MasterclassKnee osteoarthritis: key treatments and implications for physical therapy
Introduction
Life expectancy has increased globally over time; however, the growing burden of chronic diseases results in a large portion of society living longer, but in poorer health.1 This scenario is indeed a reality for people suffering from one of the leading causes of chronic pain and disability worldwide, knee osteoarthritis (OA).1 The disease is ranked as the 10th largest contributor to global years lived with disabilities,2 and its prevalence has more than doubled in the last 10 years.1, 3 In addition, medication intake, hospital stays, and joint surgeries associated with managing knee OA impose billions of dollars per year in costs to healthcare systems.2, 3
The pathology of knee OA affects the whole joint, causing synovial inflammation, cartilage damage, bone remodeling, and osteophyte formation.4 Typical symptoms include pain, muscle weakness, joint instability, brief morning stiffness, crepitus, and functional limitations.4 Frequently, symptoms are related to physical inactivity, which has been linked to morbidity and mortality in the contemporary era and is a significant contributor to the incidence of chronic diseases worldwide.5, 6 Methodologically rigorous international guidelines strongly recommend non-pharmacological strategies as the first line of treatment for knee OA.7, 8, 9, 10, 11, 12, 13 Exercise, patient education, and weight loss – when needed – are the recommended first-line strategies to manage symptoms of these patients.7, 8, 9, 10, 11, 12, 13
There is high-quality evidence demonstrating the effectiveness of education and exercise to improve function in individuals with knee OA.8, 13 Data from 9825 patients with hip or knee OA showed that a 6-week combination intervention comprising three sessions of patient education delivered over the course of two weeks and 12 sessions of neuromuscular exercise delivered twice per week had beneficial effects on OA symptoms, physical function, medication intake, and sick leave time.14 Furthermore, some beneficial effects introduced by the interventions, including increased physical activity and quality of life, were maintained after one year. These results suggest that a combination of education and exercise could result in long-term reductions in the burden of knee OA and its costs to patients and the healthcare system.
Although non-pharmacological strategies are of paramount importance, less than 40% of patients with knee OA receive this kind of treatment approach, indicating that the uptake of evidence-based guidelines in clinical practice and rehabilitation is still suboptimal.14, 15 Instead, pharmacological strategies remain dominant, despite the fact that chronic use of many of these treatments has been associated with severe adverse side effects.16, 17 The neglect of evidence-based strategies in clinical practice applies to both clinicians and patients. Factors such as the strong beliefs regarding old and low-value treatments, the lack of knowledge regarding current evidence, and a significant increase in the number of current published guidelines are considered barriers to the successful adoption of evidence-based clinical practice.18, 19, 20
A basic understanding of treatment strategies for knee OA is necessary to target and improve rehabilitation. In this article, we aim to provide updated information for physical therapists and show that exercise, weight maintenance, and patient education are vital for the optimal treatment of knee OA. We also aim to describe key outcome measures used in knee OA studies and to increase awareness about useful tools for data collection for clinicians and researchers.
Section snippets
Non-pharmacological strategies
Current clinical practice guidelines recommend education and self-management, exercise, and weight loss (for overweight or obese patients) as the first-line treatments for knee OA.7, 8, 9, 10, 11, 12, 13 We consider these strategies to be the core of knee OA rehabilitation, because they have been proven to effectively decrease pain and improve overall joint function and patient quality of life. In patients for whom knee OA has a significant impact on ambulation or joint stability, or for whom
Adjunct therapies
Several adjunct therapies are used as complements to core knee OA treatments with the goal of maximizing outcomes for patients. Thermal modalities, laser therapy, therapeutic ultrasound, electrical stimulation, manual therapy techniques, taping, acupuncture, among others, are some interventions that are commonly used. For this article, we will review some of the adjunct therapies most commonly used by physical therapists in treating knee OA, providing details about the quality of evidence and
Pharmacological strategies
For knee OA, local therapies are preferable as core pharmacological treatments. Appropriate monitoring of the patient during a pharmacological treatment, especially for the development of adverse effects, is also recommended.
Surgery
Surgery is typically a last resort for the management of knee OA. Unfortunately, a vast majority of physicians deviate from evidence-based practice regarding surgical management of knee OA. From the variety of options available, arthroscopic knee surgery, specifically arthroscopic joint lavage, is the most common procedure performed.4, 73 However, several high-quality studies have demonstrated the low efficacy of arthroscopic surgery in terms of pain relief and physical function improvement in
Key outcome measures
For researchers aiming to improve data collection in knee OA studies and for clinicians treating patients in clinical practice, there are well-established core outcome measures that can be used to evaluate the domains of pain and physical function of patients.8, 13, 85, 86, 87 In Table 1, Table 2, we provide a comprehensive description of some of the critical subjective and objective outcome measures used in knee OA studies, respectively. In addition to the content provided in the tables, the
Future perspectives
Although research in OA has been documented for more than 100 years, there are still no successful therapies to stop or reduce the progression of joint degeneration. However, with technological advancements, new approaches and therapies are emerging to aid these patients.
Biomaterials such as scaffolds, hydrogels, microspheres, and nanofibers associated with cutting-edge advances in cell-based approaches that focus primarily on cartilage regeneration, hold promise in the regeneration of the OA
Conclusion
Osteoarthritis is one of the most frequent diseases worldwide. The burden to society and health care systems is gradually increasing. It is our duty as healthcare professionals to leverage our access to high-quality evidence to increase the number of individuals receiving the appropriate core non-pharmacological treatments for knee OA. By doing so, we can increase the uptake of evidence-based guidelines in clinical practice of physical therapy. Patient education, exercise, and weight
Conflicts of interest
The authors declare no conflicts of interest.
Acknowledgements
L.O. Dantas is a Ph.D. researcher from the São Paulo Research Foundation (FAPESP, Process number #2015/21422-6).
References (108)
- et al.
Risk factors and burden of osteoarthritis
Ann Phys Rehabil Med
(2016) - et al.
Osteoarthritis
Lancet
(2019) - et al.
OARSI guidelines for the non-surgical management of knee, hip, and polyarticular osteoarthritis
Osteoarthr Cartil
(2019) - et al.
Too much opioid, too much harm
Osteoarthr Cartil
(2018) - et al.
Osteoarthritis year in review 2019: epidemiology and therapy
Osteoarthr Cartil
(2020) - et al.
Wise choices: making physiotherapy care more valuable
J Physiother
(2017) - et al.
Osteoarthritis year in review 2019: rehabilitation and outcomes
Osteoarthr Cartil
(2020) - et al.
Do we need another trial on exercise in patients with knee osteoarthritis?
Osteoarthr Cartil
(2019) - et al.
Dose–response effects of tai chi and physical therapy exercise interventions in symptomatic knee osteoarthritis
PM&R
(2018) - et al.
Exercise in osteoarthritis: moving from prescription to adherence
Best Pract Res Clin Rheumatol
(2014)