An injury can result in:

• Broken (fractured) bone
      • Patella, tibia and femur bones
• Damaged joint surface (cartilage surface)
      • Or aggravate pre-existing arthritis
• Contusion (bruise) of the soft-tissues (skin, muscle) or bone
• Sprain (tear) of the ligaments (cord-like connections between bones) or surrounding capsule that stabilize the joint
      • Anterior and posterior cruciate, medial and lateral collateral ligaments
• Scar tissue, stiffness, frozen knee (arthrofibrosis)
• Tear of the tendons that connect the muscles to the bones
      • Patella, quadriceps, hamstring tendons
• Tear of the menisci (cartilages of the knee) which function as shock absorbers between the bones
      • medial and lateral menisci
• Strain of the muscles
      • Quadriceps, hamstring and gastrocnemius muscles
• These can cause pain, swelling, stiffness, catching, grinding, popping, locking, fatigue, weakness, instability,
deformity and disordered gait