Radiofrequency lesioning refers to delivery of high frequency electrical current in the RF range (500kHz) to patient tissue via an RF electrode to induce a biological effect, such as thermal destruction of nerves that carry painful impulses. As the current is applied at destructive levels, a well-circumscribed heat lesion appears.
Cervical facet joint radiofrequency denervation treatment can provide sustained pain relief in patients with chronic neck pain emanating from the facet joints. However it is important to note that in some cases injection treatment may not provide the desired results or the pain relief may not be sustained. At Pain Spa Dr. Krishna always performs cervical radiofrequency treatment under real time fluoroscopy guidance, using state of the art equipment. This ensures 100% accuracy and our complication rates are extremely low.Information Sheet
The use of high frequency electric current to produce controlled thermocoagulation was first reported in 1974 by Sweet who described radiofrequency (RF) treatment of the Gasserian ganglion for the treatment of trigeminal neuralgia. In 1975 Shealy reported the first use of RF current for spinal pain.
The facet joint is richly innervated with nociceptors and mechanoreceptors; these nerves can be adversely affected by facet capsular strain. Inflammation of the facet joint can sensitize nociceptive neurons and lower the firing threshold, causing pain during ‘normal’ motion, or peripheral sensitization. Similarly, disruption of mechanoreceptors can cause subtle proprioceptive disturbances and result in spinal instability or uncoordinated, painful cervical muscle contraction and guarding.
The cervical spine is composed of 7 cervical vertebrae, intervertebral discs, zygapophyseal or facet joints, ligaments, muscles and fascia and neural structures. There are 7 pairs or 14 facet joints in the cervical spine. They are true synovial joints and are composed of a fibrous capsule lined with synovium and hyaline cartilage between the bony structures. The capsule is richly innervated by nociceptors and mechanoreceptors that help with cervical spine proprioception.
The orientation of the facet joint provides resistance to anterior translation and assists in weight-bearing. They are at a 45-degree angle, allowing flexion, extension, rotation, and limited translation. The atlanto- occipital and atlanto-axial joints (C1 and C2) do not have facet joints. The C2/3 joint is innervated by the medial branch of the C2 dorsal rami and the medial branch of the C3 dorsal rami (the third occipital nerve). C3/4 to C7/T1 cervical joints are innervated by the medial branches of the cervical dorsal rami located above and below the joint.
Injections are generally avoided in patients with systemic infection or skin infection over puncture site, bleeding disorders or coagulopathy, allergy to local anaesthetics or any of the medications to be administered. Radiofrequency treatment is contraindicated in patients with pacemakers or any other neural implants (spinal cord stimulator, deep brain stimulator).
The procedure is usually done on an outpatient basis. The procedure is performed under fluoroscopic guidance to ensure accuracy of needle placement. Patients need to be aware that the outcome of the procedure is variable and they may not receive the desired benefits. Similarly, they must be aware of the transient nature of the therapeutic benefits and that there may need repeated injections.
Radiofrequency treatment is a two-step procedure. The first step is diagnostic, involving injection of local anaesthetic around the medial branches innervating the relevant facet joints. Patients who experience good pain relief following diagnostic injections are offered radiofrequency denervation treatment. This involves creating a heat lesion around the nerves carrying painful impulses from the facet joints. Successful treatment can result in pain relief lasting 6 months to 2 years.
Radiofrequency treatment is performed under local anaesthesia and patient cooperation is very important in identifying the target nerves. The treatment does not work immediately and can take 4 to 6 weeks to kick in.
Complications are rare, particularly if injections are performed using a precise needle-positioning technique. Possible complications include spondylodiscitis, septic arthritis, and reaction to the injectates. Septic arthritis can be avoided with appropriate aseptic precautions. Severe allergic reactions to local anaesthetics are uncommon. Post-procedural pain flare-up is not uncommon, and may be treated with painkillers. Neurological complications including paraesthesias, numbness and paralysis have been described but are extremely rare. Radiofrequency treatment can cause patchy numbness of the over lying skin. Infections including epidural abscess and chemical meningitis can occur but the incidence is very low as the procedure is performed under strict aseptic conditions.