Facet Joint/Medial Branch Injection and Radiofrequency Ablation

Nature of the procedure

Facet joints are small joints at each segment of the spine that provide stability and help guide motion. The facet joints can become painful due to arthritis, back injury or mechanical stress.

Based on the doctor’s assessment, the suspected facet joint levels are targeted (cervical, thoracic or lumbar). The procedure involves injecting a solution around the nerves (medial branches) supplying the facet joint, or into/around the facet joint.

The procedure is performed while you are lying in the prone position. A needle is inserted under the guidance of fluoroscopy (X-ray) or ultrasound imaging. Once the needle is in position, a solution comprising local anaesthetic with or without steroids, will be injected.

The injection serves two purposes:

1. Diagnostic - to confirm the source of the pain and levels of involvement

2. Therapeutic - to provide short term pain relief so that you may undergo physiotherapy with less discomfort

The duration and degree of pain relief from the injection is variable (weeks to months). You will be followed up to determine your response to the injection, which will then guide your subsequent pain management plan, including repeat injections or radiofrequency ablation (RFA).

RFA is a procedure that uses heat to cause a destructive lesion of the sensory nerves that supply the area causing your pain. It can potentially provide a longer duration of pain relief (compared to a steroid injection) but can cost more.

Risks/possible complications of procedure

As with all invasive procedures, facet joint injections have potential risks and complications associated with the needle placement or injectate. Overall, the risks are low and complications are rare.

a. Allergic reaction: Usually, the allergy is to the X-ray contrast or steroid and rarely to local anaesthetic. Life threatening or severe allergies are rare.

b. Bleeding: This may occur superficially (bruising). The risk is increased if you have underlying bleeding disorders or are on blood thinners.

c. Infection: Minor infections may occur, but severe infections are rare.

d. Discomfort at the point of the injection or worsening of pain symptoms:

These symptoms are usually mild and short lived. Longlasting increases in pain are rare.

e. Leg weakness: This may occur if the procedure is performed at the lumbar or sacral level. It is usually due to the effect of the local anaesthetic on the nerves that supply the leg. If so, leg strength will recover once the local anaesthetic wears off.

f. Local anaesthetic toxicity: This is extremely rare.

g. Nerve damage: While extremely rare, damage to the spinal/ peripheral nerves can occur from direct trauma from the needle and may result in leg weakness or paralysis.

Additional risks/complications related to radiofrequency ablation

If radiofrequency ablation is performed, additional side effects/ risks/complications include:

a. Aggravated pain/soreness over the next 1-2 weeks: This is common and is due to damage of the surrounding tissues from the RFA (burning).

b. Bruising at the injection site: This may occur due to the use of larger needles and needle adjustment.

c. Permanent numbness: This may be an inadvertent side effect of ablating sensory nerves.

d. Permanent weakness: This is rare and may occur due to ablation of a motor nerve. This is avoided through the use of motor testing prior to ablation.

Potential side effects of steroid use

a. Facial flushing, headache

b. Elevated blood sugar

c. Elevated blood pressure, fluid retention

d. Skin thinning/bruising, weight gain

e. Suppression of hypothalamicpituitary axis (impaired stress response)

f. Impaired immunity (increased infection)

g. Neuropsychiatric effects

e.g. mood changes, irritability, confusion, insomnia

h. Bone/muscle effects

e.g. osteoporosis, avascular necrosis, muscles weakness

i. Gastrointestinal effects

e.g. gastritis, ulcer, gastrointestinal bleeding

j. Eye effects: cataract, increased eye pressure (worsening of glaucoma)

k. Cortisone flare

You can discuss further questions regarding facet joint injection and radiofrequency ablation with your chronic pain doctors when you visit the clinic.

Yishun Health is a network of medical institutions and health facilities of the National Healthcare Group in the north of Singapore. It comprises Khoo Teck Puat Hospital, Yishun Community Hospital and community extensions such as Admiralty Medical Centre and Wellness Kampung.

Khoo Teck Puat Hospital • (65) 6555 8000 • www.ktph.com.sg

Yishun Community Hospital • (65) 6807 8800 • www.yishuncommunityhospital.com.sg