Fig. 4From: How to reconstruct the lordosis of cervical spine in patients with Hirayama disease? A finite element analysis of biomechanical changes focusing on adjacent segments after anterior cervical discectomy and fusionThe maximum von Mises stress of C6–7 intervertebral disc. ACDF, anterior cervical discectomy and fusion; NLCS, non-pathological lower cervical spine; LCSHD, lower cervical spine of Hirayama disease; PWA, posterior wall angleBack to article page