Inferior gluteal artery

The inferior gluteal artery is a branch of the anterior division of the internal iliac artery that supplies blood to the lower gluteal region, including the gluteus maximus, and parts of the hip joint, hamstrings, and nearby structures. It is one of the major blood vessels responsible for providing circulation to the buttock and thigh muscles.

Location

The inferior gluteal artery is located in the pelvis and buttock region. It originates from the anterior division of the internal iliac artery, and exits the pelvis through the greater sciatic foramen below the piriformis muscle, differentiating it from the superior gluteal artery, which exits above the piriformis. Once outside the pelvis, the inferior gluteal artery travels to the lower part of the buttocks, where it supplies the gluteus maximus and contributes to the vascularization of muscles in the posterior thigh, including the hamstrings.

Structure and Anatomy

The inferior gluteal artery is an important blood vessel that supplies the gluteal region, hip joint, and parts of the posterior thigh. It originates from the anterior division of the internal iliac artery and follows a specific course, supplying several muscles and tissues. Below is a detailed description of its anatomy.

Origin

The inferior gluteal artery typically arises from the anterior division of the internal iliac artery, which also gives rise to other major branches like the obturator artery and the internal pudendal artery. In some cases, the inferior gluteal artery may originate from a common trunk with the internal pudendal artery before branching off separately.

Course

After its origin from the internal iliac artery, the inferior gluteal artery follows a posterior course through the pelvis and into the gluteal region:

• Pelvic Course: The inferior gluteal artery descends along the lateral wall of the pelvis, running between the first and second or second and third sacral nerves (S1 and S2 or S2 and S3).
• Exit through the Greater Sciatic Foramen: The artery exits the pelvis by passing through the greater sciatic foramen. It passes inferior to the piriformis muscle, distinguishing it from the superior gluteal artery, which passes superior to the piriformis. This relationship with the piriformis muscle is a key anatomical landmark for locating the artery.

Branches

Once outside the pelvis, the inferior gluteal artery gives off several branches that supply blood to the lower gluteal region, posterior thigh, and surrounding structures:

• Gluteal Branches: The artery supplies blood to the lower portion of the gluteus maximus muscle, the largest muscle in the buttock.
• Hamstring Branches: It also sends branches to the hamstring muscles in the posterior thigh, including the biceps femoris, semitendinosus, and semimembranosus muscles, which are involved in leg flexion and hip extension.
• Cutaneous Branches: Small cutaneous branches extend to the skin of the buttock, contributing to the vascular supply of the overlying skin.
• Anastomotic Branches: The artery also contributes to several important anastomoses (connections) with other arteries in the gluteal and thigh regions, including the perforating branches of the deep femoral artery.

Relations to Other Structures

The inferior gluteal artery is closely associated with several key anatomical structures, both in the pelvis and the gluteal region:

• Piriformis Muscle: The artery passes inferior to the piriformis muscle as it exits the pelvis. This relationship is critical for differentiating it from the superior gluteal artery, which exits superior to the piriformis.
• Sciatic Nerve: The inferior gluteal artery runs in close proximity to the sciatic nerve, the largest nerve in the body. This anatomical relationship is important for surgical interventions in the gluteal region to avoid nerve damage.
• Internal Pudendal Artery: The inferior gluteal artery often shares a common origin with the internal pudendal artery, which supplies the perineum and external genitalia. These two arteries may travel together for part of their course before diverging.

Anastomoses

The inferior gluteal artery forms several key anastomoses with other arteries in the pelvic and gluteal regions, contributing to a rich vascular network:

• Superior Gluteal Artery: The inferior gluteal artery anastomoses with the superior gluteal artery to ensure a comprehensive blood supply to the gluteal region.
• Perforating Branches of the Deep Femoral Artery: In the posterior thigh, the inferior gluteal artery anastomoses with the perforating branches of the deep femoral artery, which provide additional blood supply to the hamstrings.
• Medial and Lateral Circumflex Femoral Arteries: The artery also connects with the medial and lateral circumflex femoral arteries, which supply blood to the hip joint and upper thigh. These anastomoses contribute to the blood supply of the hip and surrounding muscles.

Variations

The inferior gluteal artery can show some anatomical variations:

• Origin: While it typically arises from the anterior division of the internal iliac artery, in some cases, it may arise from a common trunk with the internal pudendal artery or directly from the posterior division of the internal iliac artery.
• Size and Branching Pattern: The size and branching pattern of the inferior gluteal artery can vary between individuals, with some individuals having additional branches that supply nearby muscles or structures.

