Limitations of hair transplant?

I  recommend excision and fine closure of a 2 cm scar rather than transplants. Hair transplants can be used to refine the revised scar if necessary.

What you describe is a fairly small area. Though hair transplantation may work, it is less than optimal in an area of scar. The better option would be to excise the scar and close the area with meticulous technique. This will likely produce superior results.

Grafting into the scar is possible and the hair will survive. Having said that, this is usually my second choice! Proper excision and closure by an experienced plastic or facial plastic surgeon should give superior results.