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Test and Measures for Ortho (6)
1. observation/functional activity
2. examine all areas of symptoms
3. neuro exam
4. exam/clear spine
5. exam/clear joint above/below
6. palpate all areas of symptoms
When are diagnostic tests needed? (4)
sometimes patient history
in the absence of appropriate response to PT
if response not consistent with prognosis
positive findings will influence decision making
When are diagnostic tests NOT needed? (2)
injury responds with prognosis
if diagnosis suggests surgery and pt does not want/can't have surgery
mechanism behind radiographs
ionizing radiation passed thru body, attenuates thru tissue based on radio-density captured onto image receptor
what are radiographs useful in seeing?
useful to detect avulsions and simple-->complex fractures and later stage stress fractures
what are radiographs NOT useful for?
not useful for early detection of stress fractures because the fracture line or periosteal reaction may not be evident for up to 6 weeks
limited sensitivity for tumor or infections, tendons, muscles, ligaments
mechanism of fluroscopy?
dynamic or continuous radiographic examination
similiar to a radiographic movie
viewing of physiological function or medical procedure in real time
what are fluoroscopys useful for?
barium x-rays, cardiac catheterization, IV placement, image guided injections
what is an angiography?
injection of contrast into blood supply to find obstructions
what is an arteriography?
injection into specific artery to demonstrate blood flow
what is a barium swallow?
shows upper GI tract
what is an arthrography?
contrast injected into joint
what is a myelography?
contrast injected into subarachnoid space to look at spinal cord, nerve roots and dura mater
mechanism behind CT
x-ray tube that creates cross sectional images taken in parallel planes
Positives about CT
good at defining cortical and trabecular bone
good detail of spinal segments showing osteophytes and stress fractures
less complex and expensive than MRI
negatives about CT
limited ability to differentiate btwn types of soft tissues (tendon/ligaments)
higher doses of radiation and higher cost than conventional radiographs
MRI is challenging CT for diagnosing bone pathology
mechanism of nuclear imaging
use of radiopharmaceuticals for diagnosis and therapy
radiographic tracers absorbed by organs/tissues based on metabolic activity...increased uptake=pathology or change in metabolism
what is it good for?
Single Photon Emission Computed Tomography
localizes small abnormalities in bone, cardiac perfusion, brain, liver
what is it good for?
Positron Emission Tomography
shows normal/abnormal function of cells, used in cardiology and oncology to detect and stage tumors.
how does bone scan work?
another name for bone scan...
radiopharmaceutical substance injected into bone to detect areas of hyperfunction or increased mineral turnover
in a bone scan....areas that appear dark or "hot" = ______
what does it suggest?
areas with more uptake of substance = hot/dark
suggests bone is healing after fracture/neoplasm/infection
mechanism behind MRI
uses radio frequency waves in a magnetic field to create images of soft tissue and bone
waves produce changes in atoms which align in direction of magnetic field
T1 = _______
Positives about MRI
superior to CT in delineating combinations of soft tissue and bone insults
better at showing bone marrow abnormalities
What diagnostic test is the gold standard in detecting bone stress injuries?
mechanism of T1 MRI
subacute hemorrhage and fat = bright intensity
bone = bright intensity due to high fat content
good at delineating architecture of soft tissues
mechanism of T2 MRI
fluids have high signal intensity
bursa, inflamed tendons, tumors and abscesses= high signal intensity
reveal less details than T1 tissue structure
negatives of MRI
intolerance due to claustrophobia
patient often does not remain still
absolute contraindications to MRI
ferro magnetic implants or objects such as cerebral aneurysm clips, pacemakers, shrapnel, unstable ortho hardware
mechanism of diagnostic ultrasound
images created by tissues reflecting sound waves
what are ultrasounds good at?
useful for superficial soft tissue structures like muscle, tendon, ligament, nerve
good at detecting cysts, soft tissue tumors and blood flow
positives of US
assessing real time muscle contraction, tendle gliding, and muscle size
negatives of US
image highly dependent on skill of examiner
more useful in thin patients
bone and metal reflect sound and not adequately imaged
ABC'S of imaging
what is the responsibility of the collimator in radiographs?
