Knee Joint

• Relations of the Knee Joint

  
• Bones of Knee Joint

  •Modified hinge joint

  •3 separate articulations:

  –Femoropatellar

  –Femorotibial (x2)

  Fibula does NOT articulate at the knee joint

  
• Bones of the Knee Joint

  
• Articular Surfaces

  
• Capsule Attachments

  Anteriorly: fuses with quadriceps tendon, patella and ligamentum patellae

  Posteriorly: encloses intercodylar fossa* of femur; open posterior to lateral condyle of tibia for popliteus m

  
• Synovial Membrane Attachments

  Medial and Lateral alar folds cover the inner surface of fat pads on either side of the patellar ligament

  
• Opening the Knee Joint

  
• Bursae around the Knee Joint

  
• Ligaments

  Extracapsular:

  •Oblique Popliteal

  •Arcuate Popliteal

  •Medial and Lateral Collateral

  Intracapsular:

  •Anterior and Posterior Cruciate
• Popliteal Ligaments

  Oblique Popliteal Ligament:

  Expansion of Semimembranosus tendon

  Reinforces posterior capsule

  Arcuate Ligament:

  Thickening of capsule over popliteus

  Strengthens posterolateral joint capsule

  
• Medial (Tibial) Collateral Ligament

  •Strong, flat thickening of capsule

  •Medial epicondyle of femur

  → Medial condyle and superior medial surface of tibia

  •Deep fibres attach to medial meniscus

  
• Lateral (Fibular) Collateral Ligament

  •Strong and cord-like

  •Lateral epicondyle of femur

  → Lateral head of fibula

  Tendon of popliteus: deep

  Tendon of biceps femoris: split in two

  
• Cruciate Ligaments

  Cruciate ligaments, or parts of them, are taut in every joint position

  Maintain contact between femoral and tibial articular surfaces when knee flexed

  Wind around each other during medial rotation of the tibia → limited to 10°

  
• Cruciate Ligaments

  Posterior cruciate ligament (PCL):

  Prevents the femur from sliding anteriorly on the tibia, particularly when the knee is flexed

  Anterior cruciate ligament (ACL):

  Prevents the femur from sliding posteriorly on the tibia,  preventing hyperextension of the knee, and limits medial rotation of the femur when the foot is planted (leg is fixed

  
• Anterior Cruciate Ligament

  Anterior intercondylar area of tibia

  → Medial side of Lateral condyle of femur

  Spirals through 1100 between tibia and femur

  Anteromedial band

  →limits flexion

  Posterolateral band

  →limits extension

  
• Anterior Cruciate Ligament

  
• Posterior Cruciate Ligament

  Posterior intercondylar area of tibia

  → Lateral side of Medial condyle of femur

  Closely aligned to centre of rotation of knee

  Anterolateral band

  →limits flexion

  Posteromedial band

  →limits extension

  
• Posterior Cruciate Ligament

  
• Menisci

  Wedges of fibrocartilage

  Deepen articular surface

  Shock absorption

  Medial Meniscus

  •C-shaped

  •Broad posteriorly

  •Firmly attached to TCL

  Lateral Meniscus

  •Circular

  •Freely moveable

  •Attachment for popliteus

  
• Menisci

  
• Blood Supply to the Knee

  Periarticular Genicular Anastomosis

  Genicular branches from popliteal artery

  Descending genicular artery from femoral artery

  Descending branch from lateral circumflex femoral artery

  Branches from anterior tibial recurrent artery