How do you Treat Osteoarthritis?

The overarching principle in the management of Osteoarthritis is to retard the progression of the disease, lessen the associated symptoms, and to improve functional capacity in the context of the disease.  A notable omission from that list is cure.  Unfortunately, the damage that occurs in the process of this illness is irreversible.  Although research continues into stimulating the re-growth of native cartilage as well as, perhaps unrealistically, preventing the onset of the disease altogether, the clinical benefits of these efforts are still some time away.

Therefore, in the absence of a cure, intervention is directed at achieving the aims of therapy as mentioned above.  This involves a combination of pharmacological, physical, and (when necessary) surgical therapies.  An important issue to mention at this point is that the treatment of Osteoarthritis depends heavily upon the investment/engagement of the patients in their own care.  This will become apparent in the discussion to follow, suffice it to say that a major obstacle to optimizing the outcomes of treatment is the attitude embodied by the patient.  That is that many patients hold the idea that Osteoarthritis is ‘just a part of aging and so I just have to learn to live with it’.  Although this is true in part, this belief too often results in unnecessary suffering on the part of the patient and increases the overall burden of this disease upon them.  This is an interesting contrast to their attitudes to diseases like high blood pressure or elevated cholesterol, for which they readily comply with treatment, despite the disease being silent and having minimal impact upon their lives!

So, considering this call to action for patients with Osteoarthritis to engage in the treatment of their disease, let us further explore the physical and lifestyle interventions recommended.  This is often referred to as non-pharmacological treatments; however, I believe this is misleading since it gives the impression that medications form the foundation of treatment in this condition.  Instead, I would argue that these physical and lifestyle therapies should be acknowledged as the cornerstone of treatment.  In fact, at present, it is these interventions alone that are able to affect the long-term outcome of the disease.

As had been described and explained in the section ‘What is the pathophysiology of Osteoarthritis and what are the risk factors towards its development’; the forces imposed upon a joint contributes significantly to the onset and progression of the disease.  These forces are influenced by a number of factors, such as a person’s body weight (for the weight-bearing joints), the flexibility and strength of surrounding muscles, the overall alignment of the limbs and spine, as well as the activities performed.  Therefore, an approach that identifies these biomechanical issues and sets a plan to address them should be implemented.  The derivation of such a program should optimally involve a multidisciplinary team.  That is, not only the doctor, but also allied health professionals including physiotherapists, exercise physiologists, and dieticians.

Discussions about weight loss can be a vexed issue but in Osteoarthritis, particularly at the knee, it is unavoidable and of crucial importance.   The positive aspect of this topic is that there exists a significant relationship between weight loss and an improvement in osteoarthritic symptoms.  Even modest amounts of weight loss, in order of 5kg, can have a positive effect⁷.  It has been calculated that for every kilogram of weight lost there is 4kg less load exerted through the knee with each footstep⁸.  Most recently and rewardingly, weight loss has also been shown to preserve the amount of cartilage present and thereby have a disease modifying effect⁹.  Therefore, there is no longer any excuse for a patient presenting with Osteoarthritis (especially with involvement of the knee joint) not being counseled on a weight loss program, most likely best achieved with the assistance of a dietician.  On occasion even bariatric surgery may need to be considered.

Aerobic and resistance exercise is an integral part of any comprehensive weight loss program, and that is especially the case when the indication for exercise is Osteoarthritis¹⁰.   However, a common difficulty is that the disease itself often makes the performance of exercise a challenge.  Therefore, considerable thought is needed in deciding upon which aerobic activity is most appropriate.  Weight-bearing exercises such as walking and jogging are usually most popular with patients, as very little equipment or resources are necessary, however, when the lower limb joints are involved this is generally associated with an increase in pain.  In that case alternatives such as riding a bike or swimming may be better options.  An exercise physiologist can be most useful in navigating these choices as well as giving specific advice regarding the frequency, intensity, and duration of exercise.

An interesting development in the understanding of osteoarthritis relates to the effect of the metabolic syndrome, as mentioned previously, with specific reference to diabetes.  Weight loss and aerobic exercise are fundamental components in the management of diabetes and the associated metabolic syndrome as they are in Osteoarthritis.  Consequently, when considering the motivations to implement these lifestyle changes, patients should be informed that the benefits extend beyond the joint, including their general wellbeing and the promise of a brighter long-term health outcome.

