cost and quality-adjusted life years (QALYs) were the outcome measures.

METHODS

One- and two-year medical resource utilization, missed work, and health state values (QALYs) were assessed. Two-year resource use was multiplied by unit costs based on Medicare national payment amounts (direct cost). Patient and caregiver workday losses were multiplied by the self-reported gross-of-tax wage rate (indirect cost). Total cost (direct+indirect) was used to compute cost per QALY gained. Patients were defined as obese for body mass index (BMI) ≥35 based on the WHO definition of class II obesity. A subgroup analysis was conducted in morbidly obese patients (BMI≥40).

RESULTS

There were significant improvements in pain (neck pain or arm pain), disability (Neck Disability Index), and quality of life (EuroQol-5D and Short Form-12) at 2 years after surgery (p<.001). There was no significant difference in post-discharge health-care resource utilization, direct cost, indirect cost, and total cost between obese and non-obese patients at postoperative 1-year and 2-year follow-up. Mean 2-year direct cost for obese patients was $19,225±$8,065 and $17,635±$6,413 for non-obese patients (p=.14). There was no significant difference in the mean total 2-year cost between obese ($23,144±$9,216) and non-obese ($22,183±$10,564) patients (p=.48). Obese patients had a lower mean cumulative gain in QALYs versus non-obese patients at 2-years (0.34 vs. 0.42, p=.32). Two-year cost-utility in obese ($68,070/QALY) versus non-obese patients ($52,816/QALY) was not significantly different (p=.11). Morbidly obese patients had lower QALYs gained (0.17) and higher cost per QALYs gained ($138,094/QALY) at 2 years.

CONCLUSIONS

Anterior cervical discectomy and fusion provided a significant gain in health state utility in obese patients, with a mean 2-year cost-utility of $68,070 per QALYs gained, which can be considered moderately cost-effective. Morbidly obese patients had lower cost-effectiveness; however, surgery does provide a significant improvement in outcomes. Obesity, and specifically morbid obesity, should to be taken into consideration as physician and hospital reimbursements move toward a bundled model.

The Effects of Obesity on Spine Surgery: A Systematic Review of the Literature

Study Design Literature review. Objective The aim of this literature review is to examine the effects of obesity on postoperative complications and functional outcomes after spine surgery. Methods A review of the relevant literature examining the effects of obesity and spine surgery was conducted using PubMed, Google Scholar, and Cochrane databases. Results Obesity contributes to disk degeneration and low back pain and potentially increases the risk of developing operative pathology. Obese patients undergoing spine surgery have a higher risk of developing postoperative complications, particularly surgical site infection and venous thromboembolism. Though functional outcomes in this population may not mirror the general population, the treatment effect associated with surgery is at least equivalent if not better in obese individuals. This reduction is primarily due to worse outcomes associated with nonoperative treatment in the obese population. Conclusion Obese individuals represent a unique patient population with respect to nonoperative treatment, postoperative complication rates, and functional outcomes. However, given the equivalent or greater treatment effect of surgery, this comorbidity should not prohibit obese patients from undergoing operative intervention. Future investigations in this area should attempt to develop strategies to minimize complications and improve outcomes in obese individuals and also examine the role of controlled weight loss preoperatively to mitigate these risks.

Complications following central corpectomy in 468 consecutive patients with degenerative cervical spine disease

OBJECTIVE

This study was performed to describe the incidence and predictors of perioperative complications following central corpectomy (CC) in 468 consecutive patients with cervical spondylotic myelopathy (CSM) or ossification of the posterior longitudinal ligament (OPLL).

METHODS

The authors performed a retrospective review of a cohort of patients who had undergone surgery for CSM (n = 338) or OPLL (n = 130) performed by a single surgeon over a 15-year period. All patients underwent uninstrumented CC with autologous iliac crest or fibular strut grafting. Preoperative clinical and imaging details were collected, and the type and incidence of complications were studied. Univariate and multivariate analyses were performed to establish risk factors for the development of perioperative complications.

RESULTS

Overall, 12.4% of patients suffered at least 1 complication following CC. The incidence of major complications was as follows: C-5 radiculopathy, 1.3%; recurrent laryngeal nerve injury, 0.4%; dysphagia, 0.8%; surgical-site infection, 3.4%; and dural tear, 4.3%. There was 1 postoperative death (0.2%). On multivariate analysis, patients in whom the corpectomy involved the C-4 vertebral body (alone or as part of multilevel CC) were significantly more likely to suffer complications (p = 0.004). OPLL and skip corpectomy were risk factors for dural tear (p = 0.015 and p = 0.001, respectively). No factors were found to be significantly associated with postoperative C-5 palsy, dysphagia, or acute graft extrusion on univariate or multivariate analysis. Patients who underwent multilevel CC were predisposed to surgical-site infections, with a slight trend toward statistical significance (p = 0.094). The occurrence of a complication after surgery significantly increased the mean duration of postoperative hospital stay from 5.0 ± 2.3 days to 8.9 ± 6 days (p < 0.001).

CONCLUSIONS

Complications following CC for CSM or OPLL are infrequent, but they significantly prolong hospital stay. The most frequent complication following CC is dural tear, for which a diagnosis of OPLL and a skip corpectomy are significant risk factors.

Risk Modeling Predicts Complication Rates for Spinal Surgery

STUDY DESIGN

Retrospective review of clinical data registry.

OBJECTIVE

In the current era of quality reporting and pay for performance, neurosurgeons must develop models to identify patients at high risk of complications. We sought to identify risk factors for complications in spine surgery and to develop a score predictive of complications.

SUMMARY OF BACKGROUND DATA

We examined spinal surgeries from the American College of Surgeons National Surgical Quality Improvement Project (ACS-NSQIP) database. 22,430 cases were identified based on common procedural terminology.

METHODS

Univariate analysis followed by multivariate regression was used to identify significant factors.

RESULTS

The overall complication rate for the cohort was 9.9%. The most common complications were postoperative bleeding requiring transfusion (4.1%), nonwound infections (3.1%), and wound-related infections (2.2%). Multivariate regression analysis identified 20 factors associated with complications. Assigning 1 point for the presence of each factor a risk model was developed. The range of scores for the cohort was 0 to 13 with a median score of 4. Complication rates for a risk score of 0 to 4 was 3.7% and for scores 5 to 13 was 18.5%. The risk model robustly predicted complication rates, with complication rate of 1.2% for score of 0 (n = 412, 1.8% of total) and 63.6% and 100% for scores of 12 and 13 (n = 22 patients, 0.1% of total cohort) respectively (P < 0.001). The risk score also correlated strongly with total length of stay, mortality, and total work relative value units for the case.

CONCLUSION

Patient-specific risk factors including comorbidities are strongly associated with surgical complications, length of stay, cost of care, and mortality in spine surgery and can be used to develop risk models that are highly predictive of complications.

LEVEL OF EVIDENCE

3.