Comprehensive Radiographic Pathology: Chapter 4: Skeletal System Flashcards
Parts of bone
d. Medullary Cavity
fibrous membrane covering the outer surface
shaft of a long bone
end of a long bone that at first is separated from the main part by cartilage but later fuses with it by ossification
Halo, tube-like structure within the diaphysis
inner membrane lining the medullary cavity of a bone
What two tissues is the skeletal system composed of?
What are two types of bone?
• Compact (outer layer)
• Cancellous (spongy, inner layer)
outer layer consists of which to the naked eye appear stents and structureless
the spongy bone of the medullary cavity and bony trabeculae
Two types of bone cells:
enlarge the diameter of the medullary cavity by removing bone from the diaphysis wall
produce new bone around the outer circumference from the periosteum
bone destruction by osteoclast
bone formation from connective tissue
Congenital/Hereditary Diseases of Bone
• Vertebral Anomalies
• Spina Bifida
• Osteogenesis Imperfecta
• Congenital Hip Dysplasia (Dislocation)
vertebrate with characteristics of another spinal region
where is a transitional vertebrae most commonly located
It occurs most often at L/S junction.
is a spinal canal defect caused from failure of the
posterior elements to fuse properly.
spina bifida occulta
is a mild, insignificant form, in which there is a
splitting of the bony neural canal at the L5 or S1 level.
spina bifida Large defects have complications of herniations:
protrusion of the meninges through the skin
herniation of the spinal cord and meninges through the skin
It is a rare hereditary bone dysplasia in which failure of the
mechanism of calcified cartilage interferes with the normal
replacement by mature bone.
what is the nickname for Osteopetrosis?
Osteopetrosis is nicknamed “marble bones.”
what does Osteopetrosis result in?
It results in very brittle bones.
It is an inherited generalized disorder of connective
characterized by multiple fractures and an unusual blue color of the
normally white sclera of the eye.
Osteogenesis imperfecta is nicknamed?
Osteogenesis imperfecta is nicknamed “brittle bone disease.”
How would this disease with less dense bone affect technique?
technique would be lower
the most common form of dwarfism
Achondroplasia is the most common form of dwarfism.
what does achondroplasia result from?
It results from diminished proliferation of cartilage in the growth
(decreased enchondral bone formation).
Is achondroplasia dominant or recessive?
It is an autosomal dominant condition.
what is achondroplasia characterized by?
It is characterized by short limbs with a normal axial skeleton.
Congenital hip dysplasia/dislocation is known as?
Congenital hip dysplasia/dislocation is known as developmental hip
what does congenital hip dysplasia/dislocation result from?
It results from incomplete acetabulum formation caused
physiologic and mechanical factors
Inflammatory and Infectious Disorders
• Rheumatoid Arthritis
• Infectious Arthritis
• Tuberculous Arthritis
• Rotator Cuff Tears
• Tears of the Menisci of
• Bacterial Osteomyelitis
what is rheumatoid arthritis?
Rheumatoid arthritis is a chronic systemic idiopathic disease.
what does rheumatoid arthritis appear as?
appears primarily as a noninfectious inflammatory arthritis of
small joints of the hands and feet.
• Ankylosing spondylitis
• Reiter’s syndrome
• Psoriatic arthritis
how does rheumatoid arthritis begin?
what is osteoarthritis(Degenerative Joint Disease)?
is a very common generalized disorder characterized by
loss of joint cartilage and reactive new bone formation.
what causes osteoarthritis?
It is part of the wear and tear of the aging process.
what does osteoarthritis affect?
It affects the weight-bearing joints (spine, hip, knee, ankle) and
interphalangeal joints of the fingers.
what's the best way to show osteoarthritis on an X-ray?
what does osteoarthritis look like on an X-ray?
the earliest radiographic findings in degenerative joint disease are narrowing of the joint space, caused by thinning of the articular cartilage, and development of the small bony spurs(osteophytes) along the margins of the articular edge of the bones.
what is infectious arthritis caused by?
Infectious arthritis is caused by pyogenic organisms.
what is the most common form of infectious arthritis?
