Osteonecrosis is a condition in which part of a bone dies because its blood supply is reduced or cut off. The early symptoms of osteonecrosis may be mild, but many people develop joint pain, stiffness, and trouble walking as the damage grows. It most often affects the hip, but it can also involve the knee, shoulder, or other joints, and it can happen in adults of many ages. Not everyone will have the same experience. Treatment depends on how far osteonecrosis has progressed and may include pain relief, limiting weight on the joint, physical therapy, procedures to improve blood flow, or joint replacement, and severe cases can lead to major disability or complications from surgery.
How many people live with Osteonecrosis?
There is no single, widely accepted count of how many people are living with osteonecrosis worldwide, and the same is true in the United States. In the U.S., the figures most often reported are about 10,000 to 20,000 new cases each year, rather than a total number of all people living with the condition (MedlinePlus Genetics, 2024; StatPearls, 2024).
Overview
OsteonecrosisSymptoms
Osteonecrosis often starts with joint pain that may come and go, then become more constant. Many with osteonecrosis notice stiffness, reduced range of motion, and pain with walking or putting weight on the joint.
Outlook and prognosis
Osteonecrosis can stay stable if found early, but untreated bone damage may lead to joint collapse and arthritis. Many living with osteonecrosis do well with timely treatment, pain relief, and protecting the joint. Recovery often depends on the joint affected and how much bone is already damaged.
Causes and risk factors
Osteonecrosis happens when blood flow to bone is reduced. Risk rises with steroids, heavy alcohol use, joint injury, sickle cell disease, lupus, clotting disorders, and some cancer treatments. Smoking, diving-related decompression sickness, and organ transplant also increase risk.
Genetic influences
Genetics can matter in osteonecrosis, but they are usually only part of the picture. Some genetic variations may raise risk by affecting blood clotting, bone repair, or how the body handles certain medicines.
Diagnosis
Osteonecrosis is diagnosed with an exam and imaging, especially MRI. X-rays may look normal early on. The diagnosis of osteonecrosis is based on symptoms, risk factors, and imaging findings.
Treatment and drugs
Treatment for osteonecrosis aims to ease pain and protect the joint. Many people start with pain relief, limited weight-bearing, physical therapy, and treating causes like steroid use or heavy alcohol intake. If damage worsens, surgery may help restore bone or replace the joint.
Symptoms
Osteonecrosis often starts quietly, with discomfort in a hip, knee, shoulder, or another joint during ordinary movement. The early symptoms of osteonecrosis can be easy to brush off because the joint may feel normal at rest, and some people have no symptoms at first. Over time, many people notice pain more often, along with stiffness and trouble using the joint.
Early on, this might look like a dull ache that comes and goes, especially after walking, climbing stairs, or standing for a while. Some people with osteonecrosis notice only mild discomfort at first, while others have no symptoms until more damage has developed.
Pain often gets worse when the affected joint is working hard, such as during a long walk, exercise, or lifting the arm overhead. For many, this can mean cutting back on sports, chores, or even errands because the joint starts to hurt sooner.
As osteonecrosis progresses, pain can start to show up even during rest or sleep. A joint that only hurt with movement may begin to throb while sitting on the couch or wake you at night.
The joint may feel stiff, tight, or less willing to move through its full range. Bending the hip, straightening the knee, or reaching behind the back can become harder over time.
How people usually first notice Osteonecrosis?
Many people first notice osteonecrosis as a deep, nagging pain in a joint, most often the hip, knee, or shoulder, that shows up with standing, walking, or climbing stairs and then slowly becomes more frequent. Early on, the first warning signs of osteonecrosis can be easy to dismiss because the joint may still look normal from the outside, but over time many living with it start to notice stiffness, a limp, or pain even at rest. In some cases there are no clear symptoms at first, and the condition is only found after imaging is done for ongoing joint pain or reduced movement.
Types of Osteonecrosis
Osteonecrosis can affect daily life in different ways, depending on which bone has lost blood supply and how much damage has developed. The types of osteonecrosis are often described by the part of the body involved, because that strongly shapes the symptoms people notice. Symptoms don’t always look the same for everyone. Early on, some people have no symptoms, while others notice pain only with walking, climbing stairs, or putting weight on a joint.
