L3 LE Flashcards
Pelvis plain films
- include only an AP view
- sometimes can do an oblique view
- inlet view vs outlet views
Inlet views
AP translation
Outlet Views
cephalad/caudad translation
What type of imaging is the best view of posterior ring?
CT
Pelvic Trauma
- AP is best, CT scan is second line
- > 1 cm in pubic symphsis is abnormal
- pelvic fractures occur in more than one area, and cause hematomas and organ damage
Patient does not pelvic x-ray if
- pain free hip rotation and flexion
- painless compression of iliac and pubic symphysis
- no complain of pelvic pain
- no signs of fracture on inspection
- no other major injuries
- still conscious
- > 3 years old
Imaging for AVN of femoral neck
MRI is the gold standard
Electrophysiologic Tests
rules out lumbar root pathology
will help to rule in peripheral neuropathies about the hip
Dashboard injury
posterior dislocation of femoral head
Paget’s disease
benign lesion of pelvis
increased sclerosis and enlargement of the entire right hemi-pelvis
Malignant tumors in adults vs children
Child = ewing’s sarcoma
Adult = chondrosarcomas
Pelvic Stress Fracture
- history of overuse
- relief with non WB
- insidious in nature
- local pain, tenderness, swelling
- typical site is in pelvis at pubic ramus
- bone scan is good for early diagnosis
Hip Imaging positions
- AP view
- abducted view (frog leg)
- axial lateral
High yield areas to examine for hip trauma
- pelvis or acetabular fractures
- femoral neck or intertrochanteric fx
- widening of joint space
- hip dislocations
Anterior dislocation of hip
head displaced inferiorly and medially
Posterior dislocation of hip
most common
head displaced superior and laterally
Hip Fractures
- most common are femoral neck and intertrochanteric
- nondisplaced hip fractures are best seen with MRI
Fracture of femoral neck
- often due to osteoporosis
- stress fx may appear sclerotic
Intertrochanteric region fracture
- often due to trauma
- appears as shortened leg with IR
Hip Pain
- OA is most common cause of chronic hip pain
- pt presents with pain and loss of mobility, starting with loss of IR
DJD/OA changes include
- joint space narrowing
- subchondral cysts
- sclerotic borders
- osteophytes
Altman’s Criteria for hip pain
Cluster 1: hip pain, hip IR <15, hip flexion <115
Cluster 2, if hip IR >15. Pain w/IR, age >50, morning stiffness < 60 min
Aseptiv necrosis of hip causes
Anemia (sickle cell)
Steroids
Ethanol
Pancreatitis
Trauma
Idiopathic
Caisson’s Disease
How AVN appears on radiographs
- femoral head is flattened, irregular, and sclerotic
- best to use a MRI
Klein Line
a line drawn along superior border of femoral neck, should intersect with femoral head
Femoral Neck Stress Fracture
- history of overuse
- relief with non-WB
- insidious in nature
- local pain, tenderness, swelling
- compression or tension
- bone scan is diagnostic early
- MRI is 100% sensitive
Tension Side Fracture
muscles and tendons are pulling, causing the bone to be pulled apart. Harder to heal
Compression Side Fracture
medial side, heals better
Femur Plain Film Views
- A/P, proximal and distal
- Lateral, proximal and distal
Femur is prone to
tumors, benign and malignant
Benign Lesions of Femur
- small
- no associated periosteal reaction
- narrow transition zone between bone and lesion
- thin, well defined sclerotic margins
- fibrous cortical defects, fibrous dysplasia, non-ossifying fibroma
- often causes pathologic fractures
Malignant Lesion
- lytic lesion w/o sclerotic margins is considered malginant until proven otherwise
- breast and lung cancer produce lytic lesions
- looks bubbly in appearance
- Chondrosarcomas are destructive in nature, vary in appearance, and occur in femur, pelvis, ribs
Periosteal Reactions
- either benign or malignant
- typically in long bone
- have a sunburst pattern
- causes include infections, osteomyelitis, ewings tumor, osteogenic sarcoma
Myositis Ossificans
not pathologic
caused by lots of contusions
bone formed in soft tissue
