Injuries
Ligament Injuries: ACL/PCL/ LCL/MCL : Happend during sudden twisting of Knee( contact/ non contact)
MENISCUS Injuries: It is the tough, rubbery cartilage that acts as a shock absorber between your shinbone and thighbone. It can get injured if you suddenly twist your knee while bearing weight.
Fractures
Knee Bursitis: inflammation in the bursae, the small sacs of fluid that cushion the outside of your knee joint so that tendons and ligaments glide smoothly over the joint.
Patellor Tendonitis : Degeneration or Inflammation of Patellor tendon which could be acute/chronic /overuse.
Mechanical:
Loose Body/ Torn Meniscus : Fragment of Bone/ torn cartilage/ meniscus when get stuck in joint and sometimes present as locking itself.