Steven J. Fineberg

Epidemiological trends in cervical spine surgery for degenerative diseases between 2002 and 2009.

Study Design. Retrospective analysis of a population-based database. Objective. To investigate national epidemiological trends of cervical spine surgical procedures from 2002–2009. Summary of Background Data. Anterior cervical fusion (ACF), posterior cervical fusion (PCF), and posterior cervical decompression (PCD) are procedures routinely performed for cervical degenerative pathology. Studies regarding epidemiological trends of these procedures is currently lacking in the literature. Methods. Data from the Nationwide Inpatient Sample of the Healthcare Cost and Utilization Project was obtained for each year between 2002 and 2009. Patients undergoing ACF, PCF, and PCD for the diagnosis of cervical radiculopathy and myelopathy were identified. Demographics, costs, and mortality were assessed in the surgical subgroups. A P value of 0.001 was used to denote significance. Results. An estimated 1,323,979 cervical spine surgical procedures were performed between 2002 and 2009. There was a significant upward trend in the mean age of patients undergoing cervical spine surgery during this time period. ACF and PCF cohorts demonstrated statistically significant increases in comorbidities and costs from 2002–2009. The PCF group had the greatest mortality, comorbidities, costs, and longest hospitalizations compared with ACF and PCF cohorts across all time periods. Conclusion. Our study demonstrates that cervical spine surgical procedures have increased between 2002 and 2009 (P = 0.001). The primary increase in volume is due to the increasing number of ACFs. Despite older patients with more comorbidities undergoing ACF and PCF procedures, mortality has not changed. However, this patient population trended significant increases in costs during this time period. We hypothesize that these increased costs are due to an increased comorbidity burden in patients undergoing ACF or PCF. Results of this study can be used to set benchmarks for future epidemiological investigations in cervical spine surgery. Level of Evidence: 4

The incidence and mortality of thromboembolic events in lumbar spine surgery.

Study Design. Retrospective database analysis. Objective. A population-based database was analyzed to identify the incidence, risk factors, and mortality associated with thromboembolic events after lumbar spine surgery. Summary of Background Data. Pulmonary embolism (PE) and deep vein thrombosis (DVT) are potential complications that may occur after orthopedic procedures. The incidence of these complications is not well characterized after lumbar spine surgery. Methods. Data from the Nationwide Inpatient Sample was obtained from 2002–2009. Patients undergoing lumbar decompression (LD), or lumbar fusion (LF) for degenerative conditions were identified. Acute PE and DVT incidences and mortality rates were calculated. Comorbidities were calculated using a modified Charlson Comorbidity Index. Statistical analysis was performed using the Student t test for discrete variables and &khgr;2 test for categorical data. Logistic regression was used to identify independent predictors of thromboembolic events. A P value of less than or equal to 0.0005 was used to denote statistical significance. Results. A total 578,457 LDs and LFs were identified from 2002–2009. DVT incidences were 2.4 and 4.3 per 1000 cases in the LD and LF groups, respectively. PE incidences were 1.0 and 2.6 per 1000 cases in the LD and LF groups, respectively. Patients who had undergone LF with thromboembolic events were younger, had fewer comorbidities, and incurred greater costs than patients who had undergone LD. Statistically significant predictors of DVT were pulmonary circulation disorders, coagulopathy, fluid/electrolyte disorders, anemia, obesity, teaching hospital status, and larger hospitals. Predictors for the development of PE were pulmonary circulation disorders, fluid/electrolyte disorders, anemia, black ethnicity and teaching hospital status. Conclusion. Patients undergoing LD or LF are at inherent risk of thromboembolic events. DVT and PE are more common after LF procedures. Preoperative pulmonary circulation disorders, fluid/electrolyte disorders, deficiency anemia, and teaching hospital status were significant risk factors for developing both DVT and PE. Preventive measures in patients at risk may decrease the incidence of thromboembolic events. Level of Evidence: 4

Current trends in demographics, practice, and in-hospital outcomes in cervical spine surgery: a national database analysis between 2002 and 2011.

