knee

Function

• hinge type of synovial joint allowing flexion & extension
• connects the femur with the tibia
• supports the entire weight of the body in stride, thus is vulnerable to acute injury & osteoarthritis
• relatively weak mechanically because of the configuration of its articular surfaces
• stability depends on:
  • strength & actions of the surrounding muscles & their tendons (mainly quadriceps femoris & the fibers of vastus medialis & vastus lateralis)
  • ligaments that connect the femur & tibia

Structure

• ligaments attaching the femur to the tibia
  • patellar ligament
  • fibular collateral ligament
  • tibial collateral ligament
  • oblique popliteal ligament
  • arcuate popliteal ligament
• the patella, a sesamoid bone covering the anterior surface of the knee, connects the quadriceps tendon with the anterior tibia via the patellar ligament.

Notes

• [Latin, genu = knee; junctura = to join]

More general terms

• synovial joint (diarthrosis)
• lower extremity structure

Additional terms

• buckling or giving way of the knee
• knee injury, traumatic
• knee pain
• locking of the knee

Component of

• lower extremity; lower limb; leg

Components

• pes anserinus (L. goose's foot)
• tibial plateaus (medial & lateral)
• lateral meniscus (meniscus lateralis)
• medial meniscus (meniscus medialis, faliciform cartilage)
• posterior cruciate ligament (PCL, ligamentum cruciatum posterius)
• anterior cruciate ligament; ligamentum cruciatum anterius (ACL)
• fibular collateral ligament (lateral collateral ligament)
• posterior meniscofemoral ligament
• tibial collateral ligament (medial collateral ligament)
• patella (kneecap)
• popliteal fossa