Martus, Jeffrey E.

Background: Treatment outcomes and risk factors for neurological deficits in pediatric patients with an os odontoideum are unclear. Methods: We reviewed the data for 102 children with os odontoideum who were managed at 11 centers between 2000 and 2016 and had a minimum duration of follow-up of 2 years. Thirty-one children had nonoperative treatment, and 71 underwent instrumented posterior cervical spinal arthrodesis for the treatment of C1-C2 instability. Nonoperative treatment consisted of observation (n = 29) or immobilization with a cervical collar (n = 1) or halo body jacket (n = 1). Surgical treatment consisted of atlantoaxial (n = 50) or occipitocervical (n = 21) arthrodesis. One patient also underwent transoral odontoidectomy. Results: Thirty children (29%) presented with neurological deficits, 28 of whom had radiographic atlantoaxial instability (atlantoaxial distance >5 mm) or limited space (≤13 mm) available for the spinal cord (risk ratio, 7.8 [95% confidence interval, 2.0 to 31] compared with children with no radiographic risk factors). The 27 children without neurological deficits or atlantoaxial instability at presentation underwent nonoperative treatment and remained asymptomatic. Of the initial nonoperative cohort, one child developed atlantoaxial instability, and another had a persistent neurological deficit; both children underwent spinal arthrodesis during the study period. One child with cervical instability declined surgery and remained asymptomatic. Spinal fusion occurred in 68 patients in the surgical group by the end of the study period (mean, 3.7 years; range, 2.0 to 11.8 years). Surgical complications occurred in 21 children, including nonunion in 12, new neurological deficits in 4, cerebrospinal fluid leak in 2, symptomatic instrumentation requiring removal 2, and vertebral artery injury in 1. Nine children underwent revision surgery. In the surgical group, Japanese Orthopaedic Association neurological function scores improved significantly from preoperatively to the latest follow-up for the upper extremities (p = 0.026) and lower extremities (p = 0.007). Conclusions: The risk of developing a neurological deficit was strongly associated with atlantoaxial instability and limited space available for the spinal cord in children with os odontoideum. Nonoperative treatment was safe for asymptomatic patients without atlantoaxial instability. Spinal arthrodesis resolved the neurological deficits of children with symptomatic os odontoideum. Level of Evidence: Therapeutic Level III . See Instructions for Authors for a complete description of levels of evidence.

SummaryBackgroundChildren undergoing posterior spinal fusion experience high blood loss often necessitating transfusion. An appropriately activated coagulation system provides hemostasis during surgery, but pathologic dysregulation can cause progressive bleeding and increased transfusions. Despite receiving antifibrinolytics for clot stabilization, many patients still require transfusions.AimsWe sought to examine the association of dilutional coagulopathy with blood loss and blood transfusion in posterior spinal fusion for pediatric scoliosis patients.MethodsA retrospective, single institution study of children undergoing posterior spinal fusion >6 levels with a standardized, prospective anesthetic protocol utilizing antifibrinolytics. Blood loss was evaluated using a hematocrit‐based calculation. To evaluate transfusions, a normalized Blood Product Transfusion calculation was developed. Factors associated with blood loss and blood transfusions were determined by univariate analysis and multivariate regression modeling with multicollinearity and mediation analysis.ResultsPatients received 73.7 mL/kg (standard deviation ±30.8) of fluid poor in coagulation factors. Estimated blood loss was 42.6 mL/kg (standard deviation ±18.0). There was a significant association between estimated blood loss and total fluids delivered (Spearman's rho = 0.51, 95% confidence interval 0.33‐0.65, P < 0.001). Factors significantly associated with normalized Blood Product Transfusion in this cohort included age, weight, scoliosis type, levels fused, total osteotomies, pelvic fixation, total fluid, maximum prothrombin time, and minimum fibrinogen. Regression modeling showed the best combination of variables for modeling normalized Blood Product Transfusion included patient weight, number of levels fused, total fluid administered, and maximum prothrombin time.ConclusionBlood product transfusion remains a frustrating problem in pediatric scoliosis. Identifying and controlling dilutional coagulopathy in these patients may reduce blood loss and the need for blood transfusion.