Osteonecrosis of the femoral head, also called femoral necrosis, represents a serious disease of the hip bone. Severe impaired blood flow causes the bone tissue to die. Consequences for the avascular, i.e. no longer supplied with blood, and necrotic femoral head in the further course of development are possible collapses, hip arthrosis up to stiffening of the hip joint and, in the worst case, disability.
What is femoral head necrosis?
Osteonecrosis of the femoral head generally belongs to osteonecrosis, which is a death of bone substance as a result of circulatory problems. Among the most common osteonecroses is femoral head necrosis or femoral head necrosis, in which there is death of bone cells in the hip joint. The painful disease often occurs in middle-aged adults and, even in its early stages, is often accompanied by stabbing pain of the affected hip joint area and limited mobility. As femoral head necrosis progresses, the disease leads to collapse of the femoral head or joint surfaces. This results in arthrosis, i.e. premature wear of the hip joint. Characteristic and causative for femoral head necrosis, which is one of the aseptic bone necroses, is a circulatory disorder, which then results in necrosis of the bone tissue. A distinction must be made in femoral head necrosis between the post-traumatic form, e.g. after an injury such as a femoral neck fracture, and spontaneous femoral head necrosis. In post-traumatic femoral head necrosis, an acute circulatory disturbance occurs abruptly due to the injury, whereas spontaneous femoral head necrosis is characterized by chronic, recurrent circulatory disturbances. There are also very rare cases of femoral head necrosis in childhood, known as Perthes disease.
Causes
The causes of femoral head necrosis can be varied. In post-traumatic, or accident-related, femoral head necrosis, the cause of the circulatory disturbance is clearly trauma. Here, the vessels are damaged as a result of an accident or the acute injury, which leads to a severe circulatory disturbance in the area of the hip. This includes, for example, a fracture of the femur, a fracture of the neck of the femur, a severe injury in the joint or in the course of a hip dislocation. In spontaneous femoral head necrosis, on the other hand, there are a great many possible causes. One of the most common risks and possible causative factors is dyslipidemia, which is identifiable or suspected in about half of femoral head necrosis cases. However, the causal relationship has not been clearly proven, as with other influencing factors observed in association with femoral head necrosis: These include the use of corticoids (e.g., medications in the form of cortisone or also as steroid doping), excessive alcohol consumption, nicotine consumption, coagulation disorders, and also diving accidents that lead to decompression sickness. In many cases of femoral head necrosis, however, the exact cause remains unknown.
Typical symptoms and signs
- Hip pain
- Movement restrictions
- Hip joint arthrosis
Diagnosis and course
Patients usually seek medical attention for femoral head necrosis relatively late in the course of the disease due to pain in the hip joint. This symptomatology is usually load-dependent at this stage, and as the disease progresses, leg length discrepancy may even be detected as a result of femoral head necrosis. Diagnostic methods include magnetic resonance imaging, which is particularly useful in the early stages of the disease and can reveal (intraosseous) edema in the bone. In the further, advanced course of the disease, an X-ray image shows the progressive deformation and “de-rounding” of the femoral head. The progression of femoral head necrosis occurs in several stages, with no pain initially, later increasing after weight bearing and often in a sudden onset and stabbing form. The more the necrosis of the femoral head progresses, the more immobile and stiff the hip joint becomes and it already hurts at rest. In the later course of necrosis of the femoral head, the hip joint can collapse and lose its original shape, which can subsequently lead to severe joint damage and hip joint wear. A considerable restriction of the quality of life and mobility are the result, which can lead to invalidity.Another diagnostic possibility to recognize the stage of a femoral head necrosis in a more differentiated way is also the hip arthroscopy, which is a surgical reflection of the hip joint and helps to better assess its cartilage conditions and the condition of the bone, among other things.
Complications
As a rule, femoral head necrosis results in the death of bone tissue and thus in severe circulatory disturbance. Furthermore, the patient experiences severe pain and restricted movement, which not infrequently also causes psychological discomfort and depression. The hip is relatively painful and can also be affected by pain at rest. Pain at rest can also lead to insomnia and thus extremely reduce the patient’s quality of life. Furthermore, without treatment, a leg length discrepancy can also develop, which leads to considerable limitations in the patient’s walking and standing. The bone tissue continues to regress and so-called joint wear and tear can occur. In the worst case, the affected person is then dependent on a walking aid or a wheelchair when he or she can no longer get around by himself or herself. Osteonecrosis of the femoral head can be treated relatively well, with no further complications. Medications, therapies and surgical procedures are used. The course of the disease is always positive and the affected person can usually resume his usual activities after treatment. Life expectancy is usually not affected by femoral head necrosis.
When should you see a doctor?
