patellofemorales Gelenk
Skyline
projection of a normal patella. Lateral and medial joint space of patella are annotated, and can be used in the evaluation of patellar dislocation. Reference: (2012). "Imaging in Patellofemoral Instability". Sports Medicine and Arthroscopy Review 20 (3): 145–151. DOI:10.1097/JSA.0b013e3182553cfe. ISSN 1062-8592. Source image: File:X-ray of a normal patella.jpg (Public Domain)
Skyline
projection of a normal patella.Lateral patellofemoral angle is annotated, and can be used in the evaluation of patellar dislocation. Reference: (2012). "Imaging in Patellofemoral Instability". Sports Medicine and Arthroscopy Review 20 (3): 145–151. DOI:10.1097/JSA.0b013e3182553cfe. ISSN 1062-8592. Source image: File:X-ray of a normal patella.jpg (Public Domain)
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