Overview
Avascular necrosis (osteonecrosis) is a condition where bone tissue loses its blood supply and begins to break down. It most commonly affects weight-bearing joints, especially the hip, because the bone there has to carry high forces. As the bone weakens, the joint surface can collapse, which can lead to worsening pain and stiffness. Early treatment is important because symptoms can progress even if the injury does not feel severe.
Symptoms
People with hip avascular necrosis often notice deep groin pain or pain on the side of the hip, which may gradually worsen over weeks to months. Pain is commonly triggered by walking, standing, climbing stairs, or getting in and out of a car, and it may eventually be present even at rest. As the condition progresses, range of motion can become limited and a limp may develop to protect the painful side. Some people also report stiffness after periods of inactivity.
Causes
Avascular necrosis happens when blood flow to part of the bone is disrupted, leading to bone cell death and structural weakness. In the hip, this can follow trauma, such as a fracture or dislocation, or it can occur without a clear injury. Steroid exposure and certain medical conditions can also reduce blood supply or increase pressure within blood vessels in the bone. Over time, the affected bone can fracture under normal body weight, contributing to joint surface collapse.
Risk Factors
Risk is higher after major hip injury, including fractures and dislocations, and in people with conditions such as sickle cell disease. Long-term or high-dose corticosteroid use, whether by mouth, injection, or other routes, is a well-known risk factor, as is heavy alcohol use. Some blood-clotting disorders, chemotherapy exposure, and metabolic problems such as high lipid levels can also increase risk. Age and overall bone health matter, and early symptoms should not be ignored in anyone with these risk factors.
Prevention
You can reduce risk by limiting or avoiding heavy alcohol use and by using the lowest effective dose and shortest necessary course of corticosteroids when prescribed. After hip injury, follow a clinician's plan for protected weight-bearing and rehabilitation to reduce additional stress on the bone. Managing underlying conditions, such as sickle cell disease, lipid disorders, or clotting problems, can lower the chance of recurrence or progression. Maintaining healthy weight and avoiding repetitive high-impact loading during flare-ups or early symptoms can also help protect the joint.
How the Diagnosis Is Evaluated
Clinicians start with a focused history about hip pain timing, prior trauma, medication exposure (especially steroids), alcohol use, and medical conditions that affect blood supply. A physical exam checks hip range of motion, gait, and pain patterns, which can help narrow the cause. Imaging typically begins with X-rays, but early disease may be normal or subtle. MRI is often the most sensitive test for detecting avascular necrosis and staging its severity, and additional lab tests may be ordered when an underlying cause is suspected.
Nonsurgical Treatment Options
Treatment focuses on reducing pain, limiting stress on the affected bone, and improving function while monitoring progression. Activity modification is commonly recommended, sometimes including reduced or protected weight-bearing with a cane or crutches to decrease load on the hip. Physical therapy can improve strength and mobility of the hip and pelvis and may reduce compensatory strain. Medications such as acetaminophen and nonsteroidal anti-inflammatory drugs (NSAIDs) can help manage symptoms, though they do not restore blood supply. Some patients are treated with targeted options such as bisphosphonates in selected situations, while injection therapies like corticosteroid injections may be considered carefully for short-term pain control when benefits outweigh risks; for those with secondary arthritis, hyaluronic acid injections may provide symptom relief. Regenerative or biologic injections (such as platelet rich plasma or stem cell-based approaches) are sometimes discussed in specialized settings, but results vary and are not a guaranteed solution.
When to Seek Medical Attention
Seek prompt medical evaluation if you have persistent or worsening hip or groin pain, especially if it limits walking or is present even at rest. Get urgent care if you cannot bear weight after a hip injury, have fever or feel severely ill, or if pain rapidly intensifies with significant swelling or redness. Contact a clinician urgently for sudden loss of function or severe weakness, particularly if there are new neurologic symptoms. Because avascular necrosis can progress, early assessment is important when imaging or risk factors suggest the diagnosis.
Frequently Asked Questions
Avascular necrosis sometimes stabilizes, but it often progresses without treatment, so early evaluation and management are important.
Yes, corticosteroids are a major risk factor, particularly with higher doses or longer use, and steroid exposure should be discussed with your clinician.
Next Steps
If you have persistent hip or groin pain, especially with risk factors such as prior hip trauma, steroid use, or heavy alcohol use, schedule an evaluation with an orthopedic clinician. Ask whether MRI is appropriate to look for early avascular necrosis and discuss a plan to reduce stress on the hip and manage symptoms while your diagnosis is clarified.