Patellar anastomosis

At a glance

English

Patellar anastomosis

Latin (TA2)

Rete patellare

System

Artery

Region

Lower limb

Side

Paired, left and right

About the patellar anastomosis

The patellar anastomosis, also known as the genicular anastomosis or articular network of the knee, is not a single vessel but a mesh of interconnecting branches that surrounds the kneecap and spreads over the distal femur and proximal tibia. It brings together arteries from above, from behind and from below the knee, so that the joint is supplied from many directions at once.

Anatomists describe it in two layers. The superficial layer lies between the deep fascia and the skin around the patella and forms three fairly constant arches: one above the patella, in the loose tissue over the quadriceps tendon, and two below it, in the fat pad behind the patellar ligament. The deep layer is a tighter mesh resting on the bone of the femur and tibia around the edges of their joint surfaces, and it sends many fine twigs into the joint itself to the capsule, synovium and fat pads.

Several arteries feed the network. From the popliteal artery come the superior medial, superior lateral, inferior medial and inferior lateral genicular arteries. From above, the descending genicular artery (a branch of the femoral) and the descending branch of the lateral circumflex femoral artery join in. From below, the anterior tibial recurrent artery climbs up from the anterior tibial artery. The circumflex fibular branch also contributes on the lateral side.

Classically the anastomosis is taught as a collateral route that keeps blood flowing to the leg while the knee is fully bent and the popliteal artery is kinked, or after the femoral artery has been tied off to treat a popliteal aneurysm. In practice its capacity is limited: sudden blockage of a previously healthy femoral or popliteal artery is rarely compensated well, whereas slowly developing disease gives the links time to enlarge. The genicular branches are also used as routes for embolisation in knee pain.

Course and supply

Arises from

Fed by the four medial and lateral genicular branches of the popliteal artery, the lateral circumflex femoral artery's descending branch, the descending genicular artery and, from below, the anterior tibial recurrent artery.

Ends in

Spreads as a superficial plexus around the patella and a deep plexus over the distal femur and proximal tibia, with twigs into the joint.

Supplies

Supplies the patella, the knee joint capsule, synovium and fat pads and the adjacent distal femur and proximal tibia, and offers a collateral route around the popliteal artery.