[Open-door decompressive cervical laminotomy. Technic and initial experiences].

The cervical laminectomy is usually applied in the treatment of cervical myelopathy caused by cervical canal stenosis and multiple spondylosis. Nevertheless, late complications are often reported, especially scar formation, the so-called laminectomy membrane, between the dura and overlying paraspinal muscles, which, compressing the cord, reduces until to abolish the favourable effects of the previous laminectomy; moreover, malalignment of the cervical spine with secondary kyphosis may follow an expansive laminectomy. In order to avoid these complications, in 1977 Hirabayashi introduced a new surgical technique, the "expansive open-door laminoplasty", which permits the enlargement of the spinal canal over multiple segments by completely incising the laminae laterally on one side and partially on the opposite: elevation with tilting of the laminae upward in the incised side, allows enlargement of the canal. The Authors describe in detail the operative procedure and report their experience in 10 patients.