Pin tract histological study: preliminary clinical investigations

Histological examination was performed at the time of retrieval of external fixation pins, using a special instrument designed for biopsy of the soft tissues of the pin tract (70 samples). The reactions were evaluated in five stages, depending on the intensity of the inflammation. We also graded the edema.The importance of the inflammatory reaction depends on the thickness oí the soft tissues, being more important in the femur and the humerus than in what we considered superficial bones. We did not observe any relationship between the histological reactions and the mechanical anchorage of the pins. For the usual duration of implantation, the inflammatory reaction does not seem to be time related.