ABOUT THE DISEASE:-
Avascular necrosis (AVN) is a condition that occurs when there is a loss of blood supply to the bone. Because bone is a living tissue that requires blood, an interruption to the blood supply causes the bone to die.
WHAT IS THE CONSEQUENCE:-
When there is a lack of blood supply to the bone, small breaks can occur due to the death of its tissue. Eventually, it may lead to bone collapse.
When a bone breaks or the joint gets dislocated, there can obstruct blood flow to a part of the bone. The disease usually affects the joints of the body. It may occur on one side or is bilateral (like afflicting both hips, both knee joints, etc).
SYNONYMS:-
Osteonecrosis – osteo means bone, necrosis means death
Aseptic necrosis
Ischemic bone necrosis
Osteochondtitis Dissecans
Chandler’s Disease
WHO IS AFFLICTED BY AVN?
AVN is most commonly found to occur in people between 30-50 years of age group. But it can affect anyone. Some references tell that most people suffering from AVN are between 20-50 years of age.
TRAUMATIC AND NON-traumatic AVN:-
Gross AVN can happen due to traumatic and non-traumatic causes. Even modern medicine has described this.
According to Ayurveda-
Traumatic causes- Seeing the symptoms of Asthi-Majjagata Vata these conditions can be considered traumatic causes of AVN.Bhagna-trauma/fractures and dislocations also fall under this category.
Non-traumatic causes:- The other etiological factors enlisted above fall under this category.
SYMPTOMS:-
In many people, there may not be any symptoms, especially in the earlier stages of the disease.
The pain of AVN – In advanced conditions, the disease becomes worse. In this condition, one may experience joint pain.In the beginning, it might hurt only when you put pressure on the affected bone. Later the pain becomes constant.
– Joint hurts more when more weight is transferred onto the joint. The pain of AVN is also felt when one lies down.
-If there is the collapse of bone and surrounding tissue the pain gets severe. In this condition, one will not be able to use the joints. The range of movements too will get restricted.
-The time gap between the first symptoms of AVN i.e. pain and bone collapse may range from several months to more than one year.
-Nature of the pain – The pain of AVN may be mild or severe in nature. It usually develops gradually.
-Common seats of AVN – AVN most commonly occurs in the hips. Other sites are shoulder, knee, hand, and foot(ankles).
WHEN TO CONSULT A DOCTOR?
Joint pain is worse, persistent, and intolerable.
Feeling that your bone has been broken or joints dislocated.
CAUSES:-
Reduction or interrupted blood supply to a bone is the main cause of avascular necrosis.
Causes of reduction in blood supply to the bone:-
1.Bone /Joint trauma caused by
-dislocation of joint.
-damage to bone due to injury.
-cancer treatments weaken bones and harm blood vessels since it involves radiation.
AVN may affect 20% of people or more in whom hip dislocation takes place.
2.Deposists of fats in blood vessels – which eventually block the small blood vessels. This will reduce the blood flow to the bones and there will be the death of bone tissues.
3.Impact of diseases – like sickle cell anemia and Gaucher’s disease may cause reduced blood flow to the causing death of bone tissue.
4.Arterial pathology/damage – blood clots, inflammation and damage to arteries can block blood flow to the bones causing AVN.
5.Use of steroids in higher doses for a longer time – 35% of non-traumatic AVN are said to be caused by long term use of steroids. They are believed to increase blood fat deposists leading to hampered blood flow to bones and joints.
6.Excessive consumption of alcohol – might lower blood supply to the bones by causing deposits of fat in the blood / blood vessels.
7.Treatments – radiation therapy for cancer, organ transplants.
NOTE:- The cause of disruption of blood supply to the bones is not known in about 25% of people suffering with AVN.
AVN – Ayurveda Concept:-
Doshas and tissues involved in AVN:-
1.Doshas
All the doshas – vata and kapha are involved in the causation of AVN at one or the other stage of the disease. Predominantly Vata dosha is involved.
a. Vata dosha and bone tissue have a resident-residence relationship. Vata is located in the bones. When vata increases the bone tissue dicreases or gets damaged. Similar mechanism takes place in the manifestation of AVN. Therefore Vata is invariably involved in the causation of AVN.
b. Pitta may be indirectly involved in the pathogenesis. Pitta resides in the blood just like vata resides in bones. Since there is a lack of blood supply to the bones there cannot be high pitta in the joints . But high pitta might be causal for destruction of blood and channels (arteries and arterioles supplying the bone) carrying blood. When the blood vessels get damaged due to pitta and consequently depletion of blood supply to bones occurs, AVN is manifested.
c. Kapha too may be involved in the causation of AVN. Fat tissue is one of the seats of kapha. When kapha increases it will impair and imbalance fat tissue. The fat tissue too will increase and cause blocks in many channels of the body, including the blood carrying channels of the body. This will cause a lack of blood supply to the bones causing AVN.
