Experimental study of postoperative cervical stability after Hattori's procedure for cervical laminoplasty in rabbits

The purpose of this study is to compare the postoperative cervical support after laminoplasty with that after laminectomy radiographically and biomechanically in an animal model. Twenty-three Japanese white rabbits were assigned to undergo laminectomy (11 rabbits) or laminoplasty (12 rabbits). Lateral radiographs of the cervical spine were obtained to evaluate the presence of kyphosis and anterior vertebral slip. After the rabbits were killed, biomechanical testing was performed with the use of a cervical structural strength testing system of our own design. The incidence of vertebral slip was significantly lower in the laminoplasty group (8%) than in the laminectomy group (45%). The incidence of kyphosis was 17% in the laminoplasty group as compared with 55% in the laminectomy group (p=0.053). On biomechanical testing, the torque values at flexion 20 degree (F) remained within normal limits for up to 12 weeks after operation in the laminoplasty group. In the laminectomy group, about 3 weeks were required for recovery to the preoperative level. The results suggest that postoperative malalignment is related to the F value early after operation. We conclude that the Hattori's procedure for cervical laminoplasty is an effective technique that permits reconstruction of posterior cervical elements.

頸椎

椎弓形成術

椎弓切除術

後弩変形

生体力学

本文データは山口大学医学会の許諾に基づきCiNiiから複製したものである