Posterior Rami Blocks & RFTC

The posterior ramus of a spinal nerve, also known as the posterior (or dorsal) branch, is responsible for carrying sensory and motor information to the muscles and sensation of the back.

Structure

Upon exiting the intervertebral foramen, each spinal nerve branches into the posterior ramus, anterior ramus, and rami communicantes. These branches carry both sensory and motor information. The posterior ramus, with the exception of the first cervical, fourth and fifth sacral, and coccygeal nerves, travels backward. It further divides into medial and lateral branches that supply the muscles and skin of the back. The medial branch also provides articular branches to the zygapophyseal joints and the periosteum of the vertebral arch. In the neck and upper back, the medial branch continues through the deep and superficial back muscles to supply the overlying skin, while in the lower back, the lateral branch performs this function.

Function

As “mixed nerves,” spinal nerves carry sensory and motor information. The posterior rami specifically transmit visceral motor, somatic motor, and sensory information to and from the skin and deep muscles of the back. Each posterior ramus remains distinct and innervates a narrow strip of skin and muscle along the back at the level of its departure from the spinal nerve.

Radiofrequency Procedures

Radiofrequency (RF) nerve ablation, also known as RF rhizotomy is a therapeutic procedure that alleviates or eliminates pain symptoms originating from spinal facets. This procedure aims to temporarily deactivate the minor nerves surrounding the spine that contribute to pain.

Procedure

RF rhizotomy is performed under x-ray guidance to access the affected nerve accurately. Once properly positioned, a specialized probe delivers radiofrequency energy to the targeted area. The application of electric current cauterizes the sensory nerves responsible for innervating the facet joint(s).

Patient Evaluation

Before scheduling an RF rhizotomy procedure, patients typically undergo a series of facet injections to determine the exact source of their symptoms. These diagnostic tests may require multiple visits. If a patient experiences significant pain relief or temporary relief with a local anesthetic block, RF denervation of the nerves is usually recommended for long-term or even permanent relief. Successful RF procedures can provide pain relief lasting from months to years, surpassing the duration achieved with local anesthetic and steroid blocks.

Applicability and Recovery

RF procedures can be performed on any area of the spine, including the cervical, thoracic, or lumbar regions. Due to the temporary trauma to the nerves, patients may experience an increase in symptoms for 5-7 days after the procedure. However, pain relief benefits should become apparent within 2-4 weeks following the procedure.