Changes in dimensions of large cancellous bone specimens during histological preparation as measured on slabs from human femoral heads.

Distortion of the dimensions of large cancellous bone specimens during all stages of histological processing and cutting of paraffin sections in various directions was measured on Xerograms taken from slabs and then sections from human femoral heads. Although some shrinkage in both width and height of the specimens occurred at every stage of the histological preparation, the main shrinkage (about 6%) occurred during the embedding process, and mainly in the cutting of the sections (10-27%, depending on the direction the knife was approaching the specimen). The shrinkage of cancellous bone tissue during histological preparation appears to be a constant factor, but its magnitude during the individual stages of the preparation can be predicted. For the quantitative measurements a comparison of two Xerograms--one taken from the original fresh bone slab and the other from the final stained section--would reveal the exact extent of the tissue shrinkage.