... day, but the happiness lasted only 2 days and then the pain resumed stronger than ever. I then had a tkn in September 2010, followed by 5 months of physical therapy. I still have a great deal of pain at the site of the injection of Synvisc One. My question is can the medication cause something to harden in that area. My orthopaedist says the xrays show the knee is fine, but he isn't feeling the pain