Knee ligament injuries

• Anterior cruciate ligament injury
  • Typical sport injury
  • Etiology
    • Sudden twisting of the leg
    • Osteoarthritis of knee (osteophytes can damage ligament)
  • Clinical features
    • Swollen leg (haemarthrosis)
      • Due to bleeding from the ACL
    • Acute pain
    • Knee instability
  • Diagnosis
    • Positive Lachman test
    • Positive anterior drawer test
    • MRI
      • Gold standard
    • Not visible on x-ray
  • Treatment
    • Conservative
      • Stabilize the knee, by:
      • Strengthen muscles
      • Wear a brace
    • Surgery
      • Arthroscopic surgery
        • Not in the acute setting
        • Only if knee instability remains after a long time and after trying conservative therapy
      • An artificial ligament or a bone-tendon-bone (BTB) graft is used to replace the ACL
      • Patient can return to activity soon
• Posterior cruciate ligament injury
  • Less frequent than ACL injury
  • Occurs due to posterior injury to a flexed knee
  • Clinical features
    • Same symptoms as for ACL injury, but much less intense/significant
  • Diagnosis
    • MRI
      • Gold standard
    • Positive posterior drawer test
  • Treatment – Same as for ACL injury
• Medial collateral ligament injury
  • Most commonly injured knee ligament
  • Caused by valgus stress to the knee
  • Clinical features
    • Knee swelling
    • Pain
    • Knee instability
  • Diagnosis
    • Positive valgus stress test
    • MRI not needed
  • Treatment
    • Conservative – for isolated MCL injury
    • Surgery – if multi-ligament injury is present
• Lateral collateral ligament injury
  • Isolated LCL injury is rare
  • Clinical features
    • Knee swelling
    • Pain
    • Knee instability
  • Diagnosis
    • Positive varus stress test
    • MRI not needed
  • Treatment
    • Needs surgery