The study compares autologous grafts vs. non-autologous grafts. Non-autologous grafts include synthetics and grafts from animals. Autologous grafts have a better side-effect profile than non-autologous grafts. We believe this improved side-effect profile will result in a decreased incidence of reoperation for post-operative infections and post-operative fluid collections (pseudomeningoceles and seromas). Study is open to all non-pregnant minor and adult subjects. Subjects must have symptomatic Chiari Malformation described as \> or equal to 6mm descent of the cerebellar tonsils below the foramen magnum with accompanying headaches and/or neurologic findings (arm pain/weakness, myelopathy, etc.). After the 12-month follow-up is completed on the first 100 subjects there will be an interim analysis of the results in order to determine whether one of the treatments has a statistically superior outcome. If a statistically superior outcome is noted, the trial will stop after being reviewed by a data monitoring committee. If no statistically significant difference is seen at one year, the study will continue until the 12-month follow-up is completed on the 200th patient.
