Dorsal sacral agenesis: A study on dry sacrum bones

Abstract

Introduction: Sacral hiatus is the route for caudal epidural block. Dorsal agenesis of sacrum is a known cause for failure of caudal epidural anaesthesia. Material and Methods: 300 dry sacral bones were studied for complete dorsal agenesis, partial dorsal agenesis, elongated sacral hiatus and absent hiatus. Observations and Results: Complete dorsal agenesis was noted in 1.3% bones, elongated sacral hiatus in 3% sacrum and 0.67% bones showed absent sacral hiatus. Conclusion: Variations in the dorsal sacral wall can lead to difficulty in administering caudal blocks. Knowledge of incidence of dorsal agenesis, elongated hiatus and absent hiatus will help anaesthetists to plan for a safer approach.