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

• femoral, tibial, common fibular and obturator nerves

Variant anatomy

• variant patellar shape and position
• bipartite/multipartite patella
• absent patella
• dorsal defect of patella

Siehe auch:

• patellofemoraler Winkel