Lateral Circumflex Femoral Artery

The lateral circumflex femoral artery is an important artery of the proximal thigh that usually arises from the profunda femoris artery. It courses laterally through the femoral triangle, passing deep to muscles of the anterior thigh, and typically divides into ascending, transverse, and descending branches. These branches supply structures around the hip and proximal thigh and participate in arterial anastomoses around the hip and knee.^[1][2]

The artery is notable for its relationship to the femoral nerve and its branches. Near its origin, it passes laterally deep to sartorius and rectus femoris and among branches of the femoral nerve. Its terminal branches then follow different pathways toward the greater trochanter, lateral thigh, and knee.

Although the lateral circumflex femoral artery has a characteristic arrangement, its origin and branching pattern are variable. It may arise directly from the femoral artery rather than from the profunda femoris, and individual branches may occasionally have separate origins.

Origin

The lateral circumflex femoral artery most commonly arises from the profunda femoris artery, also called the deep artery of the thigh. Its origin is usually near the proximal part of the profunda femoris, shortly after that vessel branches from the femoral artery.^[1][3]

The profunda femoris normally arises from the posterolateral aspect of the femoral artery within the femoral triangle. The lateral circumflex femoral artery then passes laterally away from the profunda femoris toward the anterior and lateral regions of the proximal thigh.

A common variation is direct origin of the lateral circumflex femoral artery from the femoral artery. Because its origin varies, the artery should not be identified solely by the vessel from which it arises. Its course, distribution, and branching pattern are also important anatomical features.

Course

From its usual origin from the profunda femoris artery, the lateral circumflex femoral artery passes laterally through the proximal thigh. It courses deep to the sartorius and rectus femoris muscles and lies in close relationship to branches of the femoral nerve.

The artery passes across the anterior aspect of the iliopsoas region and toward the interval associated with rectus femoris and vastus lateralis. It then divides into its major branches, although the precise point and pattern of division vary.

The three classically described branches are:

• Ascending branch: Passes superiorly toward the greater trochanter and lateral hip.
• Transverse branch: Passes laterally around the proximal femur and contributes to the cruciate anastomosis.
• Descending branch: Descends along the lateral aspect of the thigh and contributes to the arterial network around the knee.

Relations

The proximal lateral circumflex femoral artery lies within the deep part of the femoral triangle. Its relationships are important because the artery passes through a region containing the femoral nerve and several of its muscular branches.

Structure	Relationship
Sartorius	The artery passes deep to the muscle proximally
Rectus femoris	The artery passes deep to the muscle before its branches diverge
Femoral nerve	The artery passes among or deep to branches of the femoral nerve
Vastus lateralis	Closely related to the descending branch
Proximal femur	Ascending and transverse branches pass toward the lateral aspect of the proximal femur

The close relationship between the artery and femoral nerve branches distinguishes the lateral circumflex femoral artery from many other vessels of the femoral triangle.

Branches

The lateral circumflex femoral artery is traditionally described as dividing into ascending, transverse, and descending branches. Additional muscular branches may arise from the main artery or from its major divisions.

Ascending Branch

The ascending branch travels superiorly and laterally toward the greater trochanter. It passes deep to structures in the proximal lateral thigh, including the tensor fasciae latae, and supplies surrounding muscles and tissues.

Near the greater trochanter, the ascending branch participates in the trochanteric anastomosis. This arterial network includes contributions from circumflex femoral and gluteal vessels and provides blood to structures around the proximal femur and hip region.^[2]

Branches from this network contribute to the vascular supply around the greater trochanter and proximal femur. The principal arterial supply to the femoral head in adults, however, is provided by retinacular branches derived predominantly from the medial circumflex femoral artery.

Transverse Branch

The transverse branch passes laterally and posteriorly around the proximal femur. It travels through the lateral thigh toward the posterior aspect of the proximal femoral region.

The transverse branch contributes to the cruciate anastomosis, an arterial network situated near the posterior aspect of the upper femur. The classic contributors to this anastomosis include:

• The transverse branch of the lateral circumflex femoral artery.
• The transverse branch of the medial circumflex femoral artery.
• The descending branch of the inferior gluteal artery.
• The ascending branch of the first perforating artery.

The cruciate anastomosis provides communication between branches of the internal iliac arterial system and the profunda femoris system.

Descending Branch

The descending branch is usually the largest and longest branch of the lateral circumflex femoral artery. It descends along the lateral side of the thigh, commonly in the interval between rectus femoris and vastus lateralis or within the region associated with these muscles.

It accompanies branches of the femoral nerve supplying the quadriceps and provides muscular branches to the anterior and lateral compartments of the thigh, particularly the vastus lateralis.

Distally, the descending branch approaches the knee and participates in the genicular arterial network, communicating with vessels around the lateral aspect of the knee.

Muscular Supply

The lateral circumflex femoral artery and its branches supply several muscles of the anterior and lateral thigh. The exact pattern varies with the branching arrangement of the artery.

Muscular branches may contribute to the supply of:

• Rectus femoris: Supplied by branches passing into its deep surface.
• Vastus lateralis: Receives substantial supply from the descending branch and associated muscular vessels.
• Tensor fasciae latae: Receives branches associated particularly with the ascending division.
• Adjacent proximal thigh muscles: Receive smaller branches according to local vascular anatomy.

These vessels communicate with neighboring muscular arteries, producing overlapping territories rather than sharply separated areas of supply.

