Coxa Plana Pathophysiology

Family history

Disturbed venous drainage

Abnormal birth presentation Racial/ ethnic factors

Intraosseous venous hypertension

Increase blood viscosity

Decrease blood flow Interruption of vascular supply to the femoral head Roentgenography Iinitial phase

Increase intraarticular pressure

- Widening of medial joint space Fragmentation phase - resorption of necrotic portion of the ossific nucleus Reparative phase - return to normal radiodensities of ossific bone Healed 

Ischemia of femoral head

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Flattened, irregular femoral head

Failure of ossific nucleus to grow Increasing pain

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MRI

Hypertrophy of articular cartilage 



Occlusion of retinaacular vessel

Loss of function/ inactivity

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Arthrography - shows shape of cartilaginous bone of femoral head

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Stage of necrosis

Slow resorption of the dead bone Replacement of new, living bone

Thigh, calf, buttock, atrophy

(+) Tredelenberg

Decrease ROM

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