What are the symptoms of talar avascular necrosis. How is talar avascular necrosis diagnosed. What are the treatment options for talar avascular necrosis. What causes avascular necrosis of the talus.

Understanding Talar Avascular Necrosis: A Comprehensive Overview

Talar avascular necrosis is a condition that affects the talus bone, a crucial component of the ankle joint. This ailment occurs when the blood supply to the talus is compromised, leading to the death of bone cells. The result can be severe pain, difficulty walking, and potential collapse of the bone structure in advanced cases.

Is talar avascular necrosis a common condition? While it’s not as prevalent as other ankle issues, it’s a serious concern that requires prompt medical attention. The rarity of this condition often leads to misdiagnosis or delayed treatment, which can exacerbate the problem.

Recognizing the Symptoms of Talar Avascular Necrosis

Identifying talar avascular necrosis early can significantly improve treatment outcomes. The primary symptoms include:

• Deep, persistent ankle pain that worsens with activity
• Gradual onset of discomfort
• Swelling around the ankle joint
• Difficulty bearing weight on the affected foot
• Reduced range of motion in the ankle

Do these symptoms always indicate talar avascular necrosis? Not necessarily. Many ankle conditions share similar symptoms, which is why professional diagnosis is crucial.

Unraveling the Causes of Talar Avascular Necrosis

Understanding the root causes of talar avascular necrosis is essential for both prevention and treatment. Several factors can contribute to this condition:

Trauma and Injury

Fractures or severe sprains of the talus can disrupt blood flow to the bone. How long after an injury can avascular necrosis develop? Typically, it’s diagnosed within a year of the initial trauma, but in some cases, it may take longer to manifest.

Steroid Use

Long-term or high-dose steroid treatment for conditions like asthma, autoimmune diseases, or cancer can increase the risk of avascular necrosis. Why do steroids cause this issue? They can interfere with the body’s ability to form and maintain healthy bone tissue.

Alcohol Abuse

Excessive alcohol consumption is linked to an increased risk of talar avascular necrosis. How does alcohol contribute to this condition? It can lead to the formation of fatty deposits in blood vessels, potentially blocking blood supply to the talus.

Blood Disorders

Certain blood conditions, such as sickle cell anemia, can increase the likelihood of developing talar avascular necrosis. These disorders can cause small blood clots that obstruct blood flow to the bone.

Diagnostic Approaches for Talar Avascular Necrosis

Accurate diagnosis is crucial for effective treatment of talar avascular necrosis. Foot and ankle orthopedic surgeons employ various diagnostic tools to confirm the condition and assess its severity:

X-rays

Weightbearing X-rays provide valuable information about bone alignment and potential joint space narrowing. Why are weightbearing X-rays preferred? They offer a more accurate representation of the ankle’s condition under normal stress.

Magnetic Resonance Imaging (MRI)

MRI scans offer detailed images of soft tissues and bone structures. How does an MRI help in diagnosing talar avascular necrosis? It can reveal the extent of bone damage and any associated cartilage issues, even in early stages of the condition.

Computed Tomography (CT) Scans

CT scans may be used to identify fractures or bone fragmentation associated with avascular necrosis. When is a CT scan most useful? It’s particularly helpful in cases where there’s suspicion of complex bone damage or when planning surgical interventions.

Treatment Options for Talar Avascular Necrosis

The treatment approach for talar avascular necrosis depends on various factors, including the extent of bone damage, presence of collapse or fragmentation, and the patient’s overall health and lifestyle needs. Here are the primary treatment options:

Conservative Management

In some cases, particularly in early stages or with minimal bone involvement, conservative treatment may be recommended. This can include:

• Medications to manage pain and inflammation
• Activity modification to reduce stress on the ankle
• Use of supportive devices like braces or crutches
• Physical therapy to maintain joint mobility and strength

Medication: Bisphosphonates

Bisphosphonates are a class of drugs that can help prevent bone collapse in talar avascular necrosis. How do bisphosphonates work? They inhibit the activity of osteoclasts, cells responsible for breaking down bone tissue, thereby slowing the progression of bone damage.

Core Decompression

This surgical procedure involves drilling into the affected area of the talus to relieve pressure and create space for new bone growth. When is core decompression most effective? It’s typically recommended for smaller areas of avascular necrosis without significant joint collapse or arthritis.

Vascularized Bone Grafting

In more advanced cases, vascularized bone grafting may be recommended. This complex procedure involves transplanting bone tissue with its blood supply to the affected area. How does this procedure benefit patients with talar avascular necrosis? It helps restore blood flow to the talus, promoting new bone formation and potentially halting the progression of the condition.

