Week 3: Bone Diseases Flashcards
Joint effusion
Accumulation of fluid in the joint associated with an underlying
condition
There are typical
appearances of effusions in the ankle, knee, elbow and hip
that aid in the diagnosis of subtle
pathologies
Sail Sign
in the elbow. Anterior fat pad elevation looks like a
sail and is a sign of joint effusion and
potential fracture
Legge-Calve-Perthe’s Disease
Flattening of the femoral head due to
vascular interruption
Avascular necrosis of the capital
femoral epiphysis of the femoral head
Most common in Caucasian males 4-8 years old
Osgood schlatter’s
Incomplete separation or
avulsion of the tibial tuberosity
A chronic fatigue injury due to
repeated microtrauma at the
patellar ligament insertion onto
the tibial tuberosity, usually
affecting boys between 10-15
years
Osteopetrosis
Rare, hereditary bone dysplasia causes “marble bones”, severity varies
Normal resorptive calcium mechanism is absent, interferes with normal bone replacement
Prevents bone marrow from forming, patients can be anemic
Bones become brittle and stress fracture often
Technical factors (mAs, kV) must be increased to account for increased bone formation
Osteogenesis imperfecta
brittle bone disease):
an inherited generalized disorder of connective tissue
Characterized by fragile bones, bowed legs and an
unusual blue color of the normally white sclera of the
eye
Patients suffer repeated fractures
Healing process can cause bizarre deformities due to
bizarre callus formation
Skull ossification is slow, producing Wormian bones
(wide sutures and intra-sutural bone development)
Extreme care must be taken when positioning these
patients
Lower kV to compensate for the loss of bone quality
Radiographically: severe osteoporosis, thin defective
cortices, Wormian bones in skull
Achondroplasia
Hereditary disorder
The most common form of
dwarfism
Growth plates of the long bones
don’t proliferate new growth
properly, leading to a normal
trunk length but abnormally short
limbs, and large head
Acromegaly
Excessive growth hormone AFTER bone growth has stopped
Often caused by a pituitary tumor
Sometimes follows gigantism (excessive
growth hormone BEFORE bone growth has stopped) if hypersecretion of growth hormone doesn’t cease at maturity
Congenital (Developmental) Hip Dysplasia
Results from incomplete acetabulum formation caused by physiologic & mechanical factors
Femoral head pops out of joint during flexion and abduction
May use x-ray or US for diagnosis
Imaging appearance:
AP pelvis & bilateral frog-leg (Cleaves)
views are required to make a diagnosis
AP - larger joint space
Cleaves – hip dislocation posteriorly and superiorly
Rheumatoid Arthritis
Chronic systemic disease of unknown
cause
Appears primarily as a non-infectious
inflammatory arthritis of the small
joints of the hands and feet
Begins as an inflammation of the
synovial membrane (synovitis) that
lines the joints
Bursitis
Inflammation of the bursae
(small fluid filled sac within joint
space to reduce friction)
Causes pain, frozen joints
(immobility)
Not seen radiographically except
by calcification deposits in
adjacent tendons (calcific
tendonitis)
Needs US diagnosis
Osteoarthritis
Degenerative condition
Loss of joint cartilage and reactive new bone formation
Usually affects the weight-bearing
joints (spine, hip, knee and ankle) and
the interphalangeal joints of the
fingers
Osteomyelitis
An inflammation of the bone and
bone marrow
Caused by infectious organism
A soft tissue infection may
spread from a skin abscess or
decubitus ulcer eg. foot of a
diabetic patient, to cause
cellulitis and eventually
osteomyelitis in adjacent bones
Osteomyelitis Image Appearance
Imaging Appearance:
* Localized, deep soft tissue
swelling adjacent to the
metaphysis
* Metaphyseal lucency which
progresses to bone destruction
(ragged, moth-eaten
appearance)
Osteoporosis
Generalized or localized
deficiency of bone density
– bone mass is decreased
Lack of calcium and
vitamin D
Compression fractures
common in spines;
fractured wrists and hips
in elderly
