The Hip Flashcards
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