The most common type is migratory arthritis from Lyme disease.
what is tuberculosis arthritis?
is a chronic, indolent infection that has a gradual
onset and a slowly progressive course.
tuberculosis arthritis usually involves one joint, commonly the:
most patients with tuberculosis arthritis also have?
Most patients have pulmonary TB.
what is bursitis?
is an inflammation of the small fluid-filled sacs located
the joints that reduce the friction caused by movement.
• Repeated physical activity (most common)
• Rheumatoid arthritis
what is the modality of choice for bursitis?
what is a rotator cuff?
The rotator cuff of the shoulder is a musculotendinous
composed of the teres minor, infraspinatus, supraspinatus, and
what do rotator cuff tears produce?
Tears produce a communication between the shoulder joint and
what is the modality of choice for a rotator cuff tear?
MRI is modality of choice for demonstration
tears of the meniscus are common cause of what?
Tears of the menisci of the knee are common cause of knee pain.
tears of the meniscus of the knee causes:
• Acute trauma
• Degeneration due to chronic trauma
what is the modality of choice for meniscus knee tears
MRI is the modality of choice to demonstrate meniscal tears
is an inflammation of the bone and marrow caused by a variety of infectious organisms.
how does bacterial osteomyelitis spread?
Infectious organisms reach bone by hematogenous spread, extension
adjacent site of infection, or direct introduction of organisms (after trauma or
what is the modality of choice for bacterial osteomyelitis?
how does bacterial osteomyelitis begin? how is it caused?
Tuberculous osteomyelitis (Pott’s disease)
Rare today – but usually affects T and L spine
Metabolic Bone Disease
• Paget’s Disease
is a generalized or localized deficiency of bone matrix in
which the mass of bone per unit volume is decreased in amount but
normal in composition.
what causes osteoporosis?
Its causes include aging and postmenopausal hormonal changes.
how do you have to change your technique for osteoporosis?
A decrease in kVp is required to obtain quality image.
what is osteomalacia?
Osteomalacia is insufficient mineralization of the adult skeleton.
what is osteomalacia caused by?
may be caused by inadequate intake or absorption of
phosphorus, or vitamin D. Other nutritional causes of osteomalacia are chronic kidney failure or kidney diseases that cause calcium secretion in the urine.
what are the results to bone from osteomalacia?
is a systemic disease of infancy and childhood that is
equivalent of osteomalacia in adults.
what is the cause of rickets?
Calcification of growing skeletal elements is defective because of
deficiency of vitamin D in the diet or a lack of exposure to ultraviolet
radiation (sunshine), which converts sterols in the skin into vitamin D.
what is gout? how does it affect the body?
is a disorder in the metabolism of purine (a component
nucleic acids). It increases uric acid in the blood, which leads to the deposition of uric acid crystals in the joints, cartilage, and kidney.
where does gout normally show up first?
Gout manifests as very painful arthritis that initially attacks a
joint, primarily the first metatarsophalangeal joint.
what is Paget's disease also known as?
Paget’s disease is also known as osteitis deformans.
what are the phases of Paget's disease?
what is the most common initial site for Paget's disease?
what is Paget's disease? what is the cure?
It is one of the most common chronic metabolic diseases of
skeleton. there is no known cure.
what is Paget's disease caused an increased risk of?
There is associated increased risk of osteosarcoma later in life.
Lead poisoning results from the ingestion of lead-containing
(especially paint) or from the occupational inhalation of lead fumes.
what causes lead poisoning from environmental exposure to occur?
Environmental exposure occurs when drinking water (leaded
and eating food that is processed, preserved, or stored in containers
made with lead.
what is the number one major environmental pollutant worldwide?
Currently, lead is the number one major environmental pollutant
what does chronic lead poisoning cause?
Chronic form of lead poisoning may cause mental
seizures, behavioral disorders, or delayed development.
why is lead poisoning more common in children?
Children are more susceptible to lower doses.
• Lead’s effects on CNS are more severe.
what is fibrous dysplasia?
