Most Pediatric C3 Pedicles Too Thin for Safe Screw Insertion
But at all other levels, morphometrics allow 3 mm cervical pedicle screws to be applied safely
MONDAY, July 18 (HealthDay News) -- Although the majority of pediatric C3 pedicles are too thin for safe cervical pedicle screw (CPS) insertion, at all other levels pedicle morphometrics allow for safe application of 3 mm CPS, according to a study published in the July 15 issue of Spine.
P. Rishimugesh Kanna, M.R.C.S., from the Ganga Hospital in Coimbatore, India, and colleagues used computed tomography images to investigate normal pediatric cervical pedicle morphometrics, the changes in pedicle morphology with skeletal growth, and the feasibility of CPS insertion at different ages. Images were analyzed for pedicle width (PW), pedicle height (PH), pedicle length (PL), pedicle axis length (PAL), transverse pedicle angle, and sagittal pedicle angle in a sample of 376 normal cervical spine pedicles of 30 children. The children were categorized according to age (=5 years, age 5 to 10, and >10 years).
The investigators found that the mean PW was lowest at C3 and widest at C7, with 60 percent of C3 pedicle widths less than 4 mm. At all levels, PW width increased with skeletal growth, with the increase significant up to the age of 10 years. By 5 years of age, more than 75 percent of adult pedicle dimensions were attained. The mean PL at all levels showed no increase with growth, but PAL showed growth similar to that of PW, with an increase from C3 to C7. At all levels, PH was greater than PW. Mild asymmetry was present between the right- and left-side pedicles in all values but this was not significant.
"Because 60 percent of the C3 pedicles have a width less than 4 mm, strict attention and care should be exercised at C3 level," the authors write.