Three-dimensional Navigation-guided, Prone, Single-position, Lateral Lumbar Interbody Fusion Technique

Okay, as you can see, this is a new surgical approach that allows the surgeon to access the spine both from the back position and from the side position. And this give the surgeons the full access and the ability to take advantage of the back, which allows the pedicle screw placement, direct decompression and osteotomy if needed for scoliosis correction. And also from the side allows the surgeon to place a very robust cage for strong support, and also for scoliosis correction, if needed.

Perform the procedure using an open Jackson table, and ensure availability of both frameless stereotactic navigation and intraoperative neuromonitoring with lower extremity electromyography. Begin by placing the patient in the prone position with the legs extended. Shift to the hip or the thigh pads quarterly before the procedure begins if they crowd into the anticipated lateral entry point below the patient's lowest ribs.

Expose the posterior elements via a midline incision over the target levels. Open the fascia in the standard fashion and dissect the paraspinal musculature off the bony elements, including the eventual pedicle screw entry points. Then place a spinous clamp and bring in the O-arm to obtain an intraoperative computed tomography scan to allow for stereotactic navigation.

Place the pedicle screws at the appropriate levels in a standard fashion with navigation assistance. To start the lateral approach, use the navigation to mark a skin incision on the flank positioning it to bring the surgeon perpendicularly across the midpoint of the target disc space. Rotate the patient's bed away for a more comfortable working position for the surgeon.

Use a sitting tool to drop the surgeon's working angle to allow for a more comfortable approach. Parallel to the patient's rib, make a two to three inch long incision in the patient's flank. Use electrocautery to dissect through the subcutaneous fat and external oblique fascia.

Using a pair of Metzenbaum scissors, dissect and spread open the external oblique, internal oblique, and transverse abdominis muscles to gain access to the retroperitoneal space. Use fingers for blunt dissection of the space to feel the peritoneal cavity pulling away through the force of gravity. And then quickly locate the bulk of the psoas muscle overlying the spine.

Feel the transverse process as a landmark posteriorly. Continue the blunt dissection to separate the retroperitoneal cavity more thoroughly from the lateral spine surface, especially in the cranial coddle direction to minimize the chance of inadvertently entering the peritoneal cavity in the subsequent steps. Use a navigation-guided fenestrated probe to select an optimal entry point and approach angle into the target disc space to enter the psoas.

Then place a K-wire through the fenestrated probe into the disc space to secure the access. Until the table mounted retractor system is brought in and secured, place sequential dilators over the probe superficial to the psoas muscle. Place a table-mounted lighted lateral access retractor system just superficial to the psoas muscle.

Connect the light source to the retractor blades. Open the retractor blades in the cranial caudal and interior posterior directions to visualize the surgical area directly. Dissect the psoas muscle under direct vision using long Penfield four and long Kittner dissectors, exposing enough disc space to accommodate cage, which is around 18 millimeters wide.

Once the disc space is fully exposed, place two pairs of pins in the cranial and caudal vertebral bodies to keep the surgical corridor through the psoas muscle open. Ensure that the disc space is adequately exposed in both the cranial caudal and the interior posterior dimensions. Perform an annulotomy with a number 15 blade and perform an initial discectomy using pituitary rongeurs and curettes.

During this step, insert the navigated cobb elevator into the disc space. Under the navigation guidance, advance the tip of the cobb elevator beyond the contralateral disc border and pop it through the contralateral annulus for annulus release. This will release the space and facilitate a larger interbody cage placement and scoliosis correction when needed.

Use sequentially larger navigated shavers and navigated cage trials to prepare the disc space further, taking care to avoid violating the bony endplates. Fill the cage with allograft bone chips or any grafting materials of the surgeon's choice. Once an appropriately sized cage trial is determined, insert the interbody cage with navigation guidance.

Remove the pins holding back the psoas muscle and achieve hemostasis. If multiple interbody cages are intended to be placed, shift the lighted retractor system to another target level. Otherwise, remove the system and close the muscle, fascia, and skin in a layered fashion.

At this point, perform further posterior decompression if needed. Place the rods to connect the pedicle screws, decorticate the spine, and place a morselized bone graft in a standard fashion. Routinely place vancomycin powder in the cavity and place wound drains.

Use liposomal bupivacaine in the back musculature. Close the muscle, fascia, subcutaneous tissues, and skin in the standard layered fashion. The mean total operative time for the prone lateral lumbar interbody fusion or pro-LLIF procedure was 4.5 hours, with the median being 4.1 hours, and the range lying between 3.2 to 6.9 hours.

The total time under anesthesia for the pro-LLIF procedure averaged 6.5 hours, with the median being 5.9 hours, and the range lying between 4.2 to 9.7 hours. The average blood loss during the pro-LLIF procedure was estimated to be 240 milliliters, with the range lying between 50 to 650 milliliters. A comparison of data between oblique lateral interbody fusion or OLIF procedure and pro-LLIF procedure patients was performed.

There was no significant difference in total operative time, total anesthesia time, lengths of stay, and estimated blood loss. So the most important part of the procedure is you want to make sure the navigation is accurate throughout the whole case. And two, is you want to make sure we dissect and visualize the psoas muscle under direct vision so that you can dissect the psoas muscle under the direct vision to avoid injury to the femoral nerve or the sensory nerve within the psoas muscle.

And you want also want to make sure that the trajectory from the side position is parallel to the patient's spine, especially this is important because we're in the sitting position. So you want to make sure the trajectory is parallel to the patient. So this new approach access the spine from both the back and the side, that give the surgeons full access to the whole spine, allows the surgeon to, allow them new opportunities to create ways to treat very complex spinal issues such as complex deformity from both the side and the back angles to give the patient the best benefit of both approaches.