Fibrous dysplasia is characterized by the proliferation of fibrous
within the medullary cavity
what does fibrous dysplasia cause?
It causes loss of trabecular markings and widening of the bone.
why does Ischemic Necrosis of Bone occur?
Occurs due to a loss of blood supply
Ischemic Necrosis of Bone causes:
• Disease of surrounding bone
• Single or repeated trauma
• Steroid therapy
• Cushing’s disease
• Hemolytic anemia (especially sickle cell disease)
• Chronic alcoholism
• Chronic pancreatitis
• Gaucher’s disease
• Radiation therapy
• Caisson disease (a complication of underwater diving, the “bends”)
Ischemic Necrosis of Bone x-ray
Benign bone tumors:
• Giant cell tumor (osteoclastoma)
• Osteoid osteoma
• Simple bone cyst
• Aneurysmal bone cyst
• Bone island
Malignant bone tumors:
• Osteogenic sarcoma
• Ewing’s sarcoma
• Multiple myeloma
• Bone metastases
what is osteochondroma? where is it commonly located?
It is a benign projection of bone with a cartilaginous cap that
childhood or the teen years.
• It is commonly near the knee.
what is osteochondroma also termed? what are the characteristics?
Osteochondroma is also termed exostosis.
• Long axis of tumor runs parallel to the bone shaft.
• Points away from the nearest joint
what are enchondromas?
Enchondromas are low-growing benign cartilaginous tumors arising
the medullary canal.
where do enchondromas occur?
They are primarily in the small bones of the hands and feet. They are often found when a fracture occurs with minimal force.
where does a giant cell tumor typically arise? does it affect the joint?
Giant cell tumor typically arises at the end of the distal femur
proximal tibia of a young adult after epiphyseal closure (20- to 40-
year olds). It does not affect the joint
where do osteomas occur? what do they cause?
Osteomas most often arise in the outer table of the skull,
paranasal sinuses (especially frontal and ethmoid), and the mandible. They cause pain.
how do osteomas appear radiographically?
They appear radiographically as well-circumscribed, extremely
round lesions that are rarely larger than 2 cm in diameter.
What is osteoid osteoma?
Osteoid osteoma is typically imaged as a small, round or oval,
center (the nidus), less than 1 cm in diameter, that is surrounded by a
large, dense sclerotic zone of cortical thickening.
What age group is osteoid osteoma most common in?
It is most common in teenagers or young adults.
what is the main symptom of osteoid osteoma?
Symptom is local pain, which increases at night and is easily
what is a simple bone cyst?
is a true fluid-filled cyst with a wall of fibrous
tissue, which most often occurs in the proximal humerus or femur at
what's another name for a simple bone cyst?
how is the simple bone cyst discovered? Why?
It is asymptomatic. It is often discovered either incidentally or after pathologic fracture.
simple bone cyst x-ray
what is an aneurysm bone cyst?
An aneurysmal bone cyst is not a true neoplasm or cyst. It consists of numerous blood-filled, arteriovenous communications thought to be caused by trauma.
aneurysmal bone cyst x-ray
what is a bone Island? where do they occur?
Bone islands are solitary, sharply demarcated areas of dense
bone that occur most commonly in the pelvis and upper femur. They appear in every bone except the skull.
malignant bone tumors appearance
what is an osteogenic sarcoma?
a malignant tumor of osteoblasts, which produce osteoid and spicules of calcified bone.
where does an osteogenic sarcoma occur?
generally occurs in the end of a long bone in the metaphysis (especially about the knee).
what age group is osteogenic sarcoma normally found in?
It is most common in persons between 10 and 25 years old. Smaller peak incidence is seen in older persons who have a preexisting bone disorder, particularly Paget’s disease.
what is chondrosarcoma?
Chondrosarcoma is a malignant tumor of cartilaginous origin that
originate anew or within a preexisting cartilaginous lesion, e.g.,
osteochondroma and enchondroma).
where does chondrosarcoma occur?
Commonly occurs in long bones, but often originates in a rib,
when does chondrosarcoma occur?
