patellofemoral joint

The patellofemoral joint is a synovial joint between the condyles of the femur and the articular surface of the patella. It is part of the knee joint.

Gross anatomy

Components
  • medial, lateral and odd facet on the posterior surface of the patella articulate with the medial and lateral condyles of the femur
  • the lateral facet is the largest and steepest facet
  • articular surface: hyaline cartilage
  • capsule: fibrous capsule and synovial membrane is continuous with the knee joint
Movement
  • sliding articulation with knee flexion and extension
  • on flexion, more parts of the bony surface are exposed to articulation (four below, odd facet) and are more proximal on the patella
  • with extension, the contact area lessens and moves distally
  • muscles attached to the patella stabilizes the joint 
Ligaments
  • patellar tendon
  • medial and lateral patellar retinaculum: parts of the patellar tendon on the edge of the patella that fuses with the joint capsule 
  • medial patellofemoral ligament: originates from the adductor tubercle to insert into the superomedial border of the patella 
  • lateral patellofemoral ligament
  • medial and lateral patellotibial ligaments
Bursa and fat pads 

Suprapatellar, prepatellar, deep and subcutaneous infrapatellar, semimembranosus and subsartorial bursa and infrapatellar fat pad.

Relations

  • anterior: patella, prepatellar bursa 
  • posterior: femoral condyles, intercondylar groove
  • inferior: patellar tendon, subcutaneous and deep infrapatellar bursa, infrapatellar fat pad, knee joint
  • superior: suprapatellar bursa, common tendon of quadriceps

Blood supply

  • superior medial and lateral geniculate arteries (popliteal artery)
  • inferior medial and lateral geniculate arteries (popliteal artery)
  • descending geniculate branches (femoral and lateral circumflex femoral arteries)

Innervation

Variant anatomy