2.Dhatus
a. Asthi Dhatu/ Bone tissue – Avn is a disease related to bone tissue, death of bone tissue to be precise. Therefore bone tissue is invariably involved.
b. Blood tissue – Since this bone tissue death is caused due to deficit or lack of blood supply to the bone, the blood tissue is also involved.
c. Medo Dhatu/ Fat tissue – Accumulation of bad fats in blood vessels causes AVN.
d. Majja Dhatu/ Bone Marrow tissue – According to Ayurveda, bone marrow is located inside the bone and fills it. Destruction, death, and depletion of bone tissue also affect bone marrow. Bone marrow tissue also forms the root of bones and joints of the body. Therefore when the bone marrow tissue gets depleted, the bones and joints which take origin from it too get weak, diseased, cracked, and collapsed, as in AVN.
NOTE:- The channels conveying the above-said tissues are also contaminated and damaged in AVN.
CAUSES:-
a. Vata aggravating factors – foods, lifestyle, and seasons favoring vata aggravation.
b. Kapha and fat aggravating factors.
c. Aggravating factors of blood tissue.
d. Malnutrition – leading to depletion of tissues.
e.Contamination of channels carrying bones, bone marrow, fat, and blood.
f. Diseases like
-vatarakta- gout / arterial diseases
-pandu- anemia
-rakta,asthi and majja kshaya – decrease in formation of blood tissue, bone tissue and bone marrow .
g. Sthoulya and medoroga – obesity and disorders of fat metabolism.
h. Asthi-Majjagata Vata – Vata located in bones and bone marrow – osteopenia / osteoporosis.
i. Agnimandya – deterioration of digestive fire.
j. Ama in circulation.
k. Trauma.
DIAGNOSIS:-
The doctor would examine your joint to elicit pain, tenderness, and any other damage so as to make the appropriate diagnosis. The range of motion may also be examined.
Imaging tests-
-X-Rays – helps in finding out the bone changes which occur in AVN, in the later stages of the disease.
-MRI and CT scan- helps in finding out the early changes occurring in the bone indicating AVN.
-Bone Scan- helps in finding out the parts of bones that are injured or healing.
PATHOGENESIS:-
One or the other form of the below-mentioned pathogenesis will be involved in the causation of AVN.
Dhatu kshaya janya vata vriddhi (Vata increase caused due to tissue depletion) –
Depletion of any tissue leads to an increase of vata at the site of the dipletion of tissue. This rule holds well with the depletion of bone tissue too. When due to a lack of blood supply to the bone when the bone tissue gets depleted due to the death of its cells,vata will increase in those regions of the bone tissue. This increase in vata will lead to an increase of Vata qualities in the bone like dryness, roughness, lightness, minuteness, etc. this will eventually lead to damage and breakage of a bone. An increase in Vata will also cause pain in the joints and bones. When vata further increases, bone tissue death will further increase and eventually lead to bone collapse. This explanation holds good in accordance with the pathogenesis explained in modern texts.
Vata Vriddhi Janya Asthi Dhatu Kshaya (Bone death due to increase in Vata)- Due to excessive consumption of vata aggravating etiological factors the bone tissue gets destroyed leading to AVN. On the other hand, the aggravated vatacan also destroys the blood tissue and blood vessels and hampers the blood supply to the bones. Among the causes of vata vitiation, excessive exercise, excessive fasting, falls and injuries, fractures, and depletion of tissues are mentioned as important ones.
Kapha and fat contaminating the channels of the body and causing blocks / Obesity and errors of fat metabolism as casual for AVN:-
a. Kapha and fat tissue have resident and residence relationship i.e. fat are one of the seats of kapha. Increased kapha causes a pathological imbalance of fat tissue and increases it. This increased free circulating fat will accumulate in the blood vessels supplying to the bones and cause deprivation of blood supply. This will cause necrosis and death of bone tissue causing AVN.
b. This pathology can occur ‘independent of vitiation of Kapha. Fat-increasing etiological factors will directly increase fat in the body subsequently leading to its accumulation in blood vessels supplying the bones causing the lack of blood supply to the bones. This eventually leads to bone death causing AVN.
Contamination of blood tissue – Among the signs and symptoms of contamination of blood tissue, vatarakta has been mentioned. In this condition, there is combined vitiation of Vata and blood leading to symptoms resembling AVN.
Malnutrition – When the tissues are not properly nourished with complete and balanced nutrition, it will cause the depletion of tissues. This is true with bone tissue too. ‘Pain in the leg, thigh and sacral joint and the small/big joints and bones’ is said to be one of the symptoms of ‘diseases caused due to deficit nutrition’. These are the sites of the body wherein pain is manifested in AVN.
Overnutrition and subsequent obstruction in the channels of the body leading to vata increase – Over-nutrition will cause many disorders due to disturbed and imbalanced metabolism. Over-nutrition will also impose a burden on the stomach and intestines leading to indigestion and the formation of ama. Less nutritive juices are formed and the tissues including bones are deprived of blood supply and nutrition.
Contamination of channels carrying –
-bones-cause destruction of bones- among the symptoms of diseases caused due to contamination of bones, bone pain and splitting pain and fracture have been mentioned.
-bone marrow – causes destruction of bone marrow.
-fat -causes obstruction in the blood vessels supplying the bone.
-blood -causes lack of blood supply to the bones.
