Osteonecrosis of the hip Flashcards
Osteonecrosis
occur with or without trauma
ALL ABOUT BLOOD SUPPLY
AND INTEGRITY OF CELLS
Blood supply to the femoral head
collateral circulation that is posterior and superior primarily from medial circumflex femoral artery
=MOST COMMON SITE OF AVN
Femoral head collapse
disturbance of circulation causes death of osteocytes
=> lead to end stage arthritis
Risk factors for osteonecrosis
ALCOHOLISM CORTICOSTERIODS SICKLE CELL DISEASE - CLOG UP CAPILLARIES AND CAUSE ISCHEMIA TRAUMA SLE INFLAMMATORY BLOWEL DISEASE TRANSPLANT CMV, HIV, HEPATITIS, RUBELLA GAUCHER'S
presentation of osteonecrosis
dull activity-related pain
groin and buttock pain
DECREASED INTERNAL ROTATION AND ABDUCTION
PROGRESSIVE - THE PAIN INCREASES
THE GAIT BECOMES ANTALGIC = the stance phase of the gait is abnormally shortened to avoid pain on weight-bearing
-decreased ROM
Radiography of AVN
early in the disease process you will note SCLEROSIS- radiopaque
LOOK FOR CRESCENT SIGN IN XR and MRI TO DETECT SUBCHONDRAL BONE COLLAPSE = radioluscency
MRI
SHOW THE EXTENT OF THE OSTEONECROSIS early detection of this condition crescent sign is more apparent fluid (edema) is also detected can show radioluscency (subchondral bone collapse) and radiopacity (sclerosis)
Steinberg classification
based on radiographic and MRI observations
STAGE I is first in any objective findings = Normal XR = abnormal MRI and/or bone scan
Tx of osteonecrosis of the hip
Not much to do for advanced osteonecrosis of the hip besides hip replacement
Small area of osteonecrosis
tx by giving biphosphates to inhibit osteoclast activity
PREcollapse tx
Surgical options
structural bone grafts osteotomies top hip arthroplasty arthidesis (fusion) Core decompression - relieve hypertension in the arteries = supply the head osteoinductive grafts
osteoinductive grafts
good in kids
make a hole in the head of the femur and fit the bone graft from fibular into it
vascular team anastomoses the lateral circumflex femoral a. in the fibular graft
