Is it possible to have a scar that progressively hurts worse a year later after surgery?

Yes it is. As scars form, if you dont masssage them, they can harden up, and that hard tissue doesn't flex as well as your regular tissue. There are some terriffic scar alleviating ointments now, available from your doctor and also from Clinque (a cosmetic company created by dermatologists). Those, applied as per instructions, coupled with massage, may help. In extreme cases, plastic surgery can also help.