Some possible side effects of facet joint injection are discomfort at the site of the injection or a short-lived increase in the pain symptoms being treated, according to Spine-health. Mild Infections at the injection site occur in less than 2 percent of patients, and severe infections are significantly more rare.
Facet joint injections treat the pain associated with facet syndrome, a condition in which one or more of the joints between the spinal vertebrae become irritated or inflamed. The doctor determines the site of injection by using X-ray or fluoroscopic guidance. The injection includes a mixture of local anaesthetic and corticosteroid anti-inflammatory medication to relieve pain and inflammation, states the National Spine and Pain Centers. If this procedure is successful at relieving pain, then it serves as a diagnostic indicator that the facet joint, and not some other spinal structure, is responsible for generating the pain.
Rarely, patients experience an allergic reaction to the X-ray contrast dye or to the corticosteroid injection. Patients that have bleeding disorders or who take blood thinners may experience bleeding. It is also possible yet extremely rare for spinal paralysis or nerve damage to occur due to the impact or injection site of the needle or as a secondary effect from bleeding or infection, writes Spine-health. The injected corticosteroid may cause transient flushing, increased blood pressure and blood sugar levels, mood disturbances and insomnia, and retention of fluid. It may also cause an increase in appetite and weight gain, and the patient's immunity may be lowered for a short time.