Prevention of leg length discrepancy in young children with pauciarticular juvenile rheumatoid arthritis by treatment with intraarticular steroids.

OBJECTIVE: To determine if intraarticular (i.a.) injection of triamcinolone hexacetonide (steroids) used early in the course of pauciarticular juvenile rheumatoid arthritis (pauci JRA) is associated with less leg length discrepancy (LLD) or thigh circumference discrepancy (TCD).
METHODS: Children with pauci JRA who had asymmetric lower-extremity arthritis diagnosed before age 7 years in Seattle, Washington (WA; n = 16) and in Chapel Hill and Durham, North Carolina (NC; n = 14) were retrospectively identified. WA children were given i.a. steroids within 2 months of diagnosis; the injections were repeated if synovitis recurred in the same joint or in a different joint. These children were compared with NC children who were not treated with i.a. steroids. Thigh circumference was measured at 10 cm above the patella, and leg length was measured from the anterior superior iliac spine to the mid-medial malleolus, by a single observer. LLD and TCD are reported as the percentage of difference between leg measurements in each subject.
RESULTS: The WA and NC subjects had comparable disease severity and duration of followup (in months). Twelve WA children had subsequent i.a. steroid injections (mean 3.25 injections per child over mean +/- SD 42 +/- 11 months). The WA subjects had significantly less LLD (P = 0.005, by Student's 2-sided t-test) and prescriptions for shoe lifts (P = 0.002, by Fisher's 2-sided exact test). There was not a significant difference in TCD between the 2 groups (P = 0.139, by Student's 2-sided t-test). Similar findings were obtained when the analysis was limited to children with monarticular knee arthritis.
CONCLUSION: Early and continued use of i.a. steroids may be associated with less LLD in young children with pauci JRA. This may indicate decreased duration of synovitis.