My husband who is diabetic had a knee replacement November 2. About two weeks later he got a leg cramp in his upper thigh (same leg) and now about 3 weeks later the muscle feels hard and tight. It is still painful and when he had an ultra sound they said there was something that resembled a large blood blister in the tissue. The Physical therapist has been doing ultra sound treatments 3 times a week since then and the swelling is gone but the hardness and lack of flexibility in the muscle concerns me.