Function

The inferior gluteal artery is responsible for supplying oxygenated blood to the muscles and tissues in the lower gluteal region, posterior thigh, and parts of the hip joint. Below is a detailed description of its functions.

Blood Supply to the Gluteus Maximus Muscle

The primary function of the inferior gluteal artery is to supply blood to the gluteus maximus muscle, the largest and most superficial muscle in the buttocks. This muscle is critical for powerful movements of the hip, such as extension, lateral rotation, and stabilizing the pelvis.

Gluteus Maximus Function: The gluteus maximus is responsible for extending the thigh, particularly during activities like standing up from a seated position, climbing stairs, running, and jumping. The blood supply provided by the inferior gluteal artery ensures that the muscle receives enough oxygen and nutrients to maintain its strength and endurance during these movements.

Blood Supply to the Hamstring Muscles

The inferior gluteal artery also provides blood to the hamstring muscles in the posterior thigh, including the biceps femoris, semitendinosus, and semimembranosus muscles.

Hamstring Function: The hamstrings are involved in flexing the knee and extending the hip, making them essential for walking, running, and jumping. By supplying these muscles with oxygenated blood, the inferior gluteal artery supports the function and movement of the lower limb.

Blood Supply to the Hip Joint

The inferior gluteal artery contributes to the vascular supply of the hip joint, particularly through its anastomoses with the medial and lateral circumflex femoral arteries, which also supply the hip joint.

Hip Joint Support: The artery helps provide blood to the ligaments, cartilage, and surrounding structures of the hip joint. This supply is essential for maintaining joint health and function, especially during activities that involve significant stress on the hip, such as running or lifting heavy objects.

Contribution to the Gluteal Region’s Vascular Network

The inferior gluteal artery is part of a larger vascular network in the gluteal and pelvic regions, which includes its anastomoses with other arteries. These connections help ensure a robust and redundant blood supply to the muscles and tissues of the buttock and thigh.

• Anastomosis with Superior Gluteal Artery: The inferior gluteal artery forms anastomoses with the superior gluteal artery, ensuring that both the upper and lower gluteal muscles are well-perfused. This connection provides a safety net in case one artery is compromised, ensuring continuous blood flow.
• Anastomosis with Perforating Branches of the Deep Femoral Artery: In the posterior thigh, the inferior gluteal artery connects with the perforating branches of the deep femoral artery, contributing to the blood supply of the posterior thigh muscles.

Blood Supply to the Cutaneous Region

The inferior gluteal artery supplies blood to the skin of the lower buttock through small cutaneous branches. This vascular supply is important for maintaining the health and integrity of the skin and subcutaneous tissues in this region.

Cutaneous Blood Supply: The artery ensures that the skin in the gluteal area remains well-nourished, supporting tissue repair, thermoregulation, and protection.

Role in Supporting Lower Limb Movements

Through its supply of the gluteus maximus, hamstrings, and other muscles, the inferior gluteal artery plays an indirect but crucial role in lower limb movement and postural stability. By ensuring that these muscles receive adequate blood flow, the artery supports essential movements such as hip extension, knee flexion, and stabilization of the pelvis during activities like walking, running, and lifting.

Pelvic and Hip Stabilization: The gluteus maximus and hamstrings work together to stabilize the pelvis and hip joint during weight-bearing activities, and the inferior gluteal artery’s blood supply is vital for their optimal function.

Contribution to Healing and Tissue Repair

The inferior gluteal artery also plays a role in tissue healing and repair, particularly after injury or surgery involving the gluteal region, posterior thigh, or hip. A healthy blood supply is essential for transporting nutrients, oxygen, and immune cells to injured tissues.

Tissue Regeneration: The artery ensures that damaged muscles and tissues in the gluteal region and posterior thigh have the resources needed for effective healing and recovery after trauma or surgical intervention.

Clinical Significance

The inferior gluteal artery is clinically significant due to its role in supplying blood to the gluteus maximus, hamstring muscles, and hip joint, as well as its contribution to the vascular network of the posterior thigh and gluteal region. During hip surgeries, particularly total hip replacements or procedures involving the gluteal muscles, the artery is at risk of injury, which can lead to excessive bleeding, compromised blood supply, and tissue damage.

In trauma cases such as pelvic fractures or deep gluteal injuries, the inferior gluteal artery may be affected, leading to complications such as hemorrhage or gluteal hematoma formation. Additionally, the artery’s proximity to the sciatic nerve makes it an important consideration during surgical interventions in the buttock region to avoid nerve injury. Its involvement in the blood supply of the posterior thigh also makes it relevant in cases of vascular disease, such as ischemia in the lower limb.