To understand the histological and morphological characteristics of the wear particles developed in the loose total hip arthroplasty, the authors performed light microscopic, polarized light microscopic and electron microscopic examination of the
membrane obtained from the prosthesis-bone interface of the patients who underwent revision surgery after hip replacement. Scanning electron microscopic examination and X-ray probe microanalysis were performed also for the wear particles.
Three patients who had different types of hip replacement were selected for this study. The types of implant were Ceramic total hip system, CST(Cementless self-cutting titanium) total hip system and Omnifit total hip system.
The wear particles were identified within the membrane associated with a foreign body giant cell reaction. Multinucleated giant cells were mainly identified surrounding large wear particles, and the smaller fragments appeared within the
cytoplasm.
These
particles were polyethlene, ceramic and metal depending on the type of each prosthesis used. Polarized light microscopic examination revealed strong birefringent polyethylene particles more clearly. Any of these substances in particulate from
seemed to
be associated with foreign body reaction. Larger particles seemed to cause more foreign body reaction than small particles.
Tissue-digestion technique was very useful for isolating wear particles. Scanning electron
microscopic examination on the wear particles seemed to characterize the morphology more
accurately than routine histological methods. Ceramic particles were identified as irregular
cubic or rectangular shape. An X-ray probe microanalysis showed high peak of carbon
component in polyethylene particles, aluminium component in ceramic particles, and cobalt
and chrome components in metal particles.
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