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Knee Dislocation/Multi-ligament Injuries

What is a knee dislocation?

Knee dislocation is a serious condition that requires immediate hospital assessment.
These injuries often occur because of a high impact injury such as a car accident or fall from a height. For a knee dislocation to occur, the surrounding ligaments must tear, and generally dislocation occurs with multi-ligament injuries where all four ligaments are involved.

What are the symptoms of a knee dislocation?

– Severe pain and swelling
– Inability to walk
– The usual straight line of the leg will look deformed or angulated
– The knee feeling unstable, loose and wobbly
– If the knee is dislocated, then serious nerve or arterial damage may have occurred and needs to be promptly assessed.
– Serious dislocations include loss of pulse below the knee, and loss of feeling below the knee

How is a knee dislocation diagnosed?

– Tests to diagnose a knee dislocation include a physical examination, (which may be done during a reduction where the knee is moved back into position, usually under sedation or with pain medication.)
– X-rays will be taken to ensure there are no breaks in the bone
– An arteriogram (x-ray of the artery) of Doppler Ultrasound may be done to detect arterial injury.
– Nerve testing will also be done clinically. Can the patient turn the foot inwards and outwards, and move the foot up and down?
– Any numbness implies significant nerve injury and needs urgent assessment and treatment
– MRI scans and MR arteriograms can assess ligament damage and blood flow.

What does surgery for knee dislocation involve?

– The knee needs to be reduced urgently and checked for vascular or neural damage.
– This may need to be done with some form of anaesthesia.
– Often the leg is splinted until swelling has reduced sufficiently to allow major surgery.
– There is no real role for non-operative treatment in this scenario and staged surgeries are often performed to reconstruct the ligaments with a combination of autograft (patient’s own tendon), allograft (tendon from a cadaver) and synthetic grafts (artificial ligaments). See more on multi-ligament injuries here.
– Recovery is up to a year.
– If you or your GP suspect a dislocation, please call our office urgently or go to your local hospital emergency department after hours.