Analysis of Risk Factors for Ultrasonographic GrafType IIa (−) Hips in Developmental Dysplasia: A Hospital-Based Case-Control Study with Follow-Up Outcomes

Abstract

Objective: To examine the association of Graf type IIa(-) hips with maternal and infant risk factors in newborns and toevaluate the follow-up outcomes. Materials and Methods: Two different risk analyses were performed. In the first analysis, Graf type I hips were groupedas “controls,” and Graf type II were grouped as “cases.” In the second analysis, all the Graf type I and Type IIa(+) hips weregrouped as “controls,” and all Graf type IIa (-) hips were considered as “cases.” Maternal age, presence of consanguinity,pregnancy, and smoking were considered as maternal risk factors. Sex, birth weight, gestational age, associated congenitalanomalies, and family history were considered as infant risk factors. Further, we determined the risk factors for Graf type IIaand type IIa (-) hips. Results: The study population included 73 cases (11.4%) and 569 controls (88.6%), including 322 (50.2%) male and 320(49.8%) female infants. Graf type IIa hips revealed significant differences for gestational age (>42 wk), birthweight (>3500g), and maternal age (≤20 y). At follow-up, all Graf type IIa(+) hips became Graf type I mature hips. In contrast, three Graftype IIa(−) hips (3/12, 25%) required additional treatment. Conclusion: Significant risk factors for Graf type IIa(-) hips were female sex, gestational age of >42 wk, and birthweight of>3500 g. Almost one-quarter of Graf type IIa (-) hips may require additional treatment. Thus, significant risk factors for Graftype IIa(-)should be remembered in clinical practice.