環軸椎不安定症に対するmesh plate併用後方固定術の経験

Posterior Fusion with a Mesh Plate for Atlantoaxial Instability

　環軸椎不安定症に対する後方固定術として，mesh plateを併用したMagerl法を施行した3症例を経験した．対象は男性3例であり，不安定症の原因は歯突起骨折後の偽関節が2例，歯突起骨折に対しての前方螺子固定術後の歯突起の転位が1例であった．後方固定術としてMagerl法に併用して，腸骨から採取した自家骨をmesh plateを用いて後方から圧着した．全例で術後頚部痛は消失し，良好な骨癒合が認められた．Mesh plateを併用した骨移植術は，環軸椎固定術の後方骨移植術のひとつとして有用である．

　We treated three patients with atlanto-axial instability by posterior fusion with a mesh plate. Two of the patients had nonunion of a dens fracture, and the third patient had nonunion of a dens fracture despite anterior screw fixation. Posterior fusion was performed by transarticular fixation (Magerl), and monocortical iliac bone was grafted on to the posterior aspects of the atlas and axis. We then used a mesh plate to add graft bone and cancellous bone to the site. The neck pain resolved postoperatively in all three cases, and solid bony fusion was achieved 4 months postoperatively in two patients and 6 months postoperatively in the third patient. The results suggest that this procedure is safe and useful for the treatment of atlantoaxial instability.