CLS Spotorno cotyle consists of an expansