The patellar network is an intricate network of vessels around and above the patella, and on the contiguous ends of the femur

Femur

The femur , or thigh bone, is the most proximal bone of the leg in tetrapod vertebrates capable of walking or jumping, such as most land mammals, birds, many reptiles such as lizards, and amphibians such as frogs. In vertebrates with four legs such as dogs and horses, the femur is found only in...

 and tibia

Tibia

The tibia , shinbone, or shankbone is the larger and stronger of the two bones in the leg below the knee in vertebrates , and connects the knee with the ankle bones....

, forming a superficial and a deep plexus.

• The superficial plexus is situated between the fascia and skin around about the patella, and forms three well-defined arches: one, above the upper border of the patella, in the loose connective tissue over the Quadriceps femoris; the other two, below the level of the patella, are situated in the fat behind the ligamentum patellæ.

• The deep plexus, which forms a close net-work of vessels, lies on the lower end of the femur and upper end of the tibia around their articular surfaces, and sends numerous offsets into the interior of the joint.

The arteries which form this plexus are the inferior medial

Inferior medial genicular artery

-Course:It first descends along the upper margin of the popliteus, to which it gives branches; it then passes below the medial condyle of the tibia, beneath the tibial collateral ligament, at the anterior border of which it ascends to the front and medial side of the joint, to supply the upper end...

 and superior medial

Superior medial genicular artery

The medial superior genicular runs in front of the Semimembranosus and Semitendinosus, above the medial head of the Gastrocnemius, and passes beneath the tendon of the Adductor magnus....

 genicular arteries, the inferior lateral

Inferior lateral genicular artery

-Course:It runs lateralward above the head of the fibula to the front of the knee-joint, passing in its course beneath the lateral head of the gastrocnemius, the fibular collateral ligament, and the tendon of the biceps femoris.-Branching:...

 and superior lateral

Superior lateral genicular artery

-Course:It passes above the lateral condyle of the femur, beneath the tendon of the Biceps femoris.-Branching:It divides into a superficial and a deep branch; the superficial branch supplies the vastus lateralis, and anastomoses with the descending branch of the lateral femoral circumflex and the...

 genicular arteries, the descending genicular artery

Descending genicular artery

The descending genicular artery arises from the femoral artery just before it passes through the opening in the tendon of the Adductor magnusIt immediately divides into:* Saphenous branch of descending genicular artery...

, the descending branch of lateral femoral circumflex artery, and the anterior tibial recurrent artery

Anterior tibial recurrent artery

The anterior tibial recurrent artery arises from the anterior tibial, as soon as that vessel has passed through the interosseous space; it ascends in the Tibialis anterior, ramifies on the front and sides of the knee-joint, and assists in the formation of the patellar plexus by anastomosing with...

.

Clinical relevance

The Genicular anastomosis provides collateral circulation to supply the leg when the knee is fully flexed.

When the knee suffers a popliteal

Popliteal artery

In human anatomy, the popliteal artery is defined as the extension of the "superficial" femoral artery after passing through the adductor canal and adductor hiatus above the knee...

 aneurysm

Aneurysm

An aneurysm or aneurism is a localized, blood-filled balloon-like bulge in the wall of a blood vessel. Aneurysms can commonly occur in arteries at the base of the brain and an aortic aneurysm occurs in the main artery carrying blood from the left ventricle of the heart...

. If the femoral artery

Femoral artery

The femoral artery is a general term comprising a few large arteries in the thigh. They begin at the inguinal ligament and end just above the knee at adductor canal or Hunter's canal traversing the extent of the femur bone....

 has to be ligated

Ligature (medicine)

In surgery or medical procedure, a ligature consists of a piece of thread tied around an anatomical structure, usually a blood vessel or another hollow structure to shut it off. With a blood vessel the surgeon will clamp the vessel perpendicular to the axis of the artery or vein with a hemostat,...

 surgically, blood can still reach the popliteal artery

Popliteal artery

In human anatomy, the popliteal artery is defined as the extension of the "superficial" femoral artery after passing through the adductor canal and adductor hiatus above the knee...

distal to the ligation via the genicular anastomosis.

External links

• Definition of Genicular Anastomosis at medilexicon.com