Can knee contusion fuse growth plates? i have been hit on knee.i can walk,run,jump normally.just pain when rubbing knee against something hard.

At almost age 30?: At almost 30 years, a person has no growth plates. They fused about a decade ago. In children with open growth plates, trauma such as from falling hard onto a surface can fracture a growth plate. Mild or typical kids' bruises don't come from big enough forces to cause fractures. Look here for details: https://www.rch.org.au/fracture-education/growth_plate_injuries/Physeal_growth_plate_injuries/