Hip 2 foot leg pain, sometimes foot turns ice cold. broke knee cap years ago, not diabetic, not over weight. cause for concern?

Go see a doctor: Pain that radiates from hip 2 toes is usually caused by a pathology above the hip. Your patella (knee cap) fracture, most likely, has nothing to do with this pain. Your back is a likely candidate, but your history of heart disease and the fact that your foot turns cold, makes me think of a vascular (arterial) cause for your pain. I would definitely recommend you see a doctor to begin a workup.