Juvenile Rheumatoid Arthritis (JRA)

• Juvenile Rheumatoid Arthritis (JRA) or Juvenile Idiopathic Arthritis (JIA) is a type of arthritis that causes joint inflammation and stiffness for more than six weeks in a child aged 16 or younger.
• Juvenile rheumatoid arthritis differs significantly from the adult form.
• The diagnosis of juvenile rheumatoid arthritis usually is made by exclusion. 

Diagnostic Criteria For Classification Of Juvenile Rheumatoid Arthritis

1. Age of onset younger than 16 years
   
2. Arthritis in one or more joints defined as swelling or effusion or by the presence of two or more of the following signs— limitation of motion, tenderness or pain on motion, and increased heat.
   
3. Duration of disease 6 weeks to 3 months
4. Exclusion of other rheumatic diseases
   

• Rheumatoid factor is positive in less than 25% of patients.
  → After patients pass the age of 8 years, laboratory tests show an increasingly higher percentage of positive results, however.

Clinical Features

Juvenile rheumatoid arthritis clinically consists of three types

1. Polyarticular (involving five or more joints
2. Monarticular (involving four or fewer joints)
3. Systemic.

1. Polyarthritis occurs (50% of children with JRA).

• The knees, wrists, elbows, and ankles are most frequently affected
• Usually symmetrical joint involvement.

2. Monarticular arthritis (in approximately one third of children with JRA).

• In about half of these, the disease begins in only one joint, usually the knee.

3. Systemic disease (occurs in 10% to 20% of patients).

• Severe constitutional symptoms precede the development of overt arthritis.
• A high spiking fever and a “rheumatoid rash” are virtually diagnostic.
• Psychosocial problems may be seen

The chief cause of morbidity 

• in systemic & polyarticular arthritis is severe joint disease (occurs in 25% of patients).
• in monarticular disease is chronic iridocyclitis, (25% to 30% of patients).
  

→ 90% of patients with JRA and iridocyclitis had a positive antinuclear antibody test.
→ Permanent blindness can occur from iridocyclitis, and patients with monarticular arthritis, should be evaluated by an ophthalmologist approximately every 3 months.



• Harris and Baum described four categories of involvement of the hip in JRA

1. Catagory 1: only mild disability and slight radiographic changes.
   
2. Catagory 2: episodic disability correlated with the activity of the disease.
   
3. Catagory 3: progressive disability associated with radiographic changes; this group of patients required surgery most frequently.
   
4. Catagory 4: marked clinical and radiographic findings, but minimal functional disability.
   

Investigations

1. X-RAY

• Initially: non-specific changes, but mainly useful to exclude other painful disorders. 
• Later there may be signs of progressive joint erosion and deformity. 

2. other investigations

• The white cell count and ESR are markedly raised in systemic JRA.
• Rheumatoid factor tests are positive only in juvenile RA. 
• Joint aspiration and synovial fluid analysis - to exclude infection or haemarthrosis. 

 TREATMENT

Open synovectomy has shown inconsistent results.
 → Patients with mild monarticular or polyarticular disease -> best results.
→ Patients with systemic disease and polyarticular involvement and children younger than 7 years old -> poor results

 Synovectomy In Juvenile Rheumatoid Arthritis

• Ideal Indications
  
  1. Involvement of one or few joints
     
  2. Hyperplastic, “wet” rheumatoid synovitis
     
  3. Failure to respond to adequate trial of nonoperative treatment
     
  4. No radiographic evidence of articular cartilage destruction
• Relative Indications
  
  1. Severe pain
     
  2. Significant loss of motion
     
  3. Contractures despite several months of nonoperative treatment
     
• Contraindications
  
  1. Seronegative “dry” synovitis
     
  2. Polyarticular involvement
     
  3. Acute inflammatory stage
     
  4. Systemic disease

Reconstructive Procedures include:

1. Soft-tissue procedures for correction of contractures
2. Osteotomy
3. Arthrodesis
4. Joint excision
5. Arthroplasty.

• Combinations of these procedures often are necessary to relieve pain and correct deformity.

1. Osteotomies - to correct severe angular deformities.
   
2. Arthrodesis usually is reserved for severely damaged joints unsuited for arthroplasty, such as the wrist, the foot, and occasionally the fingers.
3. Excision of one of the articular surfaces occasionally is indicated at skeletal maturity for severely painful, contracted joints unsuited for arthroplasty.
4. Arthroplasty may be indicated for destruction of the articular cartilage, especially in patients with multiple and bilateral joint destruction.

• Generally, young adults with severe multiple joint involvement and low activity levels are best suited for arthroplasty.