My Grandmother Had Her Third Synvisc Injection Three Weeks Ago.

My grandmother had her third Synvisc injection three weeks ago. Since then her right knee is extremely swollen and excruciatingly painful. Now the entire leg is markedly swollen. She can barely get around and cannot sleep. Her orthopedic referred her to the primary. They checked for DVT yesterday and found nothing. Pretty much told her to live with it. Any suggestions?