Diagnostic Imaging Flashcards
Distal Femur - 2nd ossification center
Birth
Distal Femur - Ossification/Fusion
14-16 yrs females
16-18 yrs males
Proximal Tibia - 2nd ossification center
Birth
Proximal Tibia - Ossification/Fusion
14-16 yrs females
16-18 yrs males
Tibial Tuberosity - 2nd ossification center
8 yrs
Tibial tuberosity - ossification/fusion
13-15 yrs females
15-19 yrs males
TRACTION EPIPHYSIS
Patella - 2nd ossification center
4 yrs
Patella - ossification/fusion
puberty
Completely cartilage until 4 yrs old
Routine projections
AP
Lateral
Axial or tunnel of intercondylar fossa
Axial patellofemoral joint
AP of the knee
Taken with knee in extension Distal femur Proximal tibia Fibular head Tibiofemoral joint Trabecular markings observable
Lateral of the knee - position and beam
Knee is positioned into 20 degrees flexion
Beam moves medial to lateral with lateral knee closest to the film
Lateral of the knee - what is present
Sesamoid bone (fabella) may be present Bursa may be observable as a radiolucent line
Axial/Tunnel Intercondylar Fossa - position
Patient is prone with knee flexed to 40 degrees
Axial/tunnel Intercondylar fossa - beam
beam moves post to ant
It is a PA
Axial view of the patellofemoral jt. is AKA
Tangential
Sunrise
Skyline
Merchant’s view
Axial view of patellofemoral joint
Articular surfaces of the femur and patella
Knee is flexed to varying degrees
Lower leg imaging
AP and Lateral
Lower leg imaging used for what
to determine the condition of the tibia and fibula
Computed Tomography
Bony elements, fractures, and degenerative processes
CT myelogram
Tends to use contrast within the subarachnoid space - stenosis
Ionizing radiation exposure
CT good for
complex fractures
bone - degenerative processes
Magnetic Resonance Imaging
Soft tissue, inflammation, hemorrhage
More expensive and slower than CT
Metal is absolute contraindication
Can also do myelogram w/o contrast
Arthrography
Use of contrast within joint spaces
Plain film, CT, and MRI
Typically air and contrast medium is injected into the joint and an image is taken
Diagnostic Ultrasound
2-15 MHz Bundled delivery (1% emission; 99% reception)
Diagnostic Ultrasound used for
Muscle and tendon architecture, fiber degeneration and tears, nerve inflammation
Downside to ultrasound for diagnosing
VERY operator dependent
Does not penetrate bone or transmit though air (lungs)
Bone scan (Scintigraphy)
Use of radionuclide to image bone
“functional” imaging
Indicates abnormal areas of bone activity
Bone Scan - Sn and Sp
Is highly sensitive but lacks specificity
Closed vs. Open fracture
Closed = skin and soft tissue are intact Open = any open wound, any size, is caused by the fractured bone
Fracture description must include
Site and extent Type Alignment Direction Special Features Associated abnormalities
Site and Extent
Anatomic location Upper, middle, lower on the bone Proximal or distal Extra-articular or intra IT, surgical neck, head...
Type and Alignment
Complete or incomplete
Relationship of the longitudinal axis of fragments to each other
Position of distal fragment as related to proximal
Displacement
Distracted
Direction
Fracture line in relationship to the longitudinal axis of the bone
Different directions
Transverse
Longitudinal
Oblique
Spiral
Comminuted
More than 2 fragments
Special Features - Impaction
Depression
Compression
Depression is common in
tibial condyle
Compression is common in
vertebrae
compression from all sides
Special features - avulsion
Most commonly where you have a traction epiphysis
Special features - epiphyseal
Salter harris classification
if using this classification you know it is younger than 17
Associated Features
Joint Dislocation
Soft tissue involvement
Ottawa Rules
Age 55 yrs or older Tenderness at head of fibula Isolated tenderness of patella Inability to flex knee to 90 Inability to WB (4 steps) immediately after injury or in ED
Pittsburgh Rules
Blunt trauma or a fall plus either of the following:
Age younger than 12 yrs or older than 50 yrs
Inability to walk 4 WB steps in the ED
Femoral Shaft Fracture
Life threatening - considerable bleeding, fat embolism (resp. issues)
Massive forces required - femoral shaft fracture
Almost always displaced Other injuries probably exist Circulatory issues Severe pain Rotation and angular displacement of distal end
Tibial Plateau Fracture
Hohl classification system
Joint instability is common
MCL and LCL often involved
OFten need CT or MRI
Tibial Plateau Fracture caused by
axial loading with valgus or varus forces such as a fall from a height or collision with bumper of a car
Due to impact of femoral condyle into tibial plateau
Tibial Plateau Fracture - WB
Generally unable to WB
Tibial Plateau Fracture - more commonly fracture where
Lateral tibial plateau is fractured more frequently than the medial
Intercondylar Fracture
Direct blow to the proximal tibia with the knee or in rotation
Hyperextension with varus or valgus stress
Loss of cruciate ligaments may occur
Patellar fractures
Disruption of the extensor mechanism
Patellar fracture - occur as result of
Most common cause
May occur as a result of an indirect force such as a jump (deceleration) (quad contraction)
Direct blow like dashboard injury in a MVA or a fall on a flexed knee
Continuous Passive Motion
Post operatively patients use this to ge tthem into flexion and extension
Data suggests not very helpful
Tibial Plateau Fracture - what do they do surgically
Supporting the fracture fragments with small bone screws and the Ilizarov fixator - removed after 12 weeks
Hemophilic Arthopathy
Common complication is bleeding into the joints
As PT you wont know until later if bleeding occurred
Meniscal injury - what type of imaging
MRI is imaging modality of choice
