Knee Osteoarthritis: Myths vs Facts

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Knee Osteoarthritis: Myths vs Facts

First, let’s start out by outlining what osteoarthritis is. Osteoarthritis is a very common condition, affecting the entire body, but mostly the articular cartilage (cartilage which covers the ends of bones). Cartilage has a smooth surface, allowing bones to slide easily on each other with movement. In the knee joint, there are also some extra shock absorbing pads called menisci between the bones. Over a lifetime, there is normal wear of the menisci and thinning of the cartilage cartilage. In some people, this is accelerated due to previous injuries sustained earlier in life (ligament injuries, etc.). This process is what leads to osteoarthritis.

In an older population, a loss in meniscal health is coupled with thinning of the cartilage of the knee, referred to as osteoarthritis. Traditionally, this has been thought of as a ‘wear and tear’ disease, leading many to think that they cannot exercise and should not be physically active. This is in fact wrong, where cartilage needs moderate load through physical activity for optimal health. Exercise should be the first line of management in any scenario of meniscus injury or knee arthritis. Only failing this, should surgery be considered1.

I’ve got knee osteoarthritis. What do I do now?

So, you have developed knee pain and your MRI shows degenerative changes in your cartilage and meniscus, and osteoarthritis in your knee, what do you do now?

If you’ve been diagnosed with this condition then you might have experienced the all too common merry-go around with scans, appointments with various health professionals and a number of different treatments. This blog will help dispel some of the myths around knee osteoarthritis and help you on the road to recovery.

KNEE OSTEOARTHRITIS MYTH 1: My scan will show exactly what is causing my knee pain

Emerging pain research has shown that scans are poorly related to pain and disability. The degree of cartilage damage, meniscal degeneration or arthritis does not correlate to pain levels. On average, we know that 20% of people with pain-free knees have meniscal tears. This research study also showed that 19% of people (almost 1 in 5) over the age of 40 had a meniscal tear, with most of these people functioning with no pain. We also know that this number substantially increases in people who have had major knee injuries earlier in life (i.e. ACL ruptures)2. This has also been demonstrated in other parts of the body, with research showing that up to 50% of people aged over 40 years will have asymptomatic (pain-free) disc bulges in their spine and up to 90% of people over 60 years will have findings of disc degeneration. This research suggests that these findings are a normal part of pain-free aging, much like the wrinkles on your skin and changes in your hair3.

KNEE OSTEOARTHRITIS MYTH 2: I shouldn’t exercise my knee as it will worsen the damage in my knees

Well designed and implemented exercise relieves pain and does not harm or damage the knee joint cartilage and meniscus. In fact, weight bearing exercises are vital to deliver nutrition to the joint surfaces/cartilage and integral to reducing pain. The belief that therapeutic exercise may harm the knee joint is still common in people with knee osteoarthritis. This leads to decreased activity levels due to fear, which in turn has negative effects for the health of the knee. It is important that your knee pain is being managed based on your current levels of strength and control, so that an appropriate and individualised exercise program can be developed. Evidence suggests that people do just as well, if not better, with physiotherapy treatment compared with surgery.

KNEE OSTEOARTHRITIS MYTH 3: Surgery is required for all cases of osteoarthritis

Due to the mismatch between the degree of meniscal/cartilage damage, arthritis and pain, findings on xrays and scans alone should not be the reason for surgery. Arthroscopic (keyhole) surgery is a frequently offered management option for arthritic knees and meniscal tears, commonly provided to ‘clean out’ the joint. The rationale for removing damaged meniscal tissue is based on the concept that the meniscus is the primary source of pain in arthritis, where commonly this is not the case, despite scan findings4. In part, this explains why not all people respond favourably to knee arthroscopy.

As mentioned above, meniscal tears are common in symptom-free middle-aged and older populations without signs of knee osteoarthritis on xray5. More recent medical practices would actually suggest that there is little to no indication for the use of arthroscopic surgery in established knee osteoarthritis. Research has demonstrated that knee arthroscopy is no more effective than placebo (fake) surgery6. This research showed that if a patient underwent a knee arthroscopy or  fake knee surgery (placebo) they would present similarly in terms of levels of pain AND function up to 2 years after surgery. Having surgery is not the only option, regardless of how severe your knee pain is.

 

Knee Osteoarthritis – Know the facts.

It’s time to change the narrative around knee pain, and the facts are:
• Rest and avoidance makes pain worse
• Graded exercise is safe and helpful
• Pain does not equate to damage, but is moreso a reflection of the sensitivity of the knee
• Unhelpful beliefs and catastrophising can reduce confidence, lead to reduced physical activity and further deterioration of your knee health
• Muscle weakness is a big contributing factor
• Lifestyle factors such as a lack of sleep, lack of physical activity, weight gain and poor nutrition can have negative influences on pain

If surgery isn’t an option, where does this leave me?

