Stability from 4 major ligaments (ACL, PCL, MCL and LCL)
Knee dislocation causes injury to multiple ligaments (usually 3 of the above).
Many of these dislocation spontaneously reduce prior to medical evaluation. Therefore, consider knee dislocation in a patient with multi ligament injury, significant hemarthrosis and bruising.
Vascular injury in up to 40% (popliteal artery)
Nerve injury in up to 23% (peroneal nerve) ((ankle dorsiflexion and sensation to the first web space of the foot))
After reduction, immobilize knee in 15-20 degrees flexion.
The degree of initial deformity, presence of strong pulses, or warm skin cannot be used to rule out popliteal injury.
