Osteoarthritis is a disease that causes joint tissues to break down over time, causing pain and stiffness in the joint. It is the most common type of arthritis, especially among older people. The disease can affect any joint but is most common in the hands, knees, hips, neck and lower back.
Osteoarthritis (OA) affects about 32.5 million American adults, according to the Centers for Disease Control and Prevention. It’s also called “wear and tear” arthritis and degenerative joint disease.
Osteoarthritis occurs when a flexible, rubber-like joint tissue called cartilage breaks down over time. Cartilage helps cushion joints and protect bones. When cartilage is damaged, it results in damage to the underlying bone. This leads to pain, swelling and stiffness, and people with osteoarthritis may have difficulty stepping up stairs, getting up from a chair, gripping things with their hands or walking.
Two main types of osteoarthritis are primary and secondary. Primary osteoarthritis is the most common. It typically affects the toes (usually the big toes), fingers, thumbs, hips, spine and knees. Secondary osteoarthritis happens after a pre-existing joint injury or abnormality, such as sports-related injuries, genetic disorders or rheumatoid arthritis.
There is no cure for osteoarthritis, and it can get worse over time. But treatments such as lifestyle changes, medications and surgery can improve and manage symptoms.
Symptoms and Signs
One of the first symptoms and signs of OA is joint pain that worsens with activity but goes away after rest. As the disease worsens and become more severe, the pain lingers even when a person is at rest. Symptoms develop slowly over the course of years rather than show up suddenly.
- Pain with activity or using the joint that may ease after rest. Pain can get worse at night for people with advanced disease.
- Morning joint stiffness that often lasts less than 30 minutes. Stiffness can also occur after activity.
- Swelling in and around the joint that can occur after heavy use of the joint.
- Difficulty moving the joint or reduced range of motion.
- An unstable or loose feeling in the joint.
Most Commonly Affected Joints
Osteoarthritis can occur in any joint. But it most often occurs in the knees, hips, spine and hands.
Osteoarthritis in the Knee
People with OA in the knee often feel a “scraping” or “grating” when moving the knee. The joint may also make a popping or cracking sound when moving, called crepitus. The knee becomes unstable and may tend to bend inward.
In some cases, fluid may build up around the joint and a fluid sack called a Baker’s cyst may develop behind the knee.
Osteoarthritis in the Hip
In OA of the hip, people most often feel pain in the hip, groin and buttocks. This pain sometimes radiates to the inside of the knee or thigh. The hip has limited range of motion, especially when moving the thigh inward from the joint.
Osteoarthritis in the Spine
OA of the spine causes pain when moving and limits range of motion. Nerve impingement (pinched nerves) causes sensory loss in the lower extremities, reflex loss and weakness. The spinal canal narrows from nerve inflammation and can lead to cramping or weakness in the legs.
Osteoarthritis in the Hands and Feet
In OA of the hand, people feel pain when moving joints. Bone spurs grow at the edge of joints and lead to swollen, tender and red fingers. Often, pain starts at the base of the thumb. Bony bumps called Heberden nodes and Bouchard nodes can form on the joint closest to the fingernail.
In people with OA in their feet, the pain usually starts in the joint of the big toe. It will feel painful and tender. Toes and ankles may also become swollen. The joints will hurt when walking. People may also develop a hallux valgus deformity — a deformity that occurs when the big toe is out of alignment. This causes a bony protrusion some people call a bunion.
Causes and Risk Factors
Doctors don’t know what the exact cause of osteoarthritis is, but they suspect it is caused by inflammation and defective injury repair mechanisms wearing down the joint over time, according to Cleveland Clinic.
Researchers do know that certain people are at higher risk for developing the disease. Osteoarthritis can be genetic and injuries to joints and other diseases may lead to developing OA.
- Joint injury or overuse that stresses a joint can damage it and increase the risk of OA. Examples include repetitive squatting or bending.
- Older people have a higher risk of developing OA and the risk increases with age.
