Osteoarthritis
Arthritis occurs across all age groups in community and there are various types including inherited and inflammatory causes of joint pain, but the most common arthritis we discuss is osteoarthritis. Whilst there are many predisposing factors towards the development of osteoarthritis, particularly in weight bearing joints, the end result is primarily the loss of the protective cushioning cartilage (articular cartilage) over the ends of the bone surfaces resulting in less impact protection and break down of the cartilage cells causing joint swelling, inflammation and pain. Predisposing factors include genetics, joint injury, alignment issues and other potential factors which will be discussed in an accompanying article.
The impact of osteoarthritis in the community is enormous with millions of dollars a year spent on various treatments as well as the economic impact of productivity loss in the workplace.
What are common symptoms of osteoarthritis?
Common symptoms will be addressed in more detail, but they include:
1. Pain
2. Swelling
3. Stiffness
4. Weakness
5. Deformity and malalignment
6. Instability
7. Crepitus
8. Reduction in functional capacity
Pain
Pain is the primary symptom which causes most patients to seek medical help. It may initially begin as pain related to certain activities, but as the disease progression occurs pain can be disabling with impacts on sleep, work and pain at rest. Studies have shown that the protective articular cartilage cushioning on bone surfaces has little or no nerve supply, so the origin of pain is more closely linked to the sensitive pain receptors which are present in the lining of the joint, synovium, capsule and possibly related to the inflammatory chemicals which occur within the excessive joint swelling which can occur with osteoarthritis.
Swelling
Every synovial joint has important synovial fluid which serves a number of important roles, three of the most important of which are – joint lubrication, cushioning protection and most importantly nutrition for the articular cartilage cells (chondrocytes). The synovial fluid is produced by the sensitive synovium (lining of the joint). When the synovium is irritated by any number of processes, excessive synovial fluid is produced. Unfortunately the fluid is not always of high quality and therefore does not provide the important function mentioned above. When the synovial fluid contains irritant chemicals this process can stimulate the pain receptors causing excessive joint pain as well as the joint swelling (effusion).
Stiffness
There is a number of reasons why joint stiffness may occur. Sometimes it is related to the poor quality of the synovial fluid which loses its ability to provide its natural lubricant effect. More commonly stiffness is associated with the loss of movement as the joint gradually changes shape with bone osteophytes or spurs occurring around the margins and the thickening of the joint capsule and ligaments which lose their elasticity and prevent the joint from achieving its normal end range movements. This can have an impact on joint function, particularly in lower limb joints such as knees and hips.
Weakness
One important symptom is joint weakness and fatigue associated with the loss of muscle function around the damaged joint. As the joint becomes progressively sore, patients will often modify the way they use the joint resulting in muscle atrophy through disuse. This can result in the most simple tasks, such as getting out of a chair, climbing stairs or walking up a ramp more difficult and lead to an increase of pain production as well as lack of confidence.
Deformity/Malalignment
This is more important in the lower limb and refers to issues such as knee bow leggedness (varus) deformity or knock kneed angulation (valgus alignment). These malalignment issues cause uneven loading and wear on the sensitive joint surfaces producing specific increased breakdown of the articular cartilage. Patellar maltracking can lead to specific patellofemoral arthritis. Sometimes the malalignment is genetic eg. hip dysplasia or post traumatic following some of the older surgical procedures particularly in the knee where an open meniscectomy has resulted in progressive deterioration in the knee joint compartment with subsequent breakdown of one half of the knee causing malalignment issues.
Instability
When joint malalignment reaches a certain stage the angulation of the joint may result in the patient having a sense of the joint moving or giving way. This is particularly relevant in the knee where extreme varus or valgus malalignment positions can result in stretching of the soft tissue capsules/ligaments on one side of the joint resulting in lack of support. This makes patients very apprehensive with certain parts of their function mobility and can result in falls.
Crepitus
Crepitus refers to the various “noises” such as creaking or crackling which patients often experience when the joint is under movement or weight bearing. This is usually associated with the breakdown of the articular cartilage where uneven patches results in roughening of the remaining articular cartilage and is common place in early stages of the disease process. Whilst on its own this is not a concern, but it does reflect the evolving breakdown of the joint surface and the shedding of some of the articular cartilage surface may result in irritation of the joint producing the inflammatory synovial effusions.
