GENERAL
One of the most common causes of chronic cervical (neck) pain is the facet joint syndrome. More than 50% of patients visiting pain clinics for cervical pain, suffer from facet joint syndrome. This percentage is far higher than the corresponding rate of patients suffering from lumbar facet joint syndrome.
ANATOMY
Every vertebra has two pairs of facet joints (zygapophyseal joints or z-joints). The two joints, one in each side of a vertebrum, connected with the upper vertebra are called “superior articular processes”, while the two joints that are connected with the lower vertebra are called ‘inferior articular processes”. They are located at the posterior part of vertebrae.
Facet joints have a synovial bursa and their articular surfaces (facets) are covered with cartillaginous tissue so that they are smooth and can move without any friction.
Facet joints allow for flexion, extension and rotation of the spine by keeping it stable.
Compared to lumbar facet joints, cervical facet joints have a higher density of mechanoceptors. Cervical facet joints from C3 to C7 are innervated by the medial branches of the posterior stem of the corresponding spinal nerve. Every facet joint is innervated by nerve branches from the immediate upper and lower level.
DIAGNOSIS
SYMPTOMS
The most common symptom reported by patients is pain in the cervical region which may probably radiate to the shoulder or/and scapula. Rarely does the pain extend beyond the shoulder and radiate to the upper arm. It is usually unilateral, but in some caes it may be bilateral. It may be static pain aggravating with the movement and rotation of the neck. The patient usually reports tenderness on local pressure in the paravertebral region.
Dwyer showed that the injection of contrast medium into the facet joints provokes referred pain of specific distribution, according to the level of facet joints. The same pain distribution was also provoked with the electrical and mechanical stimulation of the joints. This specific distribution of referred pain helps in determining the affected facet joints.
Physical examination and clinical history should include a neurologic examination to exclude the probability of cervical radicular pain. The radicular pain almost always radiates to the upper arm and, according to the level of the lesion, may extend even to the fingers.
In case the cervical pain radiates to the shoulder, the shoulder should be also examined to rule out any pathology.
Should the patient report history of any malignancy, recent and sudden weight loss, dysphagia, fever, persisting cough and continuous pain, independent from motion, remaining during night, then extensive workup should be carried out to rule out some other serious pathology.
SUPPLEMENTARY EXAMINATIONS
No correlation has been found between degenerative lesions shown by X-ray examination and pain symptoms. Thus, there are patients who suffer from facet joint syndrome and cervical pain and yet no anatomical abnormalities are shown in X-ray examination. Alternatively, there are patients with marked degenerative lesions who may not have any pain at all. Therefore, radiologic imaging techniques, such as CT scan and MRI, should be conducted only in case of suspected radicular pain or for excluding other serious and hazardous pathology.
DIAGNOSTIC FACET JOINT NERVE BLOCK (FNB)
The diagnosis of the facet joint syndrome is set with the diagnostic medial branch block of the posterior stem of the corresponding spinal nerve, with 0,5ml local anaesthetic. The block is applied under fluoroscopic guidance.
Every joint is innervated by two such nerve branches, one from the adjacent superior and one from the adjacent inferior level. For example, for blocking the C4-C5 facet joint, the medial branches of the C4-C5 posterior stem of the corresponding spinal nerve have to be blocked.
Should the patient report over 50% pain relief, following the block, lasting for as long as the duration of the local anaesthetic effect, then diagnosis is made for facet joint syndrome affecting the facet joints which have been blocked.
TREATMENT
Α. CONSERVATIVE
• physiotherapy
• physical exercise
• stretching exercises
Studies have shown that the above combination of conservative treatment may achieve improvement of symptoms, though of slight degree.
Β. INTERVENTIONAL PAIN TREATMENT
• intra-articular injection of corticosteroids
• repetitive blocks of the medial nerve branches with local anaesthetic, with or without corticosteroids
• facet joint denervation with conventional radiofrequency
Observation studies have shown that radiofrequency neurolysis (heat ablation) of nerve branches innervating facet joints, achieve analgesia that lasts one year on average. The technique can be repeated with safety. According to the guidelines for evidence-based invasive treatments in spinal pain, cervical facet joint denervation is recommended as a treatment of choice.
C. SURGICAL TREATMENT
The anterior cervical spine fusion is described as a potential technique for the confrontation of non-radicular cervical pain. A study has shown good results with regard to improvement of pain and functional effect, but the long-term result is unknown.
MEDICAL INFORMATION SOURCES
1. PAIN PRACTICE JOURNAL
2. BONICA”S MANAGEMENT OF PAIN
3. PAIN PHYSICIAN JOURNAL
4. INTERVENTIONAL PAIN MANAGEMENT BOOK
