Things going very wrong after Dynesys

[LC in UK]

Help!
I had a Dynesys op in October '04 here in the UK (my 4th back op). Level L3-5 I think.
Was very impressed with improvements after initial severe pain for a few weeks.
Then a year ago my knees started swelling,and had no strength in my thigh muscles and also had nasty pains in mt feet. Ortho registrar said I had arthritis in my knees and synovitis in my feet (no x-rays taken). She said to continue at the gym but keep off the treadmill.
So I tried but gave up, couldn't hack it, not enough energy.
In December I was admitted to hospital as an emergency patient with severe abdominal pain LH side.
Now seeing colo-rectal surgeon who says I had intussusception due to part of the sigmoid muscle not working properly and adhesions from previous abdo surgery (including anterior spinal fusion). Having to use glycerin suppositories to empty the bowel until I see him again in July when they may send me to London for more tests.
A month ago my knees started giving out and walking became extremely difficult, my legs are dragging and feel very heavy. Sharp pains shooting down into my knees and around my hips from my lower back, both pains starting when I try to bend or stand up from sitting.
Had an MRI on 6th June which doesn't show spinal cord compression so as I'm not incontinent I have had to wait ubtil next Tuesday 26th June before I can be seen by the Ortho people.
I'm very worried by whats happening to me and even more by having to wait so long. My GP has been excellent writing to the consultants and keeping them informed.
Anybody have any info for me on Dynesys probs?
Thanks