Hip osteonecrosis
This is the most common type and often causes groin, buttock, or upper thigh pain that starts with walking or standing. As it progresses, the hip may feel stiff, and pain can happen even at rest. Many living with hip osteonecrosis may also develop a limp.
Knee osteonecrosis
Pain is usually felt on the inner side of the knee and may seem to come on suddenly or gradually. Some may find the knee swells, feels tender, or becomes harder to fully bend or straighten. Weight-bearing often makes symptoms worse.
Shoulder osteonecrosis
This type often causes a deep, aching shoulder pain, especially when lifting the arm or reaching overhead. Over time, stiffness and reduced range of motion can make dressing, washing hair, or carrying items more difficult. Some people have both shoulders affected.
Jaw osteonecrosis
Jaw osteonecrosis differs from joint forms because it may cause exposed bone in the mouth, gum swelling, bad breath, or pain when chewing. In some cases, the mouth feels numb or a tooth becomes loose. It may be more noticeable after dental work, though some people have very mild symptoms at first.
Can I slow down the onset of symptoms?
Not reliably: there is no proven lifestyle change or medical treatment that clearly delays the start of symptoms from osteonecrosis once the problem has begun. Research suggests that lowering well-known risks such as smoking, heavy alcohol use, and long-term steroid medicine use when your doctor says it is safe to do so, along with getting prompt care after a joint injury, may reduce risk or slow worsening for some people, but this is not the same as preventing the condition. If you are at higher risk, early medical follow-up for new joint pain can help find it sooner and give you more treatment options, so these steps are still worth taking even though they cannot promise a delay.
What genetics can tell you about symptoms
Genetics can sometimes help explain why osteonecrosis starts earlier in some people, affects more than one bone, or happens with fewer of the usual triggers, but genes are not the whole story. Changes in genes linked to blood clotting, blood flow, bone repair, or how the body handles steroids may slightly raise risk and may influence how severe the condition becomes, although these links are not strong enough to predict symptoms for most people. For many living with osteonecrosis, day-to-day symptoms such as joint pain, stiffness, limping, or reduced movement are shaped more by which bone is affected and how much damage has occurred than by genetics alone.
Causes and risk factors
Osteonecrosis happens when blood flow to part of a bone drops, often after a broken bone or a joint dislocation. Common risk factors for osteonecrosis include long-term steroid medicines, heavy alcohol use, smoking, and some cancer treatments such as radiation. Certain health problems can also raise the risk, including sickle cell disease, lupus, and conditions that make blood clot too easily. Inherited traits can play a part too, especially when they affect blood flow, clotting, or how the body handles fats. It’s rarely just one factor, and several risks together can make osteonecrosis more likely.
What are the most common causes or risk factors?
Osteonecrosis usually happens when blood flow to part of a bone is reduced or blocked. The most common risks are a major injury to the bone or nearby joint, long-term or high-dose steroid medicine use, and heavy alcohol use; smoking can add to the risk too. Some health conditions also raise the chance, especially sickle cell disease, lupus, and inherited problems that make the blood clot too easily or affect blood flow.
Environmental and biological risk factors
Osteonecrosis develops when blood flow to part of a bone drops enough for the bone tissue to become damaged. Doctors often group risks into internal (biological) and external (environmental). When people ask what causes osteonecrosis, the main risks are injuries, certain medical treatments, and health conditions that interfere with circulation. Often, more than one risk factor is present at the same time.
A fracture or dislocation can tear or squeeze the small blood vessels that feed a bone. This is one of the clearest risk factors for osteonecrosis, especially around the hip, knee, shoulder, and ankle.
High-dose or long-term corticosteroid treatment can raise pressure inside the bone marrow and reduce blood flow. Risk usually increases with larger total exposure, although not everyone who takes steroids develops osteonecrosis.
Radiation aimed near a bone can damage tiny blood vessels and bone-forming cells. That can leave the area less able to repair itself and more prone to osteonecrosis over time.
Rapid changes in pressure, such as with decompression sickness in divers or compressed-air workers, can form bubbles that block small blood vessels. When this happens repeatedly or severely, bone tissue may not get enough oxygen.
