Ficat's 1985 review presents the complete five-stage (0–IV) classification of idiopathic femoral head osteonecrosis. It introduces the 'silent hip' (Stage 0) concept and the functional exploration of bone (FEB) technique for preradiographic diagnosis. Outcomes of core decompression in 133 hips followed for an average of 9.5 years are reported.
AVN is a disease of young patients — peak incidence 40–50 years in this series. And by the time a plain radiograph shows changes, the disease is already Stage II or beyond. Ficat's classification codified what was previously unrecognized: every hip with osteonecrosis passes through a radiographically silent phase, and that phase is exactly when treatment works best.
In practice: any patient on chronic steroids or with confirmed AVN in one hip needs FEB (or MRI, which has largely replaced FEB) of the contralateral hip, even if asymptomatic. When you see a young patient with groin pain, limited rotation, and a normal radiograph, Stage I AVN is on the differential until ruled out. Not just a muscle strain.
Core decompression is most effective in Stages 0–II; once a sequestrum or collapse appears (Stage III), the structural damage is done and the surgery's benefit drops dramatically. The Ficat system remains the most widely used AVN classification despite at least 16 competing systems. Its longevity reflects how well it maps clinical staging to treatment decision-making.
Ficat's 1985 review presents the complete five-stage (0–IV) classification of idiopathic femoral head osteonecrosis. It introduces the 'silent hip' (Stage 0) concept and the functional exploration of bone (FEB) technique for preradiographic diagnosis. Outcomes of core decompression in 133 hips followed for an average of 9.5 years are reported.
AVN is a disease of young patients — peak incidence 40–50 years in this series. And by the time a plain radiograph shows changes, the disease is already Stage II or beyond. Ficat's classification codified what was previously unrecognized: every hip with osteonecrosis passes through a radiographically silent phase, and that phase is exactly when treatment works best.
In practice: any patient on chronic steroids or with confirmed AVN in one hip needs FEB (or MRI, which has largely replaced FEB) of the contralateral hip, even if asymptomatic. When you see a young patient with groin pain, limited rotation, and a normal radiograph, Stage I AVN is on the differential until ruled out. Not just a muscle strain.
Core decompression is most effective in Stages 0–II; once a sequestrum or collapse appears (Stage III), the structural damage is done and the surgery's benefit drops dramatically. The Ficat system remains the most widely used AVN classification despite at least 16 competing systems. Its longevity reflects how well it maps clinical staging to treatment decision-making.