My Husband Cracked His Pelvis In August 2015 About A

My husband cracked his pelvis in August 2015 about a month after he started swelling in his one hand and one leg and severe joint pain in his wrists and back of neck. He had a ct scan cause his d dine test showed high for blood clots although there was none. He is on round four of prednisone what is causing this swelling? It's good until he goes off the pred and then severe Adema again