Genetic risk factors
In most people, osteonecrosis is not inherited in a simple way, but certain genetic conditions can make it more likely by reducing blood flow to bone or affecting how bone and marrow stay healthy. The strongest inherited links are sickle cell disease, Gaucher disease, rare family patterns tied to COL2A1, and some inherited clotting conditions that can block tiny blood vessels. Carrying a genetic change doesn’t guarantee the condition will appear. These risks vary from person to person, and some cases of osteonecrosis have no clear inherited cause.
Sickle cell disease: This inherited blood disorder can make red blood cells change shape and clog small blood vessels. When that happens in bone, the blood supply may drop enough to trigger osteonecrosis. It is one of the clearest genetic risk factors for osteonecrosis.
Gaucher disease: This inherited condition causes certain fatty substances to build up in the body, including the bone marrow. Over time, that can weaken bone health and raise the chance of osteonecrosis.
Clotting gene changes: Some people inherit a tendency for blood to clot too easily, which can lead to tiny clots in vessels that feed the bone. Examples include Factor V Leiden and a change in the prothrombin gene. These changes raise risk, but they do not mean osteonecrosis will definitely happen.
COL2A1 changes: Rare inherited changes in COL2A1 have been linked to family cases of osteonecrosis, especially in the hip. This gene helps support cartilage and joint structure, so changes in it may make the bone more vulnerable over time.
Lifestyle risk factors
Some everyday habits can raise the chance of osteonecrosis or make it worse by reducing blood flow to bone, increasing bone stress, or adding to other medical risks. The most important lifestyle risk factors for osteonecrosis include heavy alcohol use, smoking, patterns of activity that overload affected joints, and poor follow-through with treatment plans after early symptoms appear. Diet has no direct proven role in causing osteonecrosis, but eating patterns that promote unhealthy cholesterol levels or weight gain can add strain to vulnerable joints and may worsen overall bone and vascular health.
Long-term heavy drinking is one of the clearest lifestyle risk factors for osteonecrosis. It can disrupt fat metabolism and blood supply, which may contribute to bone tissue death. It also increases fall and injury risk, which can further damage already weakened joints.
Smoking damages blood vessels and reduces oxygen delivery to bone tissue. This may worsen the reduced blood flow that drives osteonecrosis and can slow healing after surgery or other treatment.
Repetitive high-impact activity or continued weight-bearing on a painful joint can increase collapse risk in weakened bone. Once osteonecrosis has started, ignoring pain and pushing through strenuous activity may speed joint damage. Low-impact movement is often better tolerated than pounding or twisting exercise.
Carrying excess weight increases mechanical stress on weight-bearing joints such as the hip and knee. In someone with osteonecrosis, that added load can worsen pain, limit mobility, and contribute to faster joint deterioration.
Risk prevention
Osteonecrosis cannot always be fully prevented, but many people can lower their risk by managing the things that reduce blood flow to bone or damage the bone over time. This matters in daily life because a preventable trigger, such as heavy alcohol use, long-term high-dose steroid treatment, or an untreated hip injury, can quietly raise the chance of later pain and joint problems. Prevention is about lowering risk, not eliminating it completely.
Corticosteroid medicines can raise the risk of osteonecrosis, especially at high doses or when used for a long time. If you need them, use the lowest effective dose for the shortest time your doctor recommends, and do not stop them suddenly without medical advice.
Heavy drinking is a well-known risk factor for osteonecrosis because it can affect bone health and blood supply. Cutting back or avoiding alcohol may lower risk, especially if you also have other risk factors.
Smoking can damage blood vessels and make it harder for bone tissue to get enough oxygen and nutrients. Quitting smoking may help protect bone health and lower the risk of osteonecrosis.
A serious fracture or dislocation, especially of the hip, can interrupt blood flow and lead to osteonecrosis later on. Using seat belts, preventing falls, and getting prompt care after an injury may reduce this risk.
Can you prevent Osteonecrosis?
You cannot always prevent osteonecrosis, because it can happen after a serious bone or joint injury or for reasons that are hard to control. But risk may be lowered by not smoking, avoiding heavy alcohol use, and using steroid medicines only when truly needed and exactly as prescribed. Even with these steps, prevention is not always possible.
