Overview
Idiopathic avascular necrosis (also called idiopathic osteonecrosis or idiopathic aseptic necrosis of bone) is a condition where bone tissue dies because it does not receive enough blood supply, and no clear underlying cause can be identified. The word "idiopathic" means the cause is unknown. This sets it apart from avascular necrosis caused by known factors like steroid use, alcohol abuse, or trauma. The condition most commonly affects the hip (femoral head), but it can also occur in the knee, shoulder, ankle, or other joints. When blood flow to a section of bone is disrupted, the bone cells begin to die. Over time, the affected bone can weaken and eventually collapse, leading to joint damage and painful arthritis. Symptoms typically begin with a dull ache or pain in the affected joint that worsens with activity and may progress to pain at rest. As the disease advances, range of motion decreases and walking or daily activities become increasingly difficult. Treatment depends on the stage of the disease at diagnosis. Early-stage disease may be managed with medications, physical therapy, and procedures to reduce pressure inside the bone (core decompression). More advanced cases often require surgical intervention, including bone grafting or joint replacement surgery. Research into newer treatments such as stem cell therapy and bone-stimulating drugs is ongoing, but there is currently no cure that fully restores the damaged bone to its original state.
Also known as:
Key symptoms:
Deep, aching joint pain, especially in the hip or groin areaPain that worsens with weight-bearing activities like walking or standingPain at rest or during the night as the disease progressesStiffness in the affected jointReduced range of motion in the jointLimping or difficulty walkingPain that spreads to the buttock, thigh, or kneeDifficulty climbing stairsJoint swelling in some casesMuscle weakness around the affected jointCollapse of the joint surface in advanced stagesPainful clicking or locking of the joint
Sporadic
Usually appears on its own, not inherited from a parent
Adult
Begins in adulthood (age 18 or older)
FDA & Trial Timeline
5 eventsZhongShan LaiBo RuiChen BioMedicine Co.,Ltd. — PHASE2
Duke University — NA
Zimmer Biomet — NA
University Hospital of North Norway — NA
Data sourced from FDA regulatory filings and ClinicalTrials.gov. Updated periodically.
Treatments
No FDA-approved treatments are currently listed for Idiopathic avascular necrosis.
4 clinical trialsare actively recruiting — trials can provide access to cutting-edge therapies.
View clinical trials →Treatment Centers
8 centersBaylor College of Medicine Rare Disease Center ↗
Baylor College of Medicine
📍 Houston, TX
🏥 NORDStanford Medicine Rare Disease Center ↗
Stanford Medicine
📍 Stanford, CA
🔬 UDNNIH Clinical Center Undiagnosed Diseases Program ↗
National Institutes of Health
📍 Bethesda, MD
🔬 UDNUCLA UDN Clinical Site ↗
UCLA Health
📍 Los Angeles, CA
🔬 UDNBaylor College of Medicine UDN Clinical Site ↗
Baylor College of Medicine
📍 Houston, TX
🔬 UDNHarvard/MGH UDN Clinical Site ↗
Massachusetts General Hospital
📍 Boston, MA
🏥 NORDMayo Clinic Center for Individualized Medicine ↗
Mayo Clinic
📍 Rochester, MN
👤 Mayo Clinic Center for Individualized Medicine
🏥 NORDUCLA Rare Disease Day Program ↗
UCLA Health
📍 Los Angeles, CA
Travel Grants
No travel grants are currently matched to Idiopathic avascular necrosis.
Community
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Start the conversation →Latest news about Idiopathic avascular necrosis
Disease timeline:
New recruiting trial: A Study of MACI in Patients Aged 10 to 17 Years With Symptomatic Chondral or Osteochondral Defects of the Knee
A new clinical trial is recruiting patients for Idiopathic avascular necrosis
New recruiting trial: Psychological Response and Readiness Associated With OCD of the Knee
A new clinical trial is recruiting patients for Idiopathic avascular necrosis
New recruiting trial: Evaluation of Clinical and Radiological Outcomes in Patients Undergoing Fixation of Osteochondral Fragments With Reasorbable Screws in the Knee Joint
A new clinical trial is recruiting patients for Idiopathic avascular necrosis
New recruiting trial: Triphasic Osteochondral Scaffold for the Treatment of the OCD of the Knee: Observational Study
A new clinical trial is recruiting patients for Idiopathic avascular necrosis
New recruiting trial: Knee Registry (Knieregister)
A new clinical trial is recruiting patients for Idiopathic avascular necrosis
Caregiver Resources
NORD Caregiver Resources
Support, advocacy, and financial assistance for caregivers of rare disease patients.
Mental Health Support
Rare disease caregiving can be isolating. Connect with counseling and peer support.
Family & Caregiver Grants
Financial assistance programs specifically for caregivers of rare disease patients.
Social Security Disability
Learn how rare disease patients may qualify for SSDI/SSI benefits.
Questions for your doctor
Bring these to your next appointment
- Q1.What stage is my avascular necrosis, and what does that mean for my treatment options?,Is there a chance the disease could affect other joints in my body?,Would core decompression or another joint-preserving procedure be appropriate for me?,How long can I expect my natural joint to last before I might need a joint replacement?,Are there any clinical trials or newer treatments I should consider?,What activities should I avoid, and what exercises are safe for me?,Should I be screened for any underlying conditions that might be contributing to this?
Common questions about Idiopathic avascular necrosis
What is Idiopathic avascular necrosis?
Idiopathic avascular necrosis (also called idiopathic osteonecrosis or idiopathic aseptic necrosis of bone) is a condition where bone tissue dies because it does not receive enough blood supply, and no clear underlying cause can be identified. The word "idiopathic" means the cause is unknown. This sets it apart from avascular necrosis caused by known factors like steroid use, alcohol abuse, or trauma. The condition most commonly affects the hip (femoral head), but it can also occur in the knee, shoulder, ankle, or other joints. When blood flow to a section of bone is disrupted, the bone cells
How is Idiopathic avascular necrosis inherited?
Idiopathic avascular necrosis follows a sporadic inheritance pattern. Genetic counseling can help families understand recurrence risk and testing options.
At what age does Idiopathic avascular necrosis typically begin?
Typical onset of Idiopathic avascular necrosis is adult. Age of onset can vary across affected individuals.
Are there clinical trials for Idiopathic avascular necrosis?
Yes — 4 recruiting clinical trials are currently listed for Idiopathic avascular necrosis on UniteRare. See the clinical trials section on this page for phase, sponsor, and site details sourced from ClinicalTrials.gov.
Which specialists treat Idiopathic avascular necrosis?
25 specialists and care centers treating Idiopathic avascular necrosis are listed on UniteRare, sourced from ClinicalTrials.gov principal investigators, published research, and the NPPES NPI registry.