Hip instability in patients with Down syndrome is a rare entity, currently there is still controversy about the associated anatomical anomalies. The aim of the study is to describe the anatomical changes in the hips of patients with instability in Down syndrome (DS). We have reviewed the computed tomography (CT) of patients with hip dislocation with SD. Three of the 7 patients treated in our center are performed CT had hips. All CT showed the presence of vertical linear lesion (groove) located in epiphyseal region, crossing the physis, antero-internal location. We believe that the position taken when sleeping (flexion, adduction and internal rotation) can produce overpressure of the femoral head over the posterior acetabular rim, producing a vertical groove. The presence of this lesion can be suggestive of subclinical instability in the absence of hip dislocation.

Hip instability in patients with Down syndrome is a rare entity, currently there is still controversy about the associated anatomical anomalies. The aim of the study is to describe the anatomical changes in the hips of patients with instability in Down syndrome (DS). We have reviewed the computed tomography (CT) of patients with hip dislocation with SD. Three of the 7 patients treated in our center are performed CT had hips. All CT showed the presence of vertical linear lesion (groove) located in epiphyseal region, crossing the physis, antero-internal location. We believe that the position taken when sleeping (flexion, adduction and internal rotation) can produce overpressure of the femoral head over the posterior acetabular rim, producing a vertical groove. The presence of this lesion can be suggestive of subclinical instability in the absence of hip dislocation.