Osteoarthritis

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Chapter 22 Osteoarthritis

DEFINITION AND AETIOLOGY

Osteoarthritis, also called degenerative joint disease, is primarily a disease of ageing, as 90% of all people have radiographic features of it in the weight-bearing joints by the age of 40 years.1,2,3 It is defined by degeneration of the cartilage and subsequent hypertrophy of the bone surrounding the articulations. There are no systemic signs of disease with this condition. Typically the pain is localised to joints in a non-symmetrical pattern, and is usually relieved by rest and gentle motion. There are hereditary and mechanical risk factors involved in this condition, with obesity and repetitive mechanical loading especially provocative in the lower limb articulations. Degeneration in a joint can be primary by ‘wear and tear’ or secondary to an articular injury, for example a fracture, or metabolic diseases like hyperparathyroidism.2,3

Incidence and cost

In Australia, arthritis and musculoskeletal conditions are large contributors to illness, pain and disability.4 Accounting for more than 4% of the overall disease burden, measured in terms of disability-adjusted life years (DALY), these conditions account for a significant proportion of healthy years of life lost. More than 6.1 million Australians are reported to have arthritis or a musculoskeletal condition. Most commonly reported conditions are back pain and various forms of arthritis. Further, over 1 million Australians are reported to have disability associated with arthritis and related disorders, with mobility limitation the major feature. These conditions are the second most common reason for presentation to a general practitioner,3,5 and the third leading cause of health expenditure.6 In view of this large disease burden—the number of people affected and the high disability impact—arthritis and musculoskeletal conditions were declared a National Health Priority Area (NHPA) in July 2002. 1.3 million Australians (almost 7% of the population) have diagnosed osteoarthritis and females (8%) are more likely than males (5%) to have the disease.3

RISK FACTORS

The risk factors for osteoarthritis have been categorised into a succinct list of modifiable and unmodifiable factors.7

DIAGNOSIS

A joint can be defined or diagnosed to have osteoarthritis by symptoms, structural changes, or both (see Figure 22.1). The symptoms of osteoarthritis include:

Radiological changes on X-ray are useful to identify some of the key signs of the osteoarthritic joint: the narrowing of the joint space, marginal osteophyte formation, subchondral sclerosis and the hypertrophy of the periarticular bones. However, radiological changes are not always observed in people with joint symptoms, and people with radiological changes do not always have symptoms. Cartilage is not seen on X-ray as it is not radio-opaque, so ultrasound and magnetic resonance imaging (MRI) and visualisation under arthroscopy might be necessary to clarify the joint changes.2,3

In clinical research studies, the diagnosis and severity of osteoarthritis is commonly measured using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC).The WOMAC evaluates three clinical domains including pain, stiffness and physical function in people with osteoarthritis of the hip and knee, and assesses change in symptoms of patients who have received therapeutic intervention. Ordinal Likert scales are used to grade the severity of each domain, and the instrument has been extensively evaluated for validity.12,13

The differential diagnosis of osteoarthritis from other forms of arthritide, like rheumatoid arthritis and gout, should include a consideration of the pattern of joint involvement and whether signs of inflammation are present (see Table 22.1 and Figure 22.2). If the patient has a recent history of infection or fever, is less than 40 years old or presents with abnormal routine blood tests, other forms of arthritis (such as rheumatoid or septic) should be considered (see Chapter 28 on autoimmunity). Laboratory tests (for example, ESR, rheumatoid factor and synovial fluid analysis) may be used to rule out alternative diagnoses.2,3,14

