In recent years, the medical approach to OA has shifted from a purely structural pathology model to a more holistic biopsychosocial model. This is due to the increasing evidence that OA symptoms do not always relate to the degree of joint damage seen on radiographs. The biopsychosocial model explores how biological, psychological, and social factors interact to cause disease and influence functional illness. This newer model of OA has led to the emerging field of OA phenotyping, which aims to classify different OA subgroups based on features such as genetic predisposition, systemic factors (e.g. metabolic syndrome), local biomechanical factors, and inflammatory factors. This, in turn, is hoped to allow more targeted treatment to different OA subgroups and thus improve patient outcomes.
Osteoarthritis (OA) is a major source of chronic disability. The knee is one of the commonly affected joints, with the prevalence of knee OA likely to increase in the coming years. The main reason for this is the increasing proportion of elderly persons and also the global obesity epidemic, as increased weight is a major risk factor for developing knee OA. The management of knee OA is often challenging, as it is a complex disorder with both mechanical and inflammatory components. It is the mechanical symptoms which often pose the greatest problems to patients and substantially impair their quality of life. These include pain, stiffness, swelling, and loss of function. This is because unlike other degenerative joint disorders, OA pain often occurs at rest or at night, which affects sleep quality and psychological health. Persistent pain may also lead to a reduction in muscle strength, which causes further loss of joint stability and hence a progressive increase in deformity and loss of function. This, in turn, creates a cycle of more pain and further disability. Joint replacement is the only definitive treatment for end-stage knee OA to improve pain and restore function. However, the treatment of early to moderate stage knee OA has historically been unsatisfactory with very few evidence-based treatment options.
Understanding Knee Pain
The knee joint is situated between the femur (thigh bone) and the tibia (shin bone). It is a hinge joint, meaning it can bend and straighten, and its main function is to provide motion. The joint is a meeting point of various bones, cartilage, and ligaments which are all prone to injury and stress. Damage to any of these parts may result in discomfort and pain. The knee joint is connected to the largest muscle in the body, the quadriceps which provides the main force for bending and straightening the leg. The motion of the knee is therefore dependent on the condition of the muscles that support it. Cartilage is located on the ends of the bones and works as a cushion to stop them from grinding against each other. There are 2 types of cartilage in the knee. Articular cartilage, which covers the ends of the bones and is present to allow the joints to glide effectively, and the ‘tibial’ or ‘meniscal’ cartilage which are C-shaped areas on the top of the tibia. These act as a shock absorber for the bones to prevent damage during weight bearing activities. Cartilage is a common source of knee pain when injured. The back of the kneecap also has articular cartilage to help it glide in the femoral groove during movement.
Holistic Approaches to Knee Pain Management
Physical therapy and exercise were established to be a common method of treatment for knee pain. Mr. Tan, a physiotherapist of 12 years, says that strengthening the muscles supporting the knee is very important in preventing and managing knee pain because the knee is a joint which is greatly affected by the forces exerted on it and the surrounding muscles absorb this force. If the force is uneven in strength in the muscles, which is usually the case for people with knee pain, it will cause an imbalance and lead to further injury in the joint. For example, an overweight person with knee pain decides to walk and exercise to lose weight. However, walking creates 3-6 times the body weight in force on each knee. The increased force can lead to increased pain and further injury. Therefore, the muscles surrounding the knee have to be strong to absorb this force.
Due to the fact that there are various severities of knee pain, there are also various ways to manage and reduce the pain. Our main focus of this article is to discuss the various holistic approaches to managing knee pain, insight from the specialists in knee pain Singapore.
Knee pain is a common problem with many possible causes. It can be the result of an injury, such as a ruptured ligament or torn cartilage. Some medical conditions which lead to knee pain are: gout, infections in the joint, and inflammation. One of the main causes is from the degeneration of the articular cartilage which can lead to a result of the bone-on-bone contact and the pain from this situation can be very severe. Obesity is also another common cause for knee pain.
