A Method for Cemented Bone Interface Examination Without Polymethylmethacrylate Embedment

Although effective, the embedment of bone tissue and orthopaedic devices using polymethylmethacrylate (PMMA) has challenges and limitations. To embed using PMMA, specimens must first be fixed in 70% ethanol, dehydrated in ascending grades of ethanol, and then infiltrated and polymerized in polymethylmethacrylate using standard techniques. This process can take more than 22 d for large bone specimens. Additionally, PMMA embedment has been shown to dissolve bone cement, thus enabling the analysis of the bone-cement interfaces. To conserve processing time while preserving the bone-cement interface, a method was developed for processing mineralized bone tissue in preparation for scanning electron microscopy (SEM) imaging that does not require PMMA embedment. This technique does not require the traditional dehydration and PMMA polymerization process. Instead, fresh mineralized cemented bone specimens were serially sectioned and the marrow removed after formalin fixation. The sections were air-dried then desiccated. The sections were then prepared for SEM imaging and examination. This process takes a fraction of the tissue processing time while not compromising the bone-cement integrity. The SEM image quality was shown to be comparative to images obtained with PMMA-embedded bone specimens.