The Knee

• Fixed flexion deformity

  • Line of centre of gravity passes more POSTERIORLY
• Hyperextension

  • Line of centre of gravity passes more anteriorly
• Extracapsular: Medial and Lateral Retinaculum

  Attachments:

  P: medial and lateral aspect of the patella and patellar tendon/ligament D: ITB, collateral ligaments
• Extracapsular: Medial and Lateral Retinaculum

  Limits: lateral and medial patellar glide
• Extracapsular: Medial (Tibial) Collateral ligament (MCL)

  Attachments:

  P: medial epicondyle femur

  D: superior medial tibia
• Extracapsular: Medial (Tibial) Collateral ligament (MCL)

  Limits: genu valgum

  Assisted by: Pes Anserinus
• PES ANSERINUS

  • The common insertion of sartorius, gracilis, and semitendinosus
  • Functions to support the medial aspect of the extended knee – limit valgus
• Extracapsular: Lateral (Fibular) Collateral ligament (LCL)

  Attachments:

  • P: lateral epicondyle femur
  • D: superior lateral fibula
• Extracapsular: Lateral (Fibular) Collateral ligament (LCL)

  Limits: genu varum

  Assisted by: ITB
• Extracapsular: Popliteal ligaments

  1. Arcuate popliteal
  2. Oblique popliteal
• Extracapsular: Popliteal ligaments

  Attachments: posterior

  Limits: limits screw home mechanism and hyperextension
• Intracapsular (but extrasynovial): Anterior Cruciate ligament (ACL)

  Attachments:

  • P: Posterior part of the medial surface of the lateral femoral condyle
  • D: Anterior intercondylar area of the tibia
• Intracapsular (but extrasynovial): Anterior Cruciate ligament (ACL)


  Limits: hyperextension, anterior tibial glide on the femur, posterior glide of femur on tibia, posterior rolling of condyles
• Intracapsular (but extrasynovial): Posterior Cruciate ligament (PCL) (Stronger than ACL)

  Attachments:

  • P: Anterior part of the lateral surface of the medial femoral condyle
  • D: Posterior intercondylar area of the tibia
• Intracapsular (but extrasynovial): Posterior Cruciate ligament (PCL)

  Limits: hyperflexion, posterior tibial glide on the femur, anterior femur glide on the tibia, anterior rolling of the femoral condyles
• Medial Meniscus

  Attachments:

  • A: Anterior intercondylar area of tibial plateau anterior to ACL
  • P: Posterior intercondylar area on tibial plateau anterior to PCL
• Medial meniscus

  Function: deepen the articulation, absorb shock and migrate to accommodate rolling and rotation of the femoral condyles
• Lateral Meniscus

  Attachments:

  • A: Intercondylar fossa on Tibial plateau close to the anterior attachment of the ACL
  • P: Intercondylar fossa on Tibial plateau close to the anterior attachment of the ACL
• Lateral meniscus

  Function: deepen the articulation, absorb shock and migrate to accommodate rolling and rotation of the femoral condyles
• Infrapatellar (Hoffa’s) fat pad

  • Intracapsular
  • Extrasynovial
  • Can be a source of pain when ‘pinched’.
• The movements of the knee joint are guided and limited by the cruciate ligaments and the menisci of the knee (intra-articular structures)