Pedicle morphology of the immature thoracolumbar spine.
METHODS
Human vertebral morphologic data were compiled from anatomic skeletal collections from three museums.


OBJECTIVE
To quantify the morphometric characteristics of the pedicles of the immature thoracolumbar spine.


BACKGROUND
Little is known of pedicle morphology of the immature spine as related to pedicle screw fixation.


METHODS
A total of 75 anatomic skeletal specimens were acquired from C1 to L5 in the age range of 3 to 19 years. The data were collected and analyzed using a computerized video analysis system. Each vertebral pedicle was measured in the axial and sagittal planes. The measurements included the minimum pedicle width, the pedicle angle, the distance to anterior cortex, and anteroposterior and interpedicular spinal canal diameters.


RESULTS
Wide variation in pedicle morphology between specimens at each vertebral level was found in the young population. In general, compared with the average adult data, a younger spine demonstrated a near uniform reduction in the linear pedicle dimensions at each vertebral level. Pedicles from the lower lumbar vertebrae attained dimensions acceptable for standard screw sizes at an earlier age than in the thoracic vertebrae.


CONCLUSIONS
The data in this study indicates that pedicle screws may be used in the adolescent spine. However, care should taken to accurately ascertain pedicle size before surgery so that improper use of screws can be avoided. Growth of the pedicles in relation to the spinal canal indicates that the increase in pedicle size is lateral to the spinal canal.
Zindrick
M R
MR
Hinsdale Orthopaedic Associates, SC, Hinsdale, Illinois, USA.
Knight
G W
GW
Sartori
M J
MJ
Carnevale
T J
TJ
Patwardhan
A G
AG
Lorenz
M A
MA
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D001863:Bone Screws / Q000592:standards*; D002648:Child; D002675:Child, Preschool; D006801:Humans; D008159:Lumbar Vertebrae / Q000033:anatomy & histology* / Q000254:growth & development / Q000601:surgery*; D013115:Spinal Canal / Q000033:anatomy & histology; D013123:Spinal Fusion / Q000295:instrumentation*; D013904:Thoracic Vertebrae / Q000033:anatomy & histology* / Q000254:growth & development / Q000601:surgery*