Table 22.1 Differential diagnosis of joint patterns

CHARACTERISTIC STATUS DISEASE
Inflammation Present Rheumatoid arthritis, systemic lupus erythematosus, gout
  Absent Osteoarthritis
Number of involved joints Monoarticular Gout, trauma, septic arthritis, Lyme disease, osteoarthritis
  Oligoarticular (2–4 joints) Reiter’s disease, psoriatic arthritis, inflammatory bowel disease
  Polyarticular (5 or more) Rheumatoid arthritis, systemic lupus erythematosus
Site of joint involvement Distal interphalangeal Osteoarthritis, psoriatic arthritis (not rheumatoid arthritis)
  Metacarpophalangeal, wrists Rheumatoid arthritis, systemic lupus erythematosus (not osteoarthritis)
  First metatarsophalangeal Gout, osteoarthritis

Source: Adapted from 2009 Current Medical Diagnosis and Treatment.2

CONVENTIONAL TREATMENT

The foundations of conventional treatment can be summarised as:2,3,15,16

The exercise program and weight-loss strategies are elements of the self-help management plan that all health practitioners would support—see the discussion below regarding the evidence.

Prescription of NSAIDs is included as the first choice for pain and inflammation control, with the addition of analgesics where necessary. The prescription should be accompanied by an assessment of the presence of risk factors for NSAIDs including age, hypertension, upper gastrointestinal events and cardiovascular, renal or liver disease. Other issues to be considered are aspirin allergy and polypharmacy (for example, concurrent use of diuretics, ACEI and/or anticoagulants).2,3,15,16

In Australia, the percentage of people with osteoarthritis using the common medications are: 8.0% use celecoxib (NSAID), 6.6% paracetamol, 5.3% meloxicam (NSAID), 3.9% diclofenac sodium (NSAID).3

KEY TREATMENT PROTOCOLS

The goals in the naturopathic treatment of people with osteoarthritis are to:

This schedule of therapeutic aims has a large number of individualised permutations based on the many pieces of information that are gleaned from the personal history and lifestyle analysis of each person with osteoarthritis. In naturopathic medicine, this is a vital component of the management of a multifactorial condition such as osteoarthritis. As in any naturopathic approach to case reasoning, the therapeutic order is useful to prioritise management, and to ensure the naturopathic principles are followed.19 The following is a summary of modalities that may be used within naturopathic medicine that have been investigated for this condition.

The naturopathic approach to the management of this condition reflects the evidence-based guidelines of a number of mainstream groups. The Osteoarthritis Research Society International (OARSI) has published practice guidelines for managing hip and knee osteoarthritis.20 The guidelines state that the optimal management requires

TREAT THE WHOLE PATIENT

Although clinical treatment will inevitability focus on amelioration of pain, degeneration and inflammation in arthritis patients, it is also important to consider how this affects their day-to-day lives.

Qualitative studies of patients with rheumatoid arthritis suggested that fatigue, not pain, was the factor associated with their condition that affected their life the most.17 Similar findings have since been observed in osteoarthritis patients as well.18 Fatigue may be associated with pain, pain medication, poor sleeping patterns or any number of factors. Arthritis may also affect the patient’s ability to perform daily tasks and interact socially or with their partner, and has other psychosocial or emotional ramifications, all of which need to be appropriately addressed in the naturopathic treatment of arthritis.

a combination of non-pharmacological and pharmacological approaches. The first priority is education of the patient about the condition and the importance of changes in lifestyle, exercise and weight reduction in order to unload the damaged joints. The initial focus should be on self-help and patient-driven treatments rather than on passive therapies delivered by health professionals.21 The focus on self-help in obesity and exercise management is also a key element of the guidelines from both the Royal Australian College of General Practitioners22 and the National Arthritis and Musculoskeletal Conditions Advisory Group.14

The approach in naturopathic medicine to ‘address weakened or dysfunctioning systems or organs’ coincides with the clinical approach of looking for the existence of comorbidities that may be linked to the primary problem (see Figure 22.3). This is clear in the management of osteoarthritis, where assessment and treatment may be necessary in the (among others):

image

Figure 22.3 Integrative treatment of osteoarthritis

Source: Adapted from Dieppe PA, Lohmander LS. Pathogenesis and management of pain in osteoarthritis. Lancet 2005;365(9463):965–973.

