Avascular necrosis of the femoral head

 

Avascular necrosis of the femoral head (ANFH) refers to the death of bone tissue at the proximal end of the femur (hip joint), due to a loss of blood supply, which leads to ischaemia. Such events can result from trauma to the area or can be non-traumatic and in some cases, idiopathic. The femoral head is susceptible to avascular necrosis (AVN) due to minimal collateral blood supply.

 

Avascular necrosis has been attributed to numerous causes including radiation therapy, corticosteroid use, trauma, thrombosis, infection, sickle cell disease, Gaucher disease, systemic lupus erythematosus, hereditary thrombophilia, alcohol abuse and chronic pancreatitis. Recently, mutations in COL2A1 have been linked to familial avascular necrosis of the femoral head.

The majority of patients are adults, aged between 30 and 60 years and the disease is seen more often in males than females. Studies show that ANFH prevalence is increasing

Pathogenesis

According to Mankin, the factors initiating ischaemia in ANFH can be placed in four categories:
1.    Mechanical vascular interruption:
Tissue trauma, such as fracture or repetitive mechanical force, resulting in shearing or rupture of vessels.
2.    Arterial thrombosis or embolism
3.    Injury to or pressure on a vessel wall
4.    Venous occlusion:
Increased venous pressure or stasis leading to reduced blood flow in the preceding artery

Classification

AVN is commonly classified using the Ficat and the ARCO systems, to determine the stage of disease in individual cases. In both cases, a higher number indicates more advanced AVN.

Diagnosis

A patient with ANFH may present clinically with pain or functional abnormality, however ANFH is usually diagnosed via imaging, including radiography and occasionally magnetic resonance imaging (MRI). Diagnostic imaging is based on the classification systems.

Clinical presentation

Symptomatic presentation varies depending on the stage, type and location of the infarct. Pain is the predominant symptom of ANFH, often with gradual onset. However, in traumatic cases the onset of pain can be more rapid. ANFH pain is often exacerbated with movement.

While pain is initially unilateral, the pain becomes bilateral after two years. Function often declines with disease progression, but this may be somewhat attributed to worsening pain.

Imagings will show bone collapse,loss of spherical contour, femoral head collapse.

Intervention

As ANFH usually presents in more advanced disease, prevention is difficult and the majority of current treatment options aim to remove and replace necrotic tissue and to reduce associated pain and immobility.

Surgical intervention

The most common treatment for ANFH is arthroplasty. The may be hemiarthroplasty, where half of the joint is replaced by artificial tissue, or total hip replacement (THR) where the entire joint is replaced, including the head and the neck of the femur. Unfortunately, arthroplasty only restores function and structure to the joint, without targeting ANFH-associated pain. Furthermore, artificial joints do not last permanently and are therefore more suited to the ageing population, as the younger demographic may need multiple THRs in their lifetime.

In the earlier stages of ANFH where there is no bone collapse (up to ARCO stage II), core decompression is the commonly used technique. This involves removing the necrotic tissue and potentially filling this space with a vascularised or non-vascularised bone graft. Studies show that free vascularised fibular grafting (FVFG) is the treatment that provides the best functional outcome in uncomplicated ANFH. The procedure aims to maintain the femoral head, by reducing interosseus pressure and inducing re-perfusion of the damaged tissue via the replacement vessels.

The efficacy of drug treatment for ANFH is usually unsatisfactory.

 

Stem cell therapy for ANFH in ReLife

What is stem cell therapy? As the most basic building blocks of the human body, stem cells are characterized by their ability to differentiate and mature into other types of cells with specialized functions. They are also known for their ability to self-generate, a phenomenon where they divide and produce more stem cells. During early childhood, stem cells may develop into a variety of different cell types. They are also capable of replenishing other cells, acting as the body’s own automatic repair system. This ability makes them an ideal treatment for many diseases; this treatment is called stem cell therapy.

Msenchymal Stem Cell Therapy

Mesenchymal stem cells may have an excellent repair effect for the necrosis of femoral head which had multi-directional differentiation potency, especially can differentiate into chondrocytes, osteocytes and dipocytes under suitable cultural condition. To Help the bone defect repair and reconstruction, meanwhile stem cells can dredge lesions blood vessels in the head of femur, improve the blood circulation of necrosis area and the surrounding tissue, promote angiogenesis, gradually restore the original function.

Combine Traditional Chinese Medicine

Here in ReLife, we combine TCM treatment with mesenchymal stem cell therapy to treat ANFH. It can get a better treatment effect which is proved by previous clinical application.

Traditional Chinese Medicine is a green, safe and effective treatment method, which proposes treatment according to syndrome differentiation, via acupuncture, traditional Chinese medicine, moxibustion, massage and natural therapy. TCM focuses on recovering the balance of patient’s body, strengthening the body’s ability to eliminate pathogenic factor, by adjusting the balance of Qi and activating blood circulation to dissipate blood stasis dredge the channels in the lesion area. TCM regulate the inner body environment to enhance the effectiveness of MSC therapy.

  • TCM will regulate the inner body environment to enhance the effectiveness of MSC Therapy;
  • TCM will stimulate the blood circulation.
  • TCM will focus on recovering the balance of patient’s body, increase patient’s ability to fight with the disease

The time of treatment varies according to the differentiation of patient’s condition, usually lasting for 4 weeks. Through this therapy the symptoms will be relieved, the treatment effect relates to the age and disease duration.

There is almost no series side effect during the treatment course except slight headache and low degree fever; many patients do not suffer any side effects.