The fibular artery, also known as the peroneal artery, is a major branch of the posterior tibial artery. It supplies blood to the lateral compartment of the leg and parts of the foot. It is one of the primary arteries responsible for blood supply to the lower leg, particularly in the lateral and posterior regions.
Location
The fibular artery arises from the posterior tibial artery in the upper part of the leg, near the popliteal fossa. It descends along the posterior aspect of the fibula, running deep within the flexor compartment of the leg. It is situated between the tibialis posterior and the flexor hallucis longus muscles, and it travels toward the lateral malleolus, where it provides branches to the lateral ankle and foot.
Structure and Anatomy
Origin
The fibular artery, also known as the peroneal artery, originates from the posterior tibial artery. This branching occurs in the upper portion of the leg, just below the popliteal fossa, typically about 2-3 centimeters distal to where the posterior tibial artery branches off from the popliteal artery. The fibular artery emerges as one of the key branches of the posterior tibial artery, alongside the anterior tibial artery.
Course
After originating from the posterior tibial artery, the fibular artery descends obliquely along the posterior and lateral aspect of the leg. It travels deep within the posterior compartment of the leg, positioned between two major muscles—the tibialis posterior and the flexor hallucis longus. As it moves downward, it follows the fibula’s medial surface, maintaining a close proximity to the bone throughout most of its course.
The fibular artery does not directly enter the lateral compartment but supplies it through several perforating branches. It stays within the deep posterior compartment for the majority of its path, continuing distally toward the ankle region. The artery is accompanied by venae comitantes (companion veins), which aid in the venous return from the same regions supplied by the artery.
Branches
The fibular artery gives rise to several important branches throughout its course:
- Perforating Branches: These branches pierce the interosseous membrane and supply blood to the lateral compartment of the leg. One of the major perforating branches crosses over to the anterior compartment and contributes to the blood supply of the ankle joint.
- Nutrient Arteries: These branches supply the fibula bone with nutrients. The nutrient artery typically enters the fibula near the middle third of the bone.
- Communicating Branches: These small branches connect with the posterior tibial artery and occasionally with other vessels to form collateral circulation around the ankle and foot.
- Terminal Branches: As the fibular artery approaches the lateral malleolus, it divides into terminal branches that supply the lateral and posterior aspects of the ankle and foot.
Termination
As the fibular artery continues distally toward the foot, it ends by giving rise to several small branches near the lateral malleolus. One of the most significant terminal branches is the perforating branch, which crosses the interosseous membrane and connects with the anterior lateral malleolar artery. These terminal branches contribute to the arterial network around the ankle and foot, particularly in the region of the calcaneus (heel) and lateral foot.
Associated Structures
- Tibialis Posterior Muscle: The fibular artery runs deep to this muscle, which lies along the medial aspect of the leg and plays a role in ankle movement.
- Flexor Hallucis Longus Muscle: The fibular artery is also located deep to this muscle, which runs along the posterior side of the leg and flexes the big toe.
- Fibula Bone: The artery runs along the medial surface of the fibula, giving off small branches to supply the bone with blood.
- Interosseous Membrane: This fibrous sheet separates the anterior and posterior compartments of the leg, and the perforating branches of the fibular artery pass through it to supply the lateral leg.
Size and Appearance
The fibular artery is a relatively small artery compared to the major arteries of the leg, such as the posterior tibial and anterior tibial arteries. However, it is robust enough to supply significant blood flow to the lateral and posterior compartments of the lower leg. It is long, extending from the upper third of the leg down to the lateral malleolus.
Surrounding Nerves
The fibular artery is closely associated with the tibial nerve in the posterior compartment, though the nerve does not directly accompany the artery throughout its entire course. In the lateral compartment, the superficial fibular nerve innervates the muscles supplied by the fibular artery’s branches.
