Anatomy

• Knee:

  • Hinge type synovial joint between the femur and tibia - menisci between the two help them fit together and move smoothly. Also act as a shock absorber
  • Also in the knee is a joint between the anterior femur and the patella - patellofemoral joint
• The quadriceps tendon attaches to the patella, which is attached to the tibia by the patellar tendon. Contraction of the quadriceps muscles causes knee extension by puling through the patella
• Anterior cruciate ligament (ACL):

  • Originates at lateral femoral condyle and inserts into anterior part of tibial plateau
  • Stops tibia from sliding forward in relation to femur
  • ACL smaller and weaker than PCL - ACL injuries more common
• Posterior cruciate ligament (PCL):

  • Originates from medial femoral condyle and inserts into posterior part of tibial plateau
  • Stops tibia from sliding backwards in relation to the femur
• Medial collateral ligament:

  • Runs between femur and tibia on inner side of knee
  • Prevents knee extending too far inwards - resists valgus stress
  • Not as flexible as lateral collateral ligament and more susceptible to injury
• Lateral collateral ligament:

  • Runs between femur and fibula on outer side of knee
  • Prevents knee extending too far outward - resits varus stress