A medical needle shield apparatus comprising: a needle hub having an outer needle cannula extending therefrom to a distal end, an inner needle being disposed for slidable movement with the outer needle cannula said needle hub having a hub slot; and at least one shield being extensible from a retracted position to an extended position to enclose a distal end of the inner needle, the shield including a binding member disposed within the shield and defining binding surfaces that form an aperture configured for slidable receipt of the inner needle between the retracted position and the extended position, the binding member including at least one drag inducing member such that the at least one drag inducing member engages the inner needle during slidable receipt of the inner needle to create a drag force with the inner needle, the drag force facilitates rotation of the binding member relative to a longitudinal axis of the inner needle such that the binding surfaces engage the inner needle to prevent slidable movement of the inner needle in the extended position of the shield, the binding member further including a needle communicating surface extending therefrom such that the needle communicating surface is engageable with the inner needle to prevent rotation of the binding member, characterised in that the binding member further includes a retainer extending transversely from a distal end of the needle communicating surface and having a free end for releasable engagement with its free end with the needle hub, wherein the retainer disengages with its free end from the hub slot when the binding member is rotated by the drag force. a needle hub having an outer needle cannula extending therefrom to a distal end, an inner needle being disposed for slidable movement with the outer needle cannula said needle hub having a hub slot; and at least one shield being extensible from a retracted position to an extended position to enclose a distal end of the inner needle, the shield including a binding member disposed within the shield and defining binding surfaces that form an aperture configured for slidable receipt of the inner needle between the retracted position and the extended position, the binding member including at least one drag inducing member such that the at least one drag inducing member engages the inner needle during slidable receipt of the inner needle to create a drag force with the inner needle, the drag force facilitates rotation of the binding member relative to a longitudinal axis of the inner needle such that the binding surfaces engage the inner needle to prevent slidable movement of the inner needle in the extended position of the shield, the binding member further including a needle communicating surface extending therefrom such that the needle communicating surface is engageable with the inner needle to prevent rotation of the binding member, a retainer extending transversely from a distal end of the needle communicating surface and having a free end for releasable engagement with its free end with the needle hub, wherein the retainer disengages with its free end from the hub slot when the binding member is rotated by the drag force.