%0 Journal Article
%T Analysis of skull bone thickness during growth: an anatomical guide for safe pin placement in halo fixation.
%A Domenech-Fernandez P
%A Yamane J
%A Domenech J
%A Barrios C
%A Soldado-Carrera F
%A Knorr J
%A Canavese F
%J Eur Spine J
%V 30
%N 2
%D 02 2021
%M 32248506
%F 2.721
%R 10.1007/s00586-020-06367-x
%X To assess skull bone thickness from birth to skeletal maturity at different sites to provide a reference for the correct selection of pin type and pin placement according to age.
270 children and adolescents (age: 0-17 years) with a normal CT scan obtained at Emergency Department for other medical reasons were included. Skull thickness was measured on the axial plane CT scans at eight different sites of the vault: midline anterior (A) and posterior (P), right and left lateral (L), antero-lateral (AL), postero-lateral (PL).
From birth to skeletal maturity, L thickness was increased significantly less (+ 58%) compared with AL (+ 205%), P (+ 233%), PL (+ 247%), and A (+ 269%) thickness (P < 0.01). At the end of growth, the thickest and thinnest points of the vault (absolute value) were found at the P and L measurement sites, respectively (P < 0.01). Children aged < 4 years exhibited the highest variability in AL and PL skull bone thickness, with thickness < 3 mm observed in 85% (64/75 patients) and 92% (69/75 patients) of cases, respectively.
We recommend that the tip of the pin should not exceed 2-3 mm in children aged < 4, and 4 mm in children aged 4-6 years, to decrease the risk of inner table perforation. After the age of 7 years and 13 years, standard-sized pin tips (5 and 6 mm, respectively) may be safely used. Children aged < 4 years show significant variability in skull thickness, and therefore a CT scan may be required for this particular age group.