Hi Callie
Its called Trochlear Dysplasia, my right knee has a shallow groove and my left knee has a flat groove, I've had TTTs on both knees and they have both been successful but I do not have any problems with fibrosis, all I can tell you is that my grooves are pretty non-existent but the TTTs still worked for me, I had them done 10 and 15 years ago and they're still holding up! Good luck if you decide to go ahead with the surgery.
Natalie.