Perforation in lateral wall occurred in 7 cases, 3 in medial wall, 3 in bottom wall, 1 in fanterior wall and 4 into intervertebral space.

• 18例患者中外侧壁穿破7例，内侧壁穿破3例，下侧壁穿破3例，穿破椎体前壁1例，进入上方椎间隙4例。