OSTEOLOGY OF THE PEDIATRIC SKULL - CONSIDERATIONS OF HALO PIN PLACEMENT

Study Design. Computed tomography scans of the heads of 48 normal chil dren were measured for skull thickness in areas of routine halo pin pl acement The thickest and thinnest areas were noted. Objectives. The he ad computed tomography scans were measured to identify consistently th in areas in the pediatric skull that should be avoided when pins are p laced. Summary of Background Data. Complications of halo pin placement in children are common, including loosening and dislodgment, infectio n and penetration. Methods. Normal head computed tomography scans of 4 8 normal children, 10 years old and under, were divided into four age groups. Total skull thickness was measured in five areas at the level of halo insertion. Results. There was a trend toward increasing skull thickness with age. There was a large variation in skull thickness at each area within and between age groups. None of the standard pin site s was consistently thicker. Even up to 10 years of age, the average th innest area was only 1.9 mm. Conclusions. There is no ''safe area'' fo r halo pin placement in the pediatric skull. Limited preoperative head computed tomography scans are recommended to determine safe areas for pin placement.