Study Design. Retrospective database analysis. Objective. To investigate national trends of cervical spine surgical procedures from 2002 to 2011. Summary of Background Data. There is a paucity of literature assessing the current practice trends and outcomes of cervical spine surgery following the 2008 Food and Drug Administration public health notifications regarding bone morphogenetic protein (BMP) utilization in cervical spine surgical procedures. Methods. The National Inpatient Sample database was accessed for each year across 2002 to 2011. Patients undergoing anterior cervical fusion, posterior cervical fusion, and posterior cervical decompression were identified. Patient and hospitalization parameters including demographics, BMP utilization, costs, early postoperative outcomes, and mortality were assessed for each surgical cohort. A Pearson correlation coefficient with a 95% confidence interval (P < 0.05) was used to analyze trends in patient and hospital outcome parameters during this 10-year period. Results. A total of 307,188 cervical spine procedures were performed from 2002 to 2011. Both the anterior cervical fusion and posterior cervical fusion cohort demonstrated a statistically significant increase in the number of procedures performed over time (r = +0.9, P < 0.001). A significant uptrend in patient age (r = +1.0, P < 0.001) and comorbidity burden (r = +0.9, P < 0.001) was demonstrated during the studied decade. Overall, BMP utilization (r = +0.7, P = 0.02) also demonstrated a significant increase during this time period, but demonstrated a decline after peaking in 2007. The posterior cervical fusion cohort demonstrated the greatest comorbidity, length of stay, costs, and mortality. Conclusion. This study demonstrates that the number of cervical spine procedures has increased between 2002 and 2011, irrespective of the change in BMP utilization after the 2008 Food and Drug Administration warning. Despite an older patient population with greater comorbidities undergoing cervical spine surgeries, hospital length of stay and mortality has not significantly changed. However, we did note a significant increase in costs during this time period. These findings may be related to advances in surgical technology and instrumentation that may be associated with rising hospital costs. Level of Evidence: N/A

Incidence and risk factors for postoperative delirium after lumbar spine surgery.

Study Design. Retrospective database analysis. Objective. A population-based database was analyzed to characterize the incidence, hospital costs, mortality, and risk factors associated with postoperative delirium after lumbar decompression (LD) and lumbar fusion (LF) surgical procedures. Summary of Background Data. Postoperative delirium is a common complication after surgery in the elderly that leads to increased hospitalization, cost, and other adverse outcomes. The incidence of delirium after lumbar spine surgery has not been discussed in this literature. Methods. Data from the Nationwide Inpatient Sample were obtained from 2002–2009. Patients undergoing LD or LF for degenerative pathologies were identified. Patient demographics, comorbidities, length of stay, discharge disposition, costs, and mortality were assessed. SPSS version 20 was used for statistical analysis using independent T tests for discrete variables and &khgr;2 tests for categorical data. Logistic regression was performed to identify independent predictors of delirium. A P value of less than 0.001 was used to denote significance. Results. A total of 578,457 LDs and LFs were identified in the United States from 2002–2009. Of these, 292,177 were LDs and 286,280 were LFs. The overall incidence of delirium was 8.4 events per 1000 cases. Patients undergoing LF had a statistically greater incidence of delirium than patients undergoing LD (11.8 vs. 5.0 per 1000; P < 0.001). Patients experiencing delirium were significantly older and more likely to be female than nonaffected patients (P < 0.001). Patients with delirium in both cohorts demonstrated significantly greater comorbidities, length of stay, greater costs, and more frequent discharge to skilled nursing facilities (P < 0.001). The presence of delirium in LD-treated patients was associated with an increased mortality rate (6.1 vs. 0.8 per 1000; P < 0.001). Logistic regression demonstrated that independent predictors of delirium included older age (≥65 yr), alcohol/drug abuse, depression, psychotic disorders, neurological disorders, deficiency anemia, fluid/electrolyte disorders, and weight loss. Conclusion. The results of our study demonstrated an overall incidence of 8.4 events per 1000 lumbar spine surgical procedures. Overall analysis demonstrated an increased incidence of delirium in older females with greater comorbid conditions. Delirium was found to be associated with increased length of stay, costs, and mortality in all patients undergoing lumbar spine surgery. We recommend that physicians put greater effort into recognizing risk factors of delirium and diagnosing it in a timely manner to mitigate its effects. Level of Evidence: 3

Complications of spinal fusion with utilization of bone morphogenetic protein: a systematic review of the literature.

