Blog Post

What is knee arthritis and what can be done about it?

Knee osteoarthritis–sometimes just called knee OA–is one of the most common knee maladies that we see in the PT clinic, and it is responsible for a big chunk of the disability that older adults can experience. It is by far the most common type of arthritis in the knee. Other types include rheumatoid arthritis and psoriatic arthritis. Approximately 23% of adults over 40 may have symptomatic knee OA. Of all the joints affected by OA, about 80% of cases that seek treatment are for the knee.1

What is it?

Knee OA is damage and thinning of the cartilage, osteophyte (bone spur) formation, and stress-related changes to the bone underlying the cartilage. Since the cartilage itself doesn’t have an innervation, the pain of OA is probably from stress injury to the bones and/or inflammation within the joint.

Why does it happen?

The process leading to OA is still not well-understood. Inflammation may play the largest role as we see OA is more common in those with high systemic inflammation such as people who are obese or have metabolic syndromes like diabetes. There also seems to be a genetic component to it. Additionally, people with previous knee trauma or surgery are more likely to develop OA, which is evidence for both biomechanical and inflammatory risk factors. 

One thing we have learned in recent years is that “wear and tear”, which was considered the main cause (and still is by most of the public) plays a much smaller role than once thought.

What can be done?

First of all, banish the erroneous and unhelpful idea of “wear and tear” from your mind. Focusing on it will make you avoid exercise and activities for fear of worsening your arthritis. On the contrary, stressing your joint with appropriate levels of activity is vital for maintaining your joint’s health. Just like muscles, your joints need exercise to stay healthy and strong.

There are numerous options that can help reduce your pain so that you can be more active.

  • Heat or cold: Heat applied on your joint or the muscles above and below may provide soothing relief, and could be a bit of warm-up before your first get moving. Cold therapy may reduce inflammation and swelling after activity, and it’s numbing effect can be a safe, drug-free pain reliever.
  • Orthotic insoles: Some people may find significant relief simply by putting sturdy arch support insoles in their shoes. It may alter the way your leg moves just enough to decrease some pain.
  • Electrical stimulation: At-home electrical stimulation units use safe levels of electricity applied through stick-on electrodes to provide temporary pain relief. Basically, the tingling of the current masks some of the pain in the same way as rubbing your knee would. These units can be used while you exercise to make it more comfortable. Speaking of exercise…

Some form of physical activity that stresses your knee (in a good way) will be vital to decreasing pain and disability from OA. The trick is finding the right amount. Too much exercise will, indeed, worsen your pain. But so will excessive rest. Non-weight-bearing options like cycling, swimming, or a recumbent cross-trainer are good places to start. Traditional strength training for the muscles around your hips, knees, and ankles will also be helpful.

A physical therapist can be an indispensable ally by helping to identify and modify painful daily activities to make them more tolerable. They can also prescribe and guide you through a strength training program suited to your current activity level. And, they can perform hands-on therapy like massage or joint mobilizations that help reduce stiffness and soreness, improve mobility, and make exercises a little easier.

I saved the best (or worst) advice for last, because it is the most important but also the hardest: if you are overweight losing weight will be most helpful. Being overweight 1) increases mechanical forces on the knee, 2) increases systemic inflammation, 3) and often leads to decreased physical activity all of which worsen knee OA.2 The difficulty of losing weight need not be mentioned. You will need help from several sources. Diet may be more important for weight loss than exercise, so having a dietitian or nutritionist in your corner is vital. Exercise, as I said, can be guided by a physical therapist or personal trainer experienced in working with clients with OA.

Many people with knee OA worry that they will one day need a joint replacement, but that is not inevitable. Consider that close to 100% of adults over 80 have some level of knee OA, but only about 20% get a knee replacement. These surgeries may be avoided, and you have some control over whether or not that happens. If you’re struggling, seek out some help starting with a visit to your doctor and hopefully then to a physical therapist.

Ready for some help now? Inquire about cost and availability at Gotham PT here, or download our free knee pain tip report here.

1. Cui A, Li H, Wang D, Zhong J, Chen Y, Lu H. Global, regional prevalence, incidence and risk factors of knee osteoarthritis in population-based studies. eClinicalMedicine. 2020;29. doi:10.1016/j.eclinm.2020.100587

2. Lespasio MJ, Piuzzi NS, Husni ME, Muschler GF, Guarino A, Mont MA. Knee Osteoarthritis: A Primer. Perm J. 2017;21:16-183. doi:10.7812/TPP/16-183