Transmission
Osteonecrosis is not infectious, so it cannot be transferred from one person to another. If you are wondering whether osteonecrosis is contagious, the answer is no: it does not spread through touch, coughing, kissing, sex, shared food, or other everyday contact.
Instead, osteonecrosis happens when blood flow to part of a bone is reduced or blocked, often because of an injury, long-term steroid use, heavy alcohol use, or certain medical conditions. Some of those underlying risk factors can run in families, but osteonecrosis itself is usually not directly inherited.
When to test your genes
For most people with osteonecrosis, routine genetic testing is not recommended because it usually relates to factors like steroid use, alcohol exposure, trauma, or certain medical conditions rather than a single gene change. Testing may be worth discussing if osteonecrosis appears unusually early, affects several family members, or keeps recurring without a clear cause.
Diagnosis
Osteonecrosis is often suspected when ongoing joint pain starts to affect everyday life, such as walking, climbing stairs, or putting weight on a hip or knee. Doctors usually begin with your symptoms, where the pain is located, and whether it has been getting worse over time. The diagnosis of osteonecrosis often involves imaging tests, because early changes may not show up on a regular exam alone.
Your doctor asks about pain, stiffness, limping, and trouble with daily movement, along with when symptoms began. They also look for risk factors such as steroid use, heavy alcohol use, injury, sickle cell disease, or past radiation treatment.
The joint is checked for tenderness, reduced range of motion, and pain with movement or weight-bearing. This can help show which joint is affected, although the exam by itself cannot confirm osteonecrosis.
Standard X-rays are often one of the first tests ordered for joint pain. They may look normal early on, but later they can show bone collapse, shape changes, or arthritis linked to osteonecrosis.
MRI is the most sensitive imaging test for finding osteonecrosis, especially in its early stages. It can show reduced blood supply and bone damage before those changes appear on X-rays.
How is Osteonecrosis diagnosed?
Osteonecrosis is usually diagnosed based on your symptoms, your medical history, and an exam, especially if you have ongoing joint pain, stiffness, or trouble putting weight on a hip, knee, or another joint. Doctors often start with an X-ray, but early on it can look normal, so an MRI is often the best scan to find the problem sooner; sometimes a CT scan or bone scan is used if the diagnosis is still unclear. There is no routine genetic test for osteonecrosis, and blood tests may help look for related causes but do not confirm the diagnosis on their own.
Stages of Osteonecrosis
Osteonecrosis often develops over time, but the pace can vary a lot from one person to another and from one joint to another. In everyday life, it may start as pain with walking, climbing stairs, or standing for a while, then become more constant as the bone weakens. Early and accurate diagnosis helps you plan ahead with confidence. Doctors usually describe osteonecrosis in stages based on imaging tests such as X-rays and MRI, along with symptoms and joint function.
Stage 0
There are no clear symptoms, and standard imaging may still look normal. Osteonecrosis is sometimes only suspected because of risk factors or found by more sensitive scans such as MRI.
Stage 1
Pain may begin, especially with weight-bearing or activity, but X-rays are often still normal. This is when the early symptoms of osteonecrosis can be easy to miss or confuse with a strain or arthritis. MRI usually shows the problem more clearly at this stage.
Stage 2
The damaged area becomes easier to see on imaging, and pain often happens more regularly. The bone is still keeping its shape, but changes inside the bone can now be detected on X-ray, CT, or MRI.
Stage 3
A small collapse can develop in the bone just under the joint surface. Many people with osteonecrosis notice stronger pain, more stiffness, and trouble with everyday movement, such as getting out of a chair or walking longer distances.
Stage 4
The joint surface is damaged, and arthritis often develops in the affected joint. Pain may be present even at rest, and range of motion can be clearly reduced.
