Optimal angle of needle insertion for spinal anesthesia in patients with spondylolisthesis: An ultrasonographic study

Spondylolisthesis is a common degenerative spinal deformity. At the level of spondylolisthesis, the anatomy of the interlaminar space may differ from normal spine, in which case optimal angle of the needle insertion for spinal anesthesia may change. This study compared the optimal angle of needle insertion during spinal anesthesia in patients with and without lumbar spondylolisthesis using ultrasound.