Primary Osteoarthritis

What is Primary Osteoarthritis?

Osteoarthritis, or OA, is the most frequent type of arthritis that doctors see, and it’s a top reason why people around the world experience disability. Most people will show signs of OA on X-rays by the time they’re 65, and about 80% of people aged over 75 will have it. OA can be anywhere from a condition with no symptoms at all, to a condition that causes extreme arthritis in a few (oligo) or many (poly) joints. The most common symptom is pain caused by movement. OA most often affects the hands, knees, and hips. However, it can impact any joint in the body.

What Causes Primary Osteoarthritis?

The exact cause of primary osteoarthritis is not well understood and is believed to be influenced by both genetics and environmental factors. Studies have shown that changes in our genes can affect the likelihood of developing osteoarthritis by 30% to 65%. Age is the most prominent risk factor for osteoarthritis, and it is thought to be due to the reduced ability of the joint to withstand injury, muscle loss, and increased changes in bone structure.

Women are more likely to develop osteoarthritis compared to men. This can be due to factors such as differences in joint structure, strength of the ligaments, changes during pregnancy and bone density. The change of life or menopause, is particularly linked with an increased risk of osteoarthritis, suggesting that the female hormone estrogen plays a role in the development of the disease and in sensitivity to pain.

Physical factors, like joint misalignment or birth defects, can also contribute to injury in the joint, making osteoarthritis more likely to develop. Changes in lifestyle and environment can considerably affect the likelihood of developing osteoarthritis. Jobs that require repetitive movements, obesity, smoking, vitamin D deficiency, muscle weakness, and low bone density are all factors that can increase risk.

Risk Factors and Frequency for Primary Osteoarthritis

Osteoarthritis is a condition that often affects certain areas of the body, such as the hands, knees, feet, certain joints in the spine, and hips. The knee is the most frequent site of osteoarthritis. Based on a global study from 2017, it’s estimated that about 263 million people worldwide have knee osteoarthritis, with 13 million new cases each year. Women, particularly those who have gone through menopause, are more likely to develop osteoarthritis and may experience a more severe form of the disease. This is especially true when it comes to osteoarthritis affecting the hands, feet, and knees.

Osteoarthritis typically affects the hands, knees, feet, certain spine joints, and hips, with the knee being the most affected area.
From a 2017 study, it’s estimated that 263 million people globally have knee osteoarthritis, with 13 million new cases per year.
Women, more so those post-menopause, are more predisposed to osteoarthritis and usually have more severe symptoms.
This gender difference is particularly noticeable in osteoarthritis of the hands, feet, and knees.

Signs and Symptoms of Primary Osteoarthritis

Osteoarthritis (OA) usually presents with joint pain that gets worse with activity but improves with rest. The discomfort often peaks in the late afternoon, early evening, or first thing in the morning. This pain mainly comes in two types:

A dull, aching, and constant pain that can predictably increase over time. This can also come with stiffness after long periods of inactivity, called the “gelling phenomenon”.
Intense, unexpected pain that lasts for short periods, which can be distressing and hinder a person’s willingness to carry on with their daily activities.

Considering these pain types, OA can be grouped into three stages:

Early OA: Sharp pain that is often triggered by a physical stimulus, limiting the patient’s performance in high-impact activities.
Mid OA: In addition to the mentioned pain, unpredictable joint pain or locking can appear. Over time, the pain becomes more constant and can affect everyday tasks.
Advanced OA: Constant dull ache with bouts of intense, unpredictable pain. This stage can lead to the avoidance of social or leisure activities.

Apart from joint pain, other symptoms include joint tenderness, stiffness, a grating sensation or sound, limited mobility, swelling, deformity, or instability.

Physical check-ups of osteoarthritis might reveal enlarged bones (often affecting finger joints), a grating sound, fluid build-up in the joint, tenderness, and limited movement due to pain, swelling, or joint deformity. Enlarged joints near the tip and middle of the fingers are called Heberden’s and Bouchard nodes, respectively. Osteoarthritis in the thumb joint is sometimes described as having a “shoulder appearance” or “squaring”.

