Background

Neck pain is defined as pain in the area between the base of the skull and the first thoracic vertebra. Pain extending into adjacent regions is defined as radiating neck pain. Pain may radiate into the head (cervicogenic headache), shoulder, or upper arm (radicular or nonradicular pain).¹ A distinction is made between trauma-related neck pain (whiplash-associated disorders) and degenerative neck problems. Because the causes of neck pain often are unclear, a distinction is made between the cause and source.² The following innervated structures in the neck may be sources of pain: vertebrae, discs, uncovertebral (Luschka) joints, ligaments, muscles, and facet (zygapophyseal) joints.

Beside the cervical discus intervertebralis, other structures in the neck, such as facet joints and uncovertebral joints, may also show degenerative signs. A diagnosis is defined as a clinical picture with known etiology and prognosis. A syndrome is a combination of symptoms occurring at a higher frequency in a certain population.

Cervical facet syndrome is defined as a combination of symptoms:

Axial neck pain (not or rarely radiating past the shoulders)

Pain with pressure on the dorsal side of the spinal column at the level of the facet joints

Pain and limitation of extension and rotation

Absence of neurological symptoms

There is a great deal of research into degenerative signs of the cervical vertebral column. In the discus intervertebralis (1) annular tears, (2) discus intervertebralis prolapse, and (3) endplate damage and internal discus intervertebralis disruption have been identified as potential structural discus intervertebralis pathologies.³ Other structures in the neck, such as the facet joints and uncovertebral joints, may also show degenerative signs. The hypothesis that discus intervertebralis degeneration and discus intervertebralis narrowing increase facet joint loading and consequently facet osteoarthritis seems plausible but has yet to be proven. Some researchers claim that the discus intervertebralis and the facet joints can be seen as independent pain generators.⁴

Compared with research on lumbar facet pain, research on cervical facet dysfunction is relatively recent. In 1988, Bogduk and Marsland⁵ described the positive effect of injection of local anesthetics close to the facet joints in patients with neck pain. Dwyer et al⁶ showed that injection of irritating substances into the facet joints results in a specific radiation pattern (Fig. 14-1). The same radiation pattern is seen with mechanical and electrical stimulation. However, because it was later demonstrated that stimulation of the discus intervertebralis produces the same radiation pattern as stimulation of the facet joints, this is probably a segmental phenomenon.

Fig. 14-1 Radiation pattern of cervical facet pain.

(Illustrated by Rogier Trompert Medical Art. http://www.medical-art.nl.)

Clinical findings of degenerative signs are mainly based on radiological findings. Spondylosis (disorders of the nonsynovial joints) and osteoarthritis (facet osteoarthritis) are frequent in advanced age. Degenerative disorders are usually seen at the low and midcervical levels (C4-C5, C5-C6, C6-C7). A causal relationship with pain symptoms has not been proven.

History

While taking the history, attention should be paid to signs and symptoms potentially indicating a serious underlying pathology (“red flags”). It is important to question the patient about previous trauma and previous or ongoing oncological treatments. Indications for potential spinal metastases are (1) history of malignancy, (2) pain starting after the age of 50 years, (3) continuous pain independent of posture or movement, and (4) pain at night. When symptoms such as weight loss, fever, nausea, vomiting, dysphagia, coughing, or frequent infections are reported, an extensive history and further examination are mandatory.

The most common symptom with pain arising from the cervical facet joints is unilateral pain, not radiating past the shoulder. The pain often has a static component because it does not always occur in relation to movement. Rotation and retroflexion are usually reported as painful or limited.

The radiation pattern is not distinctive for facet problems but can indicate the segmental localization. It is important to determine if the pain symptoms cause functional limitations (e.g., dressing, lifting, car driving, reading, sleeping, and in the work situation).

Physical Examination

Neurological tests (reflexes, sensibility, and motor function) are necessary to exclude radiculopathy. To examine the function of the neck, the following tests are important:

Rotation in a neutral position determines the rotation movement of the entire cervical spinal column. Rotation in flexion assesses the movement in the higher cervical segments. Rotation in extension assesses the movement in the lower cervical segments.

Local pressure pain over the facet joints can indicate problems arising from the facet joints. Recent research showed that local pressure, defined as pain with pressure of at least 4 kg, is a predictor of success of RF treatment (see Radiofrequency Treament sections).⁷ When the neck pain is accompanied by radiation to the shoulder region, shoulder pathology should be excluded.

There is no evidence for the relation between the results of clinical examination and the history with the presence of pain originating from the cervical facet joints.⁸ In daily clinical practice, history and physical examination are useful to exclude serious pathology and to obtain a working diagnosis. An indication of the segmental level (high, mid, or low cervical) involved can be obtained.

Percutaneous Facet Denervation

The (postero-)lateral approach in the supine position is described below (Fig. 14-5). The advantage of this technique is that it is possible to maintain eye contact with the patient. Sedation is rarely required.

Fig. 14-5 Posterolateral approach of the cervical ramus medialis (medial branch) of the ramus dorsalis. DRG, dorsal root ganglion.

(Illustrated by Rogier Trompert Medical Art. http://www.medical-art.nl.)

The patient is placed in the supine position with the head slightly extended on a small cushion. The C-arm is placed in an oblique position (±30 degrees). In this position, the beam runs parallel with the exiting nerve root that runs somewhat caudofrontal. Also in this position, the pedicles from the contralateral side are projected on the anterior half of the vertebral body. In the frontal plane (anteroposterior [AP] direction), the C-arm is positioned in a small angle with respect to the transverse plane. In this position, the discus intervertebralis space and neuroforamen are visible (Fig. 14-6). The ramus medialis (medial branch) of the ramus dorsalis runs over the base of the processus articularis superior. The injection point is marked on the skin, slightly posterior and caudal to the end point of the needle that is dorsal to the posterior boundary of the facet column. The first needle is introduced in a horizontal plane, slightly cranially so the tip of the needle points in the direction of the end point. It is important to understand that this is not a “tunnel-view” technique. The needle is slowly advanced anteriorly and cranially until bony contact with the facet column occurs. The farther the needle is advanced, the more difficult it becomes to change the direction. Therefore, the position of the needle needs to be checked frequently. If the needle points too much in the direction of the neuroforamen without contacting bone, the direction needs to be corrected to be more posterior. If there is no bone contact in the posterior direction, there is a risk that the needle will enter the spinal canal between the laminae. To prevent this, the needle position can be checked in the AP direction. The final position of the needle in the AP direction is in the concave “waist” of the facet column. After placement of the first needle, the other needles are introduced in the same way. The first needle acts as a guide to direction and depth.

Fig. 14-6 Radiofrequency treatment cervical ramus medialis (medial branch) of the rami dorsales/facet C4, C5, C6, left: three quarters projection.

The same technique is used for the facet joints of C3-C4 to C6-C7. For the facet joint of C2-C3, a different end point for the needle is used, just beneath the C2-C3 joint.²³

After an optimal anatomical localization is reached and controlled using fluoroscopy, the position of the needle tip at the ramus medialis (medial branch) of the dorsal ramus is confirmed using electrical stimulation. The stimulation threshold is determined: an electrical stimulation of 50 Hz must give a reaction (tingling) in the neck at less than 0.5 V. Then stimulation is carried out at 2 Hz. Contractions of the paraspinal muscles can occur. Muscle contractions in the arm indicate a position close to the exiting segmental nerve. The needle should then be placed more posterior. After the correct position has been determined, 0.5 to 1 mL local anesthetic (1% or 2% lidocaine) is given. A RF lesion at 80° C for 60 seconds is carried out.