Location

Material and Calcified Microsphere Ca:P ratio

Preparation

POR

OP

OA

Mineral front

Manual crush

1.53

1.67

2.59

Mineral front

Hydrazine digest

1.58

1.55

1.94

Subchondral bone

Manual crush

1.58

1.61

1.72

Subchondral bone

Hydrazine digest

1.66

1.53

1.68