Webster's New World Medical Dictionary

synovia
See 
synovial fluid.
synovial cyst, popliteal
See 
Baker cyst.
synovial fluid
The slippery fluid that lubricates
joints. Also known as synovia.
synovial lining
The lining of the joints, normally
only one or two cell layers thick, that is responsible
for the production of the joint fluid. Also known as
synovium.
synovial osteochondromatosis
A disorder of a
joint that features a change of the normal synovial
lining’s cellular structure to form bone-cartilage tis-
sue. Synovial osteochondromatosis is uncommon
and typically seen in young to middle-aged adults.
Synovial osteochondromatosis leads to pain in the
affected joint as well as limitation of the range of
motion and often locking. The cause of synovial
osteochondromatosis is unknown. Synovial osteo-
chondromatosis generally affects only a single joint.
The most common joints involved are the knee, hip,
or elbow. Synovial osteochondromatosis can be
diagnosed with an imaging test of the joint, such as
an X-ray, a computerized axial tomography (CAT)
scan, or a magnetic resonance imaging (MRI) scan.
Treatment of synovial osteochondromatosis typically
involves surgical removal of the synovial lining.
synovial sarcoma
See 
sarcoma, synovial.
synoviosarcoma
See 
sarcoma, synovial.
synovitis
Inflammation of the synovial mem-
brane, the lining of the joints.
syphilis
A sexually transmitted disease that is
caused by Treponema pallidum, a spiral-shaped
microscopic organism called a spirochete. The
organism infects people by burrowing into the moist
mucous membranes of the mouth or genitals. From
there, the spirochete produces a nonpainful ulcer
known as a chancre. There are three stages of
syphilis. The first (primary) stage is formation of the
chancre, and it can last from 1 to 5 weeks. At this
stage, syphilis is highly contagious and is transmit-
ted via any contact with one of the ulcers. Even with-
out treatment, the early infection usually resolves on
its own. However, 25 percent proceed to the sec-
ondary stage of syphilis, which lasts from 4 to 6
weeks. This phase can include hair loss; a sore
throat; white patches in the nose, mouth, and
vagina; fever; headaches; and a skin rash. There can
be lesions on the genitals that resemble genital
warts but are caused by spirochetes. These wart-like
lesions, as well as the skin rash, are highly conta-
gious. The rash can occur on the palms of the
hands, and the infection can be transmitted via
casual contact. The third (tertiary) stage of the dis-
ease involves the brain and heart, and at this point
the disease is usually no longer contagious. At this
point, however, the infection can cause extensive
damage to the internal organs and the brain; it can
even lead to death. Diagnosis is made via blood test,
either the rapid plasma reagin (RPR) or Venereal
Disease Research Laboratory (VDRL) test.
Treatment involves use of antibiotics. While syphilis
is relatively easily treated with antibiotics in its ear-
lier stages, late stage syphilis can leave permanent
brain and nervous system damage despite an
extended antibiotic course. See also 
chancre;
spirochete; syphilis, congenital; syphilis test, RPR;
VDRL test.