Reliability of Radiographic Assessments of the Hip in Cerebral Palsy

MP is a reproducible measure with excellent intrarater and interrater reliability. However, differences in MP of <7% should be treated with caution as these might be a consequence of measurement error. Although we found a high level of intrarater and interrater reliability of the AI, AA, and PO, these measurements are more variable and not ideal for use as discrete outcome measures. Instead, these parameters might be useful for prognostication and decision making when consistent trends are observed longitudinally over time which might be better indications of true change.