Navigating Recovery and Rehabilitation

Recovery from talar avascular necrosis, especially following surgical intervention, can be a lengthy process. What does the rehabilitation process typically involve?

• Extended periods of non-weight bearing or limited weight bearing
• Gradual reintroduction of ankle movement and strength exercises
• Use of assistive devices like crutches or a walker
• Regular follow-up appointments to monitor healing progress
• Potential need for custom orthotics or supportive footwear

How long does recovery take? The timeline can vary significantly depending on the severity of the condition and the type of treatment received. Some patients may see improvement within a few months, while others may require a year or more for full recovery.

Long-term Outlook and Potential Complications

The prognosis for talar avascular necrosis can vary widely depending on several factors. What are the potential long-term outcomes?

• Complete recovery with minimal residual symptoms
• Chronic pain and limited ankle function
• Development of ankle arthritis
• Need for additional surgical interventions, including ankle fusion or replacement

Can talar avascular necrosis recur? While recurrence is uncommon, patients who have experienced avascular necrosis in one joint may be at higher risk for developing it in other joints.

Prevention Strategies and Risk Reduction

While not all cases of talar avascular necrosis can be prevented, certain measures can help reduce the risk or mitigate the severity of the condition:

• Prompt and appropriate treatment of ankle injuries
• Careful management of steroid use under medical supervision
• Moderation or avoidance of alcohol consumption
• Regular exercise to maintain bone health and circulation
• Proper management of underlying health conditions that may increase risk

Is it possible to completely eliminate the risk of talar avascular necrosis? While risk reduction is possible, some factors, such as genetic predisposition or certain medical conditions, may be beyond an individual’s control.

Emerging Research and Future Treatments

The field of orthopedic medicine continues to evolve, offering hope for improved treatments for talar avascular necrosis. What are some promising areas of research?

• Stem cell therapy to promote bone regeneration
• Advanced imaging techniques for earlier detection
• Novel drug therapies to enhance blood vessel formation
• Improved surgical techniques for bone grafting and reconstruction

How might these advancements impact patients with talar avascular necrosis? Future treatments could potentially offer less invasive options, faster recovery times, and better long-term outcomes for those affected by this challenging condition.

Living with Talar Avascular Necrosis: Coping Strategies and Support

Dealing with talar avascular necrosis can be challenging, both physically and emotionally. What strategies can help patients cope with the condition?

• Joining support groups or online communities for individuals with similar conditions
• Engaging in low-impact exercises to maintain overall health and mobility
• Exploring pain management techniques, including physical therapy and mindfulness practices
• Working with a mental health professional to address any emotional challenges
• Making necessary lifestyle adaptations to accommodate limitations

How important is a support system in managing talar avascular necrosis? Having a strong support network, including family, friends, and healthcare providers, can significantly improve a patient’s ability to cope with the challenges posed by this condition.

The Role of Interdisciplinary Care in Talar Avascular Necrosis Management

Effective management of talar avascular necrosis often requires a team approach. Which healthcare professionals might be involved in a patient’s care?

• Orthopedic surgeons specializing in foot and ankle conditions
• Radiologists for advanced imaging and interpretation
• Physical therapists to assist with rehabilitation and mobility
• Pain management specialists for comprehensive pain control strategies
• Rheumatologists, especially if the condition is related to systemic disorders

How does an interdisciplinary approach benefit patients with talar avascular necrosis? By addressing all aspects of the condition – from diagnosis and treatment to rehabilitation and long-term management – a comprehensive care team can optimize outcomes and improve quality of life for those affected by this complex condition.

Talar Avascular Necrosis in Special Populations

While talar avascular necrosis can affect anyone, certain populations may face unique challenges or require special considerations in their treatment approach. How does the management of this condition differ in various patient groups?

Athletes and Active Individuals

For athletes and highly active individuals, talar avascular necrosis can be particularly devastating. What special considerations are needed for this group?

• More aggressive treatment approaches to facilitate faster return to activity
• Tailored rehabilitation programs focusing on sport-specific movements
• Psychological support to cope with potential career implications
• Careful monitoring and prevention strategies for the unaffected ankle

Elderly Patients

Older adults with talar avascular necrosis may face additional challenges. How does advanced age impact treatment decisions?

• Consideration of overall health status and ability to tolerate surgical interventions
• Focus on pain management and maintaining independence in daily activities
• Increased attention to fall prevention and balance training
• Potential need for assistive devices or home modifications

Patients with Comorbidities

Individuals with underlying health conditions may require a modified approach to talar avascular necrosis treatment. What factors need to be considered for these patients?