Testing for Primary Osteoarthritis

While there’s no specific lab test that can diagnose osteoarthritis (OA) – a type of joint disease that results from breakdown of joint cartilage and underlying bone – your doctor may use various tests and imaging techniques to help confirm their diagnosis. This is because osteoarthritis can often be identified through a patient’s symptoms and a physical examination.

Your doctor might conduct some tests to check for signs of inflammation, specifically the erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) tests. These are usually normal in patients with osteoarthritis but can be used to rule out other medical conditions if it’s unclear what’s causing your symptoms. They also may test for rheumatoid factor (RF) and anti-cyclic citrullinated peptide (CCP) antibodies, which can indicate rheumatoid arthritis – a different type of arthritis. Genetic tests looking at abnormalities in the formation of collagen, a protein that’s important for joint health, are currently used in research settings.

There are also many other “biomarkers” – measures that can indicate the presence or progression of a disease – being investigated as potential ways to diagnose osteoarthritis early, monitor its progression, and measure response to treatment. However, more research is needed to confirm these methods’ effectiveness.

In addition to these tests, your doctor may want to get images of your affected joints to confirm a diagnosis and assess the severity of your osteoarthritis. Plain radiography, a type of X-ray imaging, is typically the first choice; it’s recommended by the European League Against Rheumatism (EULAR) for initial assessment of knee or hand OA. X-rays can reveal trademark signs of osteoarthritis like narrowing of the space inside a joint, hardened bones beneath the cartilage (subchondral sclerosis), cysts in the bone beneath the cartilage (subchondral cysts), and bone outgrowths (osteophytes). In some cases, special X-rays might also show erosions and calcification of the joint in patients with a severe type of osteoarthritis affecting the hands.

Magnetic Resonance Imaging (MRI) can be helpful if your doctor is still uncertain about the diagnosis. It provides a detailed view of the surrounding joint structures. Ultrasound, another fast and easy imaging method, can be specifically useful for the peripheral joints, to look for signs of inflammation such as osteophytes and joint effusions – the buildup of excess fluid in a joint.

Treatment Options for Primary Osteoarthritis

Osteoarthritis management depends on how severe it is and where it’s located in the body. Improving physical health through therapy and weight loss can be very effective and should be the first things to try. Use of braces, splints, walking aids and other supportive devices could also help. Medical treatments such as over-the-counter or prescription anti-inflammatory drugs are often used when necessary. However, they should be avoided by people who have a history of heart disease or stroke and used sparingly by those at risk of developing stomach issues because of factors like old age or steroid use.

Injecting steroids directly into the joint should also be done sparingly, as this could speed up joint damage. Other treatment options include the use of antidepressants (Duloxetine), muscle relaxants, glucosamine, and chondroitin sulfate. Injections to supplement the knee’s natural lubricating fluid and pain medication are also available to manage osteoarthritis symptoms. However, pain relief treatments like acetaminophen and capsaicin cream are generally found to be ineffective. There are still many treatments that are relatively new and haven’t been proven to be effective, such as using the patient’s own plasma or stem cells, and medical cannabinoids. Antidepressants have also been used to try to control pain.

Research is being done to look at how arthritis affects the cartilage, nerves, and inflammation in the body. This is leading to the development of new treatments, but more research is needed to determine if these are safe and effective.

When treating osteoarthritis in the knees and hips, weight loss and physical therapy should be the first approaches to try, particularly when the patient’s body mass index (BMI) is above 25. All patients should aim to strengthen their muscles and improve their range of motion through low-impact exercises that can be performed on land or in water. Other treatment options include the application of hot or cold packs, therapeutic ultrasound, and electrical stimulation.

