Morphometric analysis of lumbar pedicles in the Saudi Arabian population – A CT-based study on 1500 vertebrae

Abstract

Background: Knowledge of the lumbar pedicle anatomy is vital for preoperative surgical planning of pedicle screw fixation procedures in orthopedic surgery. The morphology of lumbar vertebrae has both genetic and ethnic variations.

Study Design: Retrospective cohort study.

Objective: The objective of the study was to estimate morphometric characteristics of the lumbar vertebrae relevant for pedicle screw placements in the Saudi population and compare it with CT-based studies in other population groups.

Materials and Methods: CT scans of 300 Saudi patients (M = 150; F = 150) were reviewed. The dimensions of the lumbar pedicle, pedicle axis angle, and chord length (CL) of the L1–L5 vertebrae were measured by two investigators. The Mann–Whitney test was used to compare the genders.

Results: There was no inter-observer bias. There was no difference between the sides. Transverse pedicle diameter (TPD) increased from L1 to L5 with mean values of 5.76–13.62 mm, respectively. The longest CL was at L3 with a mean of 50.92 mm. The length of the pedicle decreased from L1 to L5 with mean values of 16.01–9.93 mm, respectively. The height of the pedicle (PH) showed a similar trend with a decrease from 9.75 to 8.3 mm. The pedicle axis angle trajectory followed a gradual medial angulation pattern of 12.68˚–28.23˚ from L1 to L5.

Conclusions: The TPD, CL, and PH showed statistically significant differences among the genders. Statistical significance was also noted among pedicle parameters compared with other population groups.