Outlook and prognosis
The outlook for osteonecrosis depends mainly on the stage at diagnosis, the size and location of the affected bone, and whether the underlying cause can be controlled. Small early lesions may remain stable or improve with reduced weight bearing, treatment of risk factors, and sometimes joint-preserving procedures, but many cases progress to collapse of the bone and secondary arthritis if blood supply is not restored. Prognosis is generally better when the condition is found before structural collapse, especially in younger people and in those without ongoing steroid use, heavy alcohol exposure, or other persistent risks. Once the joint surface has collapsed, pain and disability often worsen and joint replacement may be needed, although surgery can still provide good long-term function for many patients. Osteonecrosis is usually not directly fatal, but mortality can be higher in people whose disease is linked to serious underlying conditions such as sickle cell disease, lupus, cancer treatment, or major trauma. Early diagnosis and close follow-up are important because they offer the best chance of slowing progression and preserving the joint.
Long-term effects
Osteonecrosis can have lasting effects because reduced blood flow weakens bone over time and may damage a nearby joint. Many living with osteonecrosis find that pain, stiffness, and limits in walking or daily movement can become more noticeable as the condition advances. It’s important to remember that long-term doesn’t always mean progressive, but the outlook is usually better when osteonecrosis is found and treated before the bone collapses. The long-term picture is often different depending on which bone is affected, how large the damaged area is, and whether one or several joints are involved.
Ongoing joint pain is one of the most common long-term effects of osteonecrosis, especially with standing, walking, or climbing stairs. For many, symptoms start with activity and later can happen even at rest.
As the damaged area heals poorly or worsens, the joint may lose smooth movement and become stiff. Everyday tasks like putting on shoes, getting out of a car, or reaching overhead can take more effort depending on the joint involved.
In more advanced osteonecrosis, the weakened part of the bone can flatten or collapse under normal pressure. This is more likely if the condition is not recognized after the early symptoms of osteonecrosis begin.
When bone shape changes, the joint surface may become uneven and wear down faster, leading to osteoarthritis. This can add swelling, grinding, and a steady loss of function over time.
How is it to live with Osteonecrosis?
Living with osteonecrosis can feel like a joint that no longer fully trusts you: pain may build with walking, climbing stairs, or even standing for long periods, and over time stiffness and reduced movement can make work, exercise, and everyday routines much harder. For many people with osteonecrosis, this can mean planning the day around pain, using a cane or crutches, cutting back on sports or physically demanding tasks, and sometimes facing surgery if the bone and joint become badly damaged. It often affects more than the person living with it, too, because family, friends, and coworkers may need to help with transportation, childcare, household tasks, or emotional support as symptoms change.
Treatment and drugs
Osteonecrosis is treated by trying to relieve pain, protect the joint, and slow or prevent further bone damage, with the goal of keeping you moving and delaying joint collapse if possible. Early treatment may include limiting weight on the joint, physical therapy, and pain-relieving or anti-inflammatory medicines, while doctors also look for and treat the cause, such as steroid use, heavy alcohol use, or an underlying medical condition. Treatment plans often combine several approaches. If osteonecrosis is found early, some people may benefit from procedures that reduce pressure inside the bone and improve blood flow, but when damage is more advanced, surgery such as reshaping the bone, bone grafting, or joint replacement may be the best option. Finding the right therapy can take some time, because the best plan depends on which joint is affected, how much bone damage is present, and how much osteonecrosis is affecting daily life.
Can you cure Osteonecrosis?
There is no simple cure for osteonecrosis, and bone that has already died from poor blood flow usually cannot be restored to normal. Treatment can help ease pain, slow or sometimes stop further damage, and protect the joint, especially if it is found early. Many people with osteonecrosis are treated with activity changes, pain relief, physical therapy, and sometimes surgery, including joint replacement if the joint is badly damaged.
Non-drug treatment
Daily life with osteonecrosis can mean deep joint pain, stiffness, and trouble with basic movements like walking, climbing stairs, or getting up from a chair. Non-drug treatment aims to reduce stress on the affected bone, protect the joint, and help you stay as active and independent as possible. For many, treatment begins not at the pharmacy, but with movement changes, physical therapy, and devices that make daily tasks less painful. The best plan depends on which joint is affected, how much bone damage is already present, and whether you are in the early stages of osteonecrosis.
Resting the joint and avoiding high-impact activity can help limit further damage. Many living with osteonecrosis may need to pause running, jumping, or heavy lifting for a time.
If the hip, knee, or ankle is involved, your care team may advise putting less weight on that leg. This can mean using a cane, crutches, or a walker while the bone tries to heal and the joint is protected.