• Careful medication management to avoid interactions or complications
• Coordination with other specialists managing concurrent health issues
• Adaptation of treatment plans to accommodate limitations imposed by other conditions
• Enhanced monitoring for potential complications during treatment and recovery

The Economic Impact of Talar Avascular Necrosis

Beyond its physical and emotional toll, talar avascular necrosis can have significant financial implications for patients and healthcare systems. What are the potential economic impacts of this condition?

• Direct medical costs for diagnosis, treatment, and follow-up care
• Indirect costs due to lost productivity and time away from work
• Potential long-term expenses for ongoing management or disability
• Healthcare system burden for complex cases requiring extensive interventions

How can the economic burden of talar avascular necrosis be mitigated? Early diagnosis and appropriate treatment can help reduce long-term costs by preventing more severe complications. Additionally, comprehensive insurance coverage and patient assistance programs can help alleviate the financial strain on individuals affected by this condition.

Talar Avascular Necrosis: Navigating the Healthcare System

For patients diagnosed with talar avascular necrosis, navigating the healthcare system can be challenging. What steps can patients take to ensure they receive optimal care?

• Seek referral to a foot and ankle specialist experienced in treating avascular necrosis
• Maintain detailed records of symptoms, treatments, and medical history
• Ask questions and actively participate in treatment decisions
• Understand insurance coverage and explore financial assistance options if needed
• Consider seeking a second opinion for complex cases or when surgery is recommended

How important is patient advocacy in managing talar avascular necrosis? Being an informed and proactive patient can significantly impact the quality of care received and ultimately influence treatment outcomes.

Future Directions in Talar Avascular Necrosis Research

As medical science continues to advance, new avenues for understanding and treating talar avascular necrosis are emerging. What areas of research hold promise for the future?

• Genetic studies to identify risk factors and potential targets for therapy
• Development of biomarkers for early detection and prognosis
• Advanced imaging techniques for more precise diagnosis and treatment planning
• Innovative surgical approaches, including minimally invasive procedures
• Exploration of regenerative medicine techniques, such as tissue engineering

How might these advancements change the landscape of talar avascular necrosis treatment? Future developments could lead to more personalized treatment approaches, improved outcomes, and potentially even preventive strategies for high-risk individuals.

As research progresses and our understanding of talar avascular necrosis deepens, patients and healthcare providers alike can look forward to more effective management strategies and improved quality of life for those affected by this challenging condition. The journey towards better outcomes continues, driven by the combined efforts of medical researchers, clinicians, and the resilience of patients facing this complex disorder.

Talar Avascular Necrosis | FootCareMD

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Avascular necrosis of the talus happens when the talus bone, the bone in the center of your ankle, loses some of its blood supply and is no longer alive. Your bones are made out of living bone cells, which allow your bones to constantly remodel to stay
strong and healthy. When the bone loses its blood supply, the bone cells die. This can lead to pain and even collapse of the talus in severe cases.

Some patients may do well with no treatment or medication treatment, while others may require surgery to address the problem. Causes of avascular necrosis include trauma (previous broken bone), steroid use, alcohol abuse, and blood disorders like sickle
cell anemia.

Symptoms

People with talar avascular necrosis usually have deep pain in the ankle that comes on gradually. The pain usually gets worse after spending more time on your feet or being active and can be accompanied by swelling. Most people with ankle pain do not
have talar avascular necrosis, since it is pretty rare and there are many other causes of ankle pain.

Causes

There are various causes of talar avascular necrosis:

• Trauma: If you have broken your talus bone, whether or not it was treated with surgery, you are more likely to get talar avascular necrosis. This is because the injury may have cut off the blood supply to part of the talus, leading
  to part of the bone dying. The more severe the injury, the greater the chance of this happening. Usually talar avascular necrosis after a fracture can be diagnosed within one year after the injury, when you are still healing.

• Steroid use: If you have used steroids in high doses or for a long time, you are at increased risk for avascular necrosis. Reasons you might have taken high doses of steroids include treatment of asthma, an autoimmune disease,
  or cancer.

• Alcohol abuse: If you drink alcohol heavily on a daily basis, you are more likely to get talar avascular necrosis. Drinking heavily increases the amount of fat traveling in your blood vessels. It is thought that drops of fat block
  small blood vessels, which is what leads to avascular necrosis.

• Blood disorders: Blood disorders associated with clotting of small vessels, such as sickle cell anemia, can lead to talar avascular necrosis.