Even if hip pain occurs with exertion, a visit to the doctor is indicated. At the beginning of the disease, a femoral head necrosis manifests itself by nonspecific symptoms that need to be clarified, for example, movement restrictions and a feeling of pressure in the area of the hip. If these symptoms are noticed, the family doctor or an orthopedist should be consulted. Medical advice is needed at the latest if the hip pain also occurs during a period of rest. Increasing movement restrictions are another warning sign that requires immediate clarification by a medical professional. If complications arise, such as severe pain at rest or stiffening of the hip, the affected person must be taken to the nearest hospital. If further problems develop or the affected person suffers a fall, it is best to call the emergency physician. In the case of psychological complaints, the doctor can establish contact with a therapist. This is necessary especially in the case of protracted illnesses that have been bothering the patient for quite some time. People who notice the signs of femoral head necrosis after the fracture of the femur, a joint injury or a hip dislocation should talk to the medical doctor in charge. Alcohol use, clotting disorders, and taking certain medications are also risk factors that need to be clarified.
Treatment and therapy
The treating physician has a variety of possible therapies to choose from. Above all, the respective stage of the disease is decisive, because the further course of a femoral head necrosis can be estimated, among other things, from the shape of the femoral head, the extent of the femoral head necrosis (i.e., the dead area) as well as from the specific head changes and whether and to what extent the acetabulum is already involved. As therapy, strict relief of the hip joint by means of externally applied aids (orthoses) can be considered, as well as adapted movement therapy. As far as drug treatment is concerned, iloprost can be administered as the drug of choice to improve blood circulation; in addition, bone-building preparations (such as bisphosphonates) are also administered. At an early stage of the disease, so-called hyperbaric oxygen therapy and shock wave therapy are sometimes helpful and successful. Also the drilling of the femoral head in an initial stage of the femoral head necrosis can be considered as a therapeutic option: Here, there is the possibility of performing so-called medullary decompression as a measure to increase blood flow. Tapping the diseased femoral head bone supports the formation and ingrowth of new blood vessels to heal or at least significantly improve femoral head necrosis. If the cartilage is stable, it can also be filled with bone substitute, which is known as retrograde cancellous bone grafting.In advanced stages and in the case of a collapsed femoral head and cartilage damage, only total hip arthroplasty can help as a joint replacement. However, especially in young patients, prostheses specially adapted to the extent of necrosis are increasingly being used instead of standard prostheses. For example, there is a button-shaped prosthesis that functions as a femoral head surface replacement. These surface replacement prostheses can be used in the most “bone-saving” way possible, which is especially beneficial for younger patients. The same applies to femoral head necrosis: the earlier a clear diagnosis is made, the more favorably the course can be influenced therapeutically.
Prevention
As a preventive measure, according to current knowledge, a generally active as well as conscious and healthy lifestyle can be recommended. The permanent reduction of overweight is certainly one of the best measures to prevent femoral head necrosis. However, the most sparing consumption of stimulants such as alcohol and cigarettes is also advisable, as they are also risk factors for this disease. Excessive use of cortisone and steroids should also be avoided in connection with osteonecrosis of the femoral head, as these are considered to be extremely “favorable” for the development of osteonecrosis in general and osteonecrosis of the femoral head in particular. In addition, the slightest pain in the hip area should be followed by a medical and differential diagnostic clarification, in order to detect a possibly existing femoral head necrosis at the earliest possible stage and to be able to treat it optimally.
Follow-up care
In most cases, aftercare measures for femoral head necrosis are severely limited or not available to the affected person at all. Therefore, a diagnosis should be made very early in this disease to prevent further worsening of symptoms. As a rule, self-healing cannot occur in the case of femoral head necrosis, so that the affected person should ideally consult a doctor as soon as the first complaints and symptoms appear. Most sufferers of this condition rely on physical therapy and physiotherapy to provide lasting relief from the symptoms. Many of the exercises from these therapies can also be performed in the patient’s own home, so that the treatment is accelerated. Furthermore, the support and care of one’s own family and friends has a positive effect on the further course of the disease. This can also prevent depressive moods or other psychological complaints. The further course of femoral head necrosis depends very much on the time of diagnosis, so that a general prediction is not possible. However, the disease does not usually reduce the life expectancy of the affected person.
Here’s what you can do yourself
Patients with osteonecrosis of the femoral head suffer in particular from pain and limited mobility that interfere with everyday life. The pain emanating from the affected hip joint occurs both during movement and during periods of inactivity as pain at rest. For many patients, pain relief is an important aspect of improving their quality of life. Each patient must find the right way to deal with the pain and suitable measures to alleviate it. In general, it is important to determine the right measure and balance between stressful and relieving activities. Overexertion of the diseased hip should be avoided in any case, but it is not advisable to reduce physical activity to a minimum. Physical activities should be coordinated with the treating physician and physical therapist and help maintain a certain level of fitness and mobility. Frequently, patients with femoral head necrosis undergo various medical procedures with the goal of slowing disease progression or relieving pain. Before and after these interventions, patients must strictly follow the doctors’ instructions and, for example, change their diet or adhere to scheduled rest periods. Independent performance of physiotherapy prescribed by a doctor at home supports the well-being of sufferers.