Physical therapy can help maintain joint movement, improve muscle strength, and reduce stiffness. Supportive therapies can also teach safer ways to walk, stand, and move so daily tasks put less strain on the joint.
Low-impact exercise such as swimming, water therapy, or cycling may help keep you active without as much joint stress. Not every approach works the same way, so the right plan should match your pain level and the joint involved.
Your genes may have an impact on how drugs work for you
For people with osteonecrosis, there is not yet a well-established, routine gene test that helps doctors choose the main medicines used for this condition. In real life, how well treatments work usually depends more on things like the cause of the bone damage, how far it has progressed, and a person’s overall health, so one person may get good pain relief while another still struggles with walking or daily activity. Even so, medicine response can vary from person to person, so doctors often adjust treatment based on symptom relief, side effects, and regular follow-up rather than on inherited genetic differences.
Pharmacological treatments
Medicines for osteonecrosis are mainly used to ease pain and, in some people, to slow further bone damage in the early stages. No drug can reliably bring dead bone back to life, so treatment often works best when medication is combined with limiting weight on the joint, physical therapy, or surgery when needed. Not everyone responds to the same medication in the same way. In practice, early-stage osteonecrosis treatment is often different from treatment used after the joint has started to collapse.
Acetaminophen and nonsteroidal anti-inflammatory drugs such as ibuprofen or naproxen are often used to reduce pain and swelling from osteonecrosis. These medicines can make walking, climbing stairs, or sleeping more manageable, but they do not repair the damaged bone.
Drugs such as alendronate are sometimes used in early osteonecrosis to try to slow bone breakdown and delay collapse of the joint surface. Evidence is mixed, so they are not right for everyone, and a specialist may weigh possible benefits against side effects.
Anticoagulants such as enoxaparin or warfarin may be used when osteonecrosis is linked to blood-clotting problems or poor blood flow. These drugs do not directly heal the bone, but in selected people they may help prevent further loss of circulation.
Statins such as atorvastatin may be considered in some people, especially when long-term steroid use is part of the picture and blood fats are high. Their role in treating osteonecrosis is limited, but they may help lower one factor that can worsen blood supply to bone.
Genetic influences
Osteonecrosis can seem to come out of the blue, especially when bone pain or limping starts without a major injury. It’s natural to ask whether family history plays a role. In most people, osteonecrosis is not caused by one inherited gene change, but genes may still affect risk alongside things like steroid treatment, heavy alcohol use, trauma, or certain health conditions. Some inherited disorders, especially sickle cell disease, clearly raise the chance of osteonecrosis because they can interfere with blood flow to bone. Researchers have also found that inherited tendencies that affect blood clotting or how the body handles fats may play a part in some people, but these do not explain most cases. For many living with osteonecrosis, genetic risk factors for osteonecrosis are only one part of the picture, and having a relative with the condition does not mean you will develop it too.
Is Osteonecrosis genetic?
Genetics can matter in osteonecrosis, but they are usually only part of the picture. Some genetic variations may raise risk by affecting blood clotting, bone repair, or how the body handles certain medicines.
Having a genetic risk is not necessarily a diagnosis
Genetic variants are common in the general population and are a normal part of human biology. Most do not have a direct effect on health and are simply part of natural human diversity. For many genes, having a variant associated with a condition indicates a possible link rather than a definite diagnosis, especially when more than one gene and environmental factors are involved. In some cases, though, a single well-understood variant in a specific gene can be enough to confirm a diagnosis.
Pharmacogenetics—how genetics influence drug effects
When osteonecrosis makes it hard to walk, climb stairs, or sleep because of joint pain, treatment is usually tailored to the cause, the amount of bone damage, and how much the joint is affecting daily life. Genetics can matter most when osteonecrosis happens along with an inherited condition, such as sickle cell disease, because treating that underlying illness becomes part of the plan. Genetics is only one factor, so doctors still rely mainly on scans, symptoms, and joint function when deciding on rest, physical therapy, pain relief, or surgery. Genes may also affect how some pain medicines work; for example, codeine or tramadol may work too weakly or too strongly in some people because their liver handles these drugs differently. This means two people with osteonecrosis can have different pain control or side effects from the same dose, and a clinician may choose another medicine if needed. At this point, routine genetic testing for osteonecrosis treatment is not standard for most people, but in selected cases it can help explain risk, guide safer prescribing, or shape care for the underlying disease.
