Originally Posted by Bree123

Others have suggested some of the same techniques I'd try to push a knot through. If it broke before the knot, though, those aren't options. Yes, I would pull out some stitches & re-knot (then re-quilt that section). It's not fun, but better than having the whole line of stitching come unraveled later on in the wash.

If it breaks just past the knot (the knot is still intact) then I would make a loop of embroidery floss in a separate needle & use the loop to grab the knot & pull it through the fabric. I've done that and it's held up fine in the wash.