In addition to the aerobic exercises recommended, specific exercises that aim to strengthen particular muscles are also of value.  The example that is perhaps best known is the role of core muscle strength in the management of osteoarthritis affecting the lumbar (lower) spine.  Strengthening of these muscles assists in dissipating the forces that are transmitted across the injured spine such that those joints are in effect unloaded.  Similar examples can be given for all the other joints, such as strengthening the quadriceps for arthritis of the knees or the rotator cuff muscles for the shoulder.  Physiotherapists, I believe, are best placed in the prescription, supervision, and progression of such exercise programs.

Further to this physiotherapist are most valuable in identifying and correcting other contributing physical factors that may relate to the onset of the disease as well as its progression.  To address these issues they may employ exercises that aim to stretch tight structures, such as muscles, as well as appropriately introduce external supports to redirect forces away from the most affected parts of a joint.  An example of this would be the provision of orthotics, which a sufferer would place within their shoes, for the treatment of arthritis within the feet as well as at the knee and (even) spine.  Finally there are modalities that the physiotherapists can use specifically to assist with pain relief, such as intereferential therapy/TENS and hot packs.

Considering the issue of pain relief in Osteoarthritis, pharmacological interventions have evolved to take a central part in this regard.  There is a broad range of options available to the clinician with the general principle being to use the minimal amount of medication to render the pain tolerable (since complete pain relief may be unrealistic).  Therefore, in absence of an acute flare, most doctors will commence with the weakest analgesic, adding others as the need dictates.  The current guidelines recommend paracetamol as first-line therapy, with regular dosing (such as two tablets twice daily) being most effective.  Although paracetamol is generally considered to be safe when used as recommended, there is potential for complication that at the extreme can be life threatening.  Paracetamol has anti-inflammatory activity similar but less potent to the class of medications referred to as Non-Steroidal Anti-Inflammatory Drugs (NSAIDs).

There are a number of NSAIDs available, some of which in Australia can be purchased over the counter at pharmacies and other selected stores.  These can be either in the form of a cream or ointment, which can be applied to the area of pain, or taken as a tablet or capsule.  When compared to paracetamol overall, there has not been shown to be any difference in the effect on pain relief.  However, the majority of patients preferred the NSAID compared to paracetamol.  However, there are a number of problems that may arise as a result of their consumption, some of which having recently attracted a significant amount of media attention.

The most common complication in the past was bleeding from the upper gastrointestinal tract arising from ulcers that formed due to NSAID use.  This was found to be due to the fact that these NSAIDs blocked the production of the prostaglandin (a chemical), whose role it is to protect the lining of the stomach from the effect of the acidic environment.  Scientists then went to work in order to produce NSAIDs that did not result in such an outcome.  They were able to achieve this by producing NSAIDs that blocked only the specific enzyme that relates to inflammation, termed COX-2.  As a group, these have been called COX-2 inhibitors to differentiate them from the non-selective NSAIDs that block both COX-1 and COX-2 enzymes.

These COX-2 inhibitors have demonstrated an increased risk of significant cardiac side effects, especially in those at high risk.  Subsequent studies, however, found that this concern extended across the entire class of NSAIDs.  Therefore, prior to their use, the clinician should assess the risk of cardiovascular disease and alternatives considered when the risk is moderate or high.  A number of complications can result from the use of NSAIDs, of which the most important to mention includes impairment of kidney function and elevation of blood pressure.  Hence it is suggested that patients should have their kidney function and blood pressure monitored whilst on these treatments.

As a result of the benefit:risk ratio; NSAIDs are generally reserved for when the pain of the disease flares.  In that situation, it is often added to the regular Paracetamol and used for as short a period as required.  If the pain has not settled to previous levels after 2-3 weeks then the clinician will often consider other options/interventions.  A personal preference is the use of a COX-2 inhibitor such as Celecoxib on the basis of a lower rate of gastrointestinal complications as long as there is a low cardiovascular risk.

