Compared with traditional open surgery, minimally invasive surgeries offer patients many advantages, including a smaller incision, less postoperative pain, faster recovery and improved outcome. Non-surgical treatments such as physical therapy and medication should always be tried first. If those don”t help, surgery may be the best option.
In general, the goal of minimally invasive spine surgery is to stabilize the vertebral bones and spinal joints and/or relieve pressure being applied to the spinal nerves – often a result of conditions such as a spinal instability, bone spurs, herniated discs, scoliosis or spinal tumors.
Because of the reduced trauma to the muscles and soft tissues (compared to open procedures), the potential benefits are:
Conditions Treated Using MIS Procedures
Spinal fusion is a technique used to stabilize the spinal bones or vertebrae. The goal of lumbar fusion is to create a solid bridge of bone between two or more vertebrae. Spinal fusion may be recommended when the natural disc space has decreased or the spine is unstable.
The spine is composed of individual bones called vertebrae. There are typically five lumbar vertebrae. They are stacked one on top of another and are separated by discs, which act as elastic cushions or shock absorbers.
Discs have a soft center, the nucleus, surrounded by a tough outer ring, the annulus. Discs allow motion between the vertebrae. The interbody space is the disc space that is located between the vertebral body bones.
Each vertebral segment creates a bony circle, called the spinal canal that protects the spinal cord and spinal nerves. The spinal cord, which is the nerve center of the body, connects the brain to the rest of the body. The spinal cord and nerves travel from the cervical spine down to the lowest point of your spine, the sacrum.
Spinal nerves exit the spinal canal between the vertebrae at each level. Two nerves exit each level, one on the left and one on the right. These nerves exit through openings called foramen. The discs, bony structures, ligaments and strong muscles all work together to stabilize the spine.
Interbody fusion involves placement of fusion implants and bone graft into the area between two vertebral bodies and is an effective method for achieving fusion. The intervertebral implant may be made from a variety of materials including metal, plastic, or bone. Bone graft and bone healing protein may be placed within the implant and within the interbody space to encourage bony healing.
The implant helps by separating and holding the two vertebrae apart. This increases the opening around the nerve roots at that level, relieving pressure on the nerves. The intervertebral implants can also be used to correct spinal deformity and restore proper alignment.
Intervertebral implants can be placed from the front, side or back of the spine. The location of the surgery is dependent on the specific anatomy of each patient, as well as the location and amount of pressure that may be occurring around the nerves in the spinal canal. The decision is based on many factors including the patient”s anatomy, location of the levels that need to be fixed, degree of spinal instability, and prior abdominal surgery.
When the implant is placed from the:
In some cases, the surgeon will use additional surgical instrumentation in the front for stability. This is usually a plate and screws in the front of the spine. If support is also needed from the back of the spine, a series of screws and rods may be used. This is called a posterior instrumentation fusion and helps to achieve a posterior fusion in addition to an interbody fusion.
The procedure can be performed through a traditional open incision or a minimally invasive procedure depending on the patient and the condition to be treated. Transforaminal lumbar interbody fusion is performed under general anesthesia, meaning the patient goes to sleep.
During the surgery the patient lies face down on a special surgical bed. The procedure is performed through an incision on the back. The length of the incision depends on how many levels are being treated and if minimally invasive techniques can be used.
Once the surgeon safely creates a window to see the spine, the damaged disc is removed with surgical tools. Some of the disc wall is intentionally left behind to help contain bone graft material. Once the disc space has been cleared out, the surgeon prepares the bony surfaces for a fusion.
The bones are slightly spread apart to make more room for the bone graft. This distracts the bones to realign proper curvature and enlarges the openings to relieve pressure off any pinched nerves.
An implant filled with bone graft is placed in the now empty disc space between the two vertebral bodies. Bone graft inside the disc space will then go on to fuse, healing the two bones together in this area.
If the fusion is successful, the vertebrae will move as one unit. This reduces future problems at this spinal segment. If the bones do not fuse as planned this is called a nonunion, or pseudarthrosis.
With the TLIF, pedicle screws are inserted into the bone to allow for fixation and stability after fusion. The surgeon enlarges the opening around the nerves and works underneath the exiting nerve through the neural foramen, hence the term “transforaminal”.
Finally, rods are placed between the screws in order to maximize stability and hold the lumbar level stable while fusion occurs. Additional bone graft material is also placed along the back of the spine, providing an additional area for spine fusion to occur.
TLIF provides improved results for fusion because fusion is achieved in the front and back parts of the lumbar spine, all through a single surgical approach. The TLIF procedure increases the chance of a successful fusion because a larger surface area is available for bone graft to heal into a fusion.
Any spine surgery has surgical risks involved. You need to discuss these with your surgeon at your pre-operative appointment.
There are multiple options for bone graft material for spinal fusion. Surgeons at the Virginia Spine Institute may use your own locally harvested bone, called autograft bone. This may come from a combination of bone from the area of the spine being operated on or from your hip bone. Bone grafting can also come from donated and prepared bone, called allograft bone. Read more about how bone grafting is used as a surgical innovation.
Read about Recovery from Spine Surgery and make sure you understand your post-operative plan before your surgery date.
As mentioned earlier, transforaminal lumbar interbody fusion is an approved and effective method for fusing the lumbar spine with the goal of the surgery to decrease pain, correct spinal deformity, and improve stability.
Complications may occur but are not common. The majority of patients are satisfied with their pain relief and the results of their surgery. It is important that all patients are physically and psychologically prepared. All patients should stop smoking prior to any surgery, as smoking is extremely detrimental to your spine health, potential bone healing and successful surgical outcomes. Please review additional details with your surgeon prior to your surgery.
X-rays of the lumbar spine after Transforaminal Lumbar Interbody Fusion (TLIF). Titanium screws and rods support the bones and maintain proper alignment in the back of the spine, while an interbody device has been placed in the disc space between the bones for support in the front portion of the spine. Fusion occurs in both the front and back of the spine.