Study Design. Systematic review. Objective. A systematic review was performed to identify the types of complications and complication rates associated with the use of bone morphogenetic protein (BMP) in both anterior and posterior cervical and lumbar spine surgery. Summary of Background Data. There has been an increase in BMP use in various clinical situations typically in an “off-label” fashion. Associated with its use, however, have been reports of various complications. Methods. A MEDLINE search was conducted. All articles involving complications after spine surgery in patients receiving BMP were included. Articles were excluded on the basis of the following criteria: Non-English manuscripts and nonhuman subjects. A total of 29 articles met the inclusion and exclusion criteria and were used in the analysis. For each complication identified, the incidence was calculated by pooling the subjects from the studies that reported the complication. &khgr;2 tests were used to compare the incidence rates between those that had received BMP and the control groups. Results. Of the 29 articles included, 7 reported complication rates in anterior cervical fusions, 3 in posterior cervical fusions, 4 in anterior lumbar interbody fusions (ALIF), 9 in posterior/transforaminal lumbar interbody fusions (PLIF/TLIF), and 6 in posterolateral lumbar fusions. Individual complication rates when BMP was used was in the range from 0.66% to 20.1% in anterior cervical fusions, 3.5% to 14.6% in posterior cervical fusions, 2.0% to 7.3% in ALIFs, 1.5% to 21.8% in PLIF/TLIFs, and 1.4% to 8.2% in posterolateral lumbar fusions. Pseudarthrosis rates were statistically significantly lower with the utilization of BMP in all procedures except for PLIF/TLIFs, which only approached significance (P = 0.07). The only individual complication that was statistically significantly greater with BMP utilization was retrograde ejaculation in ALIFs (7.3 vs. 2.3%; P = 0.03). The rate of dysphagia/swelling in anterior cervical fusions was greater with BMP (20.1 vs. 15.6%), however this only approached statistical significance (P = 0.07). Conclusion. The body of literature reports complication rates with BMP ranging from 0.66% to 21.8%. However, the only statistically significant adverse complication rate was retrograde ejaculation in the ALIF population (7.3%). Despite the increased awareness of complications associated with BMP, complication rates remain spine site specific and low. Thorough patient education should be done with the physician to make an informative use regarding BMP utilization in spinal surgery. Level of Evidence: 3

A perioperative cost analysis comparing single-level minimally invasive and open transforaminal lumbar interbody fusion

BACKGROUND CONTEXT Emerging literature suggests superior clinical short- and long-term outcomes of MIS (minimally invasive surgery) TLIFs (transforaminal lumbar interbody fusion) versus open fusions. Few studies to date have analyzed the cost differences between the two techniques and their relationship to acute clinical outcomes. PURPOSE The purpose of the study was to determine the differences in hospitalization costs and payments for patients treated with primary single-level MIS versus open TLIF. The impact of clinical outcomes and their contribution to financial differences was explored as well. STUDY DESIGN/SETTING This study was a nonrandomized, nonblinded prospective review. PATIENT SAMPLE Sixty-six consecutive patients undergoing a single-level TLIF (open/MIS) were analyzed (33 open, 33 MIS). Patients in either cohort (MIS/open) were matched based on race, sex, age, smoking status, medical comorbidities (Charlson Comorbidity index), payer, and diagnosis. Every patient in the study had a diagnosis of either degenerative disc disease or spondylolisthesis and stenosis. OUTCOME MEASURES Operative time (minutes), length of stay (LOS, days), estimated blood loss (EBL, mL), anesthesia time (minutes), Visual Analog Scale (VAS) scores, and hospital cost/payment amount were assessed. METHODS The MIS and open TLIF groups were compared based on clinical outcomes measures and hospital cost/payment data using SPSS version 20.0 for statistical analysis. The two groups were compared using bivariate chi-squared analysis. Mann-Whitney tests were used for non-normal distributed data. Effect size estimate was calculated with the Cohen d statistic and the r statistic with a 95% confidence interval. RESULTS Average surgical time was shorter for the MIS than the open TLIF group (115.8 minutes vs. 186.0 minutes respectively; p=.001). Length of stay was also reduced for the MIS versus the open group (2.3 days vs. 2.9 days, respectively; p=.018). Average anesthesia time and EBL were also lower in the MIS group (p<.001). VAS scores decreased for both groups, although these scores were significantly lower for the MIS group (p<.001). Financial analysis demonstrated lower total hospital direct costs (blood, imaging, implant, laboratory, pharmacy, physical therapy/occupational therapy/speech, room and board) in the MIS versus the open group (

Incidence and risk factors for dysphagia after anterior cervical fusion

19,512 vs.

Incidence and mortality of cardiac events in lumbar spine surgery

23,550, p<.001). Implant costs were similar (p=.686) in both groups, although these accounted for about two-thirds of the hospital direct costs in the MIS cohort (

Hospital outcomes and complications of anterior and posterior cervical fusion with bone morphogenetic protein.

13,764) and half of these costs (

Clinical sequelae after rhBMP-2 use in a minimally invasive transforaminal lumbar interbody fusion

13,778) in the open group. Hospital payments were