I've had 4 surgeries on my right knee over the past 15 years. Within the last 4 years or so, my left knee started hurting when my knee was fully extended. Basically, it would be a sharp, and shooting pain, mostly in center to rear knee area. The pain has been getting progressively worse over the years. Now, it hurts anytime my knee is at full extension. When I come out of extension, my knee either cracks (like cracking your knuckles) or I feel a pop (something actually moving inside) in the center to rear knee area, which is painful. It hurts to get out of a chair, and it hurts if I do hamstring curls. All the pain is deep in the knee.
I've read some stuff about these symptoms being in line with a torn ACL. The only injury that I can think of is a snowboarding accident where I got hit by another skier. I remember hurting all over the next few days, not just my knees. I would also think that if I had a torn ACL, I would be able to remain active over the past few years. I run, bike, basketball, etc.
I've had an x-ray, which the doctor found nothing wrong. But the pain is getting worse. Any thoughts?