Abstract
Study Design
Prospective analysis of computerised tomogram images of 376 normal pediatric cervical pedicles
Objectives and Summary of Background Data
Although the usage of cervical pedicle screws (CPS) in adults has become established, the feasibility of its application in children has not been studied. There are no in-vivo studies that define the normal pediatric cervical pedicle morphometrics and its changes with growth and development of the child.
Methods
376 normal pediatric cervical spine pedicles of thirty children (mean age of 6.7 ± 3.9) were analysed for: pedicle width (PW), pedicle height (PH), pedicle length (PL), pedicle axis length (PAL), transverse pedicle angle (TPA) and sagittal pedicle angle (SPA). The study population was categorised into three age groups (A: < 5, B: 5 – 10 and C > 10). The mean values of these parameters in the different age groups and the possibility of application pedicle screws was studied.
Results
The mean PW was lowest in the C3 vertebra and increased distally to be widest at C7. 60% of C3 pedicles had a width less than 4 mm making screw passage risky and unsafe. With growth, the PW increased at all levels but this increase was significant only up to the age of 10 years. More than 75% of adult pedicle dimensions were achieved by 5 years of age. The mean PL at all levels remained the same with no significant increase with growth. However, the PAL showed continuous increase with growth similar to pedicle width. The PAL also showed an increase from C3 to C7. The PH was always more than the PW at any level. Mild insignificant asymmetry was present between the right and left side pedicles in all values.
Conclusion
With growth, there was a gradual increase in pedicle width, pedicle height and pedicle axis length but was mainly before the age of 10. Except the C3 pedicles the pedicle morphometrics per se were adequate and do not restrict safe application of 3 mm pedicle screws.
