Figure 7From: A simplified guide ruler from numeric table method in doing rotational osteotomy Use of the ruler in rotation center strategy in large radius region. Assuming that the cross-section of the bone is perfect ellipse, when we try to fix the osteotomized bone by using reference of the rotation center, the chord distance (t) is proportional to the distance to the center, the radius (r). When the radius is larger, the chord distance (t) is larger.Back to article page