Physical Therapy and Exercise
In the case of knee osteoarthritis, exercise can alleviate pain and improve function, particularly in the long term. In a review of 32 exercise-based clinical trials, it was found that exercise has a moderate effect in reducing pain and improving physical function. The effect size increased with the length of the clinical trial, indicating that exercise has cumulative long-term benefits. Different forms of exercise therapy have been evaluated and compared. Land-based therapeutic exercise with strengthening, flexibility and aerobic components are effective in improving strength and functional capacity. Comparable benefits were also seen with aquatic exercise, which appears to be a feasible alternative assuming patients have access to a pool. High intensity aerobic exercise may also be effective in reducing pain and improving function, although the association between increased aerobic activity and disease progression requires investigation with long-term studies.
Medications and Injections
Additionally, some patients may feel that physical therapy is simply too time consuming or are unable to perform the prescribed exercises due to weakness or pain. In these cases, treatments such as manual therapy and low-level laser therapy may be beneficial. One randomized control trial showed that a combination of glucocorticoid injection and physical therapy demonstrated greater improvement in knee function and reduction of pain compared to physical therapy alone. Unfortunately, glucocorticoids have the potential to cause cartilage thinning and weakened tendons/ligaments with long-term use and are not recommended for usage beyond 3-4 injections per year. Lastly, viscosupplementation is a procedure in which hyaluronic acid is injected into the knee joint. This treatment is based on the idea that osteoarthritis is, in part, caused by decreased viscosity of synovial fluid, leading to increased friction and damage in the joint. Although viscosupplementation is widely used throughout the world and is covered by health insurance in some countries, recent studies have called its efficacy into question, citing conflicting evidence in multiple reviews.
Complementary and Alternative Therapies
As these therapies are not seen as mainstream medicine, they have often been poorly understood. The chapter begins with a discussion of how these therapies can be better understood through an improved understanding of the placebo effect. It is suggested that future research and a change in perception may bring about integration of complementary and alternative therapies with more traditional medicine. The reader is then given the viewpoint of some specialists in Singapore. They seek to clarify what exactly these therapies entail and follow with a discussion of patient demand, suggesting that to meet this demand, more education for patients and knee pain specialist is required. A common perception of knee pain is that there are few treatments for such a problem. It is suggested that both the variety of complementary and alternative treatments, as well as the possibility of it being integrated with traditional medicine, may change this perception. It is hoped that improved understanding and further research of these therapies can serve to ultimately improve the management of knee pain.
An additional review after 2 years is recommended to determine long-term improvements in symptoms and function. This is in contrast to a study which suggests there is efficacy of IA HA that may extend beyond the duration of the treatment period. The amount of HA to be injected is another issue to be addressed. It is noted that some of the previous negative studies had used low-dose HA and that higher molecular weight HA has better effects on symptoms, function, and pain relief.
The specialists point out that knee OA is a heterogeneous disease and there are patients who appear to have more consistent pain relief with IA HA. Unfortunately, there is no clear predictor of response to therapy. The specialists are keen to identify the patient characteristics associated with good response to IA HA. This may help in the selection of patients who are more likely to benefit from the therapy.
The specialists are generally in agreement that IA HA is a viable option for treatment of knee OA and should be considered by patients who have not achieved adequate symptom relief with conservative non-pharmacological therapies and simple analgesics. This is in line with the recommendation by OARSI that patients whose symptoms are not adequately improved with non-pharmacological and pharmacological therapies (e.g. acetaminophen, NSAIDs) should consider IA HA therapy, taking into account the variability in patient response to therapy.
Singaporean orthopaedic surgeons and rheumatologists have reviewed the available evidence and come up with a set of recommendations on the use of IA HA for knee OA for local practice. This paper outlines the evidence and recommendations and discusses how the HA therapy may be further improved to benefit the knee OA patients in Singapore.
Knee osteoarthritis (OA) is a chronic illness prevalent among the aged population that is associated with tremendous pain and reduced function. Intra-articular (IA) injection of hyaluronic acid (HA) has been shown to improve the symptoms of knee OA in some patients. The therapy is not effective for everyone and there is wide variation in patient response.