- Men are less likely to develop OA than women, especially after age 50.
- People who are overweight or obese put more stress on their joints, such as knees and hips, and this increases the risk of OA. Metabolic effects that occur in obese people may also increase the risk of OA.
- OA is hereditary and people with family members with OA are more likely to get it.
- People with certain genes are more likely to get OA.
- Ethnicity plays a role in risk. Asian women have the lowest risk, while African American and non-white Hispanic women have a higher chance of developing OA than white women, according to results from the clinical trial and observational study of the Women’s Health Initiative (WHI).
Complications of Osteoarthritis
In addition to joint pain and joint stiffness, osteoarthritis can lead to other joint and health problems.
- Chondrolysis, a rapid breakdown of cartilage
- Osteonecrosis, bone death
- Stress fractures, hairline cracks that develop with repeated stress and use
- Bleeding and infection in the joint
- Rupture or deterioration of ligaments and tendons, leading to joint instability
- Pinched nerves, especially in OA of the spine
Other Disease Risks
People with OA also have a greater risk for other chronic diseases. Researchers call these conditions “comorbidities.” For example, people with osteoarthritis have a 2.5-times greater risk of having three or more other comorbidities, according to a 2019 study published in Arthritis Care & Research by Subhashisa Swain and colleagues at the University of Nottingham.
These conditions include stroke, peptic ulcers, depression, stroke, metabolic syndrome, hypertension and depression.
Because pain in the joints reduces mobility, people with OA may be less active. This may lead to developing diabetes and heart disease.
People with OA have a 30 percent greater risk of falls and a 20 percent greater risk of fracture, according to the Arthritis Foundation.
Most doctors can diagnose OA with just a physical examination and the patient’s medical history, according to Dr. Keith Sinusas’s article in American Family Physician.
If necessary, a doctor may recommend X-rays to confirm a diagnosis or rule out other conditions. X-rays can show narrowing of the spaces between bone — indicating cartilage loss — as well as bone spurs or cysts. More advanced imaging tests like MRIs are rarely needed to diagnose OA except in complex cases.
Typically, blood tests are not required to make a diagnosis because OA doesn’t have detectable antibodies or markers of inflammation like rheumatoid arthritis. If a doctor suspects that a patient may have rheumatoid arthritis or gout, they may order blood tests to rule out these conditions.
Osteoarthritis vs. Rheumatoid Arthritis
Unlike RA, OA is not an autoimmune disorder. It tends to affect one joint on one side of the body at a time. For example, the left knee may have OA but the right knee may function normally. In RA, both knees would be affected at the same time. Symptoms of OA develop over time, usually over years. RA symptoms develop in a few weeks or months.
The main difference between OA and RA is that patients with OA don’t have joints that are swollen and puffy to the touch, a condition called synovitis. In people with RA, this is caused by inflammation in the synovium, a connective tissue that lines the space in between joints.
Joint stiffness in OA typically only lasts 30 minutes or less, and the same symptom in RA lasts longer.
Stages of Osteoarthritis
There are four stages of OA that have symptoms ranging from mild to severe. Treatment options vary by stage.
Patient with early stage disease can take supplements and modify their exercise routine to minimize joint damage, while patients with late-stage disease may need surgery to relieve pain and loss of joint function.
Stage One, Minor
People with stage one disease have minor wear-and-tear at the joint and typically feel little to no pain. This stage doesn’t usually call for treatment, but a doctor may advise supplements and modifying exercise routines to protect joints.
Stage Two, Mild
At this stage, X-rays will begin to show bone spurs at the joint. People will start to feel some pain and stiffness in the join, especially after long periods of rest or after activity. Treatments at this stage involve over-the-counter medications, modified exercise routines and a fitted joint brace.
