Overview of Cervical Disc Replacement
Most of us are familiar with surgery for replacing arthritic joints that have become painful. In the US, approximately one million worn out knees and hips are replaced by artificial joints every year. Overall, results for these procedures are excellent, allowing patients to return to active lifestyles.
Joints in the spine, called intervertebral discs, can also become painful, similar to knees and hips, when they become arthritic. This is in fact a common condition, affecting up to 80% of adults as they get older. For a small subset of these patients, the pain may become so severe that surgery is required.
It is only recently, however, that artificial joint replacement technology has been perfected for these discs in the spine. Previously, the only treatment for rebuilding a damaged disc was to remove the entire disc and replace it with a fixed, immovable cage (spinal fusion). When performed in the cervical spine (neck), this operation was called Anterior Cervical Discectomy and Fusion (ACDF).
ACDF, though very effective at relieving pain and dysfunction caused by a damaged intervertebral disc, has a drawback: fusion leads to decreased neck range of motion. More importantly, fusing a joint in the neck can lead to accelerated wear and tear on the joints nearby. This process, known as adjacent segment disease, can create additional problems for the patient many years after a successful fusion procedure.
Cervical disc replacement solves this problem by preserving motion in the treated joint. As a result, spine patients can now experience the same motion-preserving benefits that hip and knee patients have enjoyed for decades.
Who benefits from Cervical Disc Replacement?
Patients who are experiencing neck, shoulder, and arm pain (cervical radiculopathy, pinched nerve, or cervical stenosis), and who have not improved with conservative care, can be considered for surgical intervention. Historically, Anterior Cervical Discectomy and Fusion was the surgical treatment of choice for these patients. Cervical Disc Replacement is now an excellent alternative.
Do all surgical candidates qualify for Cervical Disc Replacement?
No. Currently, the FDA approves Cervical Disc Replacement for treatment of only one or two intervertebral discs. Patients who need more levels treated may need ACDF. In addition, Cervical Disc Replacement requires certain ligaments in the spine to be intact, along with normal bone alignment. By closely studying your MRI or CAT scan, your doctor can decide whether you qualify for Cervical Disc Replacement.
How is Cervical Disc Replacement performed?
Surgery for Cervical Disc Replacement is very similar to ACDF, and takes between 60 and 90 minutes to perform. Surgery can be performed in a hospital or ambulatory surgery center.
After general anesthesia, an incision is made on the front of the neck. The windpipe (trachea) and food pipe (esophagus) are then carefully moved to the side and protected, allowing direct visualization of the spinal column (typically an inch or two under the skin). The damaged disc is then removed, and all loose disc fragments taken off the spinal cord and nerves. A replacement disc, made from metal and medical grade plastic, is then custom fitted into this space.
What can I expect postoperatively?
Cervical disc replacement is typically an outpatient procedure. Patients are usually discharged home the same day or the next day after the procedure. A cervical collar for immobilization may be required for one or two weeks depending on your surgeon’s preference. Postoperative discomfort from the procedure is tolerable and usually limited to two to three days and can be controlled with oral analgesics. Preoperative symptoms such as pain, numbness, and weakness are often markedly improved within hours of the procedure. However, full recovery may take up to weeks or even months.
Postoperative office follow ups are usually done at 2 weeks, 6 weeks, 3 months, 6 months, and 1 year. X-rays are routinely performed to check for proper positioning and functioning of the disc replacement device. Most patients are back to work on light duty in one to two weeks and full duty in about 6 weeks after surgery.
How does Cervical Disc Replacement compare to ACDF?
Cervical disc replacements are proving to be equal or superior to anterior cervical discectomy and fusion in terms of surgical outcomes. In 2016, a randomized controlled trial with 2300 patients compared cervical disc replacements to anterior cervical discectomy and fusion, with at least 4 years of follow-up. This study found that cervical disc replacements led to significantly higher rates of success and lower rates of complication.
Advantages of cervical disc replacement (over ACDF) include:
- Motion preservation at the replacement level, reducing adjacent segment disease.
- Reduced postoperative pain and recovery. With a cervical disc replacement, the need for any cervical immobilization lessens to a week or less as compared to 6 weeks with an anterior cervical discectomy and fusion.
