The Hip: Preservation, Replacement and Revision

Pauciarticular JRA


- See: juvenile RA menu

- Discussion:
    - definition: < 4 involved joints.
    - most frequently encoutered subgroup, accouting for 30-40% of JRA;
    - peak age is 2-4 years
    - more common in girls (4x)
    - differential dx

- Clinical Presentation:
    - begins w/ incidious onset which can be painless
    - swelling, warmth, and restriction of motion are common sx;
    - knee, ankle, and elbow (& wrist) may be involved (initial involvement of hip or neck is uncommon);
    - systemic signs are absent;
    - chronic iridocyclitis:
           - is a common symptom (20-35 %) at the time of diagnosis
           - w/ iridocyclitis, ANA will usually be positive;
           - may precede or follow the arthritis;
           - note that incidious blindness may occur 2nd to adhesions.
           - posterior synechiae: deform the pupil;
           - cataract formation;
           - ref: Prevalence and outcome of uveitis in a regional cohort of patients with juvenile rheumatoid arthritis.

- Labs:
    - ESR and WBC are frequently normal;
    - RF is rarely positive (if RF is positive then consider polyarticular arthritis);
    - 1/2 of patients have a positive ANA
           - however positive titers are not exceedingly high ( < 1:320)
           - if test is negative, note that it may become positive w/ time;


- Prognosis:
    - good prognosis: 70% will be in remission 15 yrs after onset.
    - < 15% have severe joint destruction or disability;
    - subluxation of the knee may occur;
    - disease may last several years;
    - leg length inequality may occur (either larger or smaller)
         - usually occurs w/ knee involvment.
         - if JRA occurs before age 9, tend to get overgrowth (< 3cm)
         - affected hip jont: in young patient there is premature growth arrest of the acetabulum and the femoral head)
         - if JRA occurs after age 9, may get premature closure which may cause subtanial shortening ( > 6 cm)



Pauciarticular arthritis in children.



Original Text by Clifford R. Wheeless, III, MD.

Last updated by Data Trace Staff on Tuesday, August 21, 2012 4:27 pm