Knee injuries are among the most common musculoskeletal injuries sustained by active individuals during sport and exercise. As many as 1 in 20 young female athletes will tear their anterior cruciate ligament (ACL) during pivoting and cutting sports such as soccer, basketball or skiing.
In North America, the standard treatment for knee injury is ACL reconstruction followed by extensive physiotherapy with the goal of restoring range of motion and strength to allow full functional recovery and return to sport. Typically, this rehabilitation period is considered to last about one year. However, the long-term consequences of knee injuries are known to have serious long-term ramifications that persist well beyond this time frame.
Between 20-50% of individuals with a previous ACL injury will go on to develop osteoarthritis (OA) in their knee within the next few decades. This means the 16-year-old who suffers an ACL tear during a soccer game, may have OA before turning 40 years old. OA is a chronic disease characterized by persistent joint pain and stiffness that progresses to limit activity level and restrict mobility. Reconstruction surgery does not prevent the future development of OA. However, there is evidence to support some key strategies on how to maximize long-term joint health. Below are further details about these principles and how they can be applied to everyday life.
- Ensure you make the most of your rehabilitation in the first year after knee injury or surgery: The physiotherapy required after a major knee injury can be overwhelming, but it is essential to persevere and complete a comprehensive rehabilitation program. The approach should be progressive from early acute management through to late sport or activity specific training.
- Avoid a second knee injury: Up to one quarter of individuals will re-tear their ACL graft or injure their other knee. Returning to sports before 9 months greatly increases the risk of re-injury. Ensure you are physically and mentally prepared to return to sport and physical activity.
- Maintain a healthy body weight: Excessive body weight increases the mechanical load on your knee joint with every step. In addition, body fat releases chemicals that promote systemic inflammation which can contribute to further joint damage. Being overweight or obese is one of the top risk factors for developing OA. Even a small reduction in weight can have large benefits in reducing pain and symptoms.
- Engage in regular knee specific and core exercises: There is strong evidence that having strong, coordinated muscles to support your knee is critical both in prevention and management of OA. This might be as little as 20 minutes of home exercises 3 times per week, although monitored or supervised programs have been found to have better results in terms of reducing pain and improving function.
- Be physically active: While exercises are targeted to address a specific goal, physical activity is any activity that involves body movement and increases your heart rate. Canadian physical activity guidelines recommend 150 minutes/week of moderate to vigorous physical activity for all adults. Importantly, physical activity will explicitly contribute to cartilage health through the repetitive loading and unloading of the joint during activity.
- Do not excessively load the knee: It will take a LOT to overload the knee joint. For example, a physically demanding job that involves hours of daily kneeling or squatting or intensive high-level training as an elite athlete. For the vast majority of the population, overloading the knee should not be a concern.
- Embrace a positive mindset: After injury many people struggle with a fear of re-injury or lack of confidence in their knee. Remember it takes time to heal, build strength, and progress your physical activity. Be realistic with your beliefs and expectations. By following many of these tips above you can re-frame your sense of control and know that you are establishing a strong foundation for the best future long-term health of your knee.
Don’t forget to consult with your CAMPT-Certified Physiotherapist for further assessment and advice!
- Whittaker JL, & Roos EM. A pragmatic approach to prevent post-traumatic osteoarthritis after sport or exercise-related joint injury. Best Practice & Research Clinical Rheumatology. 2019,33;158-171.
- Davis AM, Chahal J, Wong R et al. Limiting the risk of osteoarthritis after anterior cruciate ligament injury: Are health care providers missing the opportunity to intervene? Arthritis care Res 2020; online ahead of print.
- Ezzat AM, Whittaker JL, Toomey C et al. Knee confidence in youth and young adults at risk of post-traumatic osteoarthritis 3-10 years following intra-articular knee injury J Sci Sports Med 2018;21(7):671-675.
About Allison Ezzat
Dr Allison Ezzat is a Canadian physiotherapist and clinical researcher working at La Trobe Sport and Exercise Medicine Research Centre in Melbourne, Australia. Her research focuses on using process evaluation and implementation science to advance the prevention of knee injuries and improve access to non-surgical care for people with knee osteoarthritis. Clinically, she currently delivers the GLA:D Canada program, an individualized group-based education and exercise class for individuals with hip or knee osteoarthritis to patients in British Columbia via telehealth through North Shore Sports Medicine in North Vancouver. You can find out more about Allison on Twitter or by contacting North Shore Sports Medicine.