Osteoarthritis (OA) is one of the most common forms of musculoskeletal disorders, and its slow development over 10-15 years interferes with daily living activities and the ability to work. Clinically, OA is characterized by joint pain and crepitus, stiffness after immobility and progressive limitation of movement leading to loss of joint function in the more advanced stages. OA can develop in any joint but most commonly affects the knees, hips, hands, spine, and feet. OA of the hip and knee are responsible for a severe disease burden and, when considered together, are ranked number 11 of the 291 illnesses listed by the WHO based on years lived with disability. Involvement of the knee is second only to that of the hands, and the female-to-male ratio varies between 1.5: 1 and 4: 1.
What Are The Risk Factors For Osteoarthritis?
Both systemic and local factors determine the risk of developing OA. Several systemic factors have been identified, such as age, sex, obesity, inactivity and genetic factors; these can increase the joints’ susceptibility to injury, directly damaging joint tissues or impairing the repair process in damaged joint tissue. Local factors are most commonly biomechanical and negatively affect the forces applied to the joint; among these, we still find obesity, typical morphology and alignment, loss of muscle quality and trauma.
Is It Possible To Prevent It?
Osteoarthritis is amenable to prevention and early treatment. Primary and secondary prevention strategies are needed to prevent an aging population’s increase in OA rates. Techniques developed for knee OA may not be transferable to other joints due to anatomical differences. Primary prevention strategies aim to prevent the onset of the disease; secondary prevention, on the other hand, includes identifying and treating risk factors for progression in subjects already at risk. Below are five prevention elements that show promising results for both primary and secondary interventions.
Obesity rates are increasing dramatically in most areas of the developed world, with populations becoming more affluent and sedentary. Most worrying is the high rates of childhood obesity in industrialized countries. Weight reduction interventions have been relatively ineffective at the population level, although evidence suggests several successful strategies are available at the individual level. Clinical trials’ results have demonstrated several interventions’ ability to reduce weight in the short and medium term, and studies are now addressing the more difficult problem of maintaining weight loss for more extended periods. For those who associate exercise with diet, the weight loss maintenance rate increases; another strategy for maintaining weight loss is cognitive-behavioral psychotherapy.
Preventing Complications From Trauma
Early intervention, focusing on preventing knee injuries in young adults, has excellent potential to reduce the OA burden on the knee. Such prevention will reduce the risk of consequences for the individual throughout his life, in terms of symptoms, function and participation in work and recreational activities. Most knee injuries occur in sports and are more common in women than men. Although patients are often classified as having an anterior cruciate ligament (ACL) injury, these injuries are rarely isolated. Conversely, concomitant menisci, cartilage, bones or other ligaments are almost always observed.
About 50% of people with anterior cruciate ligament injury develop OA in 10-15 years, regardless of whether or not they have undergone reconstructive surgery. An analysis of 27,000 individuals found that neuromuscular and proprioceptive training programs successfully prevented about 50% of ACL injuries. These programs typically take 10-20 minutes to run and generally replace the ordinary warm-up session before sports 2-3 times a week. In addition, they usually also involve awareness education of high-risk positions. Neuromuscular physical therapy is based on biomechanical principles, targets the sensorimotor system, stabilizes the joint during movement and improves the patient’s confidence in the knee. Additionally, like aerobic exercise and strength training, it provides effective pain relief in people with established OA.
Improve Muscle Quality
Muscle weakness can be a significant risk factor for knee OA. Men and women with pre-existing radiographic evidence of knee OA were identified as having weaker quadriceps than those without OA, mainly when joints are symptomatic. A consequence of quadriceps weakness is that the knee becomes less stable during physical activity. Quadriceps exercises may offer a protective benefit to patients involved in activities associated with a high risk of OA or in patients who have already suffered knee trauma. Greater muscle strength is not always protective, as it corresponds to higher forces and, therefore, to an increase in joint load during activity.
In healthy knees, quadriceps muscle strength protects against new osteoarthritis. In arthritic knees, increased strength can protect the joints and thus delay the progression of osteoarthritis; however, in some collaborative environments, such as malalignment or laxity, the increased force can translate into harmful joint reaction forces. The relationship between quadriceps strength and the progression of knee osteoarthritis may differ based on these factors.
Undergo Drug Therapy
Knee osteoarthritis is characterized by joint pain. Consequently, acetaminophen and non-steroidal anti-inflammatory drugs (NSAIDs) are generally recommended in clinical practice. However, due to their vascular and gastrointestinal toxicity, the risk-benefit balance of these fast-acting drugs may not be favorable, particularly for long-term therapies and the aging population.
For this reason, treatment with intra-articular injections of corticosteroids or hyaluronic acid has become increasingly popular. Since systemic absorption occurs after corticosteroid injection, systemic adverse events can be expected, and precautions should be observed in patients with concomitant diseases such as hypertension or diabetes mellitus. For this reason, combined with greater effectiveness, hyaluronic acid has become increasingly popular for the prevention and treatment of knee OA.
If physical therapy is considered an active approach involving the sensorimotor system, including muscles, passive approaches are also available to improve joint biomechanics. Most commonly, knee pads and shoe modifications have been studied, used alone or in combination. In addition, wedge braces and orthotics were tested in patients with established knee OA. Their variety, or the mount alone, reduces pain and somehow shifts the load on the knee to the unaffected side.
This change in load or contact stress could delay or prevent the onset of OA. These are promising strategies, but poor compliance is a problem, and further device development and clinical trials are needed. To conclude, let’s summarize the critical points for the prevention and treatment of osteoarthritis of the knee :
- Obesity is a significant risk factor for OA, and weight loss effectively reduces the risk of OA, but adherence to interventions is poor and should be addressed with personalized strategies.
- Neuromuscular training programs successfully prevent 50% of knee injuries, most frequent during sports, indicating that primary prevention of knee OA is possible.
- About 50% of people who experience a severe knee injury, with or without surgical reconstruction, develop knee OA, and secondary prevention (neuromuscular physical therapy, aerobic exercise, and strength training) could be valuable.
- Joint infiltrations, mainly with hyaluronic acid, are effective in preventing and treating OA.