Thoracolumbar curve and Cobb angle in determining spread of spinal anesthesia in Scoliosis. An observational prospective pilot study

BACKGROUND AND AIMS: Disparity in spread of spinal anesthesia is a known complication in scoliosis patients. Our primary aim was to compare this disparity based on Cobb Angle and thorocolumbar spine curvature. Secondary aim was to calculate the appropriate lateral angulation of the spinal needle from midline for successful lumbar puncture. MATERIALS AND METHODS: All poliomyelitis patients with scoliosis posted for lower limb orthopedic contracture release surgeries were enrolled into Group A (Cobb Angle <50°), Group B (Cobb Angle >50°), and on thoracolumbar curve into Group R (Right), Group L (Left). Group A, B, R, and L were studied for bilateral spread of spinal anaesthesia. Lateral angle of the spinal needle from midline was noted with Goniometer in groups A and B. Statistical analysis was done using unpaired t test and Chi-square test. RESULTS: Failures in subarachnoid block (SAB) (unilateral anaesthesia/inadequate/patchy block) was significant in Group B (P = 0.033). Segmental disparity in bilateral spread of spinal anaesthesia was significant in Group R with P value of 0.042. Approximate lateral angle for needle in Group A was (4.1 ± 2.45) and in Group B was (9.14 ± 2.45). CONCLUSIONS: The study showed that there was a strong correlation between right-sided thoracolumbar curve and the spread of spinal anesthesia