Facet infiltration (synonyms: Facet Joint Infiltration (FGI); Facet Infiltration Therapy (FIT)) represents an interventional radiologic procedure for the treatment of painful facet joints. In this procedure, locally active drugs are injected in the immediate vicinity (periarticular) of the facet joints and into the joint capsule (intraarticular). The facet joints (zygapophyseal joints; intervertebral joints) are small, paired joints that exist between the articular processes (processus articularis) of adjacent vertebrae and ensure mobility of the spine.
Indications (areas of application)
- Facet syndrome (synonym: facet joint syndrome); this presents with pseudoradicular pain symptomatology (pain in which the nerve itself is not impaired in its function), usually due to chronic irritation of the facet joints. The cause of the facet syndrome are degenerative changes of the small vertebral joints
Note: Facet injection as a decisive diagnostic criterion of facet syndrome is not suitable.
Contraindications
- Acute infections or presence of inflammatory processes.
- Thrombocytopenias (deficiency of platelets) and blood coagulation disorders.
- Allergies to the drugs or contrast media to be applied.
Before treatment
- Patient education at least 24 hours before therapy.
- Current cross-sectional imaging of the therapy region.
- Current blood coagulation (Quick > 90%), blood count, C-reactive protein in erosive osteochondrosis (progression of disc degeneration involving and co-reacting with the bony endplates of adjacent vertebral bodies).
The procedures
Infiltration of the vertebral joints as a so-called facet infiltration. Even in the case of a facet joint with no degenerative changes, safe selective puncture of the joint space is only possible with the aid of imaging techniques (CT control; MRI control). Indications for the use of the image converter or CT or MRI arise in addition to securing the needle position in cases of spinal deformities and obesity with difficult palpation (palpation) of the landmarks. Between 1.0 and 5.0 ml (!!) of a local anesthetic (often combined with a glucocorticoid) is injected into the lower joint recessus. Some authors specify 3 ml as the lower limit (to avoid capsular rupture). Pain relief or anti-inflammation is achieved either by intra-articular injection or by flooding the joint. In the presence of facet syndrome, insertion of the needle into the capsule usually results in pain provocation; after an injection, there should be freedom from pain. If short-term improvement is achieved by facet infiltration, cryoanalgesia (pain-conducting nerve is iced at approximately -60 °C) or facet denervation (“denervation of the facet joints”) by thermoablation (tissue is eliminated by heat) or chemically (with 96% ethanol) may be used as longer-acting measures in selected cases.
After treatment
After therapy is complete, no further measures are usually necessary.
Possible complications
Local anesthesia
- Allergic reactions
Facet joint infiltration
- During treatment, there may be brief pain in the small of the back or neck or in the legs or arms (depending on the location of infiltration: lumbar or cervical spine) [in rare cases].
- Capsular rupture (most common risk) [to avoid, the injection volume should not exceed the capsule volume].
- Painfulness in the area of the injection site for a few days [in rare cases].
- Injury to blood vessels or occurrence of infection [1 case per 35,000 injections].
- Transient redness of the face with sensation of heat and transient elevation of blood pressure and glucose levels may occur due to glucocorticoids.
- Premature menstruation is possible in women.[rare]
