A medical needle assembly includes a needle cannula having a body and a tip. The tip is disposed at a distal end of the cannula. An elongate member has a first end and a second end. The first end is fixedly attached to the body of the needle cannula at a connection point and the second end extends radially outward from the needle body. A shield is slidingly mounted to the needle for movement between a proximal position to a distal position. The shield includes a shield body having a central chamber, a distal end and a proximal end as well as a plate secured to the shield body and defining an aperture. As the shield is moved from the proximal position to the distal position, the place displaces the second end of the elongate member to a position near the needle cannula, permitting the elongate member to pass through the aperture. When the shield is in the distal position, the send end of the elongate member extends radially outward from the needle body, preventing passage of the elongate member through the aperture. The elongate member may be a leaf spring. A feature may be secured to the body of the cannula to restrict movement of the shield with respect to the needle.
