Procedures that target the facet joints may be a choice for some people who have chronic pain in the neck or the lower back. The various terms may be confusing, because injecting medicine into the facet joint, blocking the medial branch nerve, and nerve ablation with radiofrequency are separate procedures and have different purposes. These procedures should not be regarded as being able to repair the structure of the spine, or as necessary to do before beginning rehabilitation.

The suitable approach depends on the clinical question, the position in the spine, the care that has gone before, the medical risks, and the guidelines of practice in the area. The doctor should explain the target position, whether the procedure is intended to help in diagnosis, in treatment, or in predicting the result of treatment, the length of time and the extent of the benefit expected, the other alternatives, and the plan of care after the procedure.

Facet joints are joints that lie in pairs at the back of the cervical, thoracic and lumbar spine. They have the duty of governing the movement between adjacent vertebrae and helping add stability. This kind of joint may undergo change with age, inflammation, or injury, like other synovial joints.

Degeneration is met often and may be present without causing pain. Therefore an image that finds a degenerated facet joint does not confirm that that joint is the cause of the symptoms.

Pain from the facet joint may be considered when the pain is prominent in the neck or the lower back, and sometimes radiates to the neighbouring area. However, the position of the pain, tenderness, pain on arching or rotating, and the results of imaging are all not specific enough to confirm the diagnosis by themselves. An intervertebral disc, the muscles, the nerves, the sacroiliac joint, the hip joint, or several factors together may cause similar symptoms.

The multidisciplinary guidelines for the lumbar facet joint (opens in a new tab) and the multidisciplinary guidelines for the cervical facet joint (opens in a new tab) speak of these limitations in diagnosis. The assessment should also search for abnormality of the nerve root or the spinal cord, systemic disease, the risk of a fracture, and other causes that may change the approach to care.

This procedure places a needle into the target facet joint and then injects a small amount of local anaesthetic, which in some cases may be mixed with corticosteroid medicine. The purpose may be short-term relief of the symptoms, or giving further information to help in diagnosis according to a plan that has been determined. This procedure does not create new cartilage, reverse the process of joint degeneration, or put right the alignment of the spine.

The medial branch nerve block

The medial branch nerve block is the injection of local anaesthetic near the small nerves that carry sensation from the facet joint. It is usually used as a test to help in diagnosis or in predicting the result when nerve ablation with radiofrequency is being considered. Symptoms easing after the block may support the diagnostic hypothesis, but cannot confirm it, because the spread of the anaesthetic, the effect of expectation, the natural variability of the symptoms, as well as false positives or false negatives, may affect the interpretation.

Nerve ablation with radiofrequency

This procedure uses heat from radiofrequency energy in order to cut the sending of signals of the selected medial branch nerves. It is not an injection of medicine, and in general it is considered after a block done suitably has given a response according to the criteria of the guidelines used. The procedure does not guarantee a result; the nerves may recover, and the symptoms may return.

What do the guidelines of practice and the evidence say?

The recommendations differ according to the kind of procedure, the position in the spine, the selection of patients, and the health system. The evidence supporting injecting medicine into the facet joint for treatment as a routine is still limited, while nerve ablation with radiofrequency may help some patients who have passed careful selection and who respond to a medial branch nerve block.

For lower back pain, the NICE guideline (opens in a new tab) does not recommend injecting medicine into the structures of the spine to manage lower back pain, and reserves the assessment for nerve ablation with radiofrequency for those who have passed selection and who do not respond to care without surgery, with a response to a diagnostic medial branch nerve block required before nerve ablation. The details in other professional guidelines may differ, so these differences should be explained rather than regarding facet joint procedures as normal care for everyone.

Why is the use of image guidance important?

The facet joints and the medial branch nerves are small targets that lie near blood vessels, nerve roots, and other important structures. In general, fluoroscopy or computed tomography is used to guide the needle, and ultrasound may be used in some procedures or with some patients. Guidance helps increase anatomical precision and helps detect a spread of contrast medium that is not on target, but it cannot confirm the source of the pain, guarantee the result, or remove all the risks.

Who may be considered for a procedure?

In general, consideration begins from a pattern of symptoms that corresponds, significant limitations in function, and having tried suitable care without a procedure sufficiently. The procedure should answer a clearly defined question or help a specific decision about treatment. Imaging may help in planning and in ruling out other states, but degeneration alone is not a sufficient indication.

The decision should take account of the patient's goals, the response to previous treatment, accompanying diseases, the medicines used, the ability to follow the advice, and the balance between the possible benefit and the burden and risks. Some people may be better suited to continuing conservative care or to an assessment of another source of pain.

When may a procedure not be suitable, and what risks are there?

