Musculoskeletal Disorders

Approach to a patient with joint pain

When patient approach for joint pain, we have to decide whether the pain is articular or non- articular. Non articular origin of pain is likely to be sprain or soft tissue involvement like bursitis, tendinitis, etc.

With articular involvement one has to decide whether it is inflammatory or non-inflammatory. If it is inflammatory, symmetrical involvement of small joints like PIP, MCP, joints of feet and ankle in middle aged lady is likely to be Rheumatoid arthritis.

If he is young especially male with asymmetric larger joints inflammation like knee, elbow, ankle, etc. and sacroiliac joint involvement will fit into another category of diseases i.e. seronegative spondyloarthropathy.

Degenerative joint involvement mostly occurs in knee, cervical and lumbosacral spine giving rise to osteoarthritis or cervical and lumbar spondylosis.

In inflammatory disorder one has to keep in mind tuberculosis. Occasionally one may encounter cases of gout with increase in uric acid in the blood. In gout by and large inflammation occurs in great toe.

Osteoarthritis (OA)

Osteoarthritis (OA) is most common form of arthritis we come across in practice. Osteoarthritis appears to be a better term because degeneration is predominant pathology than inflammation.

OA usually occurs after age of 50 with affinity for females. OA of Knee joints is most common.

Aging process and other predisposing factors like obesity, injury etc. contribute to produce early metabolic changes in cartilage. It disturbs balance in the contents like collagen, water and proteoglycan in the cartilage which becomes susceptible to degenerative changes leading to focal (localized) loss of cartilage. As a result, bones rub on each other producing micro fracture. In the late stage bony outgrowth develops at margin of articular cartilage.

The progress of OA is graded with intermittent exacerbation of pain. In advance cases patient may experience continuous and severe pain.

The pain is sometimes associated with mild swelling around knee joint with restricted range of movements. We may find OA nodes at DIP joints in few patients.

In advanced stage Varus deformity and quadriceps muscle atrophy occurs, leading to change in gait of patient.

The diagnosis of OA is mainly radio clinical. Plain X-ray of knee in standing position with anterior- posterior (AP) view and lateral view of flexed knee is essential for diagnosis. Joint space narrowing is early feature and useful for assessment of progression of disease. Osteophytes are the hallmark of disease and indicate relatively advanced disease.

Cervical Spondylosis –

It is a degenerative disorder of cervical spine. It occurs normally above the age of 50. However, the incidence is rising due to computer use and becoming a common problem in young age group.

Pathophysiology:

The basic pathology is degeneration of intervertebral disc followed by osteophyte formation. Pain and stiffness in cervical area is common presentation of cervical spondylosis. If nerve root compression occurs either because of osteophytes or prolapse of intervertebral disc, then pain may radiate to shoulder or hand from cervical region. It may radiate to occiput based on nerve root involvement.

Few patients present with vertigo because of vertebro-basilar ischaemia.

Plain X ray of cervical spine gives us idea about loss of natural cervical lordosis, reduction in intervertebral disc spaces and osteophytes.

It doesn’t give much idea about disc protrusion for which MRI is a sensitive modality.

Lumbar Spondylosis –

It is a degenerative disorder of lumbosacral spine. The pathophysiological changes are similar to cervical spondylosis. Lumbar spondylosis occurs in 4^th and 5^th decade, but acute lumbar disc herniation occurs in middle aged people by injury or by lifting heavy weight while spine is flexed.

The presenting symptoms include lower back pain radiating to either right or left leg is called as sciatica syndrome. If radiating pain is absent, then possibility of disc protrusion is extremely rare. Restriction of straight leg raising test is important clinical sign. MRI is essential to find out protrusion of disc.

Many patients present with low back pain without radiation, it is often called as lumbago. This pain is more common at rest.

In few old patients, intermittent claudication occurs because of lumbar canal stenosis.

X ray lumbar spine will show loss of lumbar lordosis with decreased disc space and osteophytes. We should consider possibility of Koch’s spine and Ankylosing spondylosis in cases of backache especially in young individual. In old age, the possibility of secondaries remains.

Rheumatoid Arthritis (RA)

It is a chronic, immuno-inflammatory disease which affects multiple systems in our body. It mainly affects small synovial joints and, in few cases,, it produces extraarticular manifestations.

