Musculoskeletal Pain and Chronic Pain Syndromes

Management of Musculoskeletal Pain and Chronic Pain Syndromes

By Dr. Thilaka Manel Nissanka

Introduction

Pain is the cardinal feature in musculoskeletal disorders. It is an unpleasant sensation associated with disease process. Clinically, pain may be classified in the following manner.

· Superficial or cutaneous pain

Pain that arises from skin and mucous membranes

· Deep non visceral pain from muscles, joints, ligaments and bone

It is dull in character and sometimes associated with muscle spasms

· Visceral pain

Usually it is diffuse and less easily localized. Visceral pain may be due to spasm (biliary colic), ischemia (e.g. myocardial infarction) inflammation (e.g. appendicitis)

· Referred pain

Visceral or somatic pain may be felt in some other part of the body other than the site of stimulation because of the convergence of nerve roots supplying the particular dermatome.

· Neuropathic pain

When there is damage to nerves, pain tracts or cortex, the damaged part itself starts sending messages to higher centers (e.g. herpetic neuralgia)

In assessing a pain condition of a person, the factors to be considered in the history are: onset and duration of pain, character and site of pain, radiation, severity, aggravating and relieving factors, associated symptoms, impact of pain in other activities (behavior) and impact on the sleep pattern and quality.

In general examination of the patient, more attention is paid to neurological and musculoskeletal examination in evaluation of musculoskeletal pain syndromes.

Principles of Management of Musculoskeletal Pain

A. Treat the underlying cause

B. Treatment of pain

· Pharmacological therapy – simple analgesics, NSAID, opioids, anticonvulsants, antidepressants

· Non pharmacological therapy - physiotherapy, nerve block

Cervical Pain Syndrome

Causes of cervical pain syndrome include, cervical spondylosis, disc prolapse, myofascial pain, cervical rib and inflammatory arthropathy. Clinical features include restriction of neck movements due to pain and pain referred to occiput, shoulder and arms. X ray and MRI scan are useful investigations.

Management of cervical pain

1. Rest - 3-7 days rest is required in acute cases

2. Pharmacotherapy – NSAID combined with simple analgesic is useful in relieving pain. Centrally acting muscle relaxant like diazepam should be considered.

Physiotherapy

Surgery – Persisting symptoms with increasing neurological symptoms might warrant surgery.

Low Back Pain

Causes :

· Mechanical

Lumbar spondylitis,

Prolapsed intervertebral disc,

Spinal stenosis,

· Congenital abnormalities

· Nonspecific

Inflammatory – Ankylosing spondylitis

Metabolic – Osteoporosis

Neoplastic – Myeloma, Metastases

Hematological investigation (ESR, CRP, FBC) and plain X ray are baseline investigations to arrive at a diagnosis. Further investigations such as MRI scan, CT, Myelography, bone scan (in neoplastic and chronic inflammatory conditions) are warranted in some cases with risk factors like history of trauma, infection, in elderly with no response to treatment, and in presence of sphincter disturbances.

Management of acute backache

1. Rest for 3-4 days

2. Pharmacological therapy – Analgesics, muscle relaxants

3. Physiotherapy – Heat therapy, massage, electrical stimulation, traction

4. Surgical intervention – Bladder and bowel disturbances and lack of response to conservative treatment indicate surgical interventions

Management of chronic low back pain

1. Physical therapy

2. Manual therapy and manipulations

3. Pharmacological therapy – NSAID can be given in short courses of 5-10 days, Tricyclic antidepressants are helpful in relieving pain as well as relieving associated depression.

4. Injection therapy – Trigger point injection and epidural injections

5. Education and self care – Back discipline and exercises

Osteoarthritis

Osteoarthritis is one of the most common joint diseases. Knee joints and hip joints are commonly involved. Osteoarthritis is classified as primary (no underlying cause) and secondary (due to underlying cause like inflammatory arthritis).

Symptoms of osteoarthritis include pain around the joint which is increased by weight bearing and improved with rest. There may also be swelling of the joint. The signs found on examination are tenderness, joint effusion, crepitus, limitation of joint motion and valgus or varus deformity.

Management of osteoarthritis

Non pharmacological therapy

1. Weight reduction in obese people

2. Quadriceps strengthening exercises

3. Supporting the joint by using walking aids

4. Patient education

Pharmacological Therapy

1. Paracetamol – first line therapy

2. NSAID – Ibuprofen, diclofenac, cox 2 inhibitors

3. Topical analgesic cream application

4. Intra articular injections for patients with effusion and local signs of inflammation

Other Interventions

1. Tidal irrigation

2. Arthroscopy

3. Surgery (osteotomy, arthroplasty, total joint replacement)

Complex Regional Pain Syndrome Type I

This disorder occurs due to dysfunction of the pain system. Complex central and peripheral mechanisms are involved. In some cases there is a history of preceding triggering event. CRPS may occur at any age and both males and females are affected. Usually distal part of a limb is affected. The five major symptoms of CRPS are pain, edema, autonomic dysfunction, dystrophy and atrophy, and movement disorders.

Clinical Cause

Stage 1 (acute): There is warmth and edema. Pain may be present.

Stage 2 (dystrophic): Pain continues. Limb may become cooler and skin becomes mottled, cyanosed and dystrophic.

Stage 3 (atrophic): Pain may spread or may become less. Irreversible contractures may occur.

Management of CRPS

Early intervention is important.

1. Physiotherapy – Plays an important role (heat, massage or gentle mobilization is useful)

2. Pharmacological therapy – (Analgesics, NSAID, anti-depressants, corticosteroids

3. Sympathetic blockade

4. Transcutaneous Electrical Nerve Stimulation (TENS)

References

Hochberg MC, Silman AJ, Smolen JS, Weinblatt ME, editors. Rheumatology. 3rd ed. London: Weisman MH; 2003.