Electronically they are identical, but as mentioned before the wires can cause other issues. I have seen the following failures in the past:
(a) the wire on an axial cap mounted vertically wore through the plastic insulation covering the aluminum case and eventually shorted to the case with exciting results (the cap popped its top)
(b) the wire on a radial cap mounted in place of an axial cap got bumped and one of the wires contacted a resistor lead, shorting the resistor to ground. It was fried instantly internally, but it looked fine on the outside. I only found it when I bumped the resistor with a pair of pliers while removing the radial cap to replace it with an axial cap.
(c) one of the wires on a radial cap mounted axially wore through the insulation and shorted to the ground plane below it. Pop goes the capacitor.
If you are going to use the wrong configuration capacitor, at least insulate the wires with some heat shrink tubing or some insulator pulled off a wire.
ken