I had to deal with this same repair several times (on different pants 
) I tucked a small square of fusible stabilizer and a small square of double sided fusible web into the hole, tucking in all the edges & clipping off all the frayed bits. Then I ironed it down & sewed on a new bar. Because the bar is hidden when the pants are closed, it looked alright, & it held together pretty well through washing & wearing. It might hold even better if you added a line of stitching across or around your little patch - keeping your stitches inside the area covered by the flap on the hook side.
Last edited by mindless; 11-25-2013 at 11:50 AM.