Characterization of Normal Femoral Anatomy in Pediatric Patients using Statistical Shape Models

Sammanfattning: It is still not well defined how the anatomy of the hip in healthy pediatric patients develop. Defining the span of normal anatomical development could help identify patients that deviate from healthy development and enable early diagnosis of certain pathological conditions of the hip. To study the normality range of the 3D morphology of the hip for pediatric patients, a statistical shape model (SSM) can be used. Given a large enough set of hips the SSM can describe all the expected variations within the population. In this MSc project SSMs were created for pediatric patients using CT scans of patients between the ages 7 and 20 years who had no reported hip pathologies. The method for creating the models was developed from an existing pipeline for construction of SSMs of the proximal femur of adult patients. The models created contained the variation of the proximal part of the femur for a healthy population of pediatric patients. The SSMs were used to identify anatomical differences during development by studying separate age and gender groups. When creating the SSMs all femurs were scaled so that the variation in size was not part of the model. Significant differences in the morphological development were found between three age groups with 7 - 10, 12 - 15 and 16 - 17 year old patients. No significant differences were found between female and male patients. The developed methods and results from this thesis may eventually be useful for identifying patients that are developing abnormally and thereby help the surgeon with clinical decision making.