How fast should cadaver cartilage disintegrate after rib graft rhinoplasty?

I had a septoplasty along with a rib graft rhinoplasty using cadaver cartilage just under two years ago. Within 6 months of my surgery, you could already see visible signs of the cartilage being dissolved. The graft had visible lumps and ridges, and this has only gotten worse over time. Is it normal for this to occur so quickly? Did something go wrong? Can it be fixed?