Knee Plain Film Views
- AP view = joint space narrowing
- lateral view = patella effusions
- sunrise view = patella and anterior femur
- tunnel view = tibial spines and femoral condyles
MRI is best for soft tissues
Pittsburgh Knee Rule
High spin/snout
* blunt or trauma or a fall as MOI plus either of the following –> <12 or >50 yo, inability to walk 4 WB steps in ED
Ottawa Knee Rules
- High sensitivity
- order x rays for acute knee pain if 5 items are present
- > 55 yo
- isolated tenderness over patella
- tenderness over fibular head
- Unable to flex >90°
- Unable to WB immediately or ED for 4 steps
Knees and plain films
- x-rays can be normal even with pathology of knee
- injuries to soft tissues are not seen on plain films, MRIs are better
- Joint effusion is best seen on lateral view
OA in Knee
- common
- s/s include pain with motion, limited ROM, redness, swelling, visible deformity
- xray findings include jt space narrowing, sclerosis, osteophytes
- cartilage may calcify and break off, causing loose bodies
Chondrocalcinosis
calcification of articular cartilage
Knee fractures
- include patella fractures, fractures of tibia, fibula, and femur
- tibial fx can be difficult to see, except on AP view, MRI is indicated if S/S are positive but imaging is negative
Bipartate patella
normal variant that may appear to be a fracture
Segond Fracture
- cortical avulsion fx off proximal lateral tibia just distal to tibial plateau at site of insertion of middle third of LCL, caused by IR and varus stress
- associated with ACLm meniscal tears, PLC structures
- MRI should be used because of the associated injuries
Osteochondritis Dessicans
- lesion involving both bone and cartilage
- causes 50% of loose bodies in the knee
- more common in men and posterior lateral aspect of medial femoral condyle
- can be traumatic, ischemic, abnormal ossification centers, genetic
Osgood-Schlatter Disease
- tibial tubercle apophysitis
- occurs in active kids from 11-15
- concides with periods of growth spurts
- self-limiting
- similar condition is sinding-larsen-johansson, involves patellar tendon
Possible injury with posterior dislocation of distal femur
popliteal artery
Ankle and Foot Plain Film Views
- AP view
- lateral view
- oblique/mortise view
Most common ankle fractures involve
lateral or medial malleolus
Ankle effusion
appears as anterior fat line in front of joint space on lateral view
Order ankle x-ray series if
pain in malleolar zone AND any one of following
1. bone tenderness in post half of distal tibia/fibula
2. unable to bear weight 4 steps after injury
Order foot x-ray series if
pain in midfoot zone AND any one of following
1. bone tenderness over navicular or base of 5th MT
2. unable to bear weight for 4 steps after injury
Ottawa rules are
sensitive and not specific
Danis-Weber Classification
Uses the position of level of fibular fx in its relationship to its height at the ankle joint
Weber A
fracture below the ankle joint
Weber B
fracture at the level of joint, with tibiofibular ligaments usually intact
Weber C
fractures above the joint level which tears the syndesmotic ligaments
Maisonneuve Fracture
ER force to ankle w/transmisiion of the force thru the interosseous membrane, exiting through a proximal fibular fracture
Jones Fracture
base of 5th metatarsal
Base of 5th metatarsal fractures
Stress = most distal
Jones = middle
Avulsion = proximal
Lisfranc fracture
fracture of 2nd, 3rd, 4th, 5th MT with lateral dislocation
medial plantar bruising is a hallmark sign
MOI–foot caught in a stirrup
March Fracture
stress fracture of 2nd, 3rd, 4th MT
seen in new recruits, athletes, dancers
Gout
involves the 1st MCP joint
Bunions
hallux valgus
Bone islands
benign finding
sclerotic bone growth
Bone and joint infections
Periosteal reaction is thickening of periosteum, appears white on x ray
seen with normal healing fracture, osteomyelitis, tumors
a radiating periosteal reaction = sun burst = sign of malignancy
