Method and apparatus for catheterization

A method of delivering therapeutic material to an internal joint cavity of an animal, the joint cavity being defined at least in part by bone material and including fluid therein retained by a retaining membrane;

• the joint cavity further defining a connective point for at least two bones of which at least one is movable relative to the other;
• said method comprising the steps of:
• (a) providing an access channel through a bone having a surface in association with the cavity, the access channel being provided in fluid flow communication with the cavity;
• said step of providing an access channel being conducted without a piercing of the retaining membrane;
• (b) securing a tap arrangement within the access channel and completely internally of the animal, the tap arrangement having an internal flow channel provided in fluid flow communication with the joint cavity;
• the tap arrangement having a head portion and a shank portion, the shank portion having the internal flow channel extending completely therethrough;
• (c) providing a cannula arrangement in fluid flow communication with the internal flow channel of the tap arrangement;
• said step of providing a cannula arrangement comprising providing an extension of flexible, biologically compatible material, which is resistant to bone overgrowth, in extension completely through the tap arrangement internal flow channel;
• and,
• (d) injecting a therapeutic material through the cannula arrangement and into the joint cavity.