dislocate your knee, it may look twisted, bent out of
shape, or out of its normal position. This type of injury may also
A feeling that a bone popped or moved out of
A loose or unstable knee joint. You may not be able to stand
Abnormal movement of your leg or knee.
locked knee (can't bend or straighten it).
Cool, pale skin or
numbness and tingling at or below the injury, if nerves or blood vessels were
injured or pinched by the injury.
A fracture of the knee may mean that you have broken one of the
Lower end of the
thighbone (distal femur)
Upper portion of one of the lower leg
bones (tibial plateau, tibial spine, or fibular head)
Knee fractures are most commonly caused by abnormal force, such as
a falling on the knee, a severe twisting motion, severe force that bends the
knee, or when the knee hits an automobile dashboard. Indirect injury, such as a
forceful contraction of the thigh muscle, is less common.
It is much more common to dislocate the kneecap (patella) than the
knee joint. The kneecap is more likely to dislocate when the:
Knee is in a bent (flexed) position and turned
Side of the kneecap is hit, forcing the kneecap toward
the outside of the leg.
Knee is swollen.
It takes more force to dislocate a kneecap the first time. Once you
have dislocated your kneecap, it will be more easily dislocated by another
injury or a repeat of the forces that dislocated it the first time.
Dislocation of the knee joint is rare and requires great force. A
dislocated knee, even if it goes back into place by itself, is a serious injury
that requires emergency treatment.
Immediate medical treatment may involve:
Putting the bone back in place if it hasn't
already popped back into place.
Splinting the joint or
Applying cold packs.
Elevating the injured
A fracture or dislocation of the knee requires medical
Primary Medical Reviewer
William H. Blahd, Jr., MD, FACEP - Emergency Medicine
How this information was developed to help you make better health decisions.