There is emerging evidence from La Trobe University in Melbourne suggesting that exercise often yields better results than surgery and pain killers. Regular, structured exercises have shown to have a much greater pain-relieving effect than commonly used pain relief medication. In one trial with over 13,000 participants in Europe, patients experienced less pain, better physical function and better quality of life following 12 weeks of structured, twice weekly exercise sessions1. Fewer people were taking painkillers compared to before the start of the program. Well dosed and programmed therapeutic exercise is vital for knee health and the life-long management of physical disability related to osteoarthritis.

I am already physically active, but my knee pain isn’t going away

There is a difference between being physically active and exercising. Physical activities target cardiovascular qualities of health by increasing heart rate when exercising. Exercise/strength training is a type of physical activity carried out with a specific purpose of getting you strong and improving function. Walking is great exercise but usually isn’t specific enough to improve strength. Instead, targeted strength exercises such as squatting out of a chair with purpose (i.e. with optimal joint and body position) is more likely to improve your function and pain.

Strengthening exercises help reduce pain through different factors. A good understanding of the anatomy of the knee will help explain this. The knee is a joint between two bones, the femur (thigh bone) and tibia (shin bone). The ends of each bone are lined by smooth cartilage, which allows for sliding of the bones during movement. The capsule surrounds the joint, securing it and containing synovial fluid, a lubricant providing nutrients to the cartilage. The function of the cartilage is to allow smooth movement of the bones on each other and to shock absorb and spread load over its surface.

Exercise is all important when it comes to knee cartilage health. Think of cartilage as a wet sponge. When loads are applied, fluid is pressed out of the sponge. When loads are removed, the sponge sucks the fluid back in. When we exercise, load presses down onto our cartilage. The cartilage absorbs the shock and fluid squeezes out into the articular capsule. Once loads are removed, the cartilage sucks the fluid back in from the surrounding area. This mechanism is what delivers nutrition to the cartilage, necessary for healing, pain reduction and improved shock absorption7.

What type of exercise is best for my knee?

Keeping the above information in mind, exercises that target functional movements (such as squatting) and emphasise good alignment in your joints will be best. Supervised exercise, to ensure good quality execution are required to load the knee in an optimal manner. Quality is more important than quantity!

 

The team at PhysioTec are experienced Physiotherapists with expertise in exercise prescription. We will work with you to provide a plan and structured exercise routine to improve your pain and function.

Kevin Doan is a qualified APA Sports & Exercise Physiotherapist. Call 3342 4284 to book an appointment with Kevin.

 

References

1. Skou, ST & Roos, EM (2017) Good Life with Osteoarthritis in Denmark (G:LAD): evidence-based education and supervised neuromuscular exercise delivered by certified physiotherapists nationwide. BMC Musculoskeletal Disorders, vol. 18:73, pp. 1-13

2. Guermazi, Ali, Niu, Jingbo, Hayashi, D, Roemer, FW, Englund, M, Neogi, T, Aliabadi, P, McLennan, CE & Felson, DT (2012) Prevalence of abnormalities in knees detected by MRI in adults without knee osteoarthritis: population based observational study (Framingham, Osteoarhtirits Study). BMJ, vol. 345, pp. 5339

3. Brinijkji, W, Leutmer, PH, Comstock, B, Bresnahan, BW, Chen, LE, Deyo, RA, Halabi, S, Turner, JA, Avins, AL, James, K, Wald, JT, Kallmes, DF & Jarvik, JG (2014) Systematic literature review of imaging features of spinal degeneration in asymptomatic populations. AJNR Am J Neuroradiol, vol 36, no. 4, pp. 811-6

4. Pihl, K, Ensor, J, Peat, G, Englund, M, Lohmander, S, Jorgensen, U, Nissen, N, Fristed, JV & Thorlund, JB (2019) Wild-goose chase, no predictable patient sub-groups who benefit from meniscal surgery: patient-reported outcomes of 641 patients 1 year after surgery. BMJ, vol. 0, pp. 1-11

5. Thorlund, JB (2017) Deconstructing a popular myth: why knee arthroscopy is no better than placebo surgery for degenerative meniscal tears. BJMS, vol. 51, pp. 1575

6. Moseley, JB, O’Malley, K, Petersen, NJ, Menke, TJ, Brody, BA, Kuykendall, DH, Hollingsworth, JC, Ashton, CM, Nelda, MPH & Wray, NP (2002) A Controlled Trial of Arthroscopic Surgery for Osteoarthritis of the Knee. The New England Journal of Medicine, vol. 347, pp. 81-88

7. Bricca, A, Juhl, CB, Steultjens, M, Wirth, W & Roos, EM (2018) Impact of exercise on articular cartilage in people at risk of, or with established, knee osteoarthritis: a systematic review of randomised controlled trials. BMJ, vol. 0, pp. 1-9