It develops at a later age (peak incidence in 35- to 60-year
grows more slowly, and metastasizes later.
What is Ewing’s sarcoma?
is a primary malignant tumor arising in the bone
marrow of long bones.
What age group does Ewing's sarcoma occur in?
It occurs in children and young adults.
• It is rare over age 30.
what is multiple myeloma?
Multiple myeloma is a widespread malignancy of plasma cells. It is associated with bone destruction, bone marrow failure, hypercalcemia, renal failure, and recurrent infections.
what age group is multiple myeloma found in?
The disease affects primarily persons between 40 and 70 years of age.
multiple myeloma appearance
what are bone metastases?
Bone metastases are the most common malignant bone tumors. They are more common than primary neoplasms.
how do bone metastases spread?
They spread from primary tumors by means of the bloodstream or
vessels or by direct extension.
what are common primaries for bone metastases?
The most common primary tumors are carcinomas of the breast, lung, prostate, kidney, and thyroid. Favorite sites of metastatic spread are bones containing red marrow, such as the spine, pelvis, ribs, skull, and the upper ends of the humerus and femur.
bone metastases modality of choice
types of fractures
results in two bone fragments
one side of bone cortex intact
open compound fracture
fracture with associated skin wound
fracture with skin intact
fracture line is horizontal to long axis of bone
fracture line extends at an angle to long axis of bone
fracture line encircles the shaft
small fragments pulled from bone by attached ligaments or
more than two bone fragments
triangular fragment separated from two larger fragments
a piece of the shaft is separated by proximal and
compacts the trabeculae
fragment driven inward, e.g., skull fragment pushed into
occurs in immature bone; one side of cortex remains
Torus (Buckle) fracture
compaction of one side of the cortex
plastic deformity of bone
Location of bone fragments
fragments not angled or separated
described by direction of distal fragment in relation to proximal fragment
angular deformity of the axes of the major
fracture healing Malunion
healing of fracture fragments in a faulty position
fracture healing delayed Union
fracture that takes longer to heal than the average fracture at that anatomic location
fracture healing nonunion
fracture healing process has completely stopped and the fragments remain ununited even with prolonged immobilization
when does a pathological fracture occur?
occur in diseased bones.
Stress fractures are the response of bone to repeated stressors, none of which alone would cause a fracture. Stress or force is usually not significant enough to cause a fracture in healthy bone.
what is battered child syndrome?
Battered-child syndrome refers to multiple, repeated,
induced injuries in young children caused by parents or guardians.
what is battered child syndrome known as?
It is also known as suspected nonaccidental trauma (SNAT).
what should happen if a batter child syndrome is suspected?
Imaging professionals have a legal responsibility to report
cases to their supervisors. The facility is legally obligated to notify authorities.
Transverse fracture through the distal radius with
Common for ulnar styloid to fracture, too
Transverse fracture of the neck of the 5th metacarpal
with palmar angulation of the distal fragment
Often caused by hitting an object with a closed fist
Ulnar shaft fracture associated with anterior dislocation of the
radius at the
Radial shaft fracture and a dorsal (posterior) dislocation of the
ulna at the
• Fractures of the spine are classified as either:
Stable fractures leave one of the two major columns of the spine
Unstable fractures disrupt both major columns.
Comminuted fracture of C1
Most occur at base of dens
Fracture of C2 arch with subluxation of C2–C3
clay shovelers fracture
An avulsion fracture of a spinous process in the lower C-spine or upper Tspine
seat belt fracture
Transverse fracture of lumbar vertebral body
Associated with severe visceral injuries
Herniation of Intervertebral Disks and locations?
Protrusion of a portion of the disk
Most common sites:
Scoliosis is a twisting and curvature of the vertebral column in
It is generally shaped somewhat like an “S.”
The most common types of scoliosis:
spondylolysis and most common site
Spondylolysis is a cleft in the pars interarticularis without
It is usually bilateral.
Most common site L5.
Spondylolisthesis definition, causes, and caused by?
Spondylolisthesis is the forward displacement of one vertebra
It causes chronic back pain.
It may be caused by spondylolysis.