Cervical Disc Replacement Surgery
In the backbone, spongy pads of tissue called discs lie between the small bones (called vertebrae). They act like cushions, and have a tough outer ring and a soft jelly-like inside. Acute disc herniation, which is more commonly called a slipped disc, happens when the tough outer ring of a disc tears. The jelly-like middle bulges out through the tear and this may press on nearby nerves, causing pain and weakness in the muscles.
In cervical spondylosis, the cartilage and bones in the neck become abnormally worn, and the discs between the small bones start to disintegrate. Bony growths may develop on the bones. These changes can cause pressure on nearby nerves and this can cause pain in the neck and arm, weakness, and changes in sensation.
Cervical artificial disc replacement surgery is a joint replacement procedure that involves inserting an artificial disc between the vertebrae to replace a natural spinal disc after it has been removed.
A cervical artificial disc is a prosthetic device designed to maintain motion in the treated vertebral segment. A cervical artificial disc essentially functions like a joint, allowing for flexion, extension, side bending and rotation. Some newer discs are compressible, and actually function like shock-absorbers, as do natural discs.
One problem about artificial discs of all types, however, is that we can only guess at how they will behave in the spine afters years of use. We try to make an educated guess from millions of cycles of bench-testing in the laboratory, but the only real proof will emerge over the next 20 years or so.
An exciting new technology available for the neck is disc replacement, or cervical disc arthroplasty. This procedure represents a huge step in the preservation of the patient’s normal function and activity to correct the problems associated with herniated or degenerated discs. For decades, the anterior cervical discectomy and fusion procedure (ACDF) was the standard surgical treatment for disc conditions that cause neck pain and arm pain, weakness, numbness or tingling. About 6 years ago, the FDA approved cervical disc arthroplasty for the treatment of these conditions after several studies confirmed the safety and efficacy of this procedure.
So, why is disc arthroplasty preferred to ACDF surgery? The major benefit of the disc arthroplasty is the preservation of MOTION at the surgically treated disc level. Specifically, NO FUSION is performed. Instead, a bearing-type device is used to replace the disc and this allows natural neck movements immediately following surgery. Also, the relief of arm symptoms is usually dramatic and most persons return to normal activity within several weeks.
Why Might I Need This Procedure?
The intervertebral discs of the cervical spine are very important for the normal mobility and function of your neck. When healthy, they act as "cushions" for the individual bones of the spine, or vertebrae. Each disc is made up of two parts
Over time, discs can become dried out, deflated or otherwise damaged, due to age, genetics and everyday wear-and-tear. When this happens, the nucleus pulposus may push through the annulus fibrosis. Disc degeneration also may result in boney spurs, also called osteophytes. If disc or bone material pushes into or impinges on a nearby nerve root and/or the spinal cord, it may result in pain, numbness, weakness, muscle spasms or loss of coordination, both at the site of the damage and elsewhere in the body, since most the nerves to the rest of the body (e.g., arms, chest, abdomen and legs) pass from the brain through the neck. Similar symptoms, however, may occur suddenly if the disc nucleus dislodges acutely and causes nerve root compression, a condition referred to as a herniated disc.
The goal of cervical artificial disc surgery is to remove all or part of a damaged cervical disc (discectomy), relieve pressure on the nerves and/or spinal cord (decompression) and to preserve spinal alignment, whilst restoring mobility.
Not everyone with symptoms of disc degeneration in the neck is suitable for implantation of an artificial disc. In fact, more people need an anterior interbody fusion than are suitable for an artificial disc.
Cervical artificial disc replacement surgery may be an appropriate treatment option for you if:
How Is Cervical Artificial Disc Replacement Surgery Performed?
Through a small incision made near the front of your neck (a surgical approach called the anterior approach) your surgeon will:
How Long Will It Take Me To Recover?
The amount of time that you have to stay in the hospital will depend on this treatment plan. You typically will be up and walking in the hospital by the end of the first or second day after the surgery. You may return to work in 3-6 weeks, depending on how well your body is healing and the type of work/activity level you plan to return to.
Every patient is different, however, and Prof. Brazenor will determine the appropriate recovery protocol for you. Please note that much of this advice is for your safety, and thus it is important that you follow it to the letter.
Are There Any Potential Risks Or Complications?
Any surgery and anaesthesia can result in injury or even, rarely, death. One only has to read the newspaper to confirm that fact. Complications such as infection, nerve damage, blood clots, blood loss and bowel and bladder problems, along with complications associated with anaesthesia, are some of the potential risks of spinal surgery. A potential risk inherent to spinal fusion is failure of the vertebral bone and graft to properly fuse, a condition that may require additional surgery.
The sorts of complications which can occur with surgery to cervical spine include the following:
What is cervical disc replacement surgery?
Worn or herniated discs can cause pressure on the spinal nerves, rubbing of the vertebras resulting in pain in the neck, back and upper limbs. The standard operation involves removing the part of the disc or discs that is bulging out or pressing on the nerves and replacing the void with a prosthetic disc. The prosthetic disc is designed to restore disc space and height, to restore flexibility and to minimalise the risk of disc degeneration.
Why is this surgery suitable for me?
Surgery is an option for slipped discs and cervical spondylosis if:
The aim of the procedure is to reduce the pain in the neck, back and arms.
How is it performed?
The procedure is performed under general anaesthetic. The standard surgical procedure for a disc replacement is an anterior (from the front) approach to the cervical spine. The affected disc is completely removed including any impinging disc fragments or osteophytes (bone spurs). The disc space is propped up to its previously normal disc height to help relieve pressure on the nerves. This is important because when a disc becomes worn out, it will typically shrink in its height, which can also contribute to the pinching on the nerves in the neck. At this point, the artificial disc device is implanted into the prepared disc space. X-ray images will be taken to confirm the disc has been positioned correctly. You will need a minimum two night stay in Hospital. Following surgery, you will need to undergo a physiotherapy-based rehabilitation program.
Some important considerations
The procedure is a more recent development and long term effectiveness of a prosthetic disc has not been studied, however short term reports have provided good results.
Surgery seems to get people better quicker but has some risks associated with it.
Surgery has less risk, and is safer, on fit and healthy patients. It is common sense to take responsibility as a patient to reduce the risks whenever possible. Simple measures such as stopping smoking, losing weight and improving aerobic fitness all help.
If you have had pressure on the nerve for a long time or the nerve has become damaged by the pressure, you may not get a complete recovery of the nerve function. This means that you might always have some numbness in parts of the arm or legs, or weakness of some of the muscles after surgery.