This investigation aimed to determine the degree of correlation among 3 functional scales for evaluating the hip in pediatric patients and determine the correlation between measures of global function and outcome.
We performed a prospective study of 173 consecutive patients (Mage = 13 ± 3 y) being followed for developmental dysplasia of the hip (n = 122, 71%), slipped capital femoral epiphysis (n = 31, 18%), or Legg-Calve-Perthes disease (n = 20, 12%). We evaluated patients clinically, and we compiled scores for the Iowa Hip Score (IHS), Harris Hip Score (HHS), and Children’s Hospital Oakland Hip Evaluation Scale (CHOHES). Patients concomitantly completed the Pediatric Outcomes Data Collection Instrument (PODCI) at the same clinic visit. We assessed Global Functioning Scale the and the Sports and Physical Functioning Core Scale of the PODCI. We determined the degree of correlation between the functional hip scales and between each scale and the PODCI scales using Spearman rank correlation coefficients.
The correlations between the IHS, HHS, and CHOHES scores were robust (IHS and HHS ρ = 0.991; IHS and CHOHES ρ = 0.933; HHS and CHOHES ρ = 0.938; all P < 0.001). The correlation between the Global Functioning Scale of the PODCI and the 3 hip scores was ρ = 0.343 for the IHS, ρ = 0.341 for the HHS, and ρ = 0.352 for the CHOHES (all P < 0.001). The correlation between the sports and physical functioning core scale of the PODCI and the 3 hip scores was ρ = 0.324 for the IHS, ρ = 0.329 for the HHS, and ρ = 0.346 for the CHOHES (all P < 0.001).
In a pediatric population with diverse hip pathology, there was a very strong correlation between scores on the IHS, HHS, and CHOHES. However, none of these 3 most commonly used hip scores correlated strongly with the global functioning scale or sports and physical functioning core scale of the PODCI. The most frequently used scores to determine the outcome of pediatric patients with hip pathology correlate strongly with each other but do not necessarily relate to global functional results.
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