Stage Three, Moderate
People with stage three OA have pain and stiffness during normal daily activity. This is caused by the cartilage that normally cushions the joints wearing down and further inflaming the joint. Treatments include over-the-counter medications and prescription pain medications. If symptoms are more severe, the doctor may recommend joint-lubricating injections called hyaluronic injections.
Stage Four, Severe
Stage four is the most severe stage. People experience more severe pain because the cartilage between joints is almost completely gone, and there are more bone spurs. The joint becomes stiff and may be difficult to move. In the hand, it makes gripping difficult. In the knee or foot, walking becomes a problem. At this stage, prescription pain relievers and surgery are the main treatments.
Treatment options for osteoarthritis include medications, therapy, surgery, assistive devices and at-home therapies or lifestyle changes.
Medications for OA primarily relieve pain and reduce inflammation. These include over-the-counter drugs such as Tylenol (acetaminophen) and NSAIDs, including ibuprofen drugs known by the brand names Motrin IB, Advil and others. Aleve (naproxen sodium) is another popular drug for OA pain.
OTC pain relievers are good for mild to moderate pain. For more severe pain, doctors may prescribe stronger versions of NSAIDs. These are also available in gels or creams which may have fewer side effects than oral medications.
Another option is the antidepressant Cymbalta (duloxetine). It’s also approved to treat chronic pain, including OA pain.
Two types of therapy can manage symptoms of OA. These are physical therapy and occupational therapy.
Physical therapy helps patients learn exercises to reduce pain, strengthen joints and increase flexibility. Occupational therapists teach people how to modify movements to lessen joint strain. They can also teach people how to use assistive devices such as a shower bench to avoid knee strain while standing.
Surgery and Other Procedures
If medication and therapy don’t help, medical providers may recommend joint injections or surgery.
After numbing the area around your joint, the doctor injects corticosteroid medication into the affected joint. This can relieve pain, but injections are limited to three to four times a year because too many injections can damage joints.
Lubrication injections of hyaluronic acid may help cushion weight-bearing joints such as the knee. This medicine is similar to naturally occurring joint fluid.
An osteotomy is a surgical procedure to realign bones that have more damage on one side than the other. In a knee osteotomy, a surgeon adds or removes a wedge of bone to shift body weight away from the worn out part of the knee.
Joint Replacement Surgery
Joint replacement surgery is reserved for the most severe forms of OA. The surgeon replaces the damaged joint with a synthetic implant. The most common type of joint replacement is knee replacement.
Other surgeries include hip replacement surgery and shoulder replacement surgery. Joint replacements wear out over time or may be defective and require revision surgery to replace the joint and any damaged tissue and bone.
Supportive devices help people who have OA with their mobility. These devices include braces, canes, crutches, and supportive shoes.
Using these devices on days with a lot of activity can help decrease stiffness and pain. Fitted braces take strain off joints and align them properly. Supportive shoes can alleviate pain in the knees, hips and back.
Ask your medical provider or therapist what supportive devices might be right for you.
People with mild OA may be able to manage symptoms with simple at-home treatments. People with more severe forms of the disease can add some of these treatments to their medication and therapy routines to improve symptoms.
Before trying any exercise or treatment on your own, make sure you talk to your doctor or therapist. Be sure to ask your doctor for classes that can help you learn strategies to cope with pain and improve your life. The CDC offers self-management classes for people with chronic pain like OA.
- Stretching and strengthening exercises that improve stability, flexibility and range of motion.
- Alleviating night pain by using a mattress that distributes weight more evenly, preventing pressure on the affected joint. Using a pillow under the arm or between the knees can also help.
- Using hot and cold therapy can provide pain relief. Use moist heat to promote circulation and relieve muscle spasms in pain not related to activity. Application of ice packs to joints after exercise can help with pain.
- Controlling your weight by eating a diet rich in fruits, vegetables, whole grains and lean meats and avoiding processed, high-sugar, high-fat foods.
- Educating yourself about OA and learning self-management skills to control your symptoms and live well.
Please seek the advice of a medical professional before making health care decisions.