controls size and shape of x-ray field exiting tube
what is the responsibility of the attenuation of radiographs?
interaction of x-rays and matter or tissues
not easily penetrated by x-rays which make them appear white on radiograph= ______
easily penetrated by x-rays which makes them appear black on radiograph= ______
substances based on radiolucency
increasing radiolucency (going from dark to white)
thickness and radiodensity
thicker = increased radiodensity relative to thinner object
curves and radiodensity:
object parallel to the beam= _____ x-ray beam
object perpendicular to beam= _____ x-ray beam
parallel = less x ray beam
perpendicular = more x ray beam
how many views at minimum needed for radiograph?
at least 2
what is the purpose of markers?
denote patient information and anatomic side
normal cortical bone is?
provides strength to long bones
normal trabecular bone is?
provides supportive cushioning
True/False: intra-articular fractures produce different types of effusion
what is lipohemarthrosis?
mixture of fat and blood from marrow enter joint space through break in bone
What is the FBI sign?
fat floats on surface of blood
interface can be seen on radiograph and should alert you to intra-articular fracture
what is the solid type of periosteum?
benign process, fracture healing, and osteomyelitis
what is the laminated or onion skin type of periosteum?
repetitive injury, sarcomas
what is the spiculated or sunburst type of periosteum?
malignant bone lesions
what is the codman's triangle type of periosteum?
tumor, subperiosteal hemorrhage, battered child syndrome
what is an osteolytic lesion?
bone destroyed by osteoclastic activity
bone destroys itself
what is an osteoblastic lesion?
new reparative or reactive bone is present
what type of border is suggestive of slow growing or benign lesion?
sharp, clearly defined, scleroti borders
what type of lesion is suggestive of fast growing or malignant lesions?
wide, poorly defined borders with minimal or absent reactive sclerosis
Yes/No: do tumors that are malignant or benign cross joint spaces or epiphyseal growth plates?
What type of condition causes destruction of bone on both sides of the joint?
what is a buttressing type of bony reaction?
formation of bony exostosis or osteophytes to strengthen architecture of joint
progression of RA
involves small joints of wrists, hands and feet
later stages cause joint deformities, contractures and ankylosis of large and small nonWB and WB joints
clinical features of RA (4)
pain and swelling of joint
loss of function
radiologic signs of RA:
bilateral joint involvement
MCP sublux and ulnar deviation
swan neck and boutonniere deformity of IPs
acetabular profusion of hip
radiologic signs of RA
radiologic signs of RA
symmetrical, concentric joint space narrowing
radiologic signs of RA
types and causes of OA
secondary=result of injury
clinical features of OA
joint pain with movement and/or weight bearing
limited function over time
radiologic signs of OA
unilateral involvement of synovial or cartilaginous joints
valgus/varus at knees
subluxation and joint misalignment
Heberden's Nodes are where? ______
Bouchard's Nodes are where? _______
Heberden's = DIP
Bouchard's = PIP
radiologic signs of OA
usually absence of osteoporosis
radiologic signs of OA
asymmetric, irregular joint space narrowing
sclerotic subchondral bone
osteophytes at joint margins
intra-articular loose bodies
radiologic signs of OA
joint effusion during acute exacerbations
7 elements to describing fractures
- 1. anatomic site
- 2. type (complete/incomplete)
- 3. alignment of segments
- 4. direction of fracture line
- 5. special features (avulsion/impaction)
- 6. presence of abnormalities such as dislocated joints
- 7. special types (stress/pathological)
Salter Harris fractures
Type 1-complete physeal fracture
Type 2-physeal fracture that impacts metaphysis
Type 3- physeal fracture extends thru epiphysis
Type 4- physeal fracture plus epiphyseal and metaphyseal
Type 5-compression fracture of growth plate
fracture quality pain: acute/chronic point tenderness?
most commonly missed fractures
femoral neck fracture
how are CT images viewed?
