transmitted pain. Under facet syndrome, there is a more elaborate discussion of
the type of pain transmitted by the facet joints.
TYPES OF FACET BLOCKS:
Facet joints (technically called zygapophyseal or z-joints) are the small paired
joints in the back of each spine segment from the cervical spine to the end of the
lumbar spine. They may be injected or "blocked" in cases of facet arthropathy
(joint pain). There are two basic types of injections: Intra-articular injections in
which the needle is placed directly into the joint and steroid is injected with or
without local anesthetic, and medial branch blocks which are injections of the
small nerve adjacent to the joint.
Intra-articular blocks are not diagnostic for pain but are only therapeutic due to the
fact that local anesthetic can leak out of the joint onto the spinal nerve roots and
thereby reduce the selectivity of the injection. Intra-articular blocks derive their
therapeutic effect from the steroid injected into the inflamed joint. Patients may
derive weeks to months of relief from these injections.
Medial branch blocks are only diagnostic since the injection is not into the joint
itself, but is on the nerve (medial branch) leading to the joint. This block consists
of a small amount of local anesthetic deposited onto the nerve from the joint and
the amount of relief from pain is gauged after the injection. Typically a
person having a medial branch block will be given a pain assessment sheet in
which an hour by
hour assessment of pain should be recorded for the first 6 hours after the
procedure. If a person has a positive response to a medial branch block with
significant temporary pain relief, the next step for longer term pain control would
be a radiofrequency neurotomy, cryoneurolysis, or laser neurotomy of the medial
branch which is performed at a different time with different equipment.
Either procedure may be performed as an outpatient under local anesthesia only
or with mild sedation. Both cervical and lumbar facet blocks may be performed
depending on the pain pattern.
COMPLICATIONS: Serious complications are extremely rare. The overall
complication rate is close to zero when fluoroscopic guidance is used due to the small
amounts of medications used and because this is a relatively safe "joint injection" just like
the knee or wrist. There may be medication effects which can cause slight elevations of
blood sugar and pressure temporarily and an occasional rash. There is always the
possibility of bleeding, infection, nerve injury from any injection, however the risk is
extremely small with either of the two procedures.
Needle is on the nerve to
the facet (medial branch)
and has been injected
with contrast to outline
the nerve
