The causes of back pain can be difficult to diagnose because most cases are non-specific. Pain frequently arises from a combination of muscles, joints, discs, and nerves rather than a single injury. The complex spinal anatomy, referred pain, subjective pain experiences, and limitations in imaging make pinpointing the exact source a trial-and-error process.
But, over time, the source or sources can often be identified. And when that source is determined to be in the facet joints or sacroiliac joints, there is a long-lasting, minimally invasive procedure to consider: Radiofrequency Ablation.
What Are Facet Joints and Sacroiliac Joints?
Facet joints (small joints connecting spinal vertebrae) and sacroiliac (SI) joints (connecting the spine to the pelvis) are separate structures. Both are also common sources of chronic low-back pain, especially with aging. Facet joints enable spinal movement and twist, while SI joints transfer upper-body weight.
Facet Joints
The facet joints are the connections between the bones of the spine. The nerve roots pass in front of these joints to go from the spinal cord to the arms, legs, and other parts of the body.
These joints also allow the spine to bend and twist, and they keep the back from slipping too far forward or twisting without limits. Like the knee joint, they have cartilage to allow smooth movement where two bones meet. The joints are lined with synovium and contain lubricating synovial fluid.
Facet joints have a rich nerve supply – called medial branches – that allows them to perceive pain when they are injured. Those pain signals are carried by these nerves to your spine and brain.
Sacroiliac (SI) Joints
The sacroiliac joint lies next to the bottom of the spine, below the lumbar spine and above the tailbone (coccyx). It connects the sacrum (the triangular bone at the bottom of the spine) with the pelvis (iliac crest).
Like facet joints, they are weight-bearing structures and are subject to mechanical stress. We each have two sacroiliac joints – one on either side of the sacrum.
Sacroiliac joints move very little compared to other joints of the spine. They also have a rich nerve supply – called sacral lateral branches and lumbosacral plexus – that allows them to perceive pain when they are injured.
Many Possible Levels to Carry Pain Signals
The facet joints and sacroiliac joints have multiple levels that could be sources of chronic back pain. But once the source of joint pain is identified, radiofrequency ablation can destroy the nerve supplying the damaged joint. This interrupts the pain signals, and patients no longer experience pain.
How Is Radiofrequency Ablation Performed?
Radiofrequency Ablation is a minimally invasive procedure. A local anesthetic is used to numb the treatment area.
Using fluoroscopic imaging, a doctor guides a thin needle into the area causing the pain. Fluoroscopy enables the doctor to ensure the needle goes to the desired location.
Once in position, a radiofrequency electrode is inserted through the needle. Initially, the electrode is used for nerve stimulation testing to ensure the correct target is reached. Then, using the same electrode, radiofrequency energy is delivered to disrupt the nerves that transmit pain signals.
Throughout the procedure, the doctor closely monitors the probe temperature and progress to ensure the treatment is effective and safe.
How Successful Is Radiofrequency Ablation?
Generally, radiofrequency ablation is considered very effective for patients with facet and sacroiliac joint-related pain. Since diagnostic blocks are completed prior to radiofrequency ablation procedures to confirm the cause and location of pain-carrying nerves, these procedures typically have high success rates.
Success may also depend on the patient’s adherence to post-procedure care, rehabilitation, and follow-up appointments. Most patients experience relief lasting several months to a year or more.