Diagnosis

Foot and ankle orthopaedic surgeons typically diagnose talar avascular
necrosis through X-rays and/or MRI. X-rays should be weightbearing (taken while you are standing) to enable your surgeon to better evaluate the alignment of your bones. Weightbearing X-rays also allow your surgeon to identify narrowing of the joint
spaces around the talus, which is a sign of arthritis (loss of
joint cartilage that can cause pain and stiffness).

An MRI can show exactly how much of the bone is affected, and how much damage there may be to the cartilage in the joints around the talus. CT scans can also be helpful to identify any associated fractures or fragmentation of the bone.

An MRI image showing talar avascular necrosis with fragmentation and collapse. The green arrow points to the healthy bone of the tibia, while the red arrow points to the dead bone of the talus.

Treatments

Treatment for avascular necrosis depends on the severity: how much of the talus is involved and whether there is any collapse or fragmentation. Your foot and ankle orthopaedic surgeon may recommend one of these options, based on their examination and
your goals for treatment.

• Medication: There are some medications that can help prevent collapse of the talus. This class of medications is called bisphosphonates. They work by shutting down your osteoclasts, the cells that break down bone. This prevents
  breakdown of the bone around the area of avascular necrosis.

• Core decompression: In this procedure, your foot and ankle orthopaedic surgeon drills into the area of avascular necrosis. The goal is to relieve pressure in the area of dead bone and create space for new bone to form. Usually
  some bone graft is inserted at the time of surgery to help encourage your bone to heal. This is a good surgery for patients with smaller areas of avascular necrosis, without joint collapse or arthritis.

• Vascularized bone grafting: Your surgeon may recommend a vascularized bone graft to help bring a new blood supply to the talus. A vascularized bone graft is a piece of bone from another part of the foot or even somewhere else
  in the body that is attached to a blood vessel. When the bone is inserted into the talus, it helps bring more blood to the talus, which will help new bone to form. This is a major surgery with a long recovery, but it is often successful. This
  surgery is a good option for patients with severe avascular necrosis without any collapse or arthritis.

• Joint fusion: If your avascular necrosis is
  associated with bad arthritis (loss of cartilage in one of the joints around the talus), then your surgeon may recommend a joint fusion. In a fusion, your surgeon removes the joint and connects two bones together so they grow into each other
  and become one bone. This process can help heal avascular necrosis and get rid of pain, although you will lose some motion. The amount and type of motion lost depends on the joint being fused.

• Total talus replacement: This surgery is an option
  for patients with severe avascular necrosis who may have collapse or fragmentation of the bone. It involves replacing the talus bone completely with a custom-made metal talus. This is a newer procedure, and while most patients do well in the
  first few years after surgery, we do not know how patients do in the long-term.

Recovery

Recovery from surgery depends on the procedure performed. Most surgeries require at least a few weeks of non-weightbearing after surgery. For surgeries that require bone healing, such as joint fusion, the recovery will be longer, ranging from 6-12 weeks of non-weightbearing. Full recovery can take 1-2 years as you will need to regain your strength and function after surgery.

Risks and Complications

The risks and complications depend on the procedure performed. The more extensive the surgery, the greater the risks. Prior to surgery, you should have an in-depth discussion with your foot and ankle orthopaedic surgeon about the risks of the particular surgery.

Will my talar avascular necrosis get worse if it isn’t treated?

Not necessarily. If you are not having surgery, you should have regular follow-up with X-rays and/or MRI with your foot and ankle orthopaedic surgeon to look for any worsening over time.

How will I know if my talar avascular necrosis is getting worse?

If you have been diagnosed with talar avascular necrosis and you experience increasing pain, swelling, or stiffness, you should see your foot and ankle orthopaedic surgeon for repeat X-rays/MRIs. Your surgeon will look for any changes, such as signs of
worsening arthritis, collapse, or fragmentation.

Original article by Elizabeth Cody, MD
Contributors/Reviewers: Sudheer Reddy, MD

The American Orthopaedic Foot & Ankle Society (AOFAS) offers information on this site as an educational service. The content of FootCareMD, including text, images, and graphics, is for informational purposes only. The content is not intended to substitute
for professional medical advice, diagnoses or treatments. If you need medical advice, use the “Find a Surgeon” search to locate a foot and ankle orthopaedic surgeon in your area.

Avascular Necrosis | Johns Hopkins Medicine

Avascular Necrosis | Johns Hopkins Medicine

What is avascular necrosis?

Avascular necrosis is a disease that results from the temporary or permanent loss of blood supply to the bone. When blood supply is cut off, the bone tissue dies and the bone collapses. If avascular necrosis happens near a joint, the joint surface may collapse.

