Measuring hip migration percentage in cerebral palsy using the HipScreen app

Abstract

AimsReimers migration percentage (MP) is a key measure to inform decision-making around the management of hip displacement in cerebral palsy (CP). The aim of this study is to assess validity and inter- and intra-rater reliability of a novel method of measuring MP using a smart phone app (HipScreen (HS) app).MethodsA total of 20 pelvis radiographs (40 hips) were used to measure MP by using the HS app. Measurements were performed by five different members of the multidisciplinary team, with varying levels of expertise in MP measurement. The same measurements were repeated two weeks later. A senior orthopaedic surgeon measured the MP on picture archiving and communication system (PACS) as the gold standard and repeated the measurements using HS app. Pearson’s correlation coefficient (r) was used to compare PACS measurements and all HS app measurements and assess validity. Intraclass correlation coefficient (ICC) was used to assess intra- and inter-rater reliability.ResultsAll HS app measurements (from 5 raters at week 0 and week 2 and PACS rater) showed highly significant correlation with the PACS measurements (p < 0.001). Pearson’s correlation coefficient (r) was constantly over 0.9, suggesting high validity. Correlation of all HS app measures from different raters to each other was significant with r > 0.874 and p < 0.001, which also confirms high validity. Both inter- and intra-rater reliability were excellent with ICC > 0.9. In a 95% confidence interval for repeated measurements, the deviation of each specific measurement was less than 4% MP for single measurer and 5% for different measurers.ConclusionThe HS app provides a valid method to measure hip MP in CP, with excellent inter- and intra-rater reliability across different medical and allied health specialties. This can be used in hip surveillance programmes by interdisciplinary measurers.Cite this article: Bone Jt Open 2023;4(5):363–369.

Radiological assessment of hip disease in children with cerebral palsy: development of a core measurement set

“…We hope this CMS will directly inform the development of AI tools to analyze radiographs in hip surveillance programmes. Fully-automated measurements would optimize monitoring, easing clinician work-load, 16 , 17 and potentially facilitating reliable, consistent, and accurate calculations. Moreover, this software could mitigate healthcare inequalities, especially in regions with limited healthcare access where implementing the CMS may be impractical.…”

“… 14 Radiograph analysis is time-consuming both to perform and upload data, and is prone to variability between clinicians. 15 Tools within Picture Archiving and Communication Systems (PACS) or mobile apps may have accelerated this process; 16 , 17 however, a fully-automated system is not currently available.…”

Beyond words: embracing migration percentage as the universal measurement for hip displacement in children with cerebral palsy by radiologists and orthopedic surgeons

“…As the second most prevalent orthopedic comorbidity among children with CP, hip displacement is a condition that often remains asymptomatic until it reaches a state of significant severity [1,2]. A combination of abnormal muscle tone and weakness results in abnormal forces across the hip joint, especially among non-ambulatory patients, leading to hip displacement [2–6]. This sequence of events can induce pain, alongside postural and gait irregularities, unless addressed through surgical intervention [7,8].…”