Scar tissue form the injury can lead to chronic swelling leading to the symptoms you describe.
You can image the area to ensure there isn't any new damage. This can be done via an MRI.
Another consideration would be a blood clot, which can certainly lead to swelling and pain. This can be ruled out with an ultrasound.
Otherwise, a referral to an orthopedist or physiatrist (rehabilitation MD) can be considered for further evaluation.
Followup with your personal physician is essential.
This answer is not intended as and does not substitute for medical advice - the information presented is for patient education only. Please see your personal physician for further evaluation of your individual case.
Kevin, M.D.
kevinmd_b