Spinal fusion for pediatric neuromuscular scoliosis: national trends, complications, and in-hospital outcomes
Authors: Rumalla Kavelin , Yarbrough Chester K. , Pugely Andrew J. , Koester Linda , Dorward Ian G. 
Published: May 2016

OBJECTIVE
The objective of this study was to determine if the recent changes in technology, surgical techniques, and surgical literature have influenced practice trends in spinal fusion surgery for pediatric neuromuscular scoliosis (NMS). In this study the authors analyzed recent trends in the surgical management of NMS and investigated the effect of various patient and surgical factors on in-hospital complications, outcomes, and costs, using the Nationwide Inpatient Sample (NIS) database.

METHODS
The NIS was queried from 2002 to 2011 using International Classification of Diseases, Ninth Edition, Clinical Modification codes to identify pediatric cases (age < 18 years) of spinal fusion for NMS. Several patient, surgical, and short-term outcome factors were included in the analyses. Trend analyses of these factors were conducted. Both univariate and multivariable analyses were used to determine the effect of the various patient and surgical factors on short-term outcomes.

RESULTS
Between 2002 and 2011, a total of 2154 NMS fusion cases were identified, and the volume of spinal fusion procedures increased 93% from 148 in 2002 to 286 in 2011 (p < 0.0001). The mean patient age was 12.8 ± 3.10 years, and 45.6% of the study population was female. The overall complication rate was 40.1% and the respiratory complication rate was 28.2%. From 2002 to 2011, upward trends (p < 0.0001) were demonstrated in Medicaid insurance status (36.5% to 52.8%), presence of ≥ 1 comorbidity (40.2% to 52.1%), and blood transfusions (25.2% to 57.3%). Utilization of posterior-only fusions (PSFs) increased from 66.2% to 90.2% (p < 0.0001) while combined anterior release/fusions and PSF (AR/PSF) decreased from 33.8% to 9.8% (< 0.0001). Intraoperative neurophysiological monitoring (IONM) underwent increasing utilization from 2009 to 2011 (15.5% to 20.3%, p < 0.0001). The use/harvest of autograft underwent a significant upward trend between 2002 and 2011 (31.3% to 59.8%, p < 0.0001). In univariate analysis, IONM use was associated with decreased complications (40.7% to 33.1%, p = 0.049) and length of stay (LOS; 9.21 to 6.70 days, p <0.0001). Inflation-adjusted mean hospital costs increased nearly 75% from 2002 to 2011 ($36,805 to $65,244, p < 0.0001). In the multivariable analysis, nonwhite race, highest quartile of median household income, greater preexisting comorbidity, long-segment fusions, and use of blood transfusions were found to increase the likelihood of complication occurrence (all p < 0.05). In further multivariable analysis, independent predictors of prolonged LOS included older age, increased preexisting comorbidity, the AR/PSF approach, and long-segment fusions (all p < 0.05). Lastly, the likelihood of increased hospital costs (at or above the 90th percentile for LOS, 14 days) was increased by older age, female sex, Medicaid insurance status, highest quartile of median household income, AR/PSF approach, long-segment fusion, and blood transfusion (all p < 0.05). In multivariable analysis, the use of autograft was associated with a lower likelihood of complication occurrence and prolonged LOS (both p < 0.05).

CONCLUSIONS
Increasing use of IONM and posterior-only approaches may combat the high complication rates in NMS. The trends of increasing comorbidities, blood transfusions, and total costs in spinal fusion surgery for pediatric NMS may indicate an increasingly aggressive approach to these cases.