Hi please can you help me in November 2012 I had a 15 cm sarcoma cancer removed including most of my pelvis and replaced with metal screws into my spine and pelvis area while recovering at home and trying to recover I used a hot water bottle on my back but because of the epidural I was unable to feel until my friend noticed a huge blister had formed I then allowed it to heal and then a week or two ago I pulled off a scab that looked like I tooth root and thereafter it was open with a small hole with water coming out! Yesterday I had a plaster over it and today I removed it take note having had a bath with this on I then removed it and there was pus comming out no stench just pus but I am in serious pain from my lower back to my behind I a, struggling to walk what can this be what can I do ? Please can you give me advise thank you NB: the little hole is just next to the one metal screw which I have always been able to feel even after my surgery which gets inflamed in cold weather but never really caused me unbearable pain