No i live in the USA. However what your describing the manipulating is what my chriopracter did to the muscles in my thighs and it did improve my pain. I had a acl repair, MCL repair, and 2 meniscus repairs and now my ACL has torn again, although the dr has said thats not why my knee gives way. By giving way i mean i can just be standing talking to somone and a electrical jolt like thingy goes through my knee and i almost collapse as my knee shifts out of place.
Find a good musculoskeletal physiotherapist (probably not the one who's diagnosed you with a "loose muscle"). I don't know where you are, but if you're in the UK let me know and I can recommend a couple of people who I know are good.
A decent physio should examine the stability of the joint, compare the musculature to that of the other leg and may want to do a gait pattern analysis. As a guide, a good physio will cause bruises when performing soft-tissue work - if their treatment doesn't hurt, you're wasting your time... and if they even suggest using ultrasound as a treatment leave and find another practitioner.
It sounds to me like you've been very poorly rehabbed after your surgeries; do you know exactly what each of the surgeries was intended to do? You say your knee gives way; is there any particular movement that prompts this, or do you mean that you simply can't lock the joint out?
Best of luck with it; I can testify first-hand that it IS possible to have knee surgery and come out of it with a better joint than you had to start with, but you need to find the right person to look after you.