Attenuate inflammation

The process of inflammation plays a central role in many disorders, especially those in the musculoskeletal system. Like many processes in the body, there can be positive outcomes from a resolution or there can be uncontrolled and damaging results. The activators of inflammation can include injury, radiation, infection, oxidative stress and certain foods. Tissue injury stimulates the release of inflammatory signalling molecules such as bradykinin, and the release of inflammatory cytokines such as IL-1, TNF and IL-6. Cells that respond to infection or injury include macrophages and mast cells.24 Macrophages and other immune cells secrete chemokines that recruit leukocytes from the circulation to the site of inflammation. Mast cells release histamine, prostaglandins and leukotrienes that act as chemokines, increase vascular permeability and act on the vascular endothelium to increase tissue recruitment of leukocytes.24 Cyclooxygenase (COX) is an enzyme that is responsible for the formation of pro-inflammatory prostaglandins, prostacyclins and thromboxanes from the omega-6 arachidonic acid (see Chapter 28 on autoimmunity for further detail).

Omega-3 essential fatty acids compete with the omega-6, thereby moderating the inflammatory effect. There is evidence that omega-3 oils containing eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) have anti-inflammatory actions,25,26 but clinical data are lacking with regard to the treatment of osteoarthritis.25,27 The most widely available sources of EPA and DHA are cold water oily fish such as salmon, herring, mackerel, anchovies and sardines.

Harpagophytum procumbens, a South African herb, has been reviewed for efficacy and safety in the treatment of osteoarthritis with favourable results, especially in the reduction of pain.28,26 The mechanism of action has not been established, but is thought to be the anti-inflammatory activity of harpagoside.29 An 8-week, single-group, open clinical trial demonstrated statistically significant improvements in patient assessment of global pain, stiffness and function. There were also statistically significant reductions in mean pain scores for hand, wrist, elbow, shoulder, hip, knee and back pain. Quality of life measurements (using the SF-12 health survey) were significantly increased from baseline and 60% of patients either reduced or stopped concomitant pain medication. Adverse effects have been described as no different to placebo.27,30

A proprietary blend of Solidago virgaurea, Populus tremuta and Fraxinus excelsior has been demonstrated to be effective in reducing pain and inflammation

image

Figure 22.4 The inflammatory cascade

Source: Pearlman DS. Pathophysiology of the inflammatory response. J Allergy Clin Immunol 1999;104:S132–S137.

in arthritis via a variety of mechanisms. While most of the 43 studies justifying the formulation’s use have focused on pain measures, many have also uncovered various anti-inflammatory mechanisms, with efficacy often comparable to conventional anti-inflammatory medication.31,32

The gum resin extracted from the herb Boswellia serrata has some evidence as a potent anti-inflammatory, anti-arthritic and analgesic agent.33 A recent double-blind, randomised placebo-controlled trial of 75 subjects with osteoarthritis demonstrated that an extract of B. serrata (5-Loxin®) conferred clinically and statistically significant improvements in pain scores and physical function scores, and these changes were recorded in the treatment group as early as 7 days after the start of treatment.34

Salix spp. through the active constituent salicin, has anti-inflammatory and analgesic activity. Standardised preparations of the bark have shown positive effects in a number of trials in musculoskeletal conditions, with an analgesic effect dominant in low back pain.26,35 In a recent non-blinded trial of 131 subjects with arthrosis of the hip and knee, willow bark had equivalent effect to NSAIDs, with fewer side effects.36 A recent review found that, for treating mild or fairly severe cases of gonarthrosis and coxarthrosis, the effect of willow bark extract was comparable to that of standard therapies.36 Uncaria spp. is known to have anti-inflammatory activity in vitro, possibly by inhibiting the production of the pro-inflammatory cytokine, TNF-α,26 but clinical trials have been inconclusive.27 Zingiber officinale has been found to have anti-inflammatory actions.26,37 In a double-blind, randomised controlled trial of 261 subjects with knee osteoarthritis, ginger was found to significantly reduce symptoms and had mild adverse effects.38

