Suggest Remedy For Dent On Ankle Bone After Injury

Hi my son fell playing football 18months ago. Cray showed no break but he continues to suffer badly. My doctor arranged an mri scan which showed a dent in his ankle bone. This injury has resulted in a muscle tearing too. As he is on his feet the dent and the muscle have not had a chance to heal. He is 19 and I am worried he will have long term damage. Can you suggest what we should be asking the doctor to do next please? Many thanks