Detection of experimentally produced occult microfractures at the bone-cartilage interface in decalcified sections

We compared three histological preparation methods to detect experimentally produced occult microfractures in decalcified human patellae: a paraffin t ape-transfer technique, a paraffin slab-cut method, and a paraffin method w ith methyl salicylate as the clearing agent, Microfractures were observed a t the bone-cartilage interface and were oriented either parallel or perpend icular to the tidemark, Both types of microfractures were documented with e ach preparation method, The slab-cut method was time-consuming, but the sec tion thickness allowed detailed analysis of the architecture of microcracks as they passed into the depth of the section. The methyl salicylate method was efficient and produced thin, serial sections with good morphological d etail and minimal cutting artifact. Reliable histological data were also de rived from the tape-transfer technique, but this method was inconsistent, T he methods summarized here for processing decalcified human joint tissues p rovide a basis for future orthopaedic studies investigating occult microfra ctures at the bone-cartilage interface.