An interesting pilot study using a real practice model showed that herbal medicine formulas prescribed for the individual by a herbal practitioner resulted in improvement of symptoms of osteoarthritis of the knee.39 Twenty adults, previously diagnosed with osteoarthritis of the knee, were recruited into this randomised, double-blind, placebo-controlled, pilot study carried out in a primary-care setting. All subjects were seen in consultation three times by a herbal practitioner who was blinded to the randomisation coding. Each subject was prescribed treatment and given lifestyle advice according to usual practice: continuation of conventional medication where applicable, healthy-eating advice and nutrient supplementation. Individualised herbal medicine was prescribed for each patient, but only dispensed for those randomised to active treatment—the remainder were supplied with a placebo. At baseline and outcome (after 10 weeks of treatment), subjects completed a food frequency questionnaire and the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) knee health and Measure Yourself Outcome Profile (MYMOP) wellbeing questionnaires. There was significant improvement in the active group (n = 9) for the mean WOMAC stiffness subscore at week 5 and week 10, but not in the placebo group (n = 5). Also the mean WOMAC total and subscores all showed clinically significant improvement (20%) in knee symptoms at weeks 5 and 10 compared with baseline. Moreover, the mean MYMOP symptom 2 subscore, mostly relating to osteoarthritis, showed significant improvement at week 5 and week 10 compared with baseline for the active, but not for the placebo, group. This pilot study showed that herbal medicine prescribed for the individual by a herbal practitioner resulted in improvement of symptoms of osteoarthritis of the knee. This methodology mirrors normal clinical procedures, and should encourage similar larger clinical trials that have more relevance to naturopathic practice.

Enhance joint integrity and repair damage

Primary and secondary prevention are the main foci of naturopathic medicine, and maintaining and repairing articular and periarticular tissue is a foundation for the management of osteoarthritis. Developing, maintaining and repairing collagen-based connective tissue requires optimal tissue levels of the essential amino acids, as well as vitamin C and iron as cofactors. Bone and cartilage are built on a matrix of minerals, mainly calcium and phosphorus, and an extracellular ground substance of proteoglycans (see Figure 22.5). Proteoglycans are glycoproteins that have a core protein with glycosaminoglycan (GAG) chains.

Glucosamine and chondroitin are both natural components of proteoglycans, the building blocks of cartilage, and are thought to increase its synthesis when taken orally. Glucosamine is manufactured from oyster and crab shells, and chondroitin from bovine or shark cartilage. There are conflicting results in the research findings for both symptom relief and limiting the progression of the disease.

The large Glucosamine/Chondroitin Arthritis Intervention Trial (GAIT) trials40,41 have found varying positive and negative results in both domains of clinical effect, and one study27puts forward a list of concerns that may explain why the body of evidence remains equivocal, including:

A recent randomised, double-blind, placebo-controlled trial of chondroitin sulfate given to 622 patients with knee osteoarthritis for 2 years found that the structure-modifying and symptom-modifying effects of chondroitin sulfate over the long-term suggest that it could be a disease-modifying agent.42

Methylsulfonylmethane (MSM) has been used as a sulfur-based nutritional supplement in conditions with joint pain, but a recent systematic review of clinical trials was

unable to reach a firm conclusion on its usefulness, because of methodological flaws and despite a number of positive trial findings.4345

Improving joint mobility

The result of inflammation and fibrosis in osteoarthritis is limited joint motion, and this interferes with activities of daily living and has the global effect of reducing fitness and compliance to exercise therapy.

