medullary cavity

Halo, tube-like structure within the diaphysis

Endosteum

inner membrane lining the medullary cavity of a bone

What two tissues is the skeletal system composed of?

• Bone
• Cartilage

What are two types of bone?

• Compact (outer layer)
• Cancellous (spongy, inner layer)

compact bone

outer layer consists of which to the naked eye appear stents and structureless

cancellous

the spongy bone of the medullary cavity and bony trabeculae

Two types of bone cells:

• Osteoclasts
• Osteoblasts

osteoclast

enlarge the diameter of the medullary cavity by removing bone from the diaphysis wall

osteoblast

produce new bone around the outer circumference from the periosteum

ossification

bone formation

re-absorption

bone destruction by osteoclast

Intramembranous Ossification

bone formation from connective tissue

Congenital/Hereditary Diseases of Bone

• Vertebral Anomalies
• Spina Bifida
• Osteopetrosis
• Osteogenesis Imperfecta
• Achondroplasia
• Congenital Hip Dysplasia (Dislocation)

transitional vertebrae

vertebrate with characteristics of another spinal region

where is a transitional vertebrae most commonly located

It occurs most often at L/S junction.

spina bifida

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:

- Meningocele
- Myelomeningocele

meningocele

protrusion of the meninges through the skin

myelomeningocele

herniation of the spinal cord and meninges through the skin

Osteopetrosis

It is a rare hereditary bone dysplasia in which failure of the resorptive
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.

osteogenesis imperfecta

It is an inherited generalized disorder of connective tissue
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

osteogenesis imperfecta

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 plate
(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
dysplasia.

what does congenital hip dysplasia/dislocation result from?

It results from incomplete acetabulum formation caused by
physiologic and mechanical factors

Inflammatory and Infectious Disorders

• Rheumatoid Arthritis
• Osteoarthritis
(Degenerative Joint
Disease)
• Infectious Arthritis
• Tuberculous Arthritis
• Bursitis
• Rotator Cuff Tears
• Tears of the Menisci of
the Knee
• Bacterial Osteomyelitis
• Tuberculous
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 the
small joints of the hands and feet.

RA variants

• 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 the
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:

• Spine
• Hips
• Knees

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 near
the joints that reduce the friction caused by movement.

bursitis causes:

• Repeated physical activity (most common)
• Trauma
• Rheumatoid arthritis
• Gout
• Infections

what is the modality of choice for bursitis?

@

what is a rotator cuff?

The rotator cuff of the shoulder is a musculotendinous structure
composed of the teres minor, infraspinatus, supraspinatus, and
subscapularis muscles.

what do rotator cuff tears produce?

Tears produce a communication between the shoulder joint and the
subacromial bursa.

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

Bacterial osteomyelitis

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 from an
adjacent site of infection, or direct introduction of organisms (after trauma or
surgery).

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

• Osteoporosis
• Osteomalacia
• Rickets
• Gout
• Paget’s Disease

osteoporosis

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 calcium,
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?

@

rickets

is a systemic disease of infancy and childhood that is the
equivalent of osteomalacia in adults.

what is the cause of rickets?

Calcification of growing skeletal elements is defective because of a
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 of
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 single
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 the
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

Lead poisoning results from the ingestion of lead-containing materials
(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 pipes)
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
worldwide.

what does chronic lead poisoning cause?

Chronic form of lead poisoning may cause mental retardation,
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 tissue
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:

• Thrombosis
• Vasculitis
• 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:

• Osteochondroma
• Enchondroma
• Giant cell tumor (osteoclastoma)
• Osteoma
• Osteoid osteoma
• Simple bone cyst
• Aneurysmal bone cyst
• Bone island

Malignant bone tumors:

• Osteogenic sarcoma
• Chondrosarcoma
• 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 arises in
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.

Characteristics
• 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 in
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 or
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, the
paranasal sinuses (especially frontal and ethmoid), and the mandible. They cause pain.

how do osteomas appear radiographically?

They appear radiographically as well-circumscribed, extremely dense,
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, lucent
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 relieved
by aspirin.

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
the metaphysis.

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 compact
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 may
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, scapula,
or vertebra.

when does chondrosarcoma occur?

It develops at a later age (peak incidence in 35- to 60-year olds),
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 lymphatic
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

@

complete fracture

results in two bone fragments

incomplete fracture

one side of bone cortex intact

open compound fracture

fracture with associated skin wound

closed fracture

fracture with skin intact

transverse fracture

fracture line is horizontal to long axis of bone

oblique fracture

fracture line extends at an angle to long axis of bone

spiral fracture

fracture line encircles the shaft

avulsion fracture

small fragments pulled from bone by attached ligaments or
tendons

communited fracture

more than two bone fragments

butterfly fracture

triangular fragment separated from two larger fragments

segmental fracture

a piece of the shaft is separated by proximal and distal
fracture lines

compression fracture

compacts the trabeculae

depressed fracture

fragment driven inward, e.g., skull fragment pushed into
brain

greenstick fractures

occurs in immature bone; one side of cortex remains
intact

Torus (Buckle) fracture

compaction of one side of the cortex

bowing fracture

plastic deformity of bone

Location of bone fragments

Undisplaced
Displacement
Angulation

undisplaced

fragments not angled or separated

displacement

described by direction of distal fragment in relation to proximal fragment

angulation

angular deformity of the axes of the major
fracture fragments

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

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, physically
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 suspicious
cases to their supervisors. The facility is legally obligated to notify authorities.

colles' fracture

Transverse fracture through the distal radius with dorsal
(posterior) angulation
Common for ulnar styloid to fracture, too

boxer's fracture

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

Monteggia

Ulnar shaft fracture associated with anterior dislocation of the radius at the
elbow

Galeazzi

Radial shaft fracture and a dorsal (posterior) dislocation of the ulna at the
wrist

• Fractures of the spine are classified as either:

Stable
Unstable

stable fractures

Stable fractures leave one of the two major columns of the spine
intact.

unstable fractures

Unstable fractures disrupt both major columns.

Jefferson

Comminuted fracture of C1

odontoid fractures

Most occur at base of dens

Hangman's fracture

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:
• L4–L5
• L5–S1
• C5–C6
• C6–C7
• T9–T12

scoliosis

Scoliosis is a twisting and curvature of the vertebral column in the
lateral perspective.
It is generally shaped somewhat like an “S.”

The most common types of scoliosis:

• Idiopathic
• Functional
• Neuromuscular
• Degenerative

spondylolysis and most common site

Spondylolysis is a cleft in the pars interarticularis without displacement.
It is usually bilateral.
Most common site L5.

Spondylolisthesis definition, causes, and caused by?

Spondylolisthesis is the forward displacement of one vertebra on
another.
It causes chronic back pain.
It may be caused by spondylolysis.