Knee

• 3 bones articulate in the knee:

  1. Femur
  2. Tibia
  3. Patella
• The knee is a bicondylar hinge joint
• 3 articulations in the knee joint:

  1. Medial tibiofemoral
  2. Lateral tibiofemoral
  3. Patellofemoral
• Tibiofemoral Joints:

  • Large range of motion in sagittal plane
  • Modified hinge joint
  • Articulation between medial and lateral condyles of femur and tibial plateau
• Patellofemoral joint is a saddle joint
• Stability affected by:

  • Shape of bone surface
  • Menisci (fibrocartilage semilunar discs between tibial and femoral condyles)
  • Arrangement of ligaments and muscles
  • Connective and capsular tissue
• Ligaments in the knee restrict medial and lateral rotation
• Cruciate ligaments cross the knee
• Menisci distribute force in knee over large SA and shock absorb
• Pes Anserinus:

  • Shape of goose foot
  • Stabilises medial aspect of knee
  • Conjoined tendon of sartorius, gracilis and semitendinosus
• Bursa: synovial fluid filled sac
• ITB: Strong band of fascia connecting TFL to lateral condyle of femur and lateral tuberosity of tibia
• Movements of the knee:

  1. Flexion
  2. Extension
  3. Abduction (when flexed and not weight bearing)
  4. Adduction (when flexed and not weight bearing)
  5. Internal Rotation (when flexed and not weight bearing)
  6. External Rotation (when flexed and not weight bearing)
• Passive movements at the knee:

  • Varus
  • Bow legged
  • Valgus
  • Knock kneed
• 4 ligaments of the knee:

  1. Anterior Cruciate Ligament
  2. Posterior Cruciate Ligament
  3. Lateral Collateral Ligament
  4. Medial Collateral Ligament
• Anterior Cruciate Ligament

  
• Posterior Cruciate Ligament

  
• Medial Collateral Ligament

  
• Lateral Collateral Ligament

  
• Quadriceps are the anterior muscles of the knee that perform extension
• Rectus Femoris

  
• Vastus Lateralis

  
• Vastus Medialis

  
• Vastus Intermedius

  
• Hamstrings assist flexion of the knee
• 3 muscles other than the hamstrings that assist knee flexion:

  1. Popliteus
  2. Gastrocnemius
  3. Plantaris
• 3 muscles in the knee that are biarticular:

  1. Rectus femoris
  2. Gastrocnemius
  3. Plantaris
• Popliteus

  
• Gastrocnemius

  
• Plantaris

  
• 3 hamstrings:

  1. Rectus femoris
  2. Semimembranosus
  3. Semitendinosus