Avascular necrosis Flashcards
what is avascular necrosis(AVN)
failure of the blood to the supply femoral head
what is involved in the pathophysiology of idiopathic avascular necrosis (3)
coagulation of the intraosseous microcirculation, venous thrombosis, intraosseous hypertension
what is the pathophysiology of AVN associated with trauma
injury to the femoral head blood supply, the medial femoral circumflex artery
what group of people is AVN most often seen in
males > females, age 35-50
is AVN usually uni- or bi-lateral
80% bilateral
what are some risk factors for developing AVN
although most cases are idiopathic
irradiation, trauma, haematologic disease, alcoholism, steroid use
what clinical features are seen in the presentation of AVN
insidious onset of groin pain, exacerbated by stairs or impact, examination usually normal unless advanced disease to collapse or OA
what can AVN result in (3)
decreased blood flow to femoral head, necrosis of femoral head, chondral fracture + collapse
what investigations are used for AVN
radiograph(often normal in early disease), MRI most specific
when does AVN go from being reversible to irreversible
irreversible when subchondral collapse occurs
what management can be used for reversible AVN (4)
bisphosphonates, core decompression +/- bone graft, curettage + bone graft, vascularised fibular bone graft
what management is used for irreversible AVN
total hip replacement