Interactions with other conditions
People living with osteonecrosis often notice that joint pain and stiffness become harder to manage when they also have other health problems, especially those that affect blood flow, bones, or the immune system. Conditions such as lupus, sickle cell disease, clotting disorders, high cholesterol, and diabetes can raise the risk of osteonecrosis or make joint damage progress faster. Doctors call it a comorbidity when two conditions occur together, and in osteonecrosis this can matter because the same disease process, or the medicines used to treat another illness, may reduce blood supply to part of a bone. Long-term steroid treatment is a common example: it can be very helpful for inflammatory diseases, but it is also a well-known risk factor for osteonecrosis. People with arthritis may also find that the early symptoms of osteonecrosis, like deep groin, knee, or shoulder pain with walking or climbing stairs, are mistaken for a flare of their usual joint disease. Because of this overlap, it helps to look at the whole picture so treatment can protect the joint while also managing the other condition safely.
How genes can cause diseases
Humans have more than 20,000 genes, each carrying out one or a few specific functions in the body. One gene instructs the body to digest lactose from milk, another tells the body how to build strong bones and another prevents the body's cells from beginning to multiply uncontrollably and developing into cancer. As all of these genes combined are the building instructions for our body, a defect in one of these genes can have severe health consequences.
Through decades of genetic research, we know the genetic code of any healthy/functional human gene. We have also identified that in certain positions on a gene, some individuals may have a different genetic letter from the one you have. We call these hotspots "Genetic Variations" or "Variants" in short. In many cases, studies have been able to show that having the genetic letter "G" in the position makes you healthy, but having the letter "A" in the same position disrupts the gene function and causes a disease. Genopedia allows you to view these variants in genes and summarizes all that we know from scientific research, which genetic letters (Genotype) have good or bad consequences on your health or on your traits.
What other conditions can cause similar symptoms to Osteonecrosis?
The pain, stiffness, and limp caused by osteonecrosis can also happen with more common problems such as wear-and-tear arthritis, a stress fracture, tendon injuries, or an infection in the bone or joint. In places like the hip or knee, pain from a lower back problem or other joint damage can also feel similar, so doctors often need to rule these out.
History
People living with osteonecrosis often reach a diagnosis after weeks or months of deep joint pain that does not quite make sense at first. Someone may notice hip pain while climbing stairs or a nagging ache in the knee that seems out of proportion to any recent injury. Long before scans could show the problem clearly, doctors were trying to understand this pattern of pain, stiffness, and gradual loss of joint function.
In recent decades, awareness has grown, but the history of osteonecrosis goes back much further. Earlier doctors described areas of bone that seemed to die after an injury, after interrupted blood flow, or sometimes for reasons that were not clear. As medical science evolved, osteonecrosis was recognized as a process in which part of a bone is damaged because it is not getting enough blood, which can eventually lead to collapse of the bone surface and arthritis in the nearby joint. Over time, reports also showed that it could affect more than one part of the body, most often the hip, but sometimes the shoulder, knee, or ankle.
The story of osteonecrosis changed significantly once X-rays became widely used, and later when MRI made it possible to see bone damage much earlier than before. That mattered because early symptoms of osteonecrosis can be subtle, and older imaging methods sometimes missed the condition until the joint was already badly affected. As doctors gathered more cases, they began to sort osteonecrosis into groups based on likely triggers, such as trauma, certain medicines, heavy alcohol use, or medical conditions linked to poor blood flow.
Researchers also learned that osteonecrosis is not one single experience. Many living with osteonecrosis have disease in just one joint, while others may have several areas involved, and the pace of progression can vary a lot. Looking back helps explain why diagnosis was once so difficult: the symptoms can overlap with many other joint problems, and the damage may begin silently before it becomes obvious on imaging.
Today, the history of osteonecrosis is still being written. Better imaging, earlier recognition, and a clearer understanding of risk factors have changed care in important ways, giving many people a better chance of treatment before severe joint collapse occurs.