This condition may happen in any bone. It most commonly happens in the ends of a long bone. It may affect one bone, several bones at one time, or different bones at different times.

Avascular Necrosis Q&A | Julius Oni, M.D.

What causes avascular necrosis?

Avascular necrosis may be the result of the following:

• Injury

• Fracture

• Damage to blood vessels

• Long-term use of medicines, such as corticosteroids

• Excessive, long-term use of alcohol

• Specific chronic medical conditions

What are the risk factors for avascular necrosis?

Risk factors include:

• Injury

• Steroid use

• Gaucher disease

• Caisson disease

• Alcohol use

• Blood disorders, such as sickle cell anemia

• Radiation treatments

• Chemotherapy

• Pancreatitis

• Decompression disease

• Hypercoagulable state

• Hyperlipidemia

• Autoimmune disease

• HIV

What are the symptoms of avascular necrosis?

The following are the most common symptoms of avascular necrosis. However, each person may experience symptoms differently. Symptoms may include:

• Minimal early joint pain

• Increased joint pain as bone and joint begin to collapse

• Limited range of motion due to pain

The symptoms of avascular necrosis may look like other medical conditions or bone problems. Always talk with your healthcare provider for a diagnosis.

How is avascular necrosis diagnosed?

Along with a complete medical history and physical exam, you may have one or more of the following tests:

• X-ray. This test uses invisible electromagnetic energy beams to make images of internal tissues, bones, and organs onto film.

• Computed tomography scan (also called a CT or CAT scan). This is an imaging test that uses X-rays and a computer to make detailed images of the body. A CT scan shows details of the bones, muscles, fat, and organs. CT scans are more detailed than general X-rays.

• Magnetic resonance imaging (MRI).  This test uses large magnets, radiofrequencies, and a computer to make detailed images of organs and structures within the body.

• Radionuclide bone scan. This nuclear imaging technique uses a very small amount of radioactive material, which is injected into the blood to be detected by a scanner. This test shows blood flow to the bone and cell activity within the bone.

• Biopsy. A procedure in which tissue samples are removed (with a needle or during surgery) from the body for exam under a microscope. It’s done to find cancer or other abnormal cells or remove tissue from the affected bone.

• Functional evaluation of bone. Tests that usually involve surgery to measure the pressure inside the bone.

How is avascular necrosis treated?

Specific treatment for avascular necrosis will be determined by your healthcare provider based on:

• Your age, overall health, and medical history

• Extent of the disease

• Location and amount of bone affected

• Underlying cause of the disease

• Your tolerance for specific medicines, procedures, or therapies

• Expectations for the course of the disease

• Your opinion or preference

The goal of treatment is to improve functionality and stop further damage to the bone or joint. Treatments are needed to keep joints from breaking down, and may include:

• Medicines. These are used to control pain.

• Assistive devices. These are used to reduce weight on the bone or joint.

• Core decompression. For this surgical procedure, the inner layer of bone is removed to reduce pressure, increase blood flow, and slow or stop bone and/or joint destruction.

• Osteotomy. This procedure reshapes the bone and reduces stress on the affected area.

• Bone graft. In this procedure, healthy bone is transplanted from another part of the body into the affected area.

• Joint replacement. This surgical procedure removes and replaces an arthritic or damaged joint with an artificial joint. This may be considered only after other treatment options have failed to relieve from pain and/or disability.

Other treatments may include electrical stimulation and combination therapies to promote bone growth.

Key Points about 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.

• Medicines, assistive devices or surgery may be used to improve functionality or to stop further damage to the affected bone or joint.

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causes, symptoms, diagnosis and treatment in Moscow at the Center for Surgery “SM-Clinic”

General information

Kinds

Symptoms

Diagnostics

Operations

Expert opinion of a doctor

Rehabilitation

Question answer

General information

The talus is one of the bones that form the ankle joint, the main task of which is to distribute body weight on the foot. With adverse factors that cause a violation of the blood supply to this area, aseptic (ischemic) necrosis develops, and the tissues of the talus begin to gradually die off.

Species

Symptoms of aseptic necrosis of the talus

Diagnosis

Evaluation for suspected aseptic necrosis of the talus of the ankle begins with a visual examination. The doctor assesses the condition of the skin, the position of the foot, carefully palpates. Instrumental research methods help to confirm the diagnosis, which include:

• fluoroscopy;
• computed tomography;
• magnetic resonance imaging.

Additionally, a basic set of laboratory tests is performed, which helps to determine the general level of the patient’s health, identify possible inflammatory processes in the body and evaluate the functioning of the hematopoietic system.

