I have throbbing knee pain after a bad impact injury 6 weeks ago. the knee is titanium, so no mri possible. two days after the bad fall, I was going down steps, felt like something let loose and went down on butt. since then I have instability in the knee. the initial fall, I hit cement, lost conscious, left knee and elbow along with left side of head. uneven pavement caught my foot and I flew through air approximatly 6 foot before I hit cement. six weeks later , being told weak, quads. I know my body, something is not right under my knee cap, I landed on my lower left side of my knee cap, I had a 3 inch bloody contusion, that my doctor told me it had to heal first. so after 6 weeks of constant severe throbbing I need some help. I was walking a mile and half every day to help my back.