Encyclopedia of Health and Medicine

crepitus 319
congenital hip DYSPLASIA, also called congenital hip
displacement or developmental dysplasia of the
hip. The dysplasia is sometimes apparent at birth;
doctors may suspect it when the delivery presentation
is breech because this holds the infant’s hips
in a flexed position. Symptoms may include a perceptible
clicking, often felt and heard, when moving
the legs to activate the hip JOINT. Rarely, the
leg may be obviously out of alignment with the
pelvis. X-RAY can often confirm the diagnosis,
though some dysplasias may not be detectable
until the infant is older.
The pediatrician may choose watchful waiting
for a mild dysplasia. A special brace called a Pavlik
harness holds the hips in their proper position in
moderate dysplasia, until the connective tissues
develop the STRENGTH to hold the femur snugly
within the acetabulum. Severe dysplasia or dysplasia
that is undetected until the child is walking
may require closed reduction, in which the orthopedic
surgeon manipulates the joint into place
with the child under ANESTHESIA, or open reduction,
in which the orthopedic surgeon makes surgical
repairs to the joint. Early and appropriate
treatment is important for proper mobility and
development of the leg.
See also BIRTH DEFECTS; CONGENITAL ANOMALY; SUR-
GERY BENEFIT AND RISK ASSESSMENT.
contracture An abnormal shortening or tightening
of connective tissue or MUSCLE that impedes
proper movement of a JOINT, digit, or other musculoskeletal
structure. Contractures typically
develop when fibrous tissue (scarring), which is
relatively inflexible, replaces normal connective
tissue. This process may reflect autoimmune activity
in the body (such as occurs in RHEUMATOID
ARTHRITIS), repeated trauma (such as occurs in
REPETITIVE MOTION INJURIES), or a neuromuscular
disorder (such as MUSCULAR DYSTROPHY or CEREBRAL
PALSY). Contractures can cause permanent deformity
of joints, resulting in limited function or
movement.
Common types of contracture include
• Dupuytren’s contracture, in which fibrous tissue
in the fascia of the hand causes the ring
and sometimes little (third and fourth) fingers
to draw toward the palm
• foot drop, which results from damage to the
muscles and nerves of the lower leg
• wrist drop, which results from damage to the
muscles and nerves of the lower arm
• Volksmann’s contracture, which results from
injury that restricts the flow of BLOOD to the
forearm and hand
Early symptoms of contracture include difficulty
straightening a joint and occasionally discomfort
or PAIN with movement of the joints.
Therapeutic efforts such as gentle stretching and
braces may improve function, though surgery may
be necessary to release fibrotic tissue.
See also ARTHROGRYPOSIS; SCAR; TALIPES EQUINO-
VARUS.
cramp A painful, involuntary, and often
extended contraction of a MUSCLE. Cramps may
occur in any muscle and often occur with overuse,
such as writer’s cramp and leg cramps during running.
Overexertion, DEHYDRATION, and fatigue are
key contributors to muscle cramps. Uterine cramps
are common with MENSTRUATION. Gentle stretching
and massage can relieve the contraction, allowing
the muscle to relax. Heat to the area, such as with
menstrual cramps, helps maintain the muscle in a
relaxed state. Stretching before physical exercise
helps prepare the muscles for activity. Adequate
hydration helps muscles release toxic byproducts
into the BLOOD circulation.
See also DYSMENORRHEA; SPASM.
crepitus A cracking, clicking, or snapping sound,
also called crepitation, that occurs with movement
of a JOINT. Crepitus may occur in normal, healthy
joints though is often quite pronounced in degenerative
joint disorders in which the surfaces of
joint structures are rough or irregular and protective
CARTILAGE structures have deteriorated. Crepitus
is a common feature of TEMPOROMANDIBULAR
DISORDERS, PATELLOFEMORAL SYNDROME, fractures due
to trauma, and OSTEOARTHRITIS.
See also FRACTURE; RHEUMATOID ARTHRITIS.