look up from supine patient's feet
10 Good things about CT Scan
1. identifying subtle/complex fractures
2. best for degenerative changes
3. injuries to bone and soft tissue can be seen from 1 imaging series
4. excels in eval of spinal stenosis
5. combined with diskogram to give inevitable info about IVD
10 good things about CT
6. best modality for eval of loose bodies in joint
7. less time consuming than MRI/US
8. allows accurate measurement of osseous alignment
9. less expensive than MRI
10. easier on claustrophobic patients
limits of CT
limited in differentiating between tissues of similar radiodensities
high radiation exposure
longitudinal magnetization of MRI
protons lined up like bar magnets
transverese magnetization in MRI
protons aligned in transverse plane to absorb energy from radiofrequency pulse
how is the image of an MRI made?
protons realign and release the energy absorbed from radiofrequency pulse which creates current in a receiver coil
T1 recovery =
T2 decay =
recovery--reutrn of protons to longitudinal magnetization
decay-relaxation of transverse magnetization
repetition time (TR) and echo time (TE) in conjunction with T1 and T2
T1 has a short TR and short TE
T2 has long TR and long TE
nutshell explanation for MRI
different protons in body tissue give off different signals in reaction to RF pulses
what type of MRI is good for showing anatomical details?
also has fat, bone marrow and subacute hemorrhage show up bright
what type of MRI has less detail of soft tissues?
also has fluids showing up bright
what do proton density weighted MRI's show?
favor water and fat tissue and used to eval orthopedic trauma
what is a spin echo?
90 deg pulse followed by T1 relaxation and T2 decay
what is a fast spin echo?
90 deg pulse followed by 180d pulses
2x as fast as conventional spin echo
what is a STIR and what is it good at detecting?
Short Tau Inversion Recovery
detects soft tissues and marrow pathology
what conditions do gadolinium containing contrasts detect?
anterior inferior labral tears
fractures of glenoid
radiology describes anatomy in terms of _________
MRI results are described in terms of _______ of various tissues
Advantages of MRI (5)
detecting changes in bone marrow
display soft tissues in detail
replaced invasive procedures
best at diagnosing disk herniations
stage neoplasms in bone and soft tissue
disadvantages of MRI (3)
contraindications of ferro magnetic implants
advantages of MRI over CT (4)
greater contrast resolution for soft tissue imaging
greater ability to image organs surrounded by bone
no ionizing radiation
less risk of missing disease process
frequency of US
3.5 to 15 MHz
as intensity is increased in US what happens? (3)
depth of penetration increases
strength of echo increases
potential to generate biological effects increases with tissues
amount of reflection in US is determined by what? (4)
1. degree to whih tissues reflect sound waves
2. difference in acoustic impedance of 2 tissues forming interface
3. smoothness of reflecting interfaces
4. angle of reflection (be as close to perpendicular as possible)
what is acoustic enhancement?
increase in amplitude of US echo coming from structure that lies behind a weak attenuated structure such as fluid filled cavity (bladder)
what is acoustic shadowing?
sound wave echo reduced behind strong, attenuating structure
waves hit something that blocks their path and everything blocking structure appears black
what is reverberation?
multiple reflections and is result of US echoes bouncing between tissue layers and the transducer
what does hyperechoic mean and is it associated with bone or fat?
reflects much energy.
produce bright images
what does hypoechoic mean and is it associated with bone or fat?
reflects little energy
produce dark images
are these hyperechoic or hypoechoic?
cortical bone-echogenic bright echo
structures that are hyperechoic
tendons, ligaments, fibrocartilage
structures that are hypoechoic
bone, fat, muscle, bursae, hyaline cartilage, nerve tissue
advantages of US (9)
- 1.higher resolution
- 2. low cost
- 3. no known hazards
- 4. ready comparison of opposide side
- 5. put affected joint in symptom provoking position
- 6. perform MMT or stretching to find tear
- 7. apply traction of compression
- 8. stress test ligaments
- 9. palpate for tenderness and apply probe over area
disadvantages of US (6)
- 1. limited ability to show joint surfaces and intra-articular structures
- 2. only shows cortical outline of bone
- 3. does not cross air filled interfaces
- 4. more operator dependent than other modalities
- 5. obeses patients not imaged well
- 6. metal not imaged well