Avascular Necrosis
Avascular means that body is having few or no blood vessels which brings to death of that part of the body.
Avascular necrosis is necrosis of bone tissue due to impaired or disrupted blood supply (as that caused by traumatic injury or disease) and marked by severe pain in the affected region and by weakened bone that may flatten and collapse—called also osteonecrosis.
It results by temporary or permanent loss of the blood supply to the area of bone. Without blood the bone tissue dies and the bone crashes and collapses.
If avascular necrosis involves the bones of a joint it often leads to destruction of the joint articular surfaces.
The disease can affect one bone or more different bones at the same time or more than one bone in different times.
Usually affects people between 30 and 50 years of age but when it occurs in children at the femoral head it is known as Legg-Calvé-Perthes syndrome.
In early stage of disease X-ray images usually look quite normal and bone scintigraphy and MRI can detect minimal changes. Late radiographic signs include a radiolucency area following the collapse of subchondral bone (crescent sign) and ringed regions of radiodensity resulting from saponification and calcification of marrow fat following medullary infarcts.
To determine the most appropriate treatment, the doctor considers the following aspects:
Kaplan NCLEX-RN Exam 2010 with CD-ROM: Strategies for the Registered Nursing Licensing Exam
Kaplan Medical USMLE Master the Boards Step 3 (Kaplan USMLE)
First Aid for the USMLE Step 2 CK, Seventh Edition (First Aid USMLE)
Nursing Care Plans: Nursing Diagnosis and Intervention
Harrison's Principles of Internal Medicine, 17th Edition
CURRENT Medical Diagnosis and Treatment 2009 (LANGE CURRENT Series)
Avascular necrosis is necrosis of bone tissue due to impaired or disrupted blood supply (as that caused by traumatic injury or disease) and marked by severe pain in the affected region and by weakened bone that may flatten and collapse—called also osteonecrosis.
It results by temporary or permanent loss of the blood supply to the area of bone. Without blood the bone tissue dies and the bone crashes and collapses.
If avascular necrosis involves the bones of a joint it often leads to destruction of the joint articular surfaces.
Causes of disease:
With certainty we can't say what precisely causes avascular necrosis. Here we can only speak about risk factors that can bring a stage of this disease which are:- alcoholism
- excessive steroid use
- post trauma
- caisson disease or decompression sickness
- vascular compression
- hypertension
- vasculitis
- thrombosis
- radiation damage
- bisphosphonates (particularly the mandible)
- sickle cell anaemia and
- Gaucher's disease
Manifestation
Avascular necrosis primarily affects joints at the shoulder, knee and hip. Clinical avascular necrosis mostly affects the ends of long bones such as femur and other common sites include the bone humerus, knees, shoulders, ankles and jaw.The disease can affect one bone or more different bones at the same time or more than one bone in different times.
Usually affects people between 30 and 50 years of age but when it occurs in children at the femoral head it is known as Legg-Calvé-Perthes syndrome.
Diagnosis
Orthopaedic doctors most often diagnose the disease except when it affects the jaws, when it is usually diagnosed and treated by dental and maxillofacial surgeons.In early stage of disease X-ray images usually look quite normal and bone scintigraphy and MRI can detect minimal changes. Late radiographic signs include a radiolucency area following the collapse of subchondral bone (crescent sign) and ringed regions of radiodensity resulting from saponification and calcification of marrow fat following medullary infarcts.
Treatment
Appropriate treatment for avascular necrosis is necessary to keep joints from breaking down. If untreated, most patients will experience severe pain and limitation in movement within 2 years. Several treatments are available that can help prevent further bone and joint damage and reduce pain.Ongoing Process
For most with AVN, treatment is an ongoing process. Doctors may first recommend the least complex and invasive procedure, such as protecting the joint by limiting movement, and watch the effect on the patient's condition. Other treatments then may be used to prevent further bone destruction and reduce pain. It is important that patients carefully follow instructions about activity limitations and work closely with their doctor to ensure that appropriate treatments are used.To determine the most appropriate treatment, the doctor considers the following aspects:
- age of the patient
- stage of the disease (early or late)
- location and amount of bone affected (small or large area)
- underlying cause of AVN (with ongoing causes such as corticosteroid or alcohol use, treatment may not work unless use of the substance is stopped)
Treatment Goals
The goal in treating AVN is to:- improve the patient's use of the affected joint
- stop further damage to the bone
- ensure bone and joint survival
Resources
Pocket Medicine: The Massachusetts General Hospital Handbook of Internal Medicine (Pocket Notebook Series)Kaplan NCLEX-RN Exam 2010 with CD-ROM: Strategies for the Registered Nursing Licensing Exam
Kaplan Medical USMLE Master the Boards Step 3 (Kaplan USMLE)
First Aid for the USMLE Step 2 CK, Seventh Edition (First Aid USMLE)
Nursing Care Plans: Nursing Diagnosis and Intervention
Harrison's Principles of Internal Medicine, 17th Edition
CURRENT Medical Diagnosis and Treatment 2009 (LANGE CURRENT Series)
