Beware the syndrome in neonatal hip instability: follow up assessment is required after apparent resolution.

Developmental dysplasia of the hip is one of the most common congenital musculoskeletal disorders of childhood, affecting 1-3% of newborns. An early diagnosis and prompt treatment is essential to avoid complex treatments and achieve improved results. Since 1992, we have undertaken a screening programme for clinical instability and at risk patients. During this time, there have been only two cases which have been normal on both clinical, and, static and dynamic ultrasound assessment, that have subsequently deteriorated. In these two cases there was an underlying syndrome associated with hyperlaxity, which behaves unpredictably compared to 'true' developmental dysplasia of the hip. In conclusion, if a hip has been referred as unstable but it is found to have a primary syndromal cause (especially if hyper lax) with sonographically normal hips at one to two weeks of age, it is best to review clinically and sonographically at 6 weeks and 3 months of age to confirm that the hip is maintaining stability.