Radiofrequency ablation has been used to treat a number of different conditions, from cardiac arrhythmias to cancer treatment. Results presented at the American Academy of Pain Medicine’s 2016 Annual Meeting suggest radiofrequency ablation may also be useful in treating degenerative lumbar disc disease.
Degenerative lumbar disc disease is a form of “discogenic” back pain, and is very common. About 4 out of 10 people with chronic low back pain have discogenic lumbar disease. This form of back pain is first treated with physical therapy and analgesics. If these interventions fail, degenerative disc disease may be treated with injections or spine surgery.
Some of these treatments can be quite helpful and, in some cases, can cure lower back pain. Not every person benefits from every treatment. Moreover, some of these treatments relieve symptoms for 6 to 12 months, and then the chronic back pain returns. Lumbar disc surgery can be curative, but the procedure carries some risks and recovery can be difficult for some patients.
Radiofrequency ablation may be another interim treatment that is tried before patients undergo lumbar disc surgery. As the disc degenerates, nerve fibers grow into and around the injured disc. Not only are there many new sensory fibers and nerve endings in the damaged disk, these new nerve endings tend to be more sensitive and more easily inflamed than in a healthy lumbar disc. In fact, this abnormal increase in nerve endings is thought to be a key reason people have discogenic back pain.
In radiofrequency ablation, physician or surgeon places thermal probes into the rear portion of the injured lumbar disc. These probes heat the area and destroy abnormal nerve endings that have invaded the disc. Once the nerve endings have been destroyed and the area heal has healed, presumably the lower back pain will cease or be markedly improved.
To test radiofrequency ablation treatment of degenerative lumbar disease, researchers assigned 63 patients with discogenic lumbar back pain to one of two groups. The control group received conventional medical management alone (i.e., physical therapy, analgesics, exercises, injections etc., but not surgery) or to conventional medical management plus radiofrequency ablation treatment.
Patients in the group who receive radiofrequency ablation had significantly better pain and function scores after 6 months and 12 months. Importantly, the patients in the radiofrequency ablation group were not pain-free, but they did have substantially less pain, on average, than those who underwent conventional medical management alone. Likewise, disability scores were improved after radiofrequency ablation treatment, the patients in both groups still had a certain degree of disability, on average.
Radiofrequency ablation for discogenic back pain is an outpatient procedure that lasts approximately 30 min. So far, the procedure has not been associated with any serious complications in carefully selected patients. In patients with severe degenerative disc disease, however, radiofrequency ablation can cause the pain of its own, aside from the discogenic pain. The authors of the study suggest that patients with severe degenerative disc disease should be referred for spinal fusion surgery immediately, rather than first having a radiofrequency ablation.
Other specialists have noted that radiofrequency ablation is quite similar to another procedure that was previously promising but later was shown to be ineffective. This procedure, called intradiscal electrothermal annuloplasty, also used heat energy to destroy damaged disc tissue and abnormal nerve endings. Unfortunately, this procedure has fallen into disfavor since outcomes were not as promising as people had first hoped and, as a result, medical insurers were not reimbursing patients for the procedure.
As larger, long-term radio-frequency ablation studies for lumbar disc pain are performed, we may better know if the procedure is effective over the long term or not. At this point, it is clear that people with severe lumbar disc disease should immediately proceed to spinal fusion surgery. For mild to moderate disease, it is not clear whether the patient should have radiofrequency ablation after or in addition to conventional treatment. Nevertheless, the results of this small study are somewhat promising for those who want to try it moderately aggressive procedure before spinal fusion surgery.