The patient is then prepped and draped in sterile fashion, the spinous processes are palpated to estimate levels, and a midline incision is made. Electrocautery is used to carry the incision deeply and expose the spinous processes, laminae and lateral masses of the desired levels, with care to preserve the facet capsules as well as the supraspinous and interspinous ligaments, as well as the interspinalis muscles. Localization can be confirmed by a lateral radiograph intraoperatively.
The junction of the laminae with the lateral mass is identified bilaterally. The hinge is placed at this level. We prefer to place the hinge on the less symptomatic side, allowing for better decompression and easier foraminotomies of the more symptomatic side. The ligamentum flavum is taken down at the proximal and distal ends of the laminoplasty, usually C3 and C7, but left intact throughout the other levels. Using a fine tip bipolar, usually the epidural veins can be carefully coagulated as you take down the ligamentum flavum. A high speed burr is used to create a bicortical defect on the open door side just medial to the junction of the lamina and lateral mass. Completing the open side first gives the surgeon feedback as to the thickness of the lamina for preparation of the hinge side. The burr is then used to make a unicortical defect in each lamina on the hinge side. The spinous processes are tilted gently toward the hinge allowing for opening of the door, and a Kerrison rongeur is used to take down the remaining ligamentum flavum at each level.
Fixating the door open can be done by a variety of techniques including bone block, suture, suture anchors, facial trauma plates, or laminoplasty specific plates (). We then prefer to shorten the spinous processes with a rongeur, especially at the C6-7 level, to facilitate skin closure and decrease a postoperative prominence. The spinous processes can be shortened earlier in the procedure, though they may be helpful in opening the hinge.
Post-laminoplasty view using plate fixation to hold the posterior hinge open.
A meticulous closure is done prior to leaving the operative field. We thoroughly irrigate the wound and stop all visable bleeding with cautery. A subfascial drain is placed, and the fascia is approximated with number 2 absorbable figure of eight stitches. The dermis is closed with 2–0 absorbable buried interrupted stitches, and the final skin is closed with a running subcuticular absorbable stitch. This technique should allow for adequated creating of space available for the cord (Figures and ).
Post-laminoplasty MRI showing the space available for the cord created by the posterior decompression.
Post-laminoplasty MRI showing the open hinge and space available for the cord created by the decompression.
Postoperatively, we place patients in a cervical orthosis for 4 weeks. The type of orthosis, or need for one at all, is a matter of surgeon preference. A soft collar for comfort only can be appropriate, and long-term rigid bracing certainly is not required. Current evidence suggests that a shorter period of immobilization and quicker return to motion may decrease the postoperative neck discomfort and help prevent range of motion loss [15