The spine is made up of small bones called vertebrae. These vertebrae are categorized into cervical or neck vertebrae, thoracic (upper back), lumbar (lower back), sacrum, and coccyx. These bones lie one above the other and are protected by the cushioning effects of intervertebral discs. A bundle of nerve fibers called the spinal cord passes through the vertebral column and branches out at the sides to the various parts of the body.
Any damage or deformity to the bones of the vertebral column or to the intervertebral discs can affect the stability of your spine and put pressure on your spinal nerves, causing chronic pain in the body part that the nerve supplies.
Axial lumbar interbody fusion (AxiaLIF) is a minimally invasive spinal procedure performed to treat back and leg pain caused by degenerative discs and other problems within the vertebral column. Lumbar interbody fusion involves the fusing of the affected vertebrae found in the lumbar region. In axial lumbar interbody fusion, your doctor will access the spine from a presacral approach (anterior to the sacral bone). AxiaLIF specifically treats conditions affecting the disc between the fifth lumbar and first sacral vertebral segments.(L5-S1)
Axial lumbar interbody fusion (AxiaLIF) surgery is performed to treat lower back and leg pain caused by
- spinal stenosis (abnormal narrowing of the spinal canal)
- low grade spondylolisthesis (forward dislocation of one vertebra over the other)
- degenerative disc disease
Spinal fusion is a procedure performed to fuse the diseased vertebrae together to prevent painful motion between the vertebral segments.
During AxiaLIF, you are given general anesthesia so you will sleep through the entire procedure. You will lie face down during the surgery. Your lower back is cleansed and sterilized. A tiny incision is then made next to the tail bone. Under the guidance of fluoroscopy (live action x-rays) sequential dilation tubes are inserted along the tailbone, in front of the sacrum. A drill is then inserted through the dilation tube, and a tunnel to the upper part of the sacrum is created, to access the center of the diseased disc. Special instruments are inserted through this tunnel to the diseased disc. The center of the diseased disc, known as the nucleus pulposis, is then fragmented and removed through the dilation tube using tissue extractors. Bone growth material, consisting of a mixture of autologous blood and demineralized bone material, is then filled into the hollow center of the disc.
The drill is again introduced through the dilation tube and a channel is created to reach the vertebra above the damaged disc. A 3D Axial rod is then threaded into the vertebra. The 3D Axial rod is twisted, lifting the vertebra, to restore the normal healthy height of the vertebral segment. Bone void filler is then injected and a rod plug is used to fill the channel of the 3D Axial rod. Your surgeon may further stabilize the spinal segment by implanting additional screws through a minimally invasive method. Upon completion, the operating instruments and dilation tubes are removed and the incision is sutured.
Following AxiaLIF, you will be transferred to the recovery area. It is quite normal to feel some discomfort at the incision site. This will resolve in some time. You will be given pain medication to alleviate your pain. Many patients are able to return home within 24 hours following AxiaLIF procedure.
Some of the important postoperative instructions include:
- You can shower three days after the procedure, but keep your incision sites clean and dry. Avoid lifting heavy weights, driving, and smoking until permitted by your doctor.
- You may begin physical and/or occupational therapy as instructed by your doctor.
Call your doctor’s office immediately if you have fever above 101 degrees, increased swelling and redness around the incision sites, increased pain, change in color or odor of drainage from the incision site, numbness around the genital region, or if you experience bowel or bladder dysfunction.
Advantages & Disadvantages
Interbody fusion of the lumbar spine involves the placement of bone grafts or metal implants either laterally, anteriorly, or posteriorly. These are associated with surgical risks. Axial lumbar interbody fusion is a minimally invasive procedure that overcomes many limitations of these approaches. It requires less surgical time and less time under anesthesia. The procedure is associated with less postoperative pain, scarring and blood loss as the axial approach causes very little damage to the adjacent tissues. Recovery and return to normal activities is also faster.
Risks and complications
AxiaLIF is a relatively safe procedure and complications are rare. However, like all surgical procedures, some of the potential complications may include
- Blood clots
- Fusion failure
- Loss of sensory and/or motor function at the extremities
- Loss of bowel/bladder/sexual functioning
A specific risk of AxiaLIF includes injury to the colon and rectum due to its proximity to the surgical area.
Axial lumbar interbody fusion is one of the least invasive techniques for performing lumbar fusion. It approaches the affected vertebrae through a channel that prevents damage to the major nerves, tendons and muscles in the region of the lower back. Benefits of the procedure include high fusion rates, significant improvements in pain and function, and low complication rates.