- Discussion:
- JRA is a persistent non infectious arthritis lasting more than 6 wks to 3 months after other possible etiologies have bee ruled out;
- most common chronic childhood rheumatoid dz;
- affects girls more than boys;
- synovial proliferation leads to joint destruction (chondrolysis) & soft tissue destruction;
- severe joint destruction is seen in only 5% of patients;
- differential diagnosis:
-
leukemia
-
septic arthritis
-
sarcoidosis
- in order to confirm the diagnosis, one of the following is required:
- rash, presence of RF, iridocyclitis, C-spine dz, pericarditis, tenosynovitis, intermittent fever, or AM stiffness;
-
sub-types:
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pauciarticular: 4 or less joints in > 6 mo.
-
polyarticular: 5 or more joints in > 6 mo.
-
systemic JRA: begins w/ high spiking fevers ( > 39.3) & rash;
- Labs: synovial fluid exam:
- Radiographic Changes: radiographs can show rarefeaction of juxta articular bone;
- General Clinical Findings:
-
cervical spine in JRA:
- atlantoaxial instability makes intubation potentially hazardous (consider lateral flexion and extension radiographs);
- children w/ seronegative JRA tend to have stiff necks 2nd to spontaneous fusion of the posterior fascets;
- references:
Changes in the cervical spine in juvenile rheumatoid arthritis.
-
upper extremity: JRA
-
lower extremity:
- flexion contractures (hip and knee flexed, & ankle dorsiflexed), subluxations & other deformities (hip protrusio,
valgus knees, & equinovarus feet);
-
growth deformities of the limbs:
- JRA may either cause lower extremity overgrowth (in patients less than age 9) or may lead to physeal arrest (in patients older than age 9);
- generally, when the disease develops before age 9, will have overgrowth of involved extremity, but overgrowth will not exceeded 3.0 cm;
- major discrepancy developed within the first 3-4 yrs and will then either increase very slowly thereafter, will remain level, or will decrease;
- references:
-
Leg-length discrepancies in monoarticular and pauciarticular juvenile rheumatoid arthritis.
- hip:
- references:
-
Total hip arthroplasty in juvenile rheumatoid arthritis. Two to eleven-year results.
-
Total hip and knee arthroplasty in juvenile rheumatoid arthritis.
-
Involvement of the hip in juvenile rheumatoid arthritis. A longitudinal study.
- knee:
- this joint is affected most often in JRA (66%) followed by ankle in 25%;
- references:
-
Total hip and knee arthroplasty in juvenile rheumatoid arthritis.
- foot:
- in
polyarticular JRA, simultaneous involvement of ankle & subtalar joints & remainder of the joints in the foot is common;
- ankle contracts into equinus (talipes equinus);
- subtalar joint may develop a varus or valgus deformity;
- Treatment:
- includes night splinting, salicylates, and rarely, synovectomy (for chronic swelling refractory to medical management);
- arthrodesis and arthroplasty may be required for severe JRA:
- note: mortality rate for JRA pts undergoin arthroplasty is approx 18%, w/ death occurring before the third decade;
Late results of synovectomy in juvenile rheumatoid arthritis.
Disorders of the sacro-iliac joint in children.
Methotrexate in resistant juvenile rheumatoid arthritis. Results of the U.S.A.-U.S.S.R. double-blind, placebo-controlled trial. The Pediatric Rheumatology Collaborative
Study Group and The Cooperative Children's Study Group.
Radiographic changes in juvenile chronic polyarthritis. B. Ansell and PA Kent. Skeletal Radiology. Vol 1. 1977. p 129-144.
The radiology of juvenile rheumatoid arthritis: A review of the English language literature. MH Reed and DM Wilmot. J. Rheumatol Suppl. Vol 31. 1991. p 2-22.
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