Operations for aseptic necrosis of the talus

Therapy depends entirely on the degree of the disease. At stages 3–4 of aseptic necrosis, when there are serious violations of the integrity of the talus of the ankle joint, conservative tactics are irrational, surgical treatment is indicated.

Aseptic necrosis is a rather complex pathology, and the choice of surgical methods of therapy in the later stages is limited by two optimal methods.

Endoprosthetics

The technique consists in the complete or partial replacement of the destroyed areas of the talus with a biocompatible artificial material.

More

Arthrodesis

The technique is based on fixing the damaged area in one fixed position.

More

With minor changes, it is possible to perform osteochondral autoplasty, tunneling of the necrosis zone, alloplasty.

Medical expert opinion

Rehabilitation

Question-answer

The absence of pain does not mean complete recovery. Premature loading on the injured limb in most cases will give a new start to the disease.

Aseptic – means “sterile”, that is, the process of tissue death that occurs without the participation of viruses, bacteria or other infectious agents.

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Avascular necrosis (AVN)/osteonecrosis – together by St. Jude

Other names: OH, aseptic necrosis, ischemic bone necrosis

What is avascular necrosis (AVN)?

Avascular necrosis (osteonecrosis) is a condition in which part of the bone dies due to poor blood supply. Avascular necrosis may be a side effect of certain cancers or treatments.

Children at high risk are those receiving high doses of corticosteroids (dexamethasone and prednisone).

Avascular necrosis may be mild and improve after treatment is completed, or it may be severe, accompanied by severe pain and long-term disability.

Avascular necrosis in children with cancer

Avascular necrosis (AVN) is a common side effect of treatment for leukemia and lymphoma. Nearly half of children treated for acute lymphoblastic leukemia (ALL) suffer from some degree of avascular necrosis. In addition, the high-risk group includes children who have undergone bone marrow transplantation.

In children with cancer, avascular necrosis often occurs at the ends of long bones, at a site called the epiphysis.

This disease can affect any bone. However, in children with cancer, avascular necrosis often occurs at the ends of long bones, at a site called the epiphysis.

Avascular necrosis may be accompanied by pain and affect joint function, especially knee, hip, shoulder and ankle. Damage to the bone and joint can lead to long-term problems such as joint destruction and arthritis.

In cancer treatment, avascular necrosis is more common in older children and adolescents than in young children or adults. In children younger than 10 years, this condition is less common.

In the early stages, avascular necrosis can be difficult to diagnose. The patient may not experience pain or other symptoms until severe bone damage develops. The condition of high-risk children should be monitored throughout the course of treatment.

Treatment of avascular necrosis depends on the severity of the pain and the degree of bone destruction. Pain relief and physical therapy can help manage symptoms. Some patients may require surgery to improve blood flow and relieve pressure within the bone. In case of severe damage or destruction of the joint, the patient may eventually need arthroplasty.

Symptoms of avascular necrosis

Some patients may not show symptoms at all, especially in the early stages. As the condition worsens, pain in the joint or bone may appear. Family members may notice that the child has begun to limp, tries not to use the affected joint, stiffness or limitation of range of motion may become noticeable. Occasionally, avascular necrosis can lead to bone destruction, with the pain escalating dramatically.

Avascular necrosis can develop in one place or in several bones at once (multifocal course). Chemotherapy affects the entire body, so when treating childhood cancer, avascular necrosis usually occurs in several joints, most commonly in the knee and/or hip. Other joints, such as the shoulder and ankle, may also be affected.

In general, the presence of pain and disability depends on the following factors:

• Which parts of the bone are affected
• How severe is the avascular necrosis
• How quickly progresses
• To what extent the bone is able to regenerate

However, pain cannot be considered a reliable indicator of the severity of avascular necrosis. Avascular necrosis in a small area can be very painful. At the same time, other patients may not have pain at all, despite the very large area affected by avascular necrosis.

Symptoms of avascular necrosis

• Pain (may be temporary or permanent)
• Joint stiffness or “stuck”
• Lameness or change in gait
• Tendency not to use the affected joint or avoidance of certain activities
• Problems going up or down stairs

Factors that increase the risk of developing avascular necrosis

• High doses of dexamethasone or prednisone as part of cancer treatment
• Age over 10 years
• Sickle cell disease
• High-dose bone irradiation
• Treatment with asparaginase and dexamethasone
• Congenital genetic changes

Causes of avascular necrosis

Avascular necrosis is a complex process. The main reason for the development of avascular necrosis is a decrease in blood flow to the bone. If the blood vessels are too thin, damaged, or clogged, nutrients and oxygen cannot reach the bone, causing bone cells to begin to die.

