For several decades, spinal fusion has been the gold standard for treating disc degeneration and other spinal conditions. But since the early 2000s, artificial disc replacement (ADR) for both cervical and lumbar disc degeneration has become a safe and effective alternative for patients who meet certain criteria.
Spinal fusion, which is still quite common, fuses vertebrae together which eliminates motion and in many cases exacerbates the degeneration of neighboring discs. Conversely, ADR actually preserves motion because it addresses the natural movement of the spine and helps reduce the risk of adjacent disc degeneration.
“Fusions have been tried and tested for several years,” says Dr. Matthew Hazzard, a neurosurgeon with Advanced Neurosurgery Associates in Atlanta. “But the potential of having the opportunity to preserve motion is appealing because you keep that segment moving longer, which helps not only range of motion, quality of life and reduction in pain, but also it offsets the potential of adjacent segment problems.”
Criteria and Patient Selection
ADR for cervical and lumbar disc replacement may not be right for every patient. For example, if a patient has been diagnosed with significant facet joint arthropathy, spinal instability or deformity, osteoporosis or is pregnant, has an active infection or severe psychological disorders, they are immediately ruled out.
While Dr. Hazzard’s patients have primarily been in their 30s and 40s, good candidates can be anywhere from 18 to 60 who are generally healthy and active. To make sure the procedure offers the best possible outcome for each individual, a thorough assessment is done using specific criteria.
Cervical Disc Replacement:
- Single-level degenerative disc disease with radiculopathy or myelopathy
- Preserved facet joints without significant arthrosis
- Adequate bone density
- Age typically between 18-60 years
- Failed conservative management for at least 6 weeks
Lumbar Disc Replacement:
- Single or two-level degenerative disc disease
- Predominant axial back pain with or without leg pain
- Preserved posterior elements (facets, ligaments)
- Adequate bone quality
- Height loss less than 50% of original disc space
If these criteria are met, and conservative measures like physical therapy, medications, injections, or dry needling, have failed, further tests are done. “For either cervical or the lumbar spine, we generally start with dynamic X-rays,” explains Dr. Hazzard. who with his three practice partners regularly performs the procedures. “That helps to understand the bony anatomy of the spine as well as how the spine moves and the alignment of the spinal cord.” Typically, he added, “the patient gets an MRI to further examine the soft tissue and to see if the patient’s problem matches their symptoms.” A CT scan may or may not be needed.
Using the latest imaging and navigation technologies, including intraoperative fluoroscopy and neuromonitoring, during surgery also plays a role in surgical precision and safety. “With newer technology and devices, and improved training, we see that outcomes are far better, even in terms of length of stay in the hospital.” Cervical disc replacements, for example, are same-day outpatient surgeries. “For lumbar disc replacement,” he says, “I usually like to watch people at least overnight, but I’ve had patients go home the same day for that as well.”
Recovery and Outcomes
Recovery times for ADR compared to fusion are an enormous benefit as well. “For a cervical disc replacement, you’re going to be able to get back into your normal activities within one to two weeks. For lumbar discs, it’s about six to eight weeks compared to three to six-months’ minimum healing for a fusion,” says Dr. Hazzard.
Recent clinical studies support excellent long-term outcomes for both procedures in the appropriate patients. Five-year follow-up data shows:
Cervical Disc Replacement:
- Clinical success rates of 85-92%
- Maintained range of motion at treated levels
- Low rates of adjacent segment disease (3-5% vs. 9-12% for ACDF)
- Revision surgery rates less than 5%
Lumbar Disc Replacement:
- Good to excellent outcomes in 80-85% of patients
- Maintained flexion-extension motion
- Reduced disability scores compared to fusion
- Complication rates comparable to lumbar fusion when performed by experienced surgeons
Dr. Hazzard is optimistic that as technology develops and becomes more mainstream, more patients will have access to it. “I am hopeful that within our lifetime that there will be a paradigm shift further towards not only regenerative medicine, but preservation of motion – how we keep these joints and segments moving rather than how we stop them from moving.”
Referring providers can contact Advanced Neurosurgery Associates for consultation or referral support:
Advanced Neurosurgery Associates
Phone: 678-217-2700
Website: advancedneuroassoc.com
Sponsored by Northside Hospital
