Morphological comparison between adolescent and adult lumbar pedicles using computerised tomography scanning.

BACKGROUND: To study the morphological difference between the lumbar pedicle in adolescent and adult groups as only less information is known about their pedicle morphology, especially in Malaysian population.
METHODS: The pedicle parameters of the lumbar spine in adolescent and adult groups including transverse outer pedicle diameter, transverse inner pedicle diameters, medial wall cortical thickness, lateral wall cortical thickness, pedicle length, transverse pedicle angle and sagittal pedicle angle were measured using computerised tomography (CT) scanning. The measurements in both groups were compared and analysed using statistical method.
RESULTS: In adolescent group, the mean transverse outer diameter was 8.9 +/- 1.2 mm, transverse inner diameter was 6.3 +/- 1.2 mm, medial cortical thickness was 1.6 +/- 1.2 mm, lateral cortical thickness was 1.3 +/- 1.2 mm, pedicle length was 41.7 +/- 3.8 mm, transverse angle was 20.0 +/- 2.5 degrees and sagittal angle was 16.0 +/- 1.7 degrees . In adult group, the mean transverse outer diameter was 9.8 +/- 1.3 mm, transverse inner diameter was 7.0 +/- 1.2 mm, medial cortical thickness was 1.7 +/- 1.2 mm, lateral cortical thickness was 1.4 +/- 1.6 mm, pedicle length was 44.8 +/- 5.0 mm, transverse angle was 21.7 +/- 2.3 degrees and sagittal angle was 17.4 +/- 1.7 degrees . Comparing the mean of the two age groups, all the measurements were significantly smaller (p < 0.05) in the adolescent patients.
CONCLUSIONS: Pedicle morphology in adolescent and adult population is different in all parameters, especially in males. Understanding of specific pedicle morphology for each group is imperative for safety in spinal procedures using pedicle route.