Musculoskeletal conditions are the most common causes of chronic pain leading to consultation in primary care. The most common conditions are osteoarthritis, inflammatory arthritis, chronic regional pain (e.g. back pain) and chronic widespread pain (fibromyalgia). Since musculoskeletal conditions are prevalent, it is not uncommon for a patient to suffer from more than one chronic painful musculoskeletal condition. Functional neuroimaging studies have shown that all types of pain are processed within a common human pain matrix in the brain. Inflammation causes pain in many musculoskeletal conditions. Typically, inflammation is caused by activation of the leucocytes, which release cytokines and convert arachidonic acid into prostaglandins by cyclo-oxygenase II (COX-II) enzyme. At the site of inflammation, prostaglandin E2 (PGE2) increases the responsiveness of peripheral nocioceptors and contributes to the development of peripheral sensitisation. In animal model of inflammatory arthritis, COX-2 is also upregulated in the dorsal horn of the spinal cord and contributes to the development of central sensitization. Furthermore, cytokine receptors are also expressed by sensory nocioceptive neurones, which are activated by cytokines. Therefore inflammation has direct and indirect roles in the development of chronic pain in many musculoskeletal diseases. This review will focus on treatments that could be applied to most musculoskeletal conditions rather than disease specific treatment such as disease modifying drugs for inflammatory arthritis.
The aims of treatment of chronic musculoskeletal pain are to educate patient on diagnosis, reduce severity of symptom, improve function and empower patients to self-manage. Treatment of chronic musculoskeletal pain should be tailored to the individual, addressing their particular needs and minimising the risk of side effects from treatment. The best strategy is to use a multidisciplinary holistic approach combining non-pharmacological and pharmacological interventions. National bodies such as the British Society for Rheumatology and IASP Musculoskeletal Taskforce have published management recommendations based on systematic reviews. Patient education and graded exercise are important in all patients with chronic musculoskeletal pain. Topical treatment such as ice, heat, transcutaneous nerve stimulator and manual therapies may provide symptomatic relief although the strength of evidence is weak, the risk of side effect is small. Cognitive behavioural therapy has been shown to improve pain and function. It should be considered especially in patients with difficulty in cope with pain and have significant functional impairment.
Pharmacological intervention should starts with simply analgesia such as paracetamol. Codeine phosphate or nefopam can be added if necessary. Topical and oral non-steroidal anti-inflammatory drugs (NSAIDs) or cyclo-oxygenase (COX-2) inhibitors may be added to simple analgesics for treating acute exacerbation. NSAIDs and COX2 agents should be used with caution in patients with cardiovascular diseases. Short courses of tramadol, a weak opioid analgesic with serotonergic and adrenergic activities can be used for treating moderate to severe pain. For patients with moderate to severe chronic musculoskeletal pain, satisfactory analgesia may be achieved by using a non-escalating dose of opioids with minimal risk of addiction. Depression is common in patients with chronic musculoskeletal pain. Serotonin and nor-adrenaline are important neurotransmitters involved in the pain pathway, hence many anti-depressants have pain modification property and can be used as adjunctive treatment. However, patients with severe depression should be referred for management by mental health team. All patients should be given advice for self-management and dealing with exacerbation of symptoms. For patients with persistent distress or increasing disability referral to secondary care physician, psychologist or multidisciplinary pain clinic is recommended.
Disclosure of Interest None declared