Measurement of Sacral Parameters of Surgical Importance in North Indian Population

Abstract

Introduction: Posterior screw placement on sacrum is done in various conditions. Screws are inserted into the body of first/ second sacral vertebra. So, Linear parameters form the basis for adequate fixation of bone and to avoid injury to neurovascular structures. Detailed information about sacral parameters will be helpful for surgeons performing dorsal screw placement, Anterior Lumbar Interbody Fusion (ALIF), Posterior Lumbar Interbody Fusion (PLIF) with better prognosis and lesser complications. Aim: To measure and compare various linear parameters of sacrum in males and females. Materials and Methods: In the present study, 48 dry sacra (24 males and 24 females) were taken. Linear parameters of upper sacrum like sacral length, sacral breadth, first sacral anteroposterior and transverse diameter, sacral canal anteroposterior and tranverse diameter, posterior pedicle height, pedicle depth, pedicle width, vertical and transverse diameter of auricular surface were manually measured with digital, vernier caliper. The data were analysed, using SPSS version 16.0 and compared using Student’s t-test with p value <0.05 taken as significant. Results: Statistically significant gender difference was observed in sacral length, values were more in males (10.57±0.95 cm), than in females (8.56±0.49 cm) with p<0.05 and second sacral body height was found to be more in males (2.55±0.23 cm) than in females (2.16±0.20 cm) with p<0.05. Sacral canal anteroposterior diameter values were more in males (2.31±0.33 cm) than in females (2.07±0.36 cm) with p<0.05. Vertical diameter of auricular surface values on right side were more in males (5.43±0.40 cm) than in females (5.07±0.37 cm) with p<0.05. Conclusion: Precise measurements of dry sacra and gender comparison will be helpful for the surgical intervention in sacral region. The values obtained can be used as a baseline data for making population specific prosthesis and during implant insertion.

Keywords

• dorsal screw placement
• pedicle width
• posterior pedicle height
• sacral body height
• sacral length