New double-door laminoplasty procedures to preserve the muscular attachments to the spinous processes including the axis.

Abstract

Cervical malalignment occurring after conventional laminectomy or laminoplasty is caused by intraoperative injuries to the posterior extensor mechanism, including the deep extensor muscles. To minimize such injuries, we developed a technique for muscle-preserving double-door laminoplasty below C2 (TEMPL) and TEMPL for the axis (TEMPLA) in treating patients with multisegmental cervical myelopathy. In these procedures, the posterior arches, which were sagittally split in the midline, can be opened. This leaves untouched the semispinalis cervicis and multifidus muscle attachments to each split half of the spinous process below C2, and of all five muscles to each split half of the C2 spinous process. In review of short-term surgical outcomes from 41 patients who underwent the procedures, neurological improvement was demonstrated in each patient. Postoperative kyphosis development was identified in one patient only, in whom delayed fracture occurred at the bilateral C2 laminar hinge. TEMPL and TEMPLA, in which the deep extensor musculature is preserved as an important stabilizer of the cervical spine, are effective procedures to prevent postoperative cervical malalignment.