Cancer treatments, including chemotherapy and radiation, can cause bone cell death and/or affect bone repair. As a result, the bone can break down faster than it has time to recover from damage. In addition, the treatment may affect the blood supply to the bones, leading to avascular necrosis.

Many children receive corticosteroid drugs (eg, dexamethasone, prednisone) for chemotherapy. These drugs are also used to combat side effects such as nausea and swelling. However, corticosteroids can increase the level of fatty substances (lipids) in the blood. Accumulation of fats in blood vessels can lead to blockage. In addition, these drugs can cause changes in the cells that line the walls of blood vessels, thereby thinning and weakening blood vessels.

Chronic high-dose dexamethasone is associated with a higher risk of developing avascular necrosis than prednisone or intermittent dexamethasone. Some drugs, such as asparaginase, can also interfere with the action of dexamethasone and increase the risk of developing avascular necrosis because these drugs interact with each other. Other drugs (eg, methotrexate) can also cause bone damage and increase the risk of avascular necrosis, especially when used with corticosteroids.

Diagnosis of avascular necrosis

Different medical centers have different approaches to identifying patients at risk and monitoring their condition. Imaging methods are used to identify areas of avascular necrosis (sometimes called foci). Magnetic resonance imaging (MRI) is the most sensitive diagnostic imaging modality for diagnosing avascular necrosis. X-rays are less sensitive, but may be useful for monitoring progression and for monitoring the patient’s condition in the postoperative period. Less commonly, other methods such as bone scintigraphy and computed tomography (CT) are used.

Some clinics screen children at high risk to detect avascular necrosis even if they are asymptomatic. As a rule, such screening is part of a clinical or scientific research program and is mainly carried out for the knee and hip joints. When screening high-risk patients who are asymptomatic, the most common finding of avascular necrosis is on diagnostic imaging of the knee. As a rule, necrosis is observed on both sides of the knee joint (femoral and tibial), the knee may be the only affected joint. However, if avascular necrosis is found in the hip joint, the knees are also most commonly affected.

Avascular necrosis associated with high doses of corticosteroids usually becomes visible on MRI within the first year of therapy. If a patient does not show signs of avascular necrosis on MRI after 12 months of therapy, then even continued use of corticosteroids will most likely not cause the development of this condition.

Physicians are constantly looking for more accurate diagnostic methods through the use of more sensitive imaging techniques. In addition, research is underway in the field of predicting the development of avascular necrosis.

Progression of avascular necrosis

The course of avascular necrosis is difficult to predict. Lesions may grow, remain stable, or disappear. Progression can be fast or slow.

The severity (or stage) of avascular necrosis is important to know for treatment planning. Doctors consider two main factors:

1. The size of the lesions
2. Is the bone on which the articular surface rests damaged

If the damaged bone cannot support the joint surface, the bone tissues under the cartilage will begin to break down. The normally smooth layer of cartilage that lines the joints begins to flake off. This leads to problems in the joint, including arthritis, pain and decreased mobility of the joint.

Joint destruction is more likely if the lesion is:

• close to the surface of the joint
• large, occupies 30% or more of the entire surface
• located in a weight-bearing joint (thigh, knee)

Since the knee and hip joints work under weight load, in severe cases of avascular necrosis, their destruction is quite common. If the focus of avascular necrosis in the hip joint occupies more than 30% of the joint surface, joint destruction usually occurs within 2 years.

Treatment of avascular necrosis

Treatment of avascular necrosis is always individual. Doctors take into account the following factors:

• Patient age
• Patient health and cancer stage
• Current cancer treatment and chemotherapy schedule
• Stage of avascular necrosis
• What bones and joints are affected
• Severity of pain

The main treatment is to relieve pain, keep the joint working and prevent further damage.

Treatment strategies may include the following:

Medications

Your doctor may prescribe pain medications, including NSAIDs (meloxicam, celecoxib) or acetaminophen. However, some painkillers put the patient at risk for bleeding, kidney or liver problems, or worsening the side effects of chemotherapy. Family members should check with their doctor before giving a child any medications, even over-the-counter medications, as they may interact with other medications or increase side effects.

Research is underway to prevent or treat avascular necrosis with drugs that affect blood flow, blood clotting, inflammation, fat metabolism, and/or bone cells. However, it has not yet been possible to achieve sustainable positive results.

