134. Surgeon volume affects short- and long-term surgical outcomes in idiopathic scoliosis

Abstract

BACKGROUND CONTEXT Spinal deformity surgery requires the completion of numerous complex tasks. Proper placement of pedicle screws, deformity correction and arthrodesis are learned skills that require significant training and repetition. Surgeon and hospital volume have been shown to correlate with outcomes following cervical and lumbar spine surgery. There is limited literature regarding the impact of surgeon volume on long-term outcomes following pediatric idiopathic spinal defomity correction. One prior report found lower-volume surgeons to have higher perioperative complications, length-of-stay and hospital charges when performing spinal arthrodesis in adolescents with scoliosis. However, the study included all types of scoliosis procedures (idiopathic, neuromuscular and congenital) and was limited to the primary hospital stay. As a result, there is a lack of information regarding the impact of surgeon volume on long-term outcomes following pediatric idiopathic spinal deformity surgery. PURPOSE Identify average annual surgeon volume for long-segment (>4 vertebrae) pediatric spinal fusions that corresponds to improved short- and long-term outcomes in idiopathic scoliosis surgery. STUDY DESIGN/SETTING New York Statewide Planning and Research Cooperative System (SPARCS) Inpatient Database Retrospective Review from 2004-2015. PATIENT SAMPLE Pediatric patients (18 years or younger) who underwent primary spinal arthrodesis procedures. Patients with fusion lengths less than 4 vertebrae were excluded. Surgeon volume was stratified into high- and low-volume surgeons, with high-volume surgeons representing the top 5% of surgeons performing primary pediatric spinal arthrodesis (all diagnoses) cases per year over the study duration. These high volume surgeons performed greater than 15 long-segment pediatric spinal fusions per year. International Classification of Diseases, Ninth Revision (ICD-9) were used to extract the index fusion procedure (ICD-9:81.00-81.09), diagnosis (ICD-9:737.30), and to identify patient demographics, reoperation procedures and reoperation diagnoses. OUTCOME MEASURES Number of medium length (4-8 vertebrae) fusions, patient length-of-stay, surgical complications, readmission rates within one year, revision surgery (if any) at 5 and 10 years, hardware malfunction (if any). METHODS We analyzed the SPARCS inpatient database from 2004 to 2015 to identify pediatric patients (18 years or younger) who underwent primary spinal arthrodesis procedures. Patients with fusion lengths less than 4 vertebrae were excluded. Surgeon volume was stratified into high- and low-volume surgeons, with high-volume surgeons representing the top 5% of surgeons performing primary pediatric spinal arthrodesis (all diagnoses) cases per year over the study duration. These high-volume surgeons performed greater than 15 long-segment pediatric spinal fusions per year. ICD-9 codes were used to extract the index fusion procedure (ICD-9:81.00-91.09), diagnosis (ICD-9:737.30) and to identify patient demographics, reoperation procedures and reoperation diagnoses. Patients with a diagnosis of idiopathic scoliosis (noninfantile) were longitudinally folllowed until September 2015, corresponding to a minimum two-year postsurgical follow-up, to determine the incidence of short- and long-term complications. Multivariate analyses were used to identify the odds of complication or revision. RESULTS A total of 3,910 pediatric patients underwent a primary arthrodesis of 4 or more vertebrae from January 2004 to September 2013. A total of 223 surgeons performed at least one medium- or long-segment fusion over the study duration. The high-volume surgeon category was composed of 13 surgeons (5.8%) who performed 52.9% (2067) of all fusion procedures during the study period. High-volume surgeons averaged greater than 15 cases per year over the study duration, with a one-year maximum of 51 cases. High-volume surgeons performed more medium-length fusions than low-volume surgeons (36.9% vs 32.9%, p\u202f=\u202f0.009). High volume surgeons experienced shorter lengths-of-stay (5.3 days vs 5.9 days, p CONCLUSIONS High-volume surgeons experienced decreased odds of short- and long-term complications compared to their low-volume colleagues when performing primary spinal arthrodesis in pediatric patients with idiopathic scoliosis. Low-volume surgeons experienced significantly greater odds of inpatient surgical complications, as well as increased risk of revision during long term follow-up with a significantly increased risk of hardware malfunction at 10 years postoperatively. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.