Effects of irrigation fluid on human menisci: an experimental comparison of water, normal saline, and glycine.

A technique has been developed to demonstrate the macroscopic morphology of collagen fiber arrangement in human menisci. It was observed that 0.9% normal saline solution removed the ground substance of the meniscus, leaving intact collagen bundles. This suggests that meniscal damage may occur as a direct result of using normal saline for irrigation during knee arthroscopy. Experiments were conducted using demineralized water and 1.5% glycine for comparison. The disruption of collagen fiber binding in the meniscus by normal saline is time and temperature dependent. Glycine solution causes fibroblast lysis and a lesser degree of collagen alteration. Demineralized water can cause edema in the fibroblast but no notable change in collagen fibers. None of the irrigation solutions tested has proved to be completely safe. Demineralized water is not the ideal solution but is preferable to normal saline or glycine solution, especially when it can be used in conjunction with electrosurgery.