Orthopaedics Wa’el N. Qa’dan, MSc. Rheumatoid arthritis (RA): It is the commonest cause of...

Orthopaedics

Wa’el N. Qa’dan, MSc

Rheumatoid arthritis (RA):

It is the commonest cause of chronic inflammatory joint disease.

Most typical features:

Symmetrical polyarthritis and tenosynovitis

Morning stiffness

Elevation of the erythrocyte sedimentation rate (ESR)

Appearance of anti-IgG globulins (Rheumatoid factors) in the serum.

Disease Vs arthritis.

Prevalence: 1-3%

Incidence peaks in 30s-40s

Women: men- 3-4: 1

Urban more and more severe than rural.

Cause:

Not worked out. Factors include:

1- Genetic susceptibility

2- An immunological reaction, possibly involving a foreign antigen, preferentially focused on synovial tissue

3- An inflammatory reaction in joints and tendon sheaths

4- The appearance of ant-IgG antibodies in the blood and synovium

5- Perpetuation of the inflammatory process

6- Articular cartilage destruction

Pathology:

Joints and tendons:

Stage 1: synovitis: vascular congestion and capsular thickening, intact structures.

Stage 2: destruction: tendon and articular cartilage.

Stage 3: deformity: articular destruction, capsular stretching and tendon rupture.

Extra-articular tissues:

Rheumatoid nodules

Muscle weakness

Visceral disease

Clinical features:

Onset usually insidious, emerging over a period of months. Occasionally it starts suddenly.

Early stages: a woman aged 30-40 complaining of pain, swelling and loss of mobility in the proximal joints of the fingers due to polysynovitis and soft tissue swelling and stiffness.

Back in history, usually muscle pain, tiredness, loss of weight, and a general lack of well-being.

With time symptoms spread to other joints, wrists> feet> knees> shoulders.

Morning stiffness is a classic feature.

Physical signs: symmetrically distributed swelling and tenderness of the MCPs, PIPs and wrists. Tenosynovitis is common in the extensor compartment at the wrist and flexor tendons in the fingers.

Late stage: joint deformity becomes increasingly apparent.

Acute pain due to synovitis is replaced with constant ache.

Typical rheumatoid deformities:

Ulnar deviation of fingers

Radial and palmar deviation of wrist

Valgus knees

Valgus feet

Calwed toes

Joint movements are usually restricted and very painful.

Extra-articular features of late stages include nodules: small, rubbery, at the back of elbows, tendons, viscera and eyes.