Dr. MJ Bazos MD,
Patient
Handout
Joint
Injection/Aspiration
What is done during a joint
injection/aspiration?
Joint injections or aspirations (taking fluid
out of a joint) are usually performed under local anesthesia in the office or
hospital setting. After the skin surface is thoroughly cleaned, the joint is
entered with a needle attached to a syringe. At this point, either joint fluid
can be obtained and sent for appropriate laboratory testing or medications can
be injected into the joint space. This technique also applies to injections into
a bursa or tendon to treat tendinitis and bursitis, respectively.
What benefit is derived from a joint
aspiration ?
Joint aspiration is usually done as a diagnostic
or therapeutic procedure. Fluid obtained from a joint aspiration can be sent for
laboratory analysis, which may include a cell count (the number of white or red
blood cells), crystal analysis (so as to confirm the presence of gout or
pseudogout), and/or culture (to determine if an infection is present inside the
joint). Drainage of a large joint effusion can provide pain relief and improved
mobility. Injection of a drug into the joint may yield complete or short-term
relief of symptoms.
What benefit is derived from a joint
injection ?
Joint injections are given to treat inflammatory
joint conditions, such as rheumatoid arthritis, psoriatic arthritis, gout and
occasionally osteoarthritis. Corticosteroids are frequently used for this
procedure as they are anti-inflammatory agents that slows down the accumulation
of cells responsible for producing inflammation within the joint space. Although
corticosteroids may also be successfully used in osteoarthritis, their mode of
action is less clear. Hyaluronic acid (Hyalgan ®, Synvisc ®) is a
viscous lubricating substance that may relieve the symptoms of osteoarthritis of
the knee.
What is usually injected into the joint space
?
Most joint injections utilize anti-inflammatory
medications called corticosteroids (such as methylprednisolone or
triamcinolone). These medications act locally and have few systemic side-effects
(such as a fever, rash, or a disturbance of an internal organ). In degenerative
joint diseases such as osteoarthritis, a joint lubricant such as hyaluronic acid
(described above) may be used with aim of relieving pain.
Which joints are usually injected
?
Commonly injected joints include the knee,
shoulder, ankle, elbow and wrist and small joints of the hands and feet. Hip
joint injection may require the aid of an X-Ray called fluoroscopy for guidance.
Facet joints of the lumbar spine (low back area) may also be injected by
experienced rheumatologists, orthopaedists, anesthesiologists, and
radiologists.
What are the risks of joint injections and
aspirations ?
Common side effects include allergic reactions
(to the medicines injected into joints, to tape or the betadine used to clean
the skin, etc). Infections are extremely rare complications of joint injections
and occur less than 1 time per 15,000 corticosteroid injections. Another
uncommon complication is "post-injection flare" - joint swelling and pain
several hours after the corticosteroid injection - which occurs in approximately
one out of 50 patients and usually subsides within several days. It is not known
if joint damage may be related to frequent corticosteroid injections. Generally,
repeated and numerous injections into the same joint/site should be discouraged.
Other complications, though infrequent, include depigmentation (a whitening of
the skin), local fat atrophy (thinning of the skin) at the injection site and
rupture of a tendon located in the path of the injection.
Are there situations where a joint injection
should not be given ?
Yes. The most common reasons for not performing
a joint injection are the presence of an infection in or around a joint and if
someone has a serious allergy to one or more of the medications that are
injected into a joint.