Reduction in functional capacity
Patients will often put up with many of the above symptoms until it reaches a point where it impacts on their lifestyle. Where self management strategies are no longer working patients become limited in their ability to enjoy every day activities such as walking, golf, exercise, or even simple day to day functions such as shopping, they will present for medical advice on managing their joint condition. It is important to set realistic goals for these patients in relation to what can be achieved depending on the stage of their joint disease.
Treatment Goals
In the ideal world treatment programmes aim to address all of the above symptoms and minimise them to the best level possible. Whilst complete eradication of all symptoms is frequently not achievable there are many strategies that can be introduced to deal with the primary symptoms and allow patients to return to a realistic level of function. These strategies include:
1. Patient Education – in my practice this is the most important aspect of my treatment programme as it allows the patient to understand their condition, take responsibility for many of the strategies below and allows them to set realistic expectations on what they may achieve. The more a patient understands their condition, particularly the factors that trigger their pain episodes, the more likely they are to have a successful return of function with the treatment options available.
2. Pain Management – there are a variety of simple medications such as Paracetamol which should be tried firstly in an attempt to provide simple pain relief. This will also allow some of the other therapies including exercise programmes and rehabilitation to be undertaken more comfortably.
3. Non-steroidal Anti-inflammatories – when joint swelling and inflammation is obviously present there is a role for short use of oral anti-inflammatory agents to settle the inflammation process and reduce swelling as well as assisting with pain relief. Depending on the comorbidities of the patient (eg. heart disease, gastric disturbances, inflammatory bowel) there may need to be careful prescription of these medications together with some protective medication such as medication to assist with heartburn or reflux should is occur. Fortunately, in the majority of patients these anti-inflammatories can be used effectively as a minimum in the short to medium term.
4. Stronger Medications – the use of stronger pain relief eg. opioids, has a very limited role. There are concerns with over prescribing of the opioid pain relief medications and this has become a worldwide issue. If the pain levels are so high that patients are requiring narcotic based medications then other strategies need to be looked at more thoroughly.
5. Physical Therapy – this is a critical cornerstone of osteoarthritis management. Issues such as weakness, stiffness and joint swelling can be assisted by various modalities provided by a qualified physiotherapist or other clinician trained in the management of osteoarthritis. In addition the physiotherapist can assist with planning a home exercise programme to provide ongoing self management in the interval between formal therapy visits.
6. Injection Therapy – there are a range of joint injections which are available for assistance with osteoarthritis management. At the simplest level this might be an injection of corticosteroid in the short term to assist with joint inflammation and swelling and allow the joint to respond better to the other therapies. Repeated injections of corticosteroid are rarely required in osteoarthritis, but do have a short term role in certain patients, particularly when oral anti-inflammatory medication is not as effective. Other agents such as platelet rich plasma (PRP) or autologous blood injections (ABI) have become more popular in recent times, but still are undergoing research as to their exact role in controlling joint symptoms. They can be effective in certain patients, but often this is unpredictable. Joint viscosupplementation (HA Hyaluronic Acid) agents have been popular for many decades and are designed to restore the joint fluid to its more normal status. HA injections are synthetic derivatives of perfect synovial fluid and have a high success rate in appropriate patients for restoring the lubrication, cushioning and providing some nutrient value to the damaged articular cartilage. They can be of great assistance in joint preservation, but are not known to regenerate new cartilage cells at this stage. Other injections such as stem cells (primarily derived from fatty adipose tissue or bone marrow) are widely used in certain communities, but are extremely expensive and are still subject to research. They may have benefit in reducing pain and swelling, but their predictable benefit on articular cartilage regeneration has not been established. This is an important topic of research for the future in the hope that selective stem cell therapy (SSCT) can be derived so that the stem cells have a specific effect on chondrocytes, rather than a non-specific effect on joint symptoms. At this point in time they remain an overly expensive, unpredictable form of therapy.