Massage and physical therapy provide viable options for managing osteoarthritis. There have been some trials using massage for osteoarthritis, but methodological quality is lacking, particularly with regard to the difficulties of blinding and control. A randomised controlled trial of 68 adults with radiologically confirmed osteoarthritis of the knee demonstrated significant improvements from standard Swedish massage in the WOMAC global scores, pain, stiffness and physical function domains.48 The subjects also had improvement in the visual analogue scale of pain assessment, range of motion in degrees and time to walk 50 feet (15.24 metres).

Evidence of efficacy in treating osteoarthritis may exist for the addition of physical therapy modalities. The term ‘multimodal therapy’ generally includes range of motion exercise, soft tissue mobilisation and muscle strengthening and stretching—all within the scope of the naturopath inclined to physical medicine.49 Studies suggest that patients with osteoarthritis receive moderate short-term (up to 8 weeks) clinical impact measured on WOMAC global and pain scores.

Adding therapeutic oils to the massage appears to have potential as an alternative method for short-term knee pain relief. In a double-blind, placebo-controlled trial of 59 older people, the intervention group had ginger and orange essential oils added to the massage oil, and the improvements of WOMAC-measured physical function and pain were superior in the intervention group compared with both the placebo and the control group at post 1-week time but not sustained at post 4 weeks.50

Reduce pain

Pain management is a vital component of chronic disease therapy in general, and non-pharmacological approaches should be considered in patients with osteoarthritis (see Chapter 37 on polypharmacy and pain management for more detail of pain management in osteoarthritis).

Thermotherapy may reduce the pain associated with osteoarthritis. It involves the application of heat or cold (such as a heat or ice pack and ice massage) to treat symptoms of osteoarthritis. This could be applied by a massage therapist, physical therapist or naturopath in an integrated setting. The application of cold is known to have an effect by reducing swelling and inflammation, numbing pain and blocking nerve impulses and muscle spasms to the joint.

QUALITY MATTERS

As with many complementary medicines, quality and dosing variances can affect the therapeutic application and efficacy of treatment in trials. Glucosamine comes in a variety of forms which, though they theoretically can be hydrolysed in the stomach into equivalent forms, may have effects on therapeutic dosing requirements. Additionally, quality issues may also arise. Some formulations are demonstrated to be consistently more effective than placebo or other formulations in clinical trials.46,1 Although concerns have been raised that these positive results may be related to industry sponsorship, it has been deemed equally likely that these results may also be due to the stricter quality controls of some formulations.47 In clinical practice recommending any generic complementary medicine can be fraught; it is recommended that practitioners make specific recommendations for products they know to have high standards of quality and efficacy.

A Cochrane systematic review51 found that it is most effective in an acute stage of osteoarthritis when minor joint inflammation is present and is administered through the application of an ice pack wrapped in a towel for 20 minutes, 5 days a week for 2 weeks.

Vitamin D deficiency appears to be prevalent in people with chronic musculoskeletal pain.5254 The mechanism appears to be related to a decrease in calcium absorption leading to dysfunctional collagen deposition in the periosteum, which generates painful stimuli. Oral supplementation with vitamin D in deficient subjects leads to a reduction in pain.55

The Framingham study data56 link vitamin D deficiency to osteoarthritis. In a study of 556 subjects, dietary and supplement intake of vitamin D and serum levels of 25-hydroxyvitaminD were evaluated. Osteoarthritis was measured using knee radiographs. The authors concluded that low intake and low serum levels of vitamin D each appeared to be associated with an increased risk for progression of osteoarthritis of the knee.56 These conclusions have been supported in a more recent review.57

Remove metabolic waste products

A traditional naturopathic protocol used to treat osteoarthritis involves stimulation of the body’s detoxification pathways to clear metabolic waste. While this philosophy has not yet been scientifically tested via rigorous studies, traditional evidence does support this practice.60,61 The traditional use of herbal ‘alteratives’ and ‘diuretics’ such as celery seed or dandelion leaf, or nettles to treat rheumatism, appears to be predicated upon these herbs’ abilities to stimulate the removal of metabolic waste by increasing diuresis and potentially reducing blood composition of metabolic byproducts. This protocol may be potentially beneficial in treating gout (see the box on gout below).

