12 Hip involvement in juvenile idiopathic arthritis: frequency and associated factors

Abstract

BackgroundJuvenile idiopathic arthritis (JIA) is a pediatric rheumatic disease with several subgroups. The hip is frequently affected. The frequency of this involvement can reach 50% especially in the severe and destructive forms. Arthroplasty may be indicated in advanced cases.ObjectivesTo assess the frequency and associated factors with hip involvement in (JIA).MethodsWe conducted a retrospective study including adults with long-standing JIA according to the International League of Associations for Rheumatology (ILAR) criteria over a period of 28 years (1994–2022). Demographic, clinical, biological, and radiographic data were collected. These parameters were compared according to the presence or absence of hip involvement.ResultsA total of 29 Patients were enrolled (12 men and 17 women), the mean age was 35.69 ± 11.72 [18–61] years. The mean age of disease onset was 11.10 ± 4.25 [2–16] years. The average diagnostic delay was 52.96 ± 95.97 [0–336] months. The average disease duration was 24.48 ± 12.76 [1–47] years.Sixteen patients had a polyarticular form. Mean CRP values were 42.74 ± 63.37 [2–218] mg/l, a biological inflammatory syndrome was present in 19 cases. Rheumatoid factor, ACPA and anti-nuclear antibodies were observed in 12, 7 and 5 cases respectively. At least one extra-articular manifestation was noted in 16 cases.Hip involvement was noted in 14 patients (48.3%). It was bilateral in 64.3% of cases (n = 9). Twenty-three hips were affected in total (56.9%). Hip involvement was diagnosed 14.5 ± 9.37 [1–28] years after disease onset. Arthroplasty was performed on 10 hips with a delay of 201.60 ± 104.75 [108–348] months between diagnosis of JIA and surgery.Hip involvement was associated with male gender in our study (75% vs 29.4%; p = 0.016). On the other hand, our study showed that age, age at onset, diagnostic delay, symptoms duration, smoking, BMI, extra-articular manifestations, CRP, rheumatoid factor, antinuclear antibodies, ACPA and erosive character were not associated with hip involvement.ConclusionOur study showed that hip involvement is common in JIA, mainly in male patients. It usually occurs late in the disease course. Since hip involvement is a cause of disability and functional impairment, it should be assessed regularly.