Avascular Necrosis Treatment in Singapore

What Is Avascular Necrosis (AVN)?

Avascular necrosis, also known as osteonecrosis, occurs when the blood supply to bone cells is disrupted, leading to the death of bone tissue. It commonly targets the hip joint, particularly the femoral head–the upper “ball” portion of the femur (thigh bone) that connects with the hip socket. Over time, a lack of blood supply can cause the bone structure to deteriorate and collapse, often resulting in increased pain, joint instability, and severe arthritis.

While AVN most commonly affects the hip, it can also occur in other areas, such as the shoulder, knee, and ankle.

Types of Avascular Necrosis (AVN)

There are two primary types of avascular necrosis:

Traumatic Avascular Necrosis

A significant injury can compromise blood flow to a bone, leading to avascular necrosis. This can include a fractured bone, dislocated joint, trauma from previous surgery, or severe impact that can damage the blood vessels.

Non-traumatic Avascular Necrosis

This occurs without any direct injury to the bone. Instead, it is often linked to medical conditions, such as sickle cell disease, Gaucher’s disease, systemic lupus erythematosus (SLE), and hyperlipidemia. Excessive alcohol consumption or long-term use of certain medications like corticosteroids can also impede blood from flowing to the bone tissue and cause avascular necrosis.

Symptoms of AVN to Look Out For

The symptoms of avascular necrosis vary depending on the stage of the condition. During the early stages, AVN may not cause noticeable symptoms, which can make it difficult to identify.

However, as the condition progresses, AVN can cause the following symptoms:

Dull ache or throbbing in the groin or thigh area

Progressive stiffness in the hip joint

Clicking or grinding sensation in the hip joint (crepitus)

Difficulty bearing or supporting the body’s weight on the affected hip

Limited range of motion

Limping or altered walking pattern (gait)

How Is Avascular Necrosis (AVN) Diagnosed?

During the initial diagnosis of avascular necrosis, the orthopaedic doctor will perform a physical examination. This involves applying pressure to the hip joint (palpation) to identify areas of sensitivity or pain. The doctor will also assess the range of motion by guiding the joint through various positions.

Additionally, one or more of the following tests may be done to confirm the diagnosis:

X-rays:

X-rays can detect any changes or damages in the bone structure of the hip or joint space narrowing—a potential sign of joint degeneration or arthritis.

Magnetic Resonance Imaging:

MRI scans can identify AVN in its early stages, even before any structural changes in the bones become apparent. It is often the preferred method for diagnosing AVN.

Computed Tomography (CT) Scan:

This method produces high-resolution images of the bone structure to help assess the extent of AVN, especially in complex joint areas.

What Are Treatment Options for Avascular Necrosis (AVN)?

Early-stage avascular necrosis may respond to conservative management. Although these can help alleviate symptoms, they typically cannot stop the condition from progressing. Some non-surgical treatments for AVN include:

Medication:

Nonsteroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen and naproxen, can relieve pain and discomfort. Doctors may also prescribe bisphosphonates to enhance bone density.

Resting:

An adequate time of rest and immobilisation using a brace or splint might be advised to temporarily restrict hip movement.

Activity Modification:

Patients may be advised to limit weight-bearing activities that can strain the hip joint, such as running or jumping, to reduce discomfort.

Assistive Devices:

Using crutches, canes, and walkers can help decrease the amount of weight or pressure exerted on the injured hip.

Physiotherapy:

Targeted exercises and therapeutic techniques can help improve mobility and strengthen the muscles surrounding the hip joint.

For more advanced stages, doctors may recommend surgery. Some surgical options include:

Core Decompression:

This procedure involves a drilling technique on the femoral head to alleviate pressure within the bone and create channels for the growth of new blood vessels.

Osteotomy:

The surgeon removes and repositions the femur to redistribute load-bearing pressure from the damaged bone and joint surfaces to healthier sections of the bone.

Bone Grafting:

This involves transplanting healthy bone tissue from either another part of the patient’s body (autologous bone) or obtained from a donor (allogenic bone) to the damaged area to stimulate new bone growth.

Hip Joint Replacement:

If the femoral head has collapsed or the hip joint has sustained significant damage, the surgeon will extract the damaged bone tissue and replace it with a new hip prosthesis, typically made of metal or plastic materials, to regain mobility.

FAQs About Avascular Necrosis (AVN)

Can you still walk with avascular necrosis (AVN)?

In the initial stages, individuals may still be able to walk, albeit with some discomfort. As the condition progresses, movement may become increasingly limited.

Can avascular necrosis (AWVN) resolve on its own without treatment?

Avascular necrosis (AVN) typically does not resolve on its own because the affected bone lacks adequate blood supply. Without treatment, it can result in joint collapse and the development of severe arthritis.

Dr Wang Lushun

Senior Consultant Orthopaedic Surgeon

MBBS (S’pore), MRCS (Edin), MMed (Ortho), FRCS (Ortho) (Edin)

With over 18 years of orthopaedic experience, Dr Wang Lushun is a dedicated Senior Consultant Orthopaedic Surgeon who is skilled in the diagnosis and treatment of avascular necrosis. Having previously led the Hip and Knee Division at Ng Teng Fong Hospital, patients can rest assured knowing that they will receive the best possible orthopaedic care tailored to their needs.

Dr Wang Lushun is a pioneer in Enhanced Recovery after Surgery (ERAS), and has pioneered Minimally Invasive Hip Surgeries such as Direct Superior and Direct Approaches. He has been recognised for superior outcomes in Joint Replacements and is frequently invited as international faculty for his insights into the latest treatment options.

A Comprehensive Guide to Avascular Necrosis (Osteonecrosis)