Function
Blood Supply to the Lateral Compartment of the Leg
The primary function of the fibular artery is to supply blood to the lateral compartment of the leg. This compartment contains muscles responsible for eversion and stabilization of the foot, such as the fibularis longus and fibularis brevis. Although the fibular artery itself remains in the deep posterior compartment of the leg, it sends perforating branches through the interosseous membrane to deliver oxygenated blood to these muscles. This ensures that the muscles involved in lateral movement of the foot receive sufficient blood supply to maintain their function.
Blood Supply to the Posterior Compartment of the Leg
In addition to its role in supplying the lateral compartment, the fibular artery contributes to the vascularization of the posterior compartment of the leg. This compartment houses muscles such as the tibialis posterior and flexor hallucis longus, which are essential for foot inversion and toe flexion. The fibular artery runs along the posterior compartment and delivers blood to these muscles through small branches along its course.
Perforating Branches and Ankle Supply
The fibular artery gives rise to perforating branches that pass through the interosseous membrane, supplying the anterior compartment of the leg and, more importantly, the ankle joint. These perforating branches contribute to the arterial network around the ankle, particularly near the lateral malleolus. One of the most important perforating branches of the fibular artery supplies the lower lateral part of the tibia and contributes to the blood supply of the ankle joint. This is essential for the joint’s mobility and overall health.
Blood Supply to the Foot and Heel
As the fibular artery approaches the lateral malleolus, it terminates by giving rise to small branches that supply the foot, especially the lateral aspect. These branches include arteries that vascularize the lateral side of the calcaneus (heel bone) and the lateral part of the foot. The fibular artery thus plays a critical role in ensuring that blood reaches the foot’s lateral structures, helping maintain proper circulation in these areas.
Nutrient Supply to the Fibula Bone
Another important function of the fibular artery is to provide blood to the fibula bone through the nutrient branches. These small arteries enter the fibula in its middle third, delivering essential nutrients and oxygen to support bone health and repair. This helps in maintaining the strength and integrity of the fibula, which serves as an important stabilizing bone in the leg.
Collateral Circulation
The fibular artery contributes to the collateral circulation of the lower leg. Through its communicating branches and anastomoses with the posterior tibial and anterior tibial arteries, it helps form a network of blood vessels that can compensate for any blockage or reduced blood flow in one of the main arteries. This collateral circulation is especially important in maintaining blood supply to the leg and foot in cases of arterial occlusion or damage to other vessels. The fibular artery’s role in this network ensures that the lower extremity remains adequately perfused even in cases of compromised blood flow.
Support for Ankle Joint Function
The fibular artery plays a vital role in maintaining the function of the ankle joint by providing oxygenated blood to the structures around the ankle. The perforating branches that the fibular artery sends to the anterior compartment and around the lateral malleolus are critical for supporting the soft tissues and bones of the ankle joint. Proper blood supply ensures the health of these structures, aiding in joint movement and preventing degeneration due to ischemia.
Integration with the Lower Limb Vascular Network
The fibular artery is a key contributor to the overall vascular network of the lower limb. It works in concert with the posterior tibial artery, anterior tibial artery, and the dorsalis pedis artery to ensure that the lower leg and foot are fully supplied with oxygenated blood. By supporting these other arteries through its perforating and communicating branches, the fibular artery helps maintain consistent circulation throughout the leg, especially in the lateral and posterior compartments.
Clinical Significance
The fibular artery has significant clinical importance, particularly in conditions affecting the vascular supply to the lower leg and foot. It plays a crucial role in providing blood to the lateral and posterior compartments of the leg, as well as the ankle and foot. In cases of peripheral artery disease (PAD), the fibular artery may be compromised, leading to ischemia and symptoms like pain or tissue damage, particularly in the lower extremities. Due to its deep location, the fibular artery is often spared in trauma, but it can be injured in cases of fractures to the fibula or severe lower leg injuries, potentially leading to compartment syndrome.
In surgical procedures like revascularization or during the harvesting of vessels for bypass grafts, the fibular artery may be used as a conduit. Additionally, its role in collateral circulation can be lifesaving when other major arteries in the leg are occluded, helping maintain blood flow to the lower leg and foot. Its location and branches also make it a vital landmark in procedures involving the lateral leg or ankle region.
