Hip Involvement in Juvenile Idiopathic Arthritis: A Roadmap From Arthritis to Total Hip Arthroplasty or How Can We Prevent Hip Damage?

Objectives

To describe the clinical characteristics of hip involvement in juvenile idiopathic arthritis (JIA) from arthritis to hip osteoarthritis (HOA) and total hip arthroplasty (THA). Study

Design

Seven hundred fifty-three patients aged 2-17 years with JIA were included in the study. The comparison analysis was performed between the following subgroups: (i) JIA without hip involvement (n = 600; 79.7%) vs. JIA with hip involvement without HOA (n = 105; 13.9%), (ii) JIA with hip involvement with HOA, but without THA (n = 32; 4.3%) and JIA with hip involvement with HOA and with THA (n = 16; 2.1%). Clinical, laboratory characteristics and treatment regimens compared.

Results

Hip involvement was present in 20.3% of patients. HOA was present in 6.4% (12*1,000 patient-years) of the entire JIA group and 31.4% of patients with hip involvement. Sixteen patients (2.1%; 4.0*1,000 patient-years) required THA. The following factors were associated with HOA: sJIA (OR = 3.6, p = 0.008; HR = 3.0, p = 0.002), delayed remission (OR = 4.2, p = 0.004; HR = 1.4, p = 0.538), delay in biologic therapy initiation (OR = 7.5, p = 0.00001; HR = 6.7, p = 0.002), alkaline phosphatase <165 U\l (OR = 4.1, p = 0.0003; HR = 5.2, p = 0.000004), treatment with corticosteroids (CS) (OR = 2.6, p = 0.008; HR = 1.2, p = 0.670), cumulative corticosteroids >2,700 mg (OR = 4.3, p = 0.032; HR = 1.4, p = 0.527). The following factors were associated with THA: delay in biologic treatment initiation (OR = 1.04, p = 0.0001; HR = 9.1, p = 0.034), delayed hip involvement (OR = 5.2, p = 0.002; HR = 3.0, p = 0.044), and methylprednisolone pulse therapy (OR = 10.8, p = 0.0000001; HR = 5.6, p = 0.002).

Conclusion

Both sJIA and systemic CS, impaired calcium-phosphorus metabolism, and delayed hip arthritis are associated with HOA development in JIA. HOA is considered to be a severe adverse event of CS treatment, especially delayed hip involvement.