Hi, It is a normal and usual sequel of the surgeries to get scarring tissue at the site of surgery. In yourself also as the flap surgery was done it lead to scarring of the area. After scarring there is always a type of unusual pain, irritation and varied feeling due to nerve entrapment in the scarred tissue. I suggest you to do physiotherapy exercises daily to reduce the impact of the scarring. You can meet a physiotherapist and ask for the best of exercises accordingly. Additionally you can apply a cream containing high potency steroid and silicon gel in it which helps in reducing scarring. Take care.