In terms of medication, anti-inflammatory drugs should be used at the smallest effective dose. Studies have found that diclofenac gel is better than oral anti-inflammatories for reducing pain. Pain medicines like acetaminophen haven’t been found to be effective for knee osteoarthritis because they don’t have anti-inflammatory effects. Tramadol, a weak opioid, might give some pain relief but it only has limited benefits when compared to a placebo.

Injecting steroids into the joint might be considered when faced with moderate to severe pain that isn’t alleviated with oral medications. This can provide immediate relief that may last for about three months. However, the long-term effects of these injections haven’t been proven, and they could cause further damage to the cartilage so they should not be used too frequently.

Knee replacements are usually only considered when other treatments have failed. Less invasive procedures like joint resurfacing and partial knee replacements could be considered for younger people with a smaller area of damaged joint who continue to have symptoms despite trying other treatments. However, cleaning out the joint through a small incision should be done cautiously as it may speed up the progression of osteoarthritis.

For osteoarthritis in the hands, treatments may include applying hot or cold packs, physical and occupational therapy to improve mobility and strength, and the use of anti-inflammatory medicines. Steroids are generally not recommended for treating hand flare ups but may be used on occasion. Surgical options are usually reserved for severe cases that result in loss of function and continual pain.

When dealing with joint pain, a long list of medical conditions could be the cause, these include:

Rheumatoid arthritis
Gout
Pseudogout
Septic arthritis
Hemochromatosis (a condition where the body absorbs too much iron)
Fibromyalgia (a disorder that causes widespread musculoskeletal pain)
Lyme disease (a tick-borne illness)
Ankylosing spondylitis (a type of spinal inflammation)
Psoriatic arthritis (a kind of arthritis that affects some people who have psoriasis)
Parvovirus-associated arthritis (arthritis related to infection with parvovirus)
Neuropathic arthropathy (a complication of nerve damage, often associated with diabetes)

What to expect with Primary Osteoarthritis

Osteoarthritis, a condition that affects the joints, can get worse slowly over time. This process can speed up due to injuries or overuse of the joints. It can also be seen as a gradual progression on medical imaging like X-rays. However, it’s hard to predict how fast or badly it’ll progress because there isn’t enough high-quality data to determine which symptoms indicate a worse outcome.

That said, several factors can hint at a worse prognosis. These include severe pain, muscle weakness, a high body mass index (BMI), which indicates obesity, worsening signs on radiographs (X-rays), depression, and disease affecting multiple body parts. Interestingly, people with higher BMI’s and those who engage in heavy physical labor at their jobs are more likely to need knee replacement surgery in the future.

Possible Complications When Diagnosed with Primary Osteoarthritis

Possible long-term issues include:

Chronic pain
Long term use of pain relievers
Reduced ability to move joints
Decreased stability, leading to a higher risk of falls
Misalignment of the joints
Deformities
Stress fractures
Bleeding into the joints
Bone death
Infection in the joints
Flare-ups of Gout and Pseudogout
Depression

Preventing Primary Osteoarthritis

If you have osteoarthritis, or are at risk of developing it, it’s crucial to make certain lifestyle changes to prevent the disease from getting worse or developing in the first place. You should focus on losing weight and making sure to exercise moderately each day. This helps improve your physical movement and balance.

You should also be careful not to overuse pain medication as it can lead to unwanted side effects, especially if you use it for a long period of time. Items that can help you move around, like canes or splints, are available if you need them. It’s a good idea to consider these if your doctor agrees they could be helpful for you.

Frequently asked questions

From a 2017 study, it's estimated that 263 million people globally have knee osteoarthritis, with 13 million new cases per year.

