Jan Štulík1, Gábor Geri1, Lucie Salavcová1,2, Michal Barna1, Petr Fojtík3,2, Ondřej Naňka4. 1. Department of Spinal Surgery, First Faculty of Medicine, University Hospital Motol, Charles University, V Úvalu 84, 150 06, Prague 5, Czech Republic. 2. Institute of Anatomy, First Faculty of Medicine, Charles University, U Nemocnice 3, 128 00, Prague 2, Czech Republic. 3. Department of Orthopaedics, First Faculty of Medicine, Military University Hospital Prague, Charles University, U Vojenské Nemocnice 1200, 169 02, Prague 6, Czech Republic. 4. Institute of Anatomy, First Faculty of Medicine, Charles University, U Nemocnice 3, 128 00, Prague 2, Czech Republic. ondrej.nanka@lf1.cuni.cz.
Abstract
PURPOSE: Separation of C2 growth plates and dens fractures are the most common types of injuries to the axis (C2) in children. Operative treatment of these injuries with the use of direct osteosynthesis requires a profound knowledge of detailed anatomy and dimensions of the axis. The main issue addressed by the study was the age at which the size of the dens is adequate at all levels to accommodate two screws, and the size of the posterior dens angulation angle (PDAA) in a healthy child in individual age periods. METHODS: Dimensions and angles of the dens and C2 in individual age categories in both boys and girls were measured in a series of 203 CT scans of individuals 0-18 years old and on anatomical specimens (42 samples). In addition, 5 histological series of this region from the fetal period were reviewed. RESULTS: Dimensions of the dens gradually increase with age, with a considerable acceleration during growth spurt periods that are different in boys and girls. PDAA is markedly changing with age; in the fetal period, the dens shows a slight anterior angulation which gradually transforms into posterior angulation, as early as between 4 and 6 years of age. The screw insertion angle changes accordingly. CONCLUSION: During growth, there occur changes in PDAA that should be respected in evaluation of transformation of anterior into posterior angulation, as shown by imaging methods. Dens dimensions theoretically allow insertion of two 3.5 mm screws as early as from the age of 1 year.
PURPOSE: Separation of C2 growth plates and densfractures are the most common types of injuries to the axis (C2) in children. Operative treatment of these injuries with the use of direct osteosynthesis requires a profound knowledge of detailed anatomy and dimensions of the axis. The main issue addressed by the study was the age at which the size of the dens is adequate at all levels to accommodate two screws, and the size of the posterior dens angulation angle (PDAA) in a healthy child in individual age periods. METHODS: Dimensions and angles of the dens and C2 in individual age categories in both boys and girls were measured in a series of 203 CT scans of individuals 0-18 years old and on anatomical specimens (42 samples). In addition, 5 histological series of this region from the fetal period were reviewed. RESULTS: Dimensions of the dens gradually increase with age, with a considerable acceleration during growth spurt periods that are different in boys and girls. PDAA is markedly changing with age; in the fetal period, the dens shows a slight anterior angulation which gradually transforms into posterior angulation, as early as between 4 and 6 years of age. The screw insertion angle changes accordingly. CONCLUSION: During growth, there occur changes in PDAA that should be respected in evaluation of transformation of anterior into posterior angulation, as shown by imaging methods. Dens dimensions theoretically allow insertion of two 3.5 mm screws as early as from the age of 1 year.
Authors: R Arun Babu; Arimappamagan Arivazhagan; B Indira Devi; Dhananjaya I Bhat; Somanna Sampath; B A Chandramouli Journal: Pediatr Neurosurg Date: 2015-10-29 Impact factor: 1.162