INTEGRATIVE MEDICAL CONSIDERATIONS

Self-management

Self-management education programs have an important role to play in the management of chronic conditions such as osteoarthritis, and suit an integrative model of shared care between conventional and complementary medicine practitioners. Self-management education programs are interventions designed to educate the patient in self-care activities that promote health and the management of chronic diseases, increasing their motivation and decreasing the negative effects the condition has on their daily function.63 The National Health Priority Action Council states that, by taking the behavioural approach to the management of the psychosocial aspects of chronic disease, patients have outcomes of decreased pain and improved quality of life.63 This approach matches the holistic underpinning of naturopathic medicine.

Exercise

Exercise guidance is a foundation of a naturopathic approach to wellness, and in the management of osteoarthritis coincides with the mainstream evidence-based guidelines. Exercise is important both as a treatment of symptoms and to prevent the development of osteoarthritis. Increasing physical activity improves general physical health and assists in the management of obesity, both vital risk factors for osteoarthritis, as mentioned.

Enhancing muscular strength is an outcome of exercise programs, and muscular weakness and dysfunction can cause joint instability and subsequent injury. To prevent this injury and resultant degeneration, and to prevent further injury in the degenerative joint, exercise programs must be a central component of the management plan in osteoarthritis.

Physical exercise of a light-to-moderate intensity increases muscle strength as well as range of motion, aerobic capacity and endurance that contributes to improved physical functioning and pain reduction. Various programs (see Table 22.2) offer different benefits and no specific type of exercise regimen has been shown to be superior.2,3,20,22 A number of Cochrane reviews support the application of therapeutic exercise in the management of osteoarthritis,65 with evidence for moderate intensity66 and aquatic programs.67

An interesting systematic review looked at tai chi, a traditional Chinese martial art style, which has been one of the most researched therapeutic exercises. The authors report that there is evidence suggesting that tai chi may be effective for pain control in patients with knee osteoarthritis, but the evidence is not as convincing for pain reduction or improvement of physical function.68

Acupuncture

Acupuncture is commonly used in an integrated clinical setting by acupuncturists, medical practitioners, physiotherapists and naturopaths, and has been assessed for efficacy in the treatment of osteoarthritis. In a randomised, controlled, single-blind trial of 88 subjects, acupuncture plus diclofenac was more effective than placebo acupuncture plus diclofenac for the symptomatic treatment of osteoarthritis of the knee.73 A recent meta-analysis regarding acupuncture for knee osteoarthritis was inconclusive, concluding that sham-controlled trials show clinically irrelevant short-term benefits of acupuncture for treating knee osteoarthritis.74 This study reveals the difficulties of control with research into therapies like acupuncture, where the placebo is not inert but has some effect, in many cases equal to the active intervention.

Differential diagnosis2

OSTEOARTHRITIS: COMORBID DEPRESSION AND PAIN

Patients with chronic diseases such as osteoarthritis have a higher rate of depression and anxiety than the general population.14 Osteoarthritis also has a feature of chronic pain, which can result in feelings of lowered self-worth, anxiety and depression.23 The practitioner needs to be educated about the effect these psychosocial aspects have on the condition and its progression. Osteoarthritis can also affect relationships and community and social activities,23,14 which are all addressed in the naturopathic assessment of the individual.

A recent study of depression in 1021 patients with osteoarthritis75 revealed that subjects who had concomitant depression had more contacts to general practitioners and to providers of complementary alternative medicine, resulting in increased health-service use. The authors conclude that appropriate treatment of depression would increase quality-of-life measures and also lower costs by decreasing health-service use, and that depression aggravates the burden of osteoarthritis significantly.75 See Chapter 37 on polypharmacy and pain management for further consideration of pain management in naturopathic medicine.

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