Thank you for the update!
I'm not sure it's "scar tissue" without your surgeon doing a hands on assessment. It can be residual soft tissue swelling or tight quads (possibly with some trigger points that need release before they can stretch fully).
Besides massage, are you doing some ice and elevation daily, and stretching - very slow heel slides seated on a firm chair, breathing into the slow stretch and holding it.
You might use a ball or foam roller, or even a rolling pin from the kitchen, to check for small painful knots (trigger points) and slowly apply progressively deeper pressure, breathing into any one you find, until it releases. If they are present and can be released, the muscle will be more able to stretch.