頚椎椎弓切除術から頚椎後方固定まで—その選択基準は？

What are the Criteria for Deciding Posterior Cervical Decompression with/without Fusion?

Point

・頚椎後方除圧法である椎弓切除術や椎弓形成術において，後方固定を加えるという概念がなぜ存在するのかを知っておく必要がある．

・頚椎椎弓形成術は，国内では独自の進化を遂げて後方除圧法の主流となったが，海外では必ずしもそうではなかったことを理解しておく必要がある．

・頚椎後方除圧は固定も含めて術式そのものにこだわり過ぎず，患者の病態に合わせてよりよい術式を選択することが最も重要である．

　We herein report on the knowledge regarding posterior cervical decompression with or without posterior fusion mainly performed in patients with cervical spondylotic myelopathy in the past decade（2011-2020）. In cases of preoperative cervical kyphosis ＞15° in the C2-7 Cobb angle, with a horizontal displacement ＞3 mm, and severe local kyphosis at an intervertebral space in dynamic lateral radiography, posterior fusion should be considered over laminoplasty. However, a short fusion may be sufficient in cases with apparent single local instability. Moreover, in cases with normal or mild kyphotic alignment compared to severe global cervical kyphosis, further development of laminoplasty or laminectomy aimed at the preservation and reconstruction of the posterior cervical structure is expected to maintain the alignment and avoid the unnecessary use of a spacer or mini-plate for the re-closure of the opened lamina in laminoplasty. A properly planned surgical strategy is mandatory in posterior cervical decompression. The choice of surgical procedure should not be based on a compelling motivation regarding familiarity with a surgical method or usage of implants but rather on the pathophysiology of myelopathy, age and sex of the patient, and the presence of osteoporosis, instability, or alignment.