Beyond Words: Embracing Migration Percentage as the Universal Measurement for Hip Displacement in Children With Cerebral Palsy by Radiologists and Orthopedic Surgeons

Introduction: Migration percentage (MP) is the standard radiographic measurement to quantify hip displacement in cerebral palsy (CP) hip surveillance programs. We aim to evaluate the use of MP and other descriptors of hip displacement in radiographic impressions by radiologists and orthopedic surgeons before and after the introduction of hip surveillance guidelines at our institution. Methods: CP patients who underwent hip surveillance imaging at our institution in 2016 were retrospectively identified, and their radiographic impressions were collected between 2016 and 2019. Only patients with radiology and orthopedic impressions for the same image were included. The inclusion of MP was documented and compared between the two groups before and after the hip guidelines were implemented in 2018. We also examined the use of other qualitative descriptors for hip displacement within the impressions. Fisher’s Exact test was used for statistical significance (p<0.05). Results: Two hundred and fifty-one radiographs were analyzed. One radiology (0.40%) and 33 orthopedic impressions (13.15%) incorporated MP (p<0.001). No statistical significance was found between the inclusion of MP before and after 2018 in the radiology group. In contrast, the orthopedic group showed a significant increase in MP inclusion following guideline implementation, rising from 12 to 21 incidences (p=0.013). Descriptors for hip displacement were more commonly utilized than MP for both orthopedic surgeons and radiologists. Conclusion: MP is underutilized in radiologic and orthopedic impressions in hip surveillance programs. Extensive education for both specialties regarding MP is crucial for the successful management of hip displacement in CP hip surveillance programs.