A cannula including a shaft an outer layer and an inner layer, the inner layer being composed of a material that will cause the inner layer to be destroyed when autoclaved. A pre-applied layer of lubricant covers the inner and outer surfaces of the shaft. A slide is slidingly received within the shaft. An adaptor on the cannula includes a fitting forming a tapered bore sized to allow an outer end of a receptacle post to compressively contact the end of the shaft. An elastic sealing device is configured to be compressed between the fitting and the receptacle when the receptacle post is received within the tapered bore. This sealing device further seals the connection, protecting the tissue from contamination.