As a young teen, I was scissor tackled and destroyed my knee. First surgeon said knee is messed up let's do surgery. Parents got a second opinion. He said, let's do PT. He's young. Maybe it's just a really really bad sprain. He'll heal. I was 8 weeks non-weight bearing. After 8 weeks, ortho put on a brace and let me go back at it.
Lost explosiveness out of that knee. Could never jump off of it. Lost lateral movement. Derailed soccer playing.
Saw an ortho 20 years later, who said he could do an MRI but he guaranteed it would confirm that I tore my MCL back then and that scar tissue filled in its place. Also, said probably have cartilage damage from it. Ortho said had surgery been done at the time, it should have healed back good as new.