Multilevel Oblique Lumbar Interbody Fusion in Degenerative Lumbar Disc Disease with Instability

`- [Instructor] Multilevel oblique lumbar antibody fusion in degenerative lumbar disc disease with instability. This study adheres to the guidelines set out by the Domain Specific Review Board, National Healthcare Group Singapore. Introduction. Degenerative disc disease is a leading cause of low back pain with advanced degeneration causing instability and stenosis that lead to persistent symptoms. Antibody fusion is an ideal surgical option for managing such degeneration with OLIF, also known as the oblique lumbar antibody fusion being a minimally invasive and safer option. The OLIF approach involves assessing the disc space via the plane anterior to the psoas muscle called the oblique corridor. This approach is more suitable for levels L2 to L5 and is routinely performed at our center. Our patient is a 55-year-old female who's been having symptoms of neurogenic claudication with back pain for several months. She has failed conservative treatment, and is only able to currently walk less than 500 meters before she has a sit down to relieve her symptoms. Her neurological function is intact. These are x-rays which shows on the AP view, degenerative scoliosis, and on the lateral view severe disc degeneration and loss of disc height, at L2/3, 3/4, and L4/5 with corresponding spondylolisthesis. Her MRI scan shows that there's multilevel stenosis worse at L2/3, 3/4, and L4/5. These are corresponding CT images, which shows gaps at L2/3 and L3/4, and also osteophyte seen on the lateral aspect of the vertebral bodies. Let's move on to the protocol. Here are the surgical steps for the procedure. The patient is placed on a lateral position on a Jackson table and strapped up accordingly. We then make our markings. An incision is then placed about 3 to 5cm in front of the vertebral bodies. The incision is deepened, and the first layer that is usually seen is the external oblique fascia. This is then incised, and the external oblique muscle is split, and the interval widened to reveal the underlying internal oblique muscle. The same steps are then performed to the internal oblique muscle and also the underlying transversalis muscle. To ensure that there's no peritoneal breach, a helpful tip is to go more posterior before entering the retroperitoneal space. Now, the retroperitoneal fat is seen, and the space widened with two Langenbeck retractors. Once the retroperitoneal fat is seen, we typically take a sponge stick, and aim posteriorly, and pull all the retroperitoneal fat contents anteriorly. This helps to prevent any risk of a peritoneal breach. The next important structure that can be visualized is the psoas muscle. This is our anatomical lighthouse in the retroperitoneal space, and once we see this muscle, it is important to dissect the psoas muscle out both anteriorly, caudally and cranially. This helps to prevent any retroperitoneal fat from creeping into our surgical field during this fusion procedure itself. Sometimes the urethra can be seen in the retroperitoneal space as shown by the blue arrow. We then use a lip retractor to retract the anterior border psoas posteriorly. This will then reveal a glistening white disc space, which we then clear further using bipolar cautery and also a sponge stick. A K-wire is then placed in the disc space, followed by dilators for our retractors, following which the level will then be confirmed using C-Arm. Once the retractors are placed, we then turn our attention towards the discectomy. Here, I'm performing an annulotomy using a bayoneted knife, and it's important to site your enterotomy at the middle of the disc space so that your cage will sit in the appropriate position. The discectomy is then performed under the guidance of the C-Arm, and a combination of tools are used, the Cobb protractor, and you can see that I'm using the Cobb to walk on M plates, and also to perform a contralateral annulotomy. We then use the curettes, shavers and also the pituitary rongeurs to ensure that the discectomy is complete and no residual M plate is left behind. Following which, an appropriate sized cage is then placed into the disc space. Once the L3/4 cage is inserted, we then expose the lower level just by retracting the psoas muscle posteriorly and caudally to reveal the glistening dis space like we saw at L3/4. Similar steps are then performed by inserting a K-wire into the L4/5 disc space and the retractors. The discectomy is also performed using the combination of tools like we described earlier, and the L4/5 cage is placed followed by the L2/3 discectomy and cage. Finally, at the end of the procedure, we can see that all three cages are inserted from L2/3, 3/4, and L4/5. Hemostasis is performed and we can also see that the psoas muscle is revealed once the posterior retractor is removed. The patient is then turned prone on in the Jackson table and percutaneous screws are placed from L2 to L5 with the help of the robot to complete our MI spinal fusion. These are postoperative X-rays showing good restoration of disc height, reduction of spondylolisthesis, and a satisfactory alignment both in the lateral and the AP view. The entire surgical time for the first stage took about two hours with an estimated blood loss of a hundred mils. No transfusion was required during the entire procedure. The patient was mobilized on day one and on day four was discharged uneventfully. At a three year final follow-up, a CT scan was performed which showed a solid antibody fusion without any implant related complications. These are the graphs showing the comparison between pre-op and post-op disc height and disc angles. As you can see, both parameters significantly increase post OLIF surgery. In conclusion, we have demonstrated the surgical technique for the OLIF procedure, a minimally invasive and effective fusion method associated with minimal morbidity. It is particularly suitable for addressing degenerative and deformity related lumbar pathologies.