Physiotherapy

Physiotherapy is an important part of the treatment of avascular necrosis. The physiotherapist will recommend how to reduce the weight load or eliminate painful activities. They may also prescribe special treatments, including:

• Exercises to help with the patient’s limitations (muscle weakness, joint stiffness, or trouble walking).
• Assistive devices (walker, crutches or cane) that help you move around and reduce the weight load on the affected joint. The physiotherapist will select the appropriate option and teach the patient how to walk with their help.
• Orthoses and support bandages (foot, knee or arm) support the affected joint and help reduce pain during daily tasks
• Instructions for home care, including gymnastics, recommendations for exercise and treatment with heat and/or cold

Avascular necrosis and weight-bearing activities

Reduced weight-bearing is recommended to avoid joint damage, severe pain, and for healing after surgery. However, many doctors and physiotherapists recommend that the patient perform light activities, as far as pain allows. Physical activity is important for increasing blood circulation, improving bone healing, and strengthening muscles, which reduces stress on the joints.

Patients with avascular necrosis should avoid high impact activities such as running, jumping and contact sports. This is especially important in patients with severe avascular necrosis to avoid joint destruction due to trauma.

Complementary or integrative therapies

The patient may benefit from psychosomatic therapies (eg, massage, acupuncture, biofeedback, and relaxation techniques). Special techniques help to cope with pain, reduce stress, reduce muscle tension and improve blood flow. Before using any new treatments, the patient’s family should consult with their physician to ensure they are safe and appropriate for the patient.

Adjustment of chemotherapy

In the case of severe avascular necrosis, the treatment team may recommend changing the chemotherapy plan to reduce the body’s exposure to corticosteroids. Such decisions should be made taking into account the risks to the health of patients in general.

Surgery

Some patients require surgery to treat avascular necrosis. The operation will speed up the healing of the bone and prevent its further damage. Joint replacement may also be required. The following types of procedures are possible:

• Bone decompression – This procedure is performed to reduce pressure within the bone, increase blood flow, and thereby improve the healing rate. With this decompression, the surgeon drills small holes in the bone, cracking open the damaged tissue. After the dead tissue is removed, the voids can be filled with a bone graft. This is a minimally invasive surgery requiring only a small incision. It usually takes several weeks of rest or weight-bearing to heal. Typically, patients recover quickly and report less pain and improved joint function.
• Bone graft is a surgical procedure performed for avascular necrosis to replace and restore bone tissue with a bone graft. In this case, the transplanted tissue can be taken from the patient himself (from another bone, autograft) or from a donor (allograft). In addition, artificial materials can be used. If the cartilage is damaged, a combined bone and cartilage graft may be used. In some cases, blood vessels are also transplanted along with the bone tissue. This material is called a vascularized bone graft. It can help improve the blood supply to the joint. In avascular necrosis, bone grafting is most often used in conjunction with bone decompression.
• Arthroscopy is a type of minimally invasive procedure in which a miniature camera and fine surgical instruments are inserted through small incisions. In patients with avascular necrosis, arthroscopy may be used to repair torn cartilage, smooth the surface of a bone, or remove debris from inside a joint. This can relieve symptoms such as pain, stiffness, and a “stuck” joint.
• Osteotomy – This surgical operation is used to reduce the weight load on the affected area by reshaping or repositioning the bone. During this procedure, a wedge-shaped incision is made in the bone, after which the bone can be rotated, thereby changing the load on it. In the new position, the bone is held by plates, staples or screws until it heals. Osteotomy can help prevent joint destruction, delaying or eliminating the need for a joint replacement.
• Arthroplasty (Arthroplasty) – Joint replacement surgery may be required for severe bone disease. During this operation, the affected bone is removed and replaced with an artificial joint. Endoprosthetics may be needed for young patients after joint destruction. However, arthroplasty is also a common operation for adult cancer survivors who suffer from arthritis or who complain of worsening joint function years after treatment ends. Patients who have undergone joint replacement at an early age are likely to have to undergo repeated surgery in the future. Early diagnosis and treatment of avascular necrosis is important to prevent or delay arthroplasty.

Managing Avascular Necrosis: Tips for Patients and Families

Know your risks. Discuss with the physician the patient’s cancer treatment (including doses received) and other risk factors.

Monitor your symptoms and get recommended tests. Seek medical attention if you develop pain or problems with your joints, especially if symptoms have not been observed before or worsen. Once your treatment is over, ensure that bone health is adequately addressed in your rehabilitation plan.

Stay physically active. Adjust your physical activity to reduce weight bearing and pay attention to pain as it will tell you what level of activity is acceptable. Avoid activities that involve pushing and falling, as well as contact sports – take care of bones and joints. If you’re not sure if a particular sport is okay to play, ask your doctor or physical therapist.

Wear shoes that provide support and use your prescribed orthoses and assistive devices.