Some quick facts about Knee Injuries:

• The most common cause of acute traumatic hemarthrosis of the knee is an anterior cruciate ligament tear.
  • Most patients with an ACL injury will give a history of immediate pain, disability, knee swelling and audible pop.
• The most common ligament injuried in the knee is the medial collateral ligament.
• Patella dislocations
  • Usually lateral dislocations and often spontaneous reduce.
  • Hyperextend the knee to make the reduction easier.
• Dislocation of the knee:
  • Anterior is the most common and usually secondary to hyperextension
  • Popliteal artery injury is commonly seen and must be looked for.  Easy bedside test is Ankle Brachial Index.
  • Normal pulses do NOT exclude a vascular injury.
  • Patients should be monitored for vascular complications and compartment syndrome.
  • Vascular injuries due to knee dislocation are associated with a high rate of amputation, which markedly increases if not repaired within 6-8 hours.