A dislocated knee is a serious injury in which the thigh bone (femur) and the shin bone (tibia) become disconnected. This is different from a dislocated kneecap, which is when the kneecap (patella) becomes detached from its groove at the end of the femur. It should also not be confused with a partial dislocation (subluxation) which is due to a damaged ligament and can cause the knee to give way temporarily until the bones slip back into place.
A dislocated knee is a relatively uncommon injury but is potentially very serious and no attempt should be made to reposition the knee without professional medical support as this can result in:
- Deep vein thrombosis
- Damage to the peroneal nerve, which runs along the outer edge of the calf.
- Rupture or obstruction to the popliteal artery and vein at the back of the knee.
It is essential to seek medical help immediately to prevent potentially devastating damage to the knee and lower leg. If you develop a vascular obstruction and it is not treated for eight hours or more there is an extremely high (86%) risk of amputation.
Knee dislocation is not the same as kneecap (patella) dislocation.