I have been having right knee pain for a little over a week now. I work as a PTA in a hospital and have a history of knee injury. 4 years ago I tore my lateral meniscus only to discover my meniscus was deformed. I had too much meniscus so the fix was to carve out the excess meniscus. I now have a normal amount of meniscus. Last week I was leaving worked and my knee suddenly felt weak and unstable and there was pressure in the center of my knee. Over the course of the next few hours, those symptoms increased and my knee began to swell some and be painful as well. It hurt to stand for too long and walking was difficult due to the feeling of weakness, instability, and pain. It seemed difficult to flex my knee. By the next morning, the symptoms had decreased and I wasn't in much pain and there wasn't much swelling. The rest of the symptoms remained but I was able to continue with my regular daily activities. As the day went on, the symptoms worsened and the pain and swelling set back in. Every day since, my symptoms have been as follows:
Pain when bearing body weight on right leg
Pain with squatting or taking stairs
Weakness, instability, pressure from the middle of the joint, minimal swelling as the day progresses
Aching pain when sitting with feet on ground and knee at 90 degrees of flexion
Aching pain when knee completely extended when seated
Burning sensation with every day activities when not guarding joint
Joint guarding
Limping with gait
Pain when seated with legs crossed
Positive anterior drawer test
Positive lateral pivot test
Increased moderate/severe pain within 3 or 4 hours of special tests being performed