- Discussion:
- following inital ischemic episode, most of the epiphysis is avascular;
- while
enchondral ossification temporaily halts, the articular cartilage, which
is nourished by synovial fluid, continues to grow;
- this results in widening of medial cartilage (joint) space & smaller
ossification center in involved hip;
- revascularization occurs from periphery;
- resumption of enchondral ossification within the epiphysis begins
peripherally and progresses centrally;
- new bone is deposited on avascular bone, producing a net increase in
bone density;
- in subchondral area, bone resorption exceeds new bone formation;
- point is reached during resorption when subchondral area becomes
weak & is prone to collapse;
