[Magnetic resonance imaging with multiplane histomorphometry in avascular necrosis of femoral head: analysis of trabeculae].

OBJECTIVE

To distinguish the differences of changes of bone trabecular structure between high and low signal area which could directly reflect the mechanical strength and estimate the risk of collapse in avascular necrosis of femoral head (ANFH).

METHODS

After total hip replacement, the specimen of ANFH was scanned by MR imaging. Accurate localization, consecutive slicing, multiplane histomorphometry, correspondence of MR images with slices were used. Mean trabecular width (MTW micron) and mean trabecular space (MTS micron) were selected as observation indexes.

RESULTS

MTW in the low signal area was lower than that in the high signal area. MTS in the low signal area was higher than that in the high signal area. The results indicated that the dispersive degree of bone trabeculae was higher in the low signal area.

CONCLUSION

Bone trabeculae in the low signal area necrosed and atrophied so that the bone volume and mechanical strength of trabeculae declined and bone trabeculae in the low signal area were liable to microfracture and collapse.