Literally meaning ‘inflammation of a joint’, arthritis refers to a group of more than 100 separate conditions that cause chronic joint pain.
The most common type of arthritis is osteoarthritis (OA).
OA is a progressive disease where the normal ability of the joint to repair itself fails. 3,4 The cartilage of the joint, which normally acts as a smooth, shock-absorbing surface between bones, becomes thinner, rougher and breaks down. The movement of the joint can be further restricted by weakened ligaments and the formation of bony growths called bone spurs. 5
Any joint can be affected by OA, but the most commonly affected joints are the knee, hand and hip. 5
1 in 12 New Zealanders are living with osteoarthritis
OA is the most prevalent disorder of the musculoskeletal system worldwide, 5,6 and a leading cause of disability and lost quality of life. 3 In New Zealand, around 307 500 adults are living with OA, or 9% of the population. 2,7 This is expected to rise to 382 500 people (10%) by 2020, due to the ageing population and increasing risk factors for developing OA such as obesity. 1
Risk factors for osteoarthritis
There is no single cause for OA, and many factors have been identified that increase the risk of its development. Although OA can begin at any age, it becomes increasingly common later in life, particularly after age 55. The prevalence of OA is higher in women than in men.
Genetics also play a part in OA: it tends to run in families
and is more common in those of European than of Máori, Pacific or Asian descent.
However, one of the best-established risk factors for OA is obesity. 1,3,5 Obesity is associated with increased chances of developing OA of the knee and hand, 8 although, perhaps surprisingly, the association with hip OA is not as clear. 5,8
Traumatic joint injury and high impact sports may also increase the risk of OA development later in life. 3,5
Symptoms of osteoarthritis
Symptoms include pain, aching, tenderness and stiffness in the joints, together with loss of joint function.
The primary problem for most patients with OA is pain,
which can affect mood, fatigue levels and sleep quality.
Progression of symptoms can be variable. While the onset of OA in most joints is gradual and progressive, OA of the hand can have periods of active change, interspersed with stable periods. 9 As the condition advances, deformities of the fingers and enlarged joints can occur. Typically, OA in the knee develops slowly, with little change over years. 9
The pain experienced varies: patients with OA experience persistent, aching pain, while others are only troubled with pain intermittently. In the early stages, pain may be triggered by activity, becoming more constant over time. 6
Diagnosis of osteoarthritis
The clinical symptoms of OA correlate poorly with radiographic changes.
Joint abnormalities visible on x-ray, such as loss of joint space or bony changes, may occur without symptoms. Many patients with x-ray changes in both knees may experience pain only in one knee. Equally, joint pain with no radiographic changes is common.
The intermittent nature of OA pain in many patients means that many people may experience OA pain for years before seeking medical care and a diagnosis 6,10,11 (figure 1).
Figure 1. Diagrammatic representation: symptoms and radiographic change in OA do not correlate well, and patients may have symptoms of OA but not a medical diagnosis. Adapted from Kean et al 20049.
Pharmacy care of patients with osteoarthritis
While patients may be aware of annoying pain, many do not seek medical attention and management until the OA progresses.
In New Zealand in 2005, patients with arthritis were estimated to have spent $1.65 million on over-the-counter medicines, which does not include the many patients using OTC medicines to relieve their pain without a medical diagnosis of OA.
As the first point of contact for many patients with early OA, pharmacists are ideally placed to recommend treatment and referral options for patients with symptoms of OA. 11
Non-pharmaceutical options are the cornerstone of management of OA. Exercise and muscle strengthening, together with weight loss where appropriate, is a key recommendation for all patients with OA pain. 12
International guidelines also recommend the use of topical NSAIDs, such as Voltaren ® Osteo Gel, for treatment of local osteoarthritis pain of the fingers and knees. 12-14
Voltaren ® Osteo Gel penetrates the skin, to provide an effective local concentration of diclofenac at the site of application/s. 15 A low systemic absorption is likely to reduce the risk of systemic side effects: 16 an important consideration, particularly for an older population.
Community pharmacists have an important role in identifying patients who may benefit from medical diagnosis and prevention and intervention programs. 11
References: 1. Access Economics. The economic cost of arthritis in New Zealand in 2010. Report for Arthritis New Zealand. Canberra: Access Economics; 2010. 2. Ministry of Health. The health of New Zealand adults 2011/12: key findings of the New Zealand Health Survey. Wellington: Ministry of Health; 2012. 3. Access Economics. Painful realities: the economic impact of arthritis in Australia in 2007. Report for Arthritis Australia. Canberra: Access Economics; 2007. 4. Lane N, Brandt K, Hawker G et al. Osteoarthritis Cartilage 2011;19: 478-82. 5. Cooper C, Dennison E, Edwards M et al. Medicographia 2013; 35: 145-51. 6. Neogi T. Osteoarth Cartil 2013; 21: 1145-53. 7. Ministry of Health. The health of New Zealand adults 2011/12. Data table: health conditions [Internet]. Wellington: Ministry of Health; 2012. Available from: www.health.govt.nz/publication/health-new-zealand-adults-2011-12. 8. Alekseeva L, Nasonov E. Medicographia 2013; 35: 152-7. 9. Kean W, Kean R, Buchanan W. Inflammopharmacology 2004; 12: 3-31. 10. Arthritis Australia. The voice of arthritis: a social impact study of arthritis in Australia 2004. Glebe: Arthritis Australia; 2004. 11. Marra C, Cibere J, Tsuyuki R et al. Arthritis Rheum 2007; 57: 1238-44. 12. National Collaborating Centre for Chronic Conditions (NICE). Osteoarthritis: national clinical guideline for care and management in adults. London: Royal College of Physicians; 2008. 13. Jordan K, Arden N, Doherty M et al. Ann Rheum Dis 2003; 62: 1145-55. 14. Hochberg M, Altman R, April K et al. Arthritis Care Res 2012; 64: 465-74. 15. Gondolph-Zink B et al. Akt Rheumatol 1996; 21: 298-304. 16. Roubille C, Martel-Pelletier J, Pelletier J. Medicographia 2013; 35: 172-80.