Pathophysiology:

It is believed that RA is triggered by exposure of genetically susceptible host to antigen either from internal or external environment like viruses. The protein molecule on antigen binds with specific receptors on T cell. T cells secrete various cytokines like IL-6, TNF-α, etc. TNF-α plays a pivotal role in process of synovial inflammation. Some of these cytokines activates β cell immunity and cause formation of auto antibodies like Rheumatoid factor and anti CCP antibodies which can be detected in patient’s blood. Consequently, activation of macrophages releases few cytokines which are responsible for proliferation of synovial cells and chondrocytes. In this process certain enzymes are released which are responsible for laying down fibrovascular tissue what we termed as pannus. Pannus formation causes destruction of bones, cartilage leading to fibrosis and ankylosis.

Clinical features:

RA is more common in females between 40 to 60 years of age. Initially patient feels malaise, fatigue and generalized arthralgia for few months. At this stage diagnosis is difficult.

Subsequently swelling and pain in small joints develops especially metacarpophalangeal (MCP) and proximal interphalangeal (PIP) joints. It can also affect feet, wrist and ankle joints. Symmetrical involvement of joints is a notable feature of RA. Knee and elbow involvement may occur in some cases, but lumbosacral region and hips are spared.

On examination it shows signs of synovial inflammation like boggy swelling, tenderness, warmth and restricted range of motion. The pain is associated with stiffness of small joints which remain for more than 1 hour and get relieved by activity.

Generally, the disease progresses by exacerbations and remissions and causes destruction of tendons, ligaments and joint capsule to produce characteristic deformities like swan neck or boutonniere’s deformity. These are common in late stage of disease.

In few cases we get extraarticular manifestation because of circulating antigen-antibody complex. Dryness of eyes (B Sjogren`s syndrome), pleuritic pain and carpel tunnel syndrome are some of the extraarticular manifestations. Presence of Rheumatoid nodules indicates worse prognosis.

The clinical course of RA is extremely variable, may be slow or rapid with greatest damage occurring in first 4 to 5 years. In only 20% patient partial or complete remission occurs but symptoms return eventually and affect unaffected joints.

The diagnosis of RA is mainly based on:

1. Small joints pain mostly symmetrical with observable swelling (esp. PIP and MCP)
2. Anemia
3. Increased ESR
4. Presence of RA factor or Anti CCP antibodies

If any of these finding is missing, then the diagnosis of RA is questionable.

If clinically all features of RA are present with negative antibodies or RA test it is termed as sero-negative Rheumatoid arthritis.

Lab investigations

CBC, ESR, Anti CCP antibodies, RA, X ray hands and feet may show joint effusion, juxta articular osteopenia with erosions.

D/D:

• The RA is mainly differentiated from other inflammatory arthritis like Reactive arthritis when there is affinity for lower extremities, bigger joints and asymmetric involvement of joint
• Psoriatic arthritis also affects smaller joints but especially DIP as against PIP in RA. Absence of skin eruptions rule out possibility of Psoriatic arthritis
• Collagenous disorder like SLE and Scleroderma should be differentiated from RA with presence of other clinical features of these conditions.
• OA is easily differentiated from RA by affection of large joints and absence of inflammatory features. Nodular OA occurs in DIP joints only.
• Gout also affects smaller joints, but it involves less than 3 joints and mostly affects great toe.

Seronegative Spondyloarthropathy (SSA)

These are group of diseases which have certain common clinical features. Genetic predisposition is observed quite often.

It includes:

1. Ankylosis spondylitis
2. Reactive Arthritis
3. Psoriatic arthritis
4. Enteritis associated Arthritis

Pathophysiology:

Usually inflammation starts at enthesis because of autoimmune response in genetically predisposed individual (HLA-B27). Enthesis is the site at which cartilage, ligaments and other structures attach to bones. The inflammation resolves by fibrosis and scar tissue formation and may lead to ankylosis.

Ankylosing spondylitis (AS)

It is a chronic inflammatory arthritis with affinity for sacroiliac joint and spine. Most of the time young male patient presents with backache. The pain usually improves by activity with morning stiffness persists for more than 30 minutes.

On examination we find tenderness in sacroiliac joint with substantial loss of spinal mobility. Reduced chest expansion and modified Schober’s test are good tests for measurement of spinal mobility at OPD level.

It is mainly distinguished from mechanical back pain which increases by activity. Lumbar spondylosis occurs usually after age of 40 which is extremely uncommon age for AS. Possibility of Koch’s spine should be kept in mind.

