Why is femoral head prone to avascular necrosis?

Avascular necrosis (AVN) of the femoral head is a pathologic process that results from interruption of blood supply to the bone. AVN of the hip is poorly understood, but this process is the final common pathway of traumatic or nontraumatic factors that compromise the already precarious circulation of the femoral head.

What fracture causes avascular necrosis of femoral head?

Avascular necrosis (AVN) of the femoral head is a relatively uncommon complication following an extracapsular hip fracture. Although it can occur following fixation of unstable 3-part or 4-part intertrochanteric fractures with significant posteromedial and posterolateral comminution, it remains a rare complication.

Why does femoral head lose its blood supply?

The primary cause of avascular necrosis is the interruption of blood supply within the bone which can be caused by: Trauma or injury to a joint or bone: A traumatic injury like an accident or a condition like a dislocated joint can obliterate the adjacent blood vessels.

Which bones are prone to avascular necrosis?

The most common sites for AVN to occur are the femoral head, knee, talus, and humeral head. The hip is the most common location overall. [2] AVN less commonly occurs in other bones of the body, such as the carpus and jaw. [3][4] Therefore, early recognition and treatment of osteonecrosis are essential.

What is the most common cause of avascular necrosis of the hip?

Avascular necrosis is a painful bone condition that gets worse over time and can affect your mobility. It occurs when something cuts off blood flow to one of your bones. Causes include broken bones, dislocated hips, radiation therapy and alcohol misuse.

Avascular Necrosis, Blood Supply Femoral Head- Everything You Need To Know - Dr. Nabil Ebraheim

What causes avascular necrosis?

Avascular necrosis is a disease that results from the temporary or permanent loss of blood supply to the bone. It happens most commonly in the ends of a long bone. Avascular necrosis may be the result of injury, use of medicines, or alcohol. Symptoms may include joint pain and limited range of motion.

What does the femoral head do?

The femoral head serves as the “ball” in the hip joint allowing for a high degree of motion in the hip. It is covered by articular cartilage and articulates with the lunate surface of the acetabulum.

How do you increase blood flow to the femoral head?

How is avascular necrosis of the femoral head treated?

What is necrosis of the femur?

Avascular necrosis (AVN) of the femoral head is a pathologic process that results from interruption of blood supply to the bone. AVN of the hip is poorly understood, but this process is the final common pathway of traumatic or nontraumatic factors that compromise the already precarious circulation of the femoral head.

How do steroids cause avascular necrosis?

Glucocorticoid use is one of the most important causes of avascular bone necrosis (AVN). The pathogenesis of glucocorticoid-induced AVN is not fully understood but postulated mechanisms include fat hypertrophy, fat emboli and intravascular coagulation that cause impedance of blood supply to the bones.

Which artery supplies the head of femur?

The majority of the blood supply to the head of the femur comes from the medial and lateral circumflex branches of the profunda femoris, which itself is a branch of the femoral artery (the profunda femoris is the deep penetrating branch of the upper thigh).

What is collapse of femoral head?

Collapse of the femoral head is the most significant pathogenic complication arising from osteonecrosis of the femoral head. It is related to the disruption of the maintenance of cartilage and bone, and results in an impaired function of the vascular component.

What is osteonecrosis of the femoral head?

Femoral head osteonecrosis is a condition caused by a compromise of the blood supply of the femoral head. The precarious blood supply of the head and its role as a major weight-bearing joint makes it one of the most common bones to be affected by osteonecrosis.

Does physical therapy help avascular necrosis?

Although physical therapy cannot cure avascular necrosis, it can slow down the progression of the disease and decrease associated pain. It is suggested that patients with Stage 1 and 2 osteonecrosis could benefit from a physical therapy program.

What is the femoral head in the hip?

The femoral head is the ball in the ball-and-socket joint, and fits into the acetabulum. It sits on top of the femoral neck. At the base of the neck is the greater trochanter which marks the widest point of the hip area in the skeleton. Cartilage is a tough, elastic, gel-like layer that lines the hip joint.

Where does the femoral head insert?

It is covered with articular cartilage, which serves to decrease friction. The femoral head fits into the acetabulum, the round socket of the pelvic bone.

Where is osteonecrosis most commonly found?

Osteonecrosis can happen to any bone, but most often it develops in the ends of long bones, such as the: Thigh bone (femur), especially the upper part—the ball in the hip socket. The lower end, which is part of the knee joint, is also often affected.

What is the most common cause of osteonecrosis other than fracture?

Osteonecrosis most likely develops because of the combination of factors, possibly including genetic, metabolic, self-imposed (alcohol, smoking), and other diseases that you may have and their treatment. Injury: When a joint is injured, as in a fracture or dislocation, the blood vessels may be damaged.

What are the 4 stages of avascular necrosis?

Stage 1 has a normal x-rays but MRI reveals the dead bone. Stage 2 can be seen on regular x-ray but there is no collapse of the femoral ball. Stage 3 shows signs of collapse (called a crescent sign) on x-ray. Stage 4 has collapse on x-ray and signs of cartilage damage (osteoarthritis).

What drugs cause avascular necrosis?

Can prednisone cause AVN?

Use of high-dose corticosteroids, such as prednisone, is a common cause of avascular necrosis. The reason is unknown, but some experts believe that corticosteroids can increase lipid levels in the blood, reducing blood flow.

Can corticosteroids cause avascular necrosis?

Avascular necrosis is most frequently associated with high doses of oral and intravenous steroids and prolonged duration of therapy; although, cases have been observed with short-term courses of high-dose steroids, single doses of intra-articular or intravenous injections, and administration of topical or inhaled ...

Can Covid cause avascular necrosis?

Patients who had COVID-19 infection are more susceptible to avascular necrosis (AVN) development at (a) lower threshold dose of steroid and (b) earlier onset of presentation. Hence, on early suspicion, on complaints of hip and thigh pain, diagnosis can be established by early MRI of the hips.