- No need for an anterior plate. Consequently, there is less irritation to the esophagus, and less swelling, both of which may cause difficulty swallowing and hoarseness.
What factors should I consider when choosing a spine doctor?
- Experience: The most important factor to consider is experience. There is no substitute. Repetition yields excellence in results. When choosing a surgeon to treat your cervical spine, you should ask how many of these procedures he or she performs on a routine basis, and what are the outcomes. In addition, ask whether prior patients would be willing to discuss their pre and post-operative journeys.
- Judgement: While experience does lead to technical expertise and improved outcomes, it also leads to better clinical judgement. In many ways, a doctor’s judgement is even more important than his or her technical skill, because a great deal of consideration goes into deciding whether a patient even needs surgery, and if so, what type of surgery. This careful consideration cannot be rushed, and cannot be made with a cookie-cutter approach. A surgical decision can never be made based on MRI findings alone (beware of doctors who offer free MRI reviews, without evaluating or examining you). Rather, MRI findings must be interpreted within the context of what the patient reports to the doctor, and what the doctor finds on a careful examination. It is only when the patient’s symptoms, findings on exam, and MRI results closely correlate can a surgical decision be made. Furthermore, this decision can only be made after all conservative options have been exhausted.
- Conservative Approach: When choosing your spine doctor, make sure he or she has a very conservative approach to care, offering surgery only as a last resort. The vast majority of patients (>95%) who suffer from spine ailments do not require surgery, even if their MRIs look severely abnormal. The human body has a tremendous capacity to heal itself, and it is your spine doctor’s job to show you how that can be achieved. Surgery should be reserved only for those rare cases where this healing process is not possible.
- Breadth of knowledge and skills: There are over 200 distinct types of operations that can be offered for the treatment spine conditions. Some can be performed via same-day, minimally invasive approaches, while others require large incisions with titanium hardware for complex reconstructions. Every one of these operations represents a tool in the surgeon’s armamentarium, uniquely suited to address a specific surgical need. Unfortunately, not all surgeons have a broad range of surgical skills. Some may limit themselves to the simpler procedures, that are only effective for more routine conditions. However, if your condition is more complex, you may be taking them out of their comfort zone, or they may offer surgical solutions that are not appropriate for your unique circumstance. Ask your surgeon about the range of spine conditions he or she treats, from simple disc herniations to scoliotic deformities. Is your surgeon equally comfortable with a multi-level deformity correction as with a microdiscectomy? Can your surgeon explain the difference between cervical disc replacement versus fusion, and offer either technique if appropriate? Many surgeons will offer cervical fusion simply because they lack qualifications for disc replacement.
- Time spent listening and educating: Many surgeons rush to diagnose off an MRI scan. This is the primary reason that so many patients feel dissatisfied with the results of their spine surgery. The surgery may have been performed well, but there continues to be severe pain and dysfunction, causing many to wish they had never undergone surgery to begin with. Why does this happen so often? Because most spine surgery is performed for something that cannot be measured – ie, pain. Pain is not like temperature or blood pressure, that can be objectively quantified and treated if too high. Rather, pain is very subjective; something that causes misery to one person may be minimally bothersome to another. To further complicate matters, pain is difficult to localize. There are many things in the spine that can cause pain, such as herniated discs, unstable facet joints, SI joints, or compressed nerve roots. Unfortunately, these can be packed very close together anatomically, and can all cause pain in the same general area. Finally, a joint or disc can look abnormal on X-Ray or MRI, but not actually cause pain.
Considering all these factors, it can be very difficult to accurately identify the pain generator in any particular patient. If the original diagnosis is inaccurate, then even well-executed spine surgery can leave the patient in pain, because the true source of pain was never accurately identified. Worse, there may be unnecessary complications from surgery, and scar tissue, that create even more pain.
The only way to overcome the difficult problem of accurate diagnosis in spine care is this – The doctor must spend enough time listening to the patient, and asking a lot of questions. With enough time, important clues in the patient’s story can help a doctor identify the underlying problem. The doctor must also perform a thorough and detailed examination searching for all the little clues that lead to a proper diagnosis. This takes time and patience. But with the insights gained, the doctor now can make sense of a patient’s complicated MRI, where many joints and discs look abnormal, but only one is causing a problem that may need to be fixed.
At CNSO, our philosophy is to treat the patient, not the MRI.