7. Strength Training - One of the recent advances in osteoarthritis management has been the understanding of the role of muscle strength and stability in assisting joint pain. One of the most common symptoms mentioned above is joint weakness and lack of confidence and this has been bought about by muscle wasting. A guided resistance/strength training programme under the care of an experienced therapist can have dramatic benefits in improving joint pain, function and patient confidence. In addition to the formal resistance training sessions, patients can be instructed in a follow up home exercise programme which involves some strength exercises to maintain the benefit.
8. Load Modification – a critical part of the management programme (and usually the ongoing follow up) is identifying the various trigger factors that result in joint pain eg. excessive kneeling, flexing, and prolonged standing and looking at ways of reducing these loads in a patients day to day activities. This is part of the patient’s education process and goes a long way to allowing a patient, even with end stage disease, to function well without the need for more aggressive interventions.
9. Weight Loss – part of the load management strategy is reducing the weight on the joint. Patients who are excessively overweight are known to experience more joint pain, particularly in the lower limbs. There are some significant research studies which show that patients who lose 10% of their body weight have the reduction in their knee joint pain score of 50%. This is a very significant pain management strategy and needs to be addressed early with the patient who presents for assessment and has problems with being overweight or obese.
10. Nutraceuticals – there are many products available in the market which do not require medical prescription, but are marketed and popularised for their advertised joint pain benefits. Classic products such as glucosamine, fish oil, turmeric and other “natural anti-inflammatories” are widely available. Whilst the scientific studies of these are quite weak or contradictory from anecdotal and testimonial views many patients have noticed an improvement in pain and swelling with their use. Whilst I do not advocate spending a lot of money on unproven supplements, patients will often have a trial of these products for a 3 to 6 month period to see if they assist with their pain management.
11. Surgical Options
1. Arthroscopy – there is no doubt that introduction of arthroscopic surgery in the 1970s has revolutionised joint surgery, especially in knees. The advantages of minimal invasiveness, shorter hospital stays and faster rehabilitation have been a game changing improvement in patient outcomes and health care costs. Its’ role in simple mechanical problems such as a meniscal tear, loose body, or unstable cartilage flap removal are well established. The role of arthroscopy in management of medium to end stage osteoarthritis however remains controversial. Whilst it is true that arthroscopy cannot replace damaged joint tissue, my experience has been that it has a definite role in improving those patients who have mechanical symptoms such as loose bodies, locking or catching which are causing significant pain episodes, instability and joint swelling. Whilst there may be a limited role in arthroscopy in advanced osteoarthritic changes in the joint, patient selection becomes critical for the clinician and the ability to stabilise the patients’ mechanical symptoms and pain where medium term gains are often in the 3 to 5 year time period are worth considering. This is particularly relevant where the patient has had a stable osteoarthritic joint, feeling well with their symptoms, then a single incident such as twisting or slipping introduces new symptoms such as more frequent catching or locking associated with an unstable meniscochondral segment. In these situations joint arthroscopy can be of significant benefit regardless of the age of the patient or the state of their degenerative knee.
2. Joint Realignment Surgery – the ability of modern surgery techniques to correct limb alignment, particularly in the lower limb, has been beneficial. Knee realignment procedures can be performed to deal with excessive valgus or varus malalignment, can assist in avoiding the need for more significant joint replacement surgery for many years in appropriate patients. Similarly hip realignment surgery, particularly in the younger patient, has assisted in slowing the progression of joint deterioration. These decisions need to be taken in the full light of discussion with the treating clinician.
3. Joint Replacement Surgery – when all of the appropriate non operative treatment measures have failed to provide adequate pain relief (pain being the key indicator for patient dissatisfaction) then joint replacement will be discussed. This continues to be an evolving area of expertise and surgical techniques and available implants are constantly changing. Nevertheless, following joint replacement surgery the expectation would be that patients obtain significant pain relief, return of function and the ability to go back to many of their lifestyle activities they had previously had to curtail. Again, realistic expectations need to be discussed with the patient prior to surgery as high impact sports and certain other physical activities are not compatible with the long term beneficial results of joint replacement surgery, particularly in hips, knees and ankles.
Summary
Joint osteoarthritis is a major cause of disability and health care costs in the community.The causes and symptom combinations are generally well documented and there are many non-operative interventions that can be considered.It is important to undertake optimal non-operative treatment (whether that be short term or long term) before deciding that major joint replacement surgery is indicated.