Osteoarthritis: What is it?

Osteoarthritis is something not only physio nerds hear about, but everyone knows that their knees or hips could start hurting at any point due to a loss of cartilage in their joints. But what exactly is this thing called osteoarthritis? and what can we do about it?

Believes vs Reality :

Osteoarthritis (OA) is often described as a degenerative joint disease affecting the cartilage. Many believe it to be an integral and thereby inevitable part of the human experience. And why shouldn't it be? It is simply logical to assume that when we put enough pressure or tension on something as easily destructible as cartilage, which is the only thing that is keeping our bones from rubbing onto each other (a painful image), that then the cartilage slowly fades away.

The wear and tear belief is stuck into peoples minds. With this belief being so common, it's no wonder people avoid movement and exercises that could impact their joints after being diagnosed with OA by their orthopedic surgeon. Who would voluntarily force bone on bone movements if they can also sit still and avoid further damage?

But that's not what the literature is telling us. An abundance of research has been conducted on the topic of OA and with clinical practice guidelines constantly recommending exercise as one of the main treatment modalities. This is a pretty radical finding when thinking about the wear and tear belief, for which exercise doesn't quite fit the picture.

A paper on peoples beliefs about OA noted that many people have been shown X-rays of the affected joint (knee, hip...) and that the surface or space between the bones has diminished over time and that they cane "no cushioning" in their joint no more. But what they haven't been told is that there is a weak correlation between advancement of OA and pain levels. Which means that e.g. knee pain is a weak predictor for having knee OA in older adults, while at the same time being diagnosed with radiographic knee OA is a weak predictor that knee pain will be present. This is because pain is a bio-psycho-social phenomenon influenced by various factors, which may explain the discrepancy between structural changes and the pain experienced. Even in people with advanced OA (radiographic KL grade 4) up to 31% of people have no knee pain.
In that same paper, people also believed that the only treatment for OA was joint replacement and that OA, once present, could only get worse.

We as clinicians, physiotherapists and movement professionals need to be aware of our language when dealing with people with OA. Inappropriate language can negatively impact the patient’s beliefs, potentially influencing their mood and, consequently, their treatment outcomes.

As the authors of a 2006 paper stated: "the problem in fact is not structural changes in the cartilage, which almost all of us will develop in time. Rather, the problem is progressive, painful osteoarthritis", which, as it seems, is not the same thing. OA should not be seen as a disease of the cartilage, but rather as a result of unfavorable mechanical loading, which could stem from changes in the musculature, ligaments, nerves, or menisci.

A review on the origin of OA pointed out that inflammatory mediators are playing an important role in the initiation and progression of OA. This can be due to local (inside of the affected joint due to e.g. a traumatic injury) or systemic (excessive adipose tissue) inflammation or both.

A Point for Exercise:

The 2019 clinical practice guidelines (CPG) for OA (knee, hip and hand) strongly recommended the use of exercise. And they point out that while no consensus on acceptable pain levels during exercise exists, people in pain should exercise according to their own perceived tolerance on the basis of a common-sense approach. The type of exercise can be chosen individually from a broad pool of choices (walking, strengthening, neuromuscular training, aquatic exercise...).

The pain relieving impact of exercise has been shown to be of comparative effectiveness as oral medication (such as paracetamol and NSAID). This is likely due to reduced fear of movement and increased self-efficacy that accompany a structured exercise program, as shown in a recent analysis.

A Cochrane review found that exercise could deliver pain-relieving benefits that lasted up to 2 to 6 months after treatment cessation, with improvements in physical function being maintained for even longer.

A very recent 2024 meta analysis on the topic of exercise found that there are no existing recommendations for exercise intensity and training volume. But they recommended sticking to a exercise program that can be individually chosen (as no real guidelines exist) for 3 to 6 months, to reduce pain and increase physical function.

What about running?
It is often said that running is "bad for the knees" and that it might accelerate OA development (due to the repeated impacts). In reality, running might even be associated with a decreased risk for OA development (but evidence is still in its infancy), and might be a good preventative activity for the recreational runners. For elite athletes, the risk might really be slightly higher, when compared to sedentary folks. Therefore, advising a runner to stop running after he or she has been diagnosed with OA is not evidence-based, because running has not been shown to progress knee OA in recreational runners. Although no real guidelines exist to tell what makes a recreational runner in terms of volume, intensity and frequency, people should self-select running intensity according to their pain levels, which might mean a decrease in frequency and running duration, but not a complete cessation of running.

Limitations of exercise:

Although always recommended as a first line treatment for OA, exercise has its own limitations. Some studies suggesting small effect sizes for pain relief and not all people will see similar benefits of exercising. So what can be done in addition to exercise for long-term OA treatment?

Additional recommendations:

Weight loss:

In the CPG, exercise was more effective when combined with a weight-loss program and that a weight-loss program was more effective when combined with exercise. Weight loss benefits arise already with a loss of >5% bodyweight, with incremental benefits with increased weight loss (up until >20%) and is strongly recommended for the overweight and obese population.

Self-efficacy programs:

They also recommended adding self-efficacy / self-management programs in addition to an exercise protocol, which included goal-setting, problem solving and positive thinking.

Bracing:

Knee bracing for the knee and first CMC joint OA was strongly recommended in the CPG. Especially for those people who suffer greatly due to OA.
For the knee, the tibiofemoral brace is strongly recommended, while the patellofemoral brace is occasionally recommended. So the brace should be chosen according to the problem at hand, depending on which joint (tibiofemoral or patellofemoral) is generating more symptoms.

Education:

Educating patients on the prognosis, therapeutic modalities and tackling false believes of OA is crucial in getting patients to adhere to a certain intervention and to decrease fear of movement and thereby pain.

Summary:

Osteoarthritis, while commonly viewed as an inevitable part of aging, is not just a matter of "wear and tear." Research shows that exercise, when done appropriately, can help maintain joint health, reduce pain, and improve function. Misconceptions around OA often lead to unnecessary avoidance of physical activity, but staying active is one of the best strategies to manage the condition. While exercise alone may not cure OA, combining it with weight loss, self-management programs, and bracing can provide long-term relief and enhance quality of life. By addressing the condition holistically, individuals with OA can maintain mobility and manage their symptoms effectively.