Background/Purpose

Although treatment options have increased and morbidity has decreased in the last decade Juvenile Idiopathic Arthritis (JIA) may still result in disability. Increasingly ultrasonography (US) has been used to measure cartilage thickness in children with JIA and normal values have been established. Although treatment of JIA has moved away from the use of long term steroids bone health remains a consistent worry in patients with JIA. The relation between cartilage thickness and bone health in patients with JIA has not been studied before.  The aim of this study is to determine if there is a correlation between cartilage thickness and bone health index in children with JIA.

Methods

We clinically examine joint activity in 68 children with JIA. Joint cartilage thickness was assessed by greyscale USin knee, ankle, wrist, metacarpophalangeal, and proximal interphalangeal  (PIP) joints. Measurements were compared to reference values of a healthy cohort of a previous study. Medical records were reviewed for JIA subtype, treatment and disease duration. Automated determination of bone health index and bone age was made by using BoneXpert (Visiana) software implying digital programmetry (DXR) and conventional hand radiographs.

 Results

In total 68 patients (17 males, 51 females) with a median age at investigation of 11 years (range 5-15 years) and median disease duration of 42 months were included. Subtypes represented were; 26 oligoarticular persistent; 13 oligoarticular extended; 17 polyarticular rheumatoid factor (RF) negative; 4 polyarticular RF positive; 8 systemic onset. In total 680 joints were examined for cartilage thickness. Decreased cartilage thickness was present in 27% of the examined joints (181 joints). Most common joint with decreased cartilage thickness was the PIP, followed by the wrist, the least common was the ankle joint. 34 patients had a decreased bone health index and 23 patients a decreased bone age; only 14 patients examined showed a combined decreased bone health index and decreased bone age. Decreased cartilage thickness of the left wrist is found in 29 patients; 48% of these patients also have a decreased bone health index but only 17% have a decreased bone age.

Conclusion

Decreased cartilage thickness is a prominent and frequent feature in JIA. Decreased bone health and bone age is found in approximately half of the patients. Cartilage thickness seems to be correlated with decreased bone health, but less with decreased bone age. Further studies are necessary to study these correlations as decreased cartilage thickness might be an indicator for future bone health and steer treatment decisions.

---

« Back to 2014 ACR/ARHP Annual Meeting

ACR Meeting Abstracts - https://acrabstracts.org/abstract/cartilage-thickness-and-bone-health-in-children-with-juvenile-idiopathic-arthritis/