Though X ray of lumbosacral spine will guide us in diagnosis. MRI is more informative.

HLA B27 test is positive in 90% cases.

The role of exercise is crucial in management of AS.

Reactive Arthritis

It develops after episode of diarrhea or urethritis because of autoimmune reaction caused by prior infection. Many patients present with single joint involvement that turns into an asymmetric oligoarthritis with affinity for lower extremities. Inflammation occurs at synovium as well as periarticular structures.

The triad of conjunctivitis, urethritis and reactive arthritis together is termed as Reiter’s syndrome.

The diagnosis is mainly clinical.

Psoriatic Arthritis

Similar to Reactive arthritis, it is asymmetric inflammatory oligoarthritis involving articular and periarticular structures. It is associated in 7% of Psoriatic patients. It predominantly involves small joints especially distal interphalangeal joints (DIP) but may affect knee also. The E.S.R and C reactive protein increases during active phase. Whereas the diagnosis is mainly based on clinical symptoms associated with psoriasis.

Gout

It is the result of defective uric acid metabolism where monosodium urate monohydrate (MSU) crystals deposits in and around synovial joints.

In most of the cases first attack of gout occurs in first MTP joint especially in middle aged to elderly men and post-menopausal women. It involves commonly small joints like ankle, midfoot, hand and wrists. Patient presents with severe pain and swelling with overlying red, shiny skin. The attack subsides within 5 to 14 days time. Recurrence of acute attack is common in many patients. Tophi (irregular firm nodules) formation is characteristic of chronic gout.

 Neutrophil and C reactive protein increases during acute attack. Hyperuricemia is usually present, but it does not confirm the diagnosis of Gout.

Periarticular Disorders (Soft Tissue Rheumatism)

It involves structures outside the synovial linings e.g. bursae, ligaments, tendons etc.

It is caused by excessive unaccustomed use of joint which produces injury. Chronic repetitive trauma interrupts blood supply leads to poor healing. Ultimate result is early degeneration. The pain and swelling is often localized to anatomical location of the involved structure.

Following conditions come under periarticular disorders:

Bursitis –

Inflammation of bursae is called bursitis. Subacromial bursitis, prepatellar or infrapatellar bursitis causes painful swelling around knee joint.

Frozen shoulder (Adhesive Capsulitis) –

In this condition thickening of capsule covering the shoulder joint occurs leading to fibrosis. This condition is common in diabetic patients. The movements of shoulder get affected in all planes.

The diagnosis is mainly clinical.

Physiotherapy plays an important role in the management of frozen shoulder.

Bicep tendinitis –

It occurs by friction of tendon of bicep muscle as it passes through bicipital groove. The patient experiences pain in anterior shoulder which radiates to bicep and forearm with restriction of abduction and external rotation at arm. On examination bicipital groove is tender on palpation.

Tennis elbow –

Inflammation at lateral epicondyle is called as tennis elbow. The pain starts in lateral epicondyle and may radiate into forearm and dorsum of wrist. Shaking hand usually reproduces pain.

Golfer’s elbow –

Inflammation at medial epicondyle is called a Golfer’s elbow.

Rotator Cuff tendinitis –

Rotator cuff consists of tendon of supraspinatus, infraspinatus, subscapularis and teres minor muscles and it inserts on humeral tuberosities. It provides additional stability to shoulder joint. The condition is common in persons participating in overhead activity like Tennis.  It causes dull aching pain in shoulder and disturbs sleep. If neglected Frozen shoulder may develop. MRI is necessary for diagnosis.

Physiotherapy plays crucial role in the management.

Plantar Fasciitis –

It is inflammation of plantar fascia. Obesity, faulty shoes and aerobic dancing are contributing factors. In few cases calcaneal spur is present concomitantly. It produces heel pain especially during first movement. In natural course complete resolution of symptoms occur. However, the symptom free period is variable.

Tenosynovitis –

It is the inflammation of synovial tendon sheath. It causes pain and swelling near the snuff box i.e. It can occur secondary to RA or infectious diseases like TB.

Fibromyalgia –

It is not uncommon but under diagnosed disorder. It is more common in females. Patients get pain all over the body with tender points at specific location like mid upper trapezium muscle, 2 cm distal to lateral epicondyle. It is accompanied by fatigue and sleep disturbances. The diagnosis is confirmed by ruling out other major rheumatological disorders.