I met with an accident 10 years ago and i had foot injury, my skin teared off from foot but it healed over time and wound closed but the dead skins still comes off and it haven't fully healed.
If those yellowish parts are moist then its probably an infection under the skin and needs to be treated professionally.
As this injury was 10 years ago and is still shedding skin like this you may need to see a doctor who may need to run some blood tests.
It may be simple and just need some emollient cream to smooth into the wound each night but you do need to see a doctor.