Trochanteric Anastomosis

The trochanteric anastomosis is an arterial network around the greater trochanter and proximal femur. The ascending branch of the lateral circumflex femoral artery contributes to this network along with branches of the medial circumflex femoral and gluteal arteries.

The network provides arterial communication around the proximal femur. Branches arising from circumflex femoral vessels also contribute to the extracapsular vascular network near the base of the femoral neck.

Although traditional descriptions emphasize the trochanteric anastomosis in relation to the blood supply of the femoral head, the medial circumflex femoral artery is the dominant source of the retinacular vessels supplying the adult femoral head and neck.^[1][2]

Cruciate Anastomosis

The cruciate anastomosis lies posterior to the proximal femur near the level of the lesser trochanter. The transverse branch of the lateral circumflex femoral artery contributes to this network.

Contributor	Parent Vessel
Transverse branch of lateral circumflex femoral artery	Usually profunda femoris artery
Transverse branch of medial circumflex femoral artery	Usually profunda femoris artery
Descending branch of inferior gluteal artery	Internal iliac artery
Ascending branch of first perforating artery	Profunda femoris artery

This arrangement provides an anastomotic connection between arterial territories above and below the gluteal region. Its importance is primarily as part of the collateral arterial network of the proximal thigh.

Contribution to the Genicular Network

The descending branch of the lateral circumflex femoral artery extends toward the knee and communicates with branches participating in the genicular anastomosis.

This network includes contributions from the femoral, popliteal, anterior tibial, and profunda femoris arterial systems. Anastomoses around the knee provide vascular connections between vessels proximal and distal to the joint.

The descending branch is therefore unusual among the branches of the lateral circumflex femoral artery because it extends from the proximal thigh to the distal thigh and knee region.

Anatomical Variations

The lateral circumflex femoral artery shows considerable variation in its origin and branching pattern. These variations are common enough to be important in anatomical interpretation and operative planning.

Variation in Origin

Although the artery usually arises from the profunda femoris artery, it may arise directly from the femoral artery. Its level of origin and relationship to the profunda femoris can also vary.

Less commonly, individual branches that would normally arise from a common lateral circumflex femoral trunk may originate independently.

Variation in Branching

The classic division into three branches is a useful anatomical model but is not universal. Accessory ascending, transverse, descending, or muscular branches may occur, and one of the major branches may arise separately from the femoral or profunda femoris artery.

For this reason, the artery may appear different during dissection, angiography, or surgery while still supplying the expected anatomical territories.

Relationship to the Femoral Nerve

The relationship between the lateral circumflex femoral artery and the femoral nerve is an important feature of the proximal thigh. The femoral nerve enters the thigh deep to the inguinal ligament and divides into multiple branches within or near the femoral triangle.

The lateral circumflex femoral artery passes laterally through this branching region. Its vessels may pass deep to, between, or among branches of the femoral nerve depending on individual anatomy.

This interrelationship is important during surgical exposure because identification of the artery does not eliminate the need to account for nearby motor branches supplying the quadriceps femoris.

Clinical Significance

Hip and Proximal Femoral Surgery

The ascending and transverse branches of the lateral circumflex femoral artery lie near surgical approaches to the hip and proximal femur. These vessels may be encountered during dissection through the anterior or anterolateral regions of the hip.

Knowledge of their expected course and possible variation helps distinguish them from neighboring circumflex and muscular vessels and allows their relationship to nearby femoral nerve branches to be anticipated.

Anterior Approach to the Hip

Branches of the lateral circumflex femoral artery are particularly relevant to anterior approaches to the hip. The ascending branch and related vessels can cross operative planes in the proximal anterior thigh and may require identification and control during exposure.

The exact vessels encountered vary because the lateral circumflex femoral branching pattern is not constant.

Vascularized Tissue Flaps

Branches of the lateral circumflex femoral artery are important in reconstructive surgery because they can supply vascularized tissue from the anterolateral thigh. The descending branch is especially relevant to the vascular anatomy of the anterolateral thigh flap.

Cutaneous perforators supplying the flap commonly arise from the descending branch, although their number, course, and precise origin vary. Perforators may pass through or between muscles before reaching the skin and subcutaneous tissues.

This variability makes preoperative and intraoperative identification of the relevant vascular anatomy important when the artery or its perforators are used as the vascular basis of a flap.

Femoral Head Blood Supply

The lateral circumflex femoral artery contributes to vascular networks around the hip, but it should not be described as the principal source of blood to the adult femoral head. The major supply is derived from retinacular branches of the medial circumflex femoral artery.

This distinction is clinically important when considering fractures of the femoral neck and procedures around the hip, where preservation of the medial circumflex femoral arterial supply is particularly significant.

Imaging and Angiography

The lateral circumflex femoral artery and its branches can be identified on CT angiography, MR angiography, conventional angiography, and Doppler studies when the proximal thigh vascular anatomy is evaluated.

Because direct origin from the femoral artery and variation in individual branches are relatively common, imaging should establish the actual vascular pattern rather than assuming the classic arrangement.

The lateral circumflex femoral artery forms an important arterial pathway through the anterior and lateral thigh. Its ascending branch contributes to vascular networks around the hip, its transverse branch participates in the cruciate anastomosis, and its descending branch supplies the lateral thigh and extends toward the genicular arterial network. Its variable origin and close relationship to branches of the femoral nerve are particularly important in surgical and imaging anatomy.