KNEE JOINT

Knee joint
- Features
  - Largest and most complex joint
  - 3 joints in to one
- Parts of joints
  - Lateral femorotibial
  - Medial femoro tibial
  - Femoro patellar joint
- Type
  - Condylar ( synovial )
  - Two condylar joints between
    - Femur and tibia
  - One saddle joint
    - Femur and patella
- Articular surfaces
  - Condyles of femur
  - Patella
  - Condyles of tibia
  - Femoral condyles articulates with
    - tibial condyles below and behind
    - Front
      - Patella
- Ligaments
  - Names in brief
    - Fibrous capsule
    - Ligamentum patellae
    - Tibial collateral. or medial ligament
    - Fibular collateral or lateral ligament
    - Oblique popliteal ligament
    - Arcuate popliteal ligament
    - Anterior cruciate ligament
    - Posterior cruciate ligament
    - Medial meniscus
    - Lateral meniscus
    - Transverse liganent
  - Names in detail
    - Fibrous or articular capsule
      - Femoral attachment
        
        1 cm beyond articular margins
        
        3 special features
        
        Anteriorly
        
        It is deficient
        
        Posteriorly
        
        Intercondylar line
        
        Laterally
        
        Enclose origin of popliteus
      - Tibial attachment
        
        Anteriorly
        
        Descends along margins of condyles
        
        To tibial tuberosity
        
        Posteriorly
        
        Attached to intercondylar ridge
        
        Limits attachment of posterior cruciate ligament
        
        Posterolaterally
        
        Gap behind lateral condyle for passage of tendon of popliteus
      - Coronary ligament
        
        Part of Fibrous capsule
        
        Between menisci and tibia
      - Short lateral ligament
        
        Thickening of capsule
        
        Deep to fibular collateral ligament
        
        Extends from lateral epicondyle of femur
        
        Blends with tendon of popliteus to the medial border of Apex of fibula
      - Capsular ligament
        
        Weak
        
        Strengthened anteriorly by medial and lateral patellar retinacula
        
        Which are Extensions from vastus medialis and lateralis
      - Openings
        
        Two gaps
        
        One leading to supraptellar bursa
        
        For exit of tendon of popliteus
    - Ligamentum patellae
      - Long band of great strength
      - Attached
      - Superiorly
        
        To medial epicondyle of femur
        
        Just below adductor tubercle
      - Inferiorly
        
        Divides in to anterior and posterior parts
        
        Anterior part or superificial part.
        
        10 cm long and 1.25 cm broad
        
        Separated from capsule by 2 or more bursa
        
        Attached
        
        below to medial border and posterior part of
        
        Medial surface of shaft of tibia
        
        Covers inferior medial geniculate vessels and nerve
        
        Covers anterior part of tendon of semimembranosus
        
        Crossed by tendons of sartorius , gracilis and semitendinosus
        
        Posterior or deep part
        
        Short
        
        Blends with capsule and with medial meniscus
        
        Attached
        
        To medial condyle of tibia above the groove for semitendinosus
    - Fibular collateral or lateral ligament
      - Ligament is strong and cord like
      - Superiorly
        
        Attached to lateral epicondyle of femur just above popliteal groove
      - Inferiorly
        
        Attached to
        
        Head of fibula infront of its Apex
        
        Embraced by tendon of biceps Femoris
      - Separated from
        
        Lateral meniscus
        
        By tendon of popliteus
        
        Inferior lateral genixular vessels and nerves seprate it from capsule
    - Oblique popliteal ligament
      - Expansion from tendon of semimembranosus
      - Runs upward and laterally
        
        Blends with posterior surface of capsule
      - Attached to
        
        intercondylar line
        
        lateral condyle of femur
      - Related to
        
        Popliteal artery
      - Pierced by
        
        Middle genicular vessels and nerve
        
        Terminal division of posterior division of obturator nerve
    - Arcuate popliteal ligament
      - Posterior expansion from short lateral ligament
      - Extends backwards from head of fibula
      - Arches over tendon of popliteus
    - Cruciate ligaments
      - Anterior cruciate ligament
        
        Begins
        
        Anterior part of intercondylar area of tibia
        
        Ends
        
        Posterior part of medial surface of llateral condyle of femur
      - Posteriro curicate ligament
        
        Begins
        
        Posterior part of intercondylar area of tibia
        
        Ends at
        
        Anterior part of lateral surface of medial condyle of femur
    - Menisci or semilunar cartilage
      - Fibrocartilaginous disc
      - Shaped like crescent
      - Divide articular cavity in
        
        Upper compartment
        
        Lower compartment
      - Parts
        
        Two ends
        
        Anterior end called as anterior horn
        
        Medial meniscus Posterior fibres are continuous with transverse ligament
        
        Posterior end called as posterior horn
        
        Lateral meniscus
        
        Posterior end attached to medial condyle of femur through two meniscofemorsl ligaments
        
        Two borders
        
        Outer border is thick , convex and close to fibrous capsule
        
        Inner border is thin , concave and free
        
        Two surfaces
        
        Upper surface
        
        Concave
        
        Articulates with femur
        
        Lower surface
        
        Flat
        
        Rests on peripheral two thirds of tibial condyle
        
        Peripheral thick part is vascular
        
        Inner part is avascular and nourished by synovial fluid
      - Medial meniscus
        
        Nearly semicircular
      - Lateral meniscus
        
        Nearly circular
    - Transverse ligament
      - Connects
        
        Medial and lateral menisci anterior ends
- Bursae
  - Anterior
    - Patellar bursa
      - Subcutaneous
        
        prepatellar bursa
        
        Infrapatellsr bursa
      - Deep
        
        Infrapatellar
      - Supraptellar bursa
    - Lateral
      - Deep to
        
        lateral head of gastrocnemius
      - Between
        
        Fibular collateral and tenon of popliteus
        
        Fibular collateral and biceps Femoris
        
        Tendon of popliteus and lateral condyle of tibia
  - Medial
    - Deep
      - To medial head of gastrocnemius
      - To Tibial collateral liagemt
      - To semimembranosus
    - Anserine bursa
- Relations
  - Anteriorly
    - Anterior bursa , ligamentum patellae
  - Posteriorly
    - To middle
      - Popliteal vessels , tibial nerve
    - Posterolaterally
      - Lateral head of gastrocnemius , plantaris , peroneal nerve
    - Posteromedially


Type	Tibiofemoral joint: Synovial hinge joint; uniaxial
	Patellofemoral joint: Plane joint
Articular surfaces	Tibiofemoral joint: lateral and medial condyles of femur, tibial plateaus
	Patellofemoral joint: patellar surface of femur, posterior surface of patella
Ligaments and Menisci	Extracapsular ligaments: patellar ligament, medial and lateral patellar retinacula, tibial (medial) collateral ligament, fibular (lateral) collateral ligament, oblique popliteal ligament, arcuate popliteal ligament, anterolateral ligament (ALL)
Ligaments and Menisci	Intracapsular ligaments: anterior cruciate ligament (ACL), posterior cruciate ligament (PCL), medial meniscus, lateral meniscus
Innervation	Femoral nerve (nerve to vastus medialis, saphenous nerve) tibial and common fibular (peroneal) nerves, posterior division of the obturator nerve
Blood supply	Genicular branches of lateral circumflex femoral artery, femoral artery, posterior tibial artery, anterior tibial artery and popliteal artery
Movements	Extension, flexion, medial rotation, lateral rotation