RETURN trial


Dislocated DDH hips can often be successfully treated with a Pavlik harness. However, 20-40% of initially dislocated hips are reported to not concentrically reduce with this method. To date it has not been clarified how long Pavlik treatment should be continued, before it should be considered unsuccessful and abandoned for more invasive treatment modalities.

Prolonged Pavlik treatment in not reducing hips might lead to impaired acetabular or femoral development and AVN. Therefore, it would be beneficial to be able to better determine when no improvement in hip position can be expected in the Pavlik harness. For some patients it might be beneficial to discard the harness and not unnecessarily delay initiation of further treatment, whereas for other patients prolonged Pavlik treatment might result in reduction and avoid the need for more invasive treatment.


The RETURN trial is a prospective study, using serial trans-inguinal sonographic measurement of hip reduction to asses when dysplastic hips reduce and when no further improvement in hip position can be expected in the Pavlik harness. This will allow us to come to an optimized treatment protocol, and more accurately time when to discard Pavlik treatment in not reducing hips. Secondary aim of the proposed study is to asses gradual improvement of the femoral head position in the acetabulum after reduction (the ‘docking effect’) in the Pavlik harness.