What Is Avascular Necrosis of the Hip?
Avascular necrosis is a condition in adults caused by microscopic blockages in the blood vessels supplying the hip bone, leading to impaired nutrition of the bone and subsequent insufficiency fractures. These fractures can deform the shape of the hip joint and cause loss of movement in the joint. Approximately 10% of patients with total hip replacement in adulthood have undergone the procedure due to avascular necrosis.
What Are the Risk Factors for Avascular Necrosis?
Although this disease primarily causes deformities in the bone, the underlying issue lies in the blood vessels. Any condition that can cause vascular obstruction is a risk factor for hip avascular necrosis. These include excessive fatty diets, smoking, bleeding-coagulation disorders, and diseases like sickle cell anemia. Some patients may also experience this due to treatments for other conditions. The most common of these include patients undergoing steroid (cortisone) treatment for rheumatic diseases, leukemia, or COVID-19. Cortisone plays a significant role in causing thrombosis, which can obstruct blood flow to the hip.
What Are the Symptoms of Avascular Necrosis of the Hip?
Patients with hip avascular necrosis typically present with gradually increasing pain in the hip and groin. As days pass, the pain intensifies, leading to difficulties in walking and limping. As the disease progresses, symptoms worsen, and hip mobility decreases. Although many patients may initially present with symptoms on one side, over 90% of cases affect both hips.
How Is It Diagnosed?
The diagnosis of hip avascular necrosis begins with a hip X-ray for patients suspected of having the disease. However, it can be very challenging to detect early-stage disease even with careful examination. Therefore, if the disease is suspected, an MRI of the hip is necessary for diagnosis. In some cases, additional tests such as tomography and scintigraphy may be required. Blood tests may also be requested to evaluate risk factors.
MRI has a very high accuracy for diagnosis, and treatment is initiated based on the stage of the disease after the MRI.
What Is the Treatment?
The treatment for the disease varies according to its stage. Generally, the disease is divided into four stages. The critical stages are Stage 1 and Stage 2a, which occur before collapse fractures develop in the hip. In this phase, it is essential to relieve the load on the hip quickly. This means that the patient should acquire crutches to reduce the stress on the hip bones and prevent collapse fractures.
For patients in these stages, interventions can be performed to prevent collapse fractures and restore blood flow to the bone. One basic intervention is a procedure called hip core decompression, which involves opening channels in the bone with special instruments. This can facilitate healing without collapse by reducing pressure inside the bone and aiding revascularization. Additionally, stem cell applications obtained from bone marrow or adipose tissue can enhance this healing. Patients may also receive hyperbaric oxygen therapy, which has proven efficacy.
As the disease progresses and collapse is observed, more significant interventions may be needed. Surgical techniques that involve placing vessels from the fibula (the bone on the outer side of the ankle) or directly into the hip bone without a vessel can be options for patients in early collapse stages. In very advanced cases, particularly when deformation of the hip joint is evident, total hip replacement may be necessary for many patients.
Alongside surgical treatments, medications that prevent bone destruction, cholesterol-lowering drugs for patients with disturbed fat profiles, and some anticoagulants may also be used to support increased blood flow and prevent collapse.
The Course of the Disease
Even if the disease is caught very early, it is difficult to predict its exact course. Although there is a calculation method based on MRI images, some patients respond well to treatments while others do not. Particularly, avascular necrosis related to steroid (cortisone) use tends to respond less to treatment.
In the natural course of the disease, it is essential to protect the hip joint from deterioration. After the initial MRI images, treatment begins, and monthly X-rays, as well as MRI when necessary, are performed to monitor the resolution of early bone edema and revascularization, which may take 3-6 months. In more advanced stages, the disease may take longer than a year to self-limit.
Results
Patients diagnosed with hip avascular necrosis in the early stages, who receive appropriate treatment methods without developing collapse fractures in the hip joint, can recover without any long-term sequelae. For patients with observed collapse fractures, the progression of the disease will depend on the degree of deformity that arises. If the deformity is limited and does not restrict hip movement or cause limping, patients can be monitored over a longer term. However, if the deformity progresses significantly and restricts movement in the hip joint, total hip replacement surgery may be required.
Q&A
I received cortisone treatment for my rheumatic disease. What should I do to avoid hip avascular necrosis?
It is not accurate to speak of a truly protective treatment. However, these patients are advised to be closely monitored and to take calcium and vitamin D supplements to support bone health.
I have avascular necrosis in both hips. How should I mobilize?
This situation is seen in approximately 90% of hip avascular necrosis cases. Patients are advised to use crutches to minimize the load on the hips and reduce daily activities to a minimum.
I have been diagnosed with hip avascular necrosis. Are there any nutritional supplements I can take to enhance recovery?
This topic is quite controversial. Calcium and vitamins C and D are generally recommended as they play a direct role in bone metabolism. However, one scientifically validated compound is resveratrol, found in red grape seeds. Although the exact dosage is unknown, consuming about one teaspoon of red grape seed extract daily may be advisable.
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