Hip Flashcards
Where do hip dislocations occur
MC: posterior
10% anterior
What causes hip dislocations
Trauma at the axis of femur- Axial load with flexed knee, or MVA
Etiology of a posterior hip dislocation is
Hip and knee flexed 90 degrees and there is force exerted at knee through femoral shaft
Causes femur head to be driven posteriorly= Posterior displacement of femoral head from acetabulum
How can you tell someone has a posterior hip dislocation
Lower extremities in scissor position (hip internally rotated, adducted, flexed, with knee flexed
Shortened extremity
Greater trochanter and femoral head prominent under gluteal muscles
Etiology an an anterior hip dislocation
Abduction and external rotation of femur causing anterior displacement of femoral head from acetabulum
How can you tell someone has an anterior dislocation
LE in “helpless eversion”, hip externally rotated and abducted
flattened lateral hip
prominence of femoral head in groin
Complications of hip dislocations include
Acetabular fracture
Sciatic nerve injury
Rupture of ligamentum teres artery causing avascular necrosis of femoral head
How do you perform a posterior hip reduction
Two providers. Patient lies in fetal position with affected leg on top
P1: Stand in front of affected knee, wrap band around pt’s posterior knee and his torso
P2: Stand at pt’s rear, wrap band around pit’s hip and his torso
Two providers pull opposite each other until it pops back in
MOI of hip fractures are
Fall: elderly w/ osteoporosis
Stress: long distance runner
Pathologic: mets and primary bone lesions
How do hip fractures present clinically
Pain radiating to groin and inner thigh
Difficulty w/ flexion and IR (so hold legs in ER and abducted)
Leg may appear shorter
What imaging do you get for suspected hip Fx
1st line: X-Ray
CT for detailed evaluation
What are the types of hip fractures
Subcapital
Intertrochanteric
Subtrochanteric
How do you treat hip fractures
ORIF vs arthroplasty (artificial hip)
What is avascular necrosis of the hip
Los of blood supply leading to destruction of femoral head
Explain avascular necrosis of hip in adults
30-50 y/o
Uni or B/l
RF: Hx trauma, long term steroid use, EtOH abuse, radiation therapy, RA, SLE
What is Legg Calve Perthes disease
2-11 y/o
M>F
Unilateral, idiopathic avascular necrosis of the hip
How does avascular necrosis present
Insidious onset, loss of ROM to IR and abduction
adult: groin pain is initial complaint- pain with weight bearing/limp
kid: painless limp is initial complaint- groin, thigh or knee pain may follow
What are the Ficat stages of avascular necrosis
I- normal
II- sclerotic or cystic lesions, no subchondral prolapse
III- subchondral collapse (crescent sign)
IV- OA w/ decreased articular cartilage and osteophytes
What is the earliest imaging finding in avascular necrosis
Crescent sign; a dark sliver along the medial superior portion of the femoral head
-if it’s a peds XR, always pay attention to open growth plates; dont mistake for pathologic finding
What is thlack mortinson sign
When you can see the male genitalia pointing to the side of the pathology on XR
this is a joke… lol..
What is imaging of choice for early detection of avascular necrosis
MRI!
How do you treat avascular necrosis in adults
Core decompression w/ bone graft
total hip replacement if advanced disease, or graft fails
How do you treat avascular necrosis in children
Bed rest followed by progressive weight bearing
What is femoroacetabular impingement
hip impingement between femoral head and neck bump straight (cam lesion), and acetabular over coverage (pincer lesion)
-Can have Cam and Pincer separate or simultaneously
