DEFORMITY SPINE Volume 37, Number 19, pp 1683–1687 ©2012, Lippincott Williams & Wilkins Spine www.spinejournal.com 1683 Does Patient Diagnosis Predict Blood Loss During Posterior Spinal Fusion in Children? Amit Jain, MD,* Dolores B. Njoku, MD,† and Paul D. Sponseller, MD* Study Design. A retrospective review. Objective. To assess the relationship between diagnosis and blood loss in children undergoing posterior spinal fusion surgery for deformity correction. Summary of Background Data. To our knowledge, this relationship is not well established. It has important implications for understanding the mechanisms for blood loss and planning for surgery. Methods. Clinical records were reviewed for all patients 10 to 18 years of age who underwent spinal fusion surgery (at least 5 levels) by the senior author from 2001 through 2011. Patients were excluded for antifibrinolytic use, vertebral column resections, history of spinal surgery, nonpedicle screw instrumentation, cervical spine fusion, or anterior approaches. The 617 patients (with 37 diagnoses) were categorized into 5 groups: idiopathic scoliosis (IS), Scheuermann kyphosis (SK), cerebral palsy, other neuromuscular disorders, and genetic and syndromic disorders. Analysis of covariance was used to assess differences in blood loss across the diagnostic groups. Normalized blood loss (NBL) was calculated by dividing blood loss by number of levels fused and by patient’s weight; NBL differences between groups were analyzed using Bonferroni correction method. Significance was set at P < 0.05. Results. Blood loss differed significantly by diagnostic group, adjusting for extent of fusion and patient weight ( P < 0.001). Patients with cerebral palsy had a significantly higher NBL than patients with IS ( P < 0.001), SK ( P < 0.001), other neuromuscular disorders ( P = 0.049), or genetic and syndromic disorders ( P = 0.006). Patients with other neuromuscular disorders had a significantly higher NBL than patients with IS ( P < 0.001) or SK ( P < 0.001). Patients with P osterior spinal fusion for the correction of pediatric spinal deformity often involves substantial blood loss, which can be a major source of morbidity. An under- standing of factors associated with increased intraoperative blood loss is necessary for comprehensive surgical planning. More fundamentally, defining diagnosis-related differences may be a first step toward developing strategies to minimize blood loss. Previous studies have suggested that an increased num- ber of vertebrae fused 1 and a diagnosis of neuromuscular scoliosis 2 ,3 are associated with high intraoperative blood loss and the need for allogeneic blood transfusion. 4 In an effort to minimize intraoperative losses, numerous studies have investi- gated the use of antifibrinolytic agents in patients with neuro- muscular disorders 5 –8 and in those with idiopathic scoliosis. 9 –13 The main goal of our study was to assess the relationship between patient diagnosis and blood loss in children undergo- ing posterior spinal fusion surgery for deformity correction. To our knowledge, this relationship, although suggested, has not been well established in the literature. We analyzed the association of patient diagnosis and blood loss, adjusting for extent of vertebral fusion and patient weight. Secondarily, we compared the normalized blood loss (NBL) between various diagnostic groups to identify differences. We hypothesized that connective tissue and neuromuscular factors may influence blood loss during surgery and that, therefore, patients with these diagnoses would have significantly increased blood loss. MATERIALS AND METHODS Patient Source This study was approved by our institutional review board. We queried the electronic medical records of all pediatric patients who underwent posterior spinal fusion by the senior author during the 10-year period from October 2001 through October 2011. From the Departments of *Orthopaedic Surgery; and †Anesthesiology and Critical Care Medicine, The Johns Hopkins University, Baltimore, MD. Acknowledgment date: January 10, 2012. First revision date: March 1, 2012. Acceptance date: March 3, 2012. The manuscript submitted does not contain information about medical device(s)/drug(s). No funds were received in support of this work. One or more of the author(s) has/have received or will receive benefits for personal or professional use from a commercial party related directly or indirectly to the subject of this manuscript: e.g., honoraria, gifts, consultancies, royalties, stocks, stock options, decision-making position. Address correspondence and reprint requests to Paul D. Sponseller, MD, c/o Elaine P. Henze, BJ, ELS, Department of Orthopaedic Surgery, The Johns Hopkins University/Johns Hopkins Bayview Medical Center, 4940 Eastern Ave., #A665, Baltimore, MD; E-mail: ehenze1@jhmi.edu genetic and syndromic disorders also had a significantly higher NBL than patients with IS ( P < 0.001) or SK ( P < 0.001). Conclusion. There is a significant relationship between patient diagnosis and blood loss during posterior spinal fusion surgery in children. Key words: posterior spinal fusion, pediatric, blood loss, diagnosis. Spine 2012;37:1683–1687 DOI: 10.1097/BRS.0b013e318254168f Copyright © 2012 Lippincott Williams & Wilkins. Unauthorized reproduction of this article is prohibited.