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What is Pipkin fracture is defined as - and explain in detail?
Pipikin's classification of femoral head fracture
Type I: Femoral head fracture inferior (caudal) to fovea
Type II: Femoral head fracture superior (cephalad) to fovea
Type III: Femoral head fracture with associated femoral neck fracture
Type IV : Type I, II or III with associated acetabular fracture