The Hip Flashcards
(35 cards)
MOA of hip dislocation?
Trauma directed at axis of femur
- Axial load with flexed knee
- MVA
> 90% posterior
< 10% anterior
MOA of posterior hip dislocation?
Forced exerted at the knee, through the femoral shaft (hip and knee flexed to 90˚)
Head of femur driven posteriorly (“dashboard injury”)
Posterior displacement of femoral head from acetabulum
Presentation of posterior hip dislocation?
LE in “scissors” position:
Hip internally rotated, adducted and flexed
Knee flexed
Shortened extremity
Prominence of greater trochanter and femoral head under gluteal muscles
MOA of anterior hip dislocation?
Abduction and external rotation of the femur
Anterior displacement of femoral head from acetabulum
Presentation of hip dislocation?
LE in “helpless eversion”
Hip externally rotated and abducted
Flattened lateral hip
Prominence of femoral head in groin
Complications of hip dislocations?
Acetabular fractures
Sciatic nerve injury
Rupture of ligamentum teres artery → avascular necrosis of femoral head
MOA of hip fx?
Fall → elderly w/ osteoporosis
Stress → long distance runners
Pathologic → metastatic and primary bone lesions
Clinical presentation for hip fx?
Pain radiates to groin and inner thigh
Difficulty with flexion and internal rotation
Will hold leg in external rotation and abduction
Leg may appear shorter
Imaging for hip fx?
X-rays first line
CT for detailed evaluation
Which type of hip fracture has higher incidence of non union and necrosis of the femoral head? why?
sub-capital (intra capsular)
disrupts blood supply to femoral head
surg tx options for hip fx?
ORIF v. arthoplasty
What is avascular necrosis of the hip?
Loss of blood supply leads to destruction of the femoral head
Describe avascular necrosis of the hip in adults
30 – 50 y/o range
Unilateral or bilateral
RF: h/o trauma, long term corticosteroid use, EtOH abuse, radiation therapy, RA & SLE
Describe avascular necrosis of the hip in kids
“Legg Calve Perthes disease”
2 – 11 y/o range (peak 4-10)
M:F of 4:1
Unilateral
Idiopathic
Presentation of avascular necrosis in adults?
MC insidious onset
Groin pain is initial complaint
Pain with weight bearing / limp
ROM loss: internal rotation and abduction
Presentation of avascular necrosis in peds?
Painless limp is initial presentation
Groin, thigh or knee pain may follow
ROM loss (both adult and peds) Internal rotation and abduction
Staging for avascular necrosis
Ficat stages -based upon x-rays:
I – Normal
II – Sclerotic or cystic lesions, without subchondral collapse
III – Subchondral collapse demonstrated by Crescent sign
IV – Osteoarthrosis with decreased articular cartilage and osteophyte formation
What is usually the earliest xray finding of avascular necrosis? Wjay is the diagnostic study of choice?
crescent sign
stage III
MRI- detects early changes
Tx for avascular necrosis in adults?
Core decompression w/ bone graft
Total hip replacement if advanced disease or failure with graft
Tx for avascular necrosis in children?
Period of bed rest followed by progressive weight bearing
What is a Femoroacetabular Impingement?
Hip impingement between a femoral head/neck bump (CAM lesion) and acetabular over coverage/retro-version (Pincer lesion)
can be Cam, Pincer or both
Femoroacetabular Impingement may lead to…
hip labral tears
chondral injury
early onset osteoarthritis
Etiology of femoroacetabular impingement?
Generally caused by the development of the hip and acetabulum during childhood
Incidence of 10-15%
Which pts with Femoroacetabular Impingement are at risk for developing pathological changes and sxs earlier?
Athletes / active individuals
due to high demand on hips
