- Step 1: Once the patient has been intubated in the supine position, the surgical level is localized with intraoperative fluoroscopic guidance and marked. Then the patient’s ventral neck is prepped and draped in the usual sterile fashion. The operative incision can be made either side midline of the neck depending on surgeon preference. Subcutaneous dissection is done to expose the platysma muscle. The platysma muscle is then opened in either the caudal rostral direction or in a horizontal direction. The opening of the platysma should not extend laterally past the sternocleidomastoid muscle and should not extend past the ventral midline aspect of the neck. Careful subplatysmal dissection is extended towards the prevertebral fascia. The subplatysmal dissection is made between the sternocleidomastoid muscle and carotid artery laterally and the esophagus and trachea medially of the dissection. Intraoperative radiographs are used to localize the appropriate level of treatment. Careful elevation of the longus colli muscle is done on either side of the vertebral bodies to expose the disc space of interest. Once the longus colli muscle is elevated, retracting plates are placed under the longus colli bilaterally. Utilize caution to ensure no direct compression or direct retraction of the esophagus, trachea or vascular structures is made by the retraction plates.
- Step 2: Once localization of the disc space is verified, a rectangular incision is made in the annulus anteriorly of the disc space. The incision should extend from bilateral uncovertebral joints. The disc material is then removed with pituitary rongeurs. A high speed drill can be used to prepare the adjacent endplates and remove the anterior and posterior osteophytes of the vertebral bodies encompassing the disc space.
- Step 3: A rasp or curette may be used to decorticate the superior and inferior endplate surfaces. Once the endplates have been prepared, trial sizers are used to determine the implant size. Trials may be viewed by the aid of intraoperative fluoroscopic images to determine the placement and adequate size of the implant for the disc space. Care must be taken to prevent the placement of the trial dorsally against the neurologic structures. Once the trial has been verified for proper size and position, a Slate implant is selected and packed with autograft and/or allogenic bone graft.
- Step 4: An inserter is attached to the implant by aligning inserter and implant interface and turning inserter handle to engage threads. Introduction of the implant into the disc space is done cautiously. Intraoperative fluoroscopic guidance is used to insure proper placement of the implant and to prevent injury to neurologic structures. The implant has two tantalum markers that are radiopaque and mark the most ventral and dorsal aspect of the implant. Before releasing the implant from the inserter, perform a final check that the tantalum beads are within the vertebral body boundaries and the implant is in the position desired by the Surgeon. The inserter is removed from the implant by turning handle to unthread from the implant. Fluoroscopy should be utilized to confirm implant position. Supplemental fixation, such as an anterior cervical plate, should be used in addition to the implant. Failure to provide supplemental fixation may result in loosening, displacement or expulsion of the implant . A pusher can be used to fine tune placement of the implant and move it dorsally to keep the implant and ventral bodies in line in the caudal rostral direction. Again verification of the implant must be done after any manipulation with fluoroscopic images.
