The spinal column is a critical structure in the human body. It houses and protects the spinal cord, the superhighway of the nervous system, and the connecting point between the central nervous system (the brain and cord) and the rest of the body.
As a whole, the spinal column is composed of multiple bony structures called vertebrae. They are connected via spongy discs which absorb impact and allow for spinal flexion, extension, and twisting.
Healthy, strong discs allow us to move, jump and lift objects in our day-to-day lives. Yet disease, age, and injury can weaken the discs and surrounding structures. In other cases, bone spurs and arthritic inflammation and growth can compromise the area surrounding our discs and vertebrae.
This is important because, in addition to acting as a suit of armor around our spinal cord, our vertebrae also have multiple openings, called foramen, through which individual spinal nerve roots connect with the rest of the nervous system throughout the entire body. Damage to the discs, disc degeneration, or spinal disease can narrow the gap between our vertebrae, compressing our nerve roots and causing significant pain.
Indirect decompression is one way of reducing that pain by surgically increasing the space in which our nerves exist. There are multiple different minimally invasive surgeries that achieve indirect decompression of the spine, and help patients lead pain-free lives.
How Indirect Decompression Is Achieved?
Indirect decompression is achieved through a variety of different surgeries by reducing the pressure on the nerves in the lower back through a series of different implants.
Some procedures cleanout degenerated and diseased disc tissue and utilize a combination of a biocompatible polymer frame and bone grafts to achieve spinal fusion, turning two unstable vertebrae into one solid unit, while reducing pressure on the surrounding nerves caused by compression.
Other procedures, like the use of a variable Vertiflex implant, achieve decompression by placing a stabilizing implant between the lamina of two vertebrae, much in the same way a car jack can be used to lift the chassis of your car and reduce pressure on your tires.
Lumbar Spinal Stenosis & Indirect decompression
Indirect decompression can be used to treat lumbar spinal stenosis or help achieve decompression in cases of advanced disc degeneration, spinal arthritis, instability caused by spondylolisthesis, and other spinal conditions.
Surgical decompression is not always necessary when a patient is presenting with back pain caused by spinal compression. Conditions like sciatica, where the nerve roots of the sciatic nerve are compressed by a herniated disc in the lower back, can be treated conservatively to help induce disc recovery, reduce swelling, and eliminate pain.
Lifestyle changes and exercise can reduce the likelihood of recurring disc issues, strengthen, and rehydrate spinal discs, reduce pressure on the discs caused by excess body weight, and introduce adaptations in the spine that reduce the likelihood of spinal nerve compression.
But when conservative treatments no longer work, minimally invasive indirect decompression is one of the most successful ways to reduce pain and reintroduce better quality of life for back pain patients.
Lumbar Interbody Fusion and Decompression
Indirect decompression is often achieved through interbody spinal fusion. Because most examples of disc degeneration, spinal instability, and nerve compression occur in the lower back, lumbar interbody fusion is the most common kind of minimally invasive spinal fusion surgery. However, spinal fusion may also be considered for the neck and upper back.
During a lumbar interbody fusion surgery, a patient is put under general anesthesia, and an incision is made in the lower back, over the point where nerve compression is occurring.
The surgeon will utilize a telescopic device called a tubular retractor to create a safe tunnel between the incision site and the affected area and utilize their instruments to clean out and remove diseased disc tissue, as well as affected bone in cases of bone spurs, abnormal bone growth, or certain kinds of arthritis.
During this process, the surgeon may adjust your spine to correct any misalignment caused by spondylolisthesis (slipped vertebrae) or a degenerated disc.
Synthetic or Bone Graft Material
The next step is to prepare and place a synthetic frame implant in the area where the disc used to be. This frame is biocompatible, meaning the body won’t reject it, and it is filled with bone graft material. The rest of the area will also be filled with similar synthetic or bone graft material.
The idea is that the frame will maintain the stability and spacing between the vertebrae while the grafted tissue slowly heals into a stable bone, fusing both vertebrae together. To further stabilize the area, your surgeon will use four small screws, metal plates, and/or a pair of metal rods to keep the target vertebrae still and stable during the recovery and healing process. This is called a posterior fixation.
It can take several months for the fusion to be complete. A patient undergoing spinal fusion will usually be kept for observation for at least four to five days, to rule out any post-surgical complications. Part of the healing process involves physical therapy to strengthen the area, and teach you how to move, walk, sit, and stand with proper spinal alignment.
Despite the prospect of fusing two bones together, spinal fusion surgeries are considered minimally invasive. Openings are selected carefully, utilizing natural gaps between the bone such as Kambin’s triangle to avoid unnecessarily damaging surrounding tissue.
In addition to the incision made to reach the disc, you may have two or three more incision sites used for the installation of metal screws and rods. Once your spine has fused and healed, all you’ll be able to see from the surgery is a series of three or four small scars on your lower back.
That being said, while these procedures are superficially minimal, they’re still major surgeries, and the process is irreversible. A pair of fused vertebrae will stay fused. And recovery takes months.
Is Spinal Fusion Necessary For Indirect Decompression?
Spinal fusion is not the only way to achieve indirect decompression. It is also far from the only type of surgical intervention for spinal disease or back pain.
In cases where spinal fusion might not be necessary to reduce pain symptoms, for example in cases where there is no reason to remove or replace the disc, indirect decompression may be achieved through a minimally invasive implant.
Unique Implant Designs
There are many of these implants, each designed in a unique way to adjust or improve the spinal structure, stabilize the spine, reduce nerve compression, and correct spinal deformities (such as excessive flexion or extension resulting in pain).
Other than spinal fusion, decompression may be achieved through conservative means, or through endoscopic surgery. For example, if your spinal stenosis is the result of a bone spur, a surgeon can make a small incision and carefully remove the offending bone material in a laminectomy without installing an implant. This can reduce compression on the nerve.
A surgeon may also remove herniated disc material, then recommend a treatment plan to strengthen the disc and surrounding tissues to avoid recurring pain symptoms.
Other alternatives to fusion include interventions that target malfunctioning or disordered nerves, such as nerve blocks and radiofrequency ablation.
Who Is a Candidate for Spinal Fusion?
While spinal fusion can be avoided, there are a few indications where spinal fusion might not be avoidable. These include:
- Severe spinal instability caused by cancer, a previous surgery, or spinal deformities (kyphosis/scoliosis).
- Shattered vertebrae or trauma requiring fusion.
In such cases, spinal fusion can help reintroduce stability and keep the spinal cord and surrounding nerves safe, at a limited cost to patient mobility and quality of life.
If you are concerned about your recurring back pain and want to consult your doctor about potential surgical options, be sure to discuss the ramifications and viability of surgery, no matter how minimally invasive. Conservative treatments and non-surgical interventions are always going to be a safer option until they’re no longer an option at all.