The Surprising Reason Why X-rays Can Persuade Osteoarthritis Patients to Undergo Surgery

Osteoarthritis is one of the leading causes of chronic pain and disability. Nearly half of new patients with knee osteoarthritis who visit a general practitioner in Australia are referred for imaging. Imaging for osteoarthritis costs the healthcare system $104.7 million Australian dollars annually. A new study by researchers at the University of Melbourne shows that using X-rays to diagnose knee osteoarthritis can influence a person’s attitude toward their knee pain—and may cause them to consider potentially unnecessary knee replacement surgery. Therefore, according to the researchers, routine X-rays should not be recommended to diagnose the condition. Instead, family doctors can make a diagnosis based on symptoms and medical history.

Avoidable Joint Replacement Surgery

Osteoarthritis is caused by changes in the joint and the additional strain placed on the joint to repair itself. It affects the entire joint, including the bones, cartilage, ligaments, and muscles. It most commonly occurs in older adults, people who are overweight, and individuals with a history of knee injury. Many people with knee osteoarthritis suffer from persistent pain and have difficulty with everyday activities such as walking and climbing stairs.

In 2021–22, more than 53,000 Australians underwent knee replacement surgery for osteoarthritis. Hospital services for osteoarthritis, primarily caused by joint replacement surgery, cost $3.7 billion in 2020–21. Although joint replacement surgery is often considered unavoidable for osteoarthritis, it should only be considered for patients with severe symptoms who have already tried appropriate non-surgical treatments. Surgery carries the risk of serious side effects such as blood clots or infections, and not everyone recovers fully from it.

Most people with knee osteoarthritis can treat it effectively with:

• Education and self-management
• Exercise and physical activity
• Weight management (if necessary)
• Medications for pain relief (such as paracetamol and non-steroidal anti-inflammatory drugs).

Refuting a Common Misconception

A common misconception is that osteoarthritis is caused by “wear and tear.” However, research shows that the extent of structural changes seen on an X-ray of a joint does not reflect the degree of pain or disability a person experiences, nor does it predict how symptoms will change. Some people with minimal joint changes have very severe symptoms, while others with more severe joint changes have only mild symptoms. For this reason, routine X-rays are not recommended for the diagnosis of knee osteoarthritis or as a basis for treatment decisions. Instead, the guidelines recommend a “clinical diagnosis” based on a person’s age (45 years or older) and symptoms. Joint pain during movement and no joint stiffness in the morning, or stiffness that lasts less than 30 minutes. Nevertheless, many healthcare professionals in Australia continue to use X-rays to diagnose knee osteoarthritis. And many people with osteoarthritis still expect or want them.

Findings of the Study

The study aimed to find out whether the use of X-rays to diagnose knee osteoarthritis influences a person’s beliefs about the treatment of osteoarthritis, compared to a clinical diagnosis without X-rays. The researchers recruited 617 people from across Australia and randomly assigned them to one of three video groups. Each video showed a hypothetical consultation with a general practitioner for knee pain. One group received a clinical diagnosis of knee osteoarthritis based on their age and symptoms, without an X-ray being taken. The other two groups received X-rays to determine their diagnosis (the doctor showed one group their X-rays, but not the other). After watching their assigned video, participants completed a questionnaire about their perceptions of osteoarthritis treatment.

People who received a diagnosis based on X-rays and were shown their X-rays had a 36% greater need for knee replacement surgery than those who received a clinical diagnosis (without X-rays). They also believed that exercise and physical activity could damage their joints, were more concerned about their condition worsening, and were more afraid of exercise. Interestingly, people with an X-ray-based diagnosis were slightly more satisfied than those with a clinical diagnosis. This may reflect the widespread misconception that osteoarthritis is caused by “wear and tear,” as well as the assumption that the “damage” in the joint must be visible in order to guide treatment.

What Does this Mean for People with Osteoarthritis?

The findings highlight why it is important to avoid unnecessary X-rays when diagnosing knee osteoarthritis. While changing clinical practice can be challenging, reducing unnecessary X-rays could help alleviate patient anxiety, prevent unnecessary concerns about joint damage, and reduce the demand for costly and potentially unnecessary joint replacement surgery. It could also help reduce exposure to medical radiation and lower healthcare costs.

Previous research on osteoarthritis and back and shoulder pain also shows that patients may become more anxious about their condition and more concerned about damage to their joints when healthcare professionals focus on the “wear and tear” of the joints. An X-ray can increase anxiety and make patients more receptive to surgery. However, there are a number of non-surgical options that relieve pain, improve mobility, and are less invasive.