Greater operative volume is associated with lower complication rates in adolescent spinal deformity surgery

Abstract

Study design: Retrospective analysis of prospectively collected data from the 2001 to 2010 Nationwide Inpatient Sample database.

Objective: To assess complication rates in adolescent spinal deformity by surgeon operative volume for procedures with a range of complexity.

Summary of background data: Surgeons performing higher volumes of lumbar spinal fusion have been associated with improved surgical outcomes, according to studies using the Nationwide Inpatient Sample. This relationship has not been shown in adolescent spinal deformity surgery.

Methods: The Nationwide Inpatient Sample was queried for patients aged 10 to 18 years with in-hospital stays including spinal arthrodesis for scoliosis (adolescent idiopathic, neuromuscular, and congenital scoliosis). The primary end point was hospital stay morbidity: database-defined surgical, mechanical, major medical, and neurological complications. Length of stay and hospital charges were also analyzed. Annual surgeon volumes were stratified into quartiles based on number of cases (Q1: 1, Q2: 2-7, Q3: 8-19, and Q4: 20-97). To account for variation in surgical invasiveness, an operative complexity index was used. One-way analysis of variance was used to assess differences between quartiles for continuous measures and χ for categorical measures.

Results: A total of 6100 spine fusion cases met inclusion criteria for adolescent scoliosis. All complications categories were less frequent for higher volume surgeons after a primary fusion for all diagnoses. This pattern held for increasing surgical invasiveness, such as fusing 9 or more levels and became more distinct for neurological complications when comparing surgeons performing combined anterior-posterior procedures. Including all adolescent scoliosis fusions, higher surgical volume was associated with decreased length of stay and hospital charges.

Conclusion: Perioperative complications after adolescent scoliosis fusion surgery are more frequent in lower volume settings. This may reflect a learning curve required for more complex cases as the trends are magnified in neuromuscular/congenital scoliosis cases or simply that higher volume surgeons are more adept at these fusions. The impact of volume on reduced length of stay and hospital charges has implications for future health care economics measures.

Level of evidence: 2.