Pain in the groin, ocassionaly in buttock or knees: deep throbbing, intermittent with insidious onset.
Pain and restriction of hip range of movement.
Differential rotation: due to sectorial involvement:Greater restriction of internal rotation with flexion of the hip.
FICAT AND ARLET:
Stage I : Normal X rays, abnormal bone scan, and/or MRI findings.
Stage IIa: Cystic and sclerotic changes in the femoral head.
Stage IIb: Subchondral collapse(crescent sign) without flattening.
Stage III: Femoral head flattening.
Stage IV: Joint narrowing and secondary arthritic changes.
Other classification systems:
Radiographic classification of Marcus and Enneking.
MRI classification by Sugano et al.