The signs and symptoms of Primary Osteoarthritis include: - Joint pain that worsens with activity but improves with rest. - Discomfort that often peaks in the late afternoon, early evening, or first thing in the morning. - Two types of pain: - Dull, aching, and constant pain that can increase over time. This pain may be accompanied by stiffness after long periods of inactivity, known as the "gelling phenomenon". - Intense, unexpected pain that lasts for short periods and can hinder daily activities. - Three stages of OA based on pain types: - Early OA: Sharp pain triggered by physical stimulus, limiting performance in high-impact activities. - Mid OA: Unpredictable joint pain or locking, with pain becoming more constant over time and affecting everyday tasks. - Advanced OA: Constant dull ache with bouts of intense, unpredictable pain, leading to avoidance of social or leisure activities. - Other symptoms include joint tenderness, stiffness, a grating sensation or sound, limited mobility, swelling, deformity, or instability. - Physical check-ups may reveal enlarged bones, a grating sound, fluid build-up in the joint, tenderness, and limited movement due to pain, swelling, or joint deformity. - Enlarged joints near the tip and middle of the fingers are called Heberden's and Bouchard nodes, respectively. - Osteoarthritis in the thumb joint may be described as having a "shoulder appearance" or "squaring".

The exact cause of primary osteoarthritis is not well understood and is believed to be influenced by both genetics and environmental factors.

The doctor needs to rule out the following conditions when diagnosing Primary Osteoarthritis: - Rheumatoid arthritis - Gout - Pseudogout - Septic arthritis - Hemochromatosis - Fibromyalgia - Lyme disease - Ankylosing spondylitis - Psoriatic arthritis - Parvovirus-associated arthritis - Neuropathic arthropathy

To properly diagnose primary osteoarthritis, a doctor may order the following tests: - Erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) tests to check for signs of inflammation - Rheumatoid factor (RF) and anti-cyclic citrullinated peptide (CCP) antibodies tests to rule out rheumatoid arthritis - Genetic tests to look for abnormalities in collagen formation (currently used in research settings) - Plain radiography (X-ray imaging) to assess the severity of osteoarthritis and reveal characteristic signs such as joint space narrowing, subchondral sclerosis, subchondral cysts, and osteophytes - Magnetic Resonance Imaging (MRI) to provide a detailed view of the surrounding joint structures if the diagnosis is uncertain - Ultrasound to look for signs of inflammation, such as osteophytes and joint effusions, in peripheral joints.

Primary osteoarthritis is treated through a combination of approaches depending on the severity and location of the condition. The first line of treatment includes improving physical health through therapy and weight loss. Supportive devices like braces, splints, and walking aids can also be used. Medical treatments such as over-the-counter or prescription anti-inflammatory drugs are often used when necessary, but caution should be exercised for individuals with a history of heart disease or stroke, as well as those at risk of stomach issues. Other treatment options include injections, muscle relaxants, glucosamine, chondroitin sulfate, and antidepressants. Research is ongoing to develop new treatments, but more research is needed to determine their safety and effectiveness. For osteoarthritis in the knees and hips, weight loss, physical therapy, and low-impact exercises are recommended. Medications like anti-inflammatory drugs should be used at the smallest effective dose. Injections of steroids into the joint may be considered for moderate to severe pain. Knee replacements are considered when other treatments have failed, while hand osteoarthritis may be treated with hot or cold packs, therapy, and anti-inflammatory medicines. Surgical options are reserved for severe cases.

When treating Primary Osteoarthritis, some possible long-term issues and side effects may include: - Chronic pain - Long-term use of pain relievers - Reduced ability to move joints - Decreased stability, leading to a higher risk of falls - Misalignment of the joints - Deformities - Stress fractures - Bleeding into the joints - Bone death - Infection in the joints - Flare-ups of Gout and Pseudogout - Depression

The text does not provide a specific prognosis for primary osteoarthritis. It mentions that it is difficult to predict how fast or badly the condition will progress, and there is not enough high-quality data to determine which symptoms indicate a worse outcome. However, several factors such as severe pain, muscle weakness, high BMI, worsening signs on X-rays, depression, and disease affecting multiple body parts can hint at a worse prognosis.

Rheumatologist