Introduction: Developmental dysplasia of the hip (DDH) is one of the most common musculoskeletal conditions in children. Not treated DDH leads to disability, gait abnormalities, limb shortening and chronic pain. Our study aims to determine the impact of multiple risk factors on the occurrence of DDH and develop an interactive risk assessment tool.Materials and Methods: We conducted a retrospective cohort study in the Outpatient Clinic for Children of University Hospital. The Graf classification system was used for ultrasonographic universal screening. In total, 3102 infants met the eligibility criteria (n =6204 hip joints). Results: The incidence of DDH was 4.45%. In multivariate analysis, risk factors for DDH were weight (OR = 2.17 (1.41-3.32)), week of delivery (OR = 1.18 (1.00-1.37)), gender (OR = 8.16 (4.86-13.71)), breech delivery presentation (OR = 5.92 (3.37-10.40)), symptoms of DDH (25.28 (8.77-72.83)) and positive family history in siblings (5.74 (2.68-12.31)). Multivariate logistic regression predictive model was used to construct the interactive risk calculator.Conclusion: We confirmed well-known DDH risk factors in the studied population. Our results support the recent hypothesis that preterm infants (37 < week) have lower rate of DDH. The DDH risk calculator was built but needs external validation in prospective study before being used in a clinical setting.Level of Evidence: Retrospective cohort study: Level III

Introduction: Developmental dysplasia of the hip (DDH) is one of the most common musculoskeletal conditions in children. Not treated DDH leads to disability, gait abnormalities, limb shortening and chronic pain. Our study aims to determine the impact of multiple risk factors on the occurrence of DDH and develop an interactive risk assessment tool.Methods: We conducted a retrospective cohort study in the Outpatient Clinic for Children of University Hospital. The Graf classification system was used for ultrasonographic universal screening. In total, 4881 infants met the eligibility criteria (n = 9762 hip joints). Hypothesis testing was performed with χ² test and logistic regression.Results: The incidence of DDH was 4.57%. We have proven risk factors of DDH: female gender (OR=7.11), breech position (OR=3.65), Caesarean section (OR=1.43), positive family history in parent (OR=1.92) or sibling (OR=3.84). Preterm delivery decreased the risk (OR=0.17). Logistic regression was used to construct the interactive risk calculator.Conclusion: The DDH risk calculator was built but needs external validation in prospective study before being used in a clinical setting. We confirmed well-known DDH risk factors in the studied population. Our results support the recent hypothesis that preterm infants (37 < week) have lower rate of DDH.Level of Evidence:Retrospective cohort study: Level III

Total hip arthroplasty (THA) is one of the most frequent orthopedic procedures worldwide and its surgical volume is constantly growing. To address the patients' restricted access to healthcare resources and limited one-on-one contact with the surgeon during the COVID-19 pandemic, we created a reliable source of information for patients undergoing THA. The use of mHealth is increasing with access to modern technology in Poland. Information related to health issues is the second most common web search performed by older adults. Our project aimed to create the first Polish mobile application for THA patients: Endopedia. Endopedia was developed for the Android platform based on a survey performed among patients and a collection of frequently asked questions on patients' internet forums. The content was adapted to the elderly and visually impaired requirements. mHealth solutions should not replace one-on-one conversation, but they can provide substantial support for patients in conditions of limited information.