In some, however, their pain persists despite these interventions and the clinician is then left to explore the other options available.  These include the intra-articular injection therapies, corticosteroid, Protein-Rich Plasma (PRP) and hyaluronic acid, and the opiate (morphine like) medications.  Generally the latter are reserved as last resort treatments in those not suitable for a surgical procedure, given that these are addictive and often associated with complications including constipation and drousiness.  Of the injection treatments, costicosteroids are the most frequently used.  These steroid injections can be quite effective in settling a flare of the disease but the duration of the effect is variable.  On their own symptoms may be lessened for up to 3 months, although the effect can be prolonged if other interventions (especially the physical treatments) are simultaneously implemented.  Hyaluronic acid is purported have a longer duration of effect compared to steroid injections, however, patient selection is crucially important and at present there are few studies to support the use of PRP.  Currently, these therapies are not subsidized and as such can be quite costly to the patient.

There is a common belief held by many patients that there is only a certain number of steroid injections that can be performed.  This evolved as a result of previous reports that suggested that these injections cause further cartilage damage.  However, that has not been reproduced by more recent investigations into this issue.  Having said that though, there are a number of potential complications that can ensue from a steroid injection.  The most serious of these is infection.   The risk of infection has been estimated to be between 1 in 10-50,000 procedures.  Ensuring an aseptic or sterile technique can optimally minimize this risk.  Symptoms that may indicate the presence of infection following a steroid injection include an increase in pain and swelling and/or the onset of fever a few days following the procedure.  If these symptoms were to occur then patients should be instructed to seek urgent medical care.

Before considering the indications for surgery, it is worthwhile to mention the ever-increasing number of complementary therapies used in the management of Osteoarthritis. Glucosamine, Chondroitin, and Fish oil are probably the most well known of these class of therapies.  There is, however, very little evidence to confirm their benefit in the treatment of this disease.  Perhaps the best studied of these is Glucosamine.  Initially it was reported that Glucosamine retards the progression of the disease at the knees, however, following further research this does not seem to be the case.

Nevertheless, there are a proportion of patients that do find symptomatic improvement with the use of this medication.  The challenge though, is predicting in whom this would be the case.  However, given that there are very few risks associated with its use, a trial of therapy may be worthwhile.   This should continue for at least a period of 6 weeks as it may take some time for an effect to become apparent.  A similar approach can be taken with the other complementary therapies available.

So finally, what is the place of surgery?  There is two points at which surgery can be a worthwhile enterprise.  The first presents itself in the earlier phase of the disease, where a clear structural abnormality is a major contributor to the onset and progression of disease.  In that situation surgery can correct those abnormalities and as such impact upon the long-term outcome of the disease.  Examples of this include the removal of excess bone that abuts against the pelvis predisposing to hip disease, the correction of mal-alignment at the knees, or the release of excessively tight tendons.

However, when the disease is far advanced, conservative treatments (as mentioned above) exhausted, and quality of life significantly impaired then replacement of the joint would be appropriate.  The success and durability of such procedures is forever improving, with prosthetic hip and knees joints, in the current era, often lasting between 20-30 years.   It should be remembered though that there are a number of significant risks with these operations, which in some may be too great.  In those that are able to proceed to surgery, it is important to highlight that post-operative rehabilitation is crucially important to ensure optimal outcomes are achieved.

This therefore represents the current approach and armamentarium in the management of Osteoarthritis.  However, the Holy Grail remains.  That is, treatments which prevent the onset of the disease and/or halt its progression.  There have been a number of attempts but none have translated into clinical use.   Thankfully though there are many who continue their efforts in this regard and hopefully one day such treatment will exist.  At present the most promising of these include techniques that aim to stimulate cartilage regeneration, such as stem cell therapy.  We wait in anticipation for the results of this research, as has commenced for example with stem cells derived from adipose (fat) tissue.

So in conclusion, although Osteoarthritis is common in the elderly and as such is often considered as simply a part of aging, the associated symptoms should not be accepted as the cost of growing old.  Instead the burden of the disease can be lessened by the multitude of therapies available that can assist in all stages of the disease, whereby the physical therapies form the cornerstone of treatment.

References:

7. Felson DT, Chaisson CE. Understanding the relationship between body weight and osteoarthritis.Baillieres Clin Rheumatol 1997; 11(4): 671–81.
8. Messier SP, Gutekunst DJ, Davis C et al. Weight loss reduces knee-joint osteoarthritis in overweight and obese older adults with knee osteoarthritis. Arthritis Rheum 2005; 52(7):2026–32.
9. Anandacoomerasamy A, March L, et al ARD 2012
10. Royal Australian College of General Practitioners. Guideline for non-surgical management of hip and knee osteoarthritis. Melbourne2009.