Before the procedure, the treating team should review an infection that is currently present, abnormality of the clotting of the blood and the use of antithrombotic medicines, a history of allergy to relevant medicines or substances, disease that is still not stably controlled, pregnancy or possible pregnancy when radiation is used, as well as states that may be affected by corticosteroid, such as diabetes. Patients should not stop their medicines by themselves without advice from the prescriber or the person carrying out the procedure.

The adverse effects that may arise are temporary soreness or a flare-up of pain, bruising, bleeding, infection, an allergic reaction to the medicine or the contrast medium, effects from the steroid, as well as temporary numbness or weakness. Complications that are met infrequently but are severe may include unintended injection into a blood vessel, injury to a nerve or the spinal cord, or puncture through the dura and headache. The risks depend on the position, the technique, the medicine used, and the health of each person. The patient guide from RadiologyInfo (opens in a new tab) gives an overview, while the treating doctor should explain the risks of the particular procedure proposed.

What can the response to a block or an injection tell us?

The period and the degree to which the symptoms ease should be interpreted against the medicine used, the length of time the anaesthetic should act, the normal variability of the symptoms, the activities done during the period of observation, and the criteria agreed in advance. A pain score without information on function and activity may be misleading.

Symptoms improving temporarily may add weight to the diagnostic hypothesis or help determine the next decision, but it does not prove that all the symptoms come from one joint, does not show that the structure has healed, does not predict that the result will be permanent, and does not rule out other causes. If the symptoms ease little or not at all, there should be a careful review rather than repeating the procedure automatically.

Where does rehabilitation come in?

Rehabilitation may be suitable before a procedure, after a procedure, or without a procedure at all. Its role is to help the patient move, work, exercise, and cope with daily routines better, not to make the effect of the injection "last longer" or to put right a presumed abnormality.

If the procedure reduces the pain for a period, that period may be favourable to increasing activity in an ordered way, but the plan must still follow the advice after the procedure and the patient's response. Reduced pain does not mean that the tissue is ready to bear load without limit. At the same time, temporary soreness does not always mean that all activity must be stopped.

Building the control of the trunk and tolerance of activity

The control of the trunk is the coordinated working of the muscles around the spine, the pelvis, the hip, and the shoulder blade. It does not mean tensing the abdomen or keeping the spine still all day.

Exercise may gradually develop from comfortable movement and control with low force, through to walking, reaching, lifting, carrying, occupational tasks, training in the gym, or sport. The starting point and the increase in level should correspond with the previous capacity, the symptoms, the neurological findings, other health states, and the goals of each person. There is no single best exercise programme for everyone who is suspected of having pain from the facet joint.

Posture and mobility without clinging to a perfect posture

Posture may have an effect on the symptoms, but there is no single ideal posture that everyone must maintain all day. Changing posture, alternating tasks, and gradually increasing endurance are usually more useful than forcing a strict arrangement of posture.

Training mobility should aim at coming back to movement that can be controlled, without forcing the neck or the back through severe or continually increasing pain. The training may cover the cervical or lumbar spine, the thoracic area, the hip, or the shoulder according to the result of the assessment. Mobility and stability support each other, because daily life requires both movement and control.

Recurrence, reassessment, and danger signals

Neither a procedure nor rehabilitation can guarantee that the pain will not return. There should be a reassessment when the pattern of the symptoms changes, when the benefit is less or shorter than expected, when the ability to function decreases, or when repeating a procedure is being considered without a clear goal.

Newly arisen abnormality in the control of urine or faeces, numbness in the area of the buttocks and the genitals, or weakness of the limbs that deteriorates rapidly must receive an urgent medical assessment. Newly arisen abnormality of walking or balance, a reduced ability to use the hands for fine tasks together with symptoms in the neck, fever or illness throughout the body, severe pain after a high-force accident, or pain in those who have risks related to cancer or infection, should also receive an assessment quickly.

Questions that should be asked before deciding

Which diagnosis is being considered, and what other causes have already been assessed?
Is the procedure proposed an injection of medicine into the joint, a medial branch nerve block, or nerve ablation with radiofrequency?
Is the purpose to help in diagnosis, to predict the result, to treat, or several of these together?
What kind of result is regarded as meaningful, and how will the pain and the function be recorded?
What are the risks, the effects of the medicine, the alternatives, and the particular limitations after the procedure?
How will the result obtained change the next step, including rehabilitation or further examination?

Using the period in which the pain is reduced with care

Facet joint procedures may be of benefit for selected patients, when the procedure answers a clear clinical question, and when there has been a well-rounded discussion of the uncertainties, the alternatives, and the risks. They should not be presented as proof of the source of the pain, as a repair of the structure, or as a path to recovery that guarantees a result.

When the symptoms ease, activity can in general be gradually built back up according to a plan specific to the individual. The most useful outcome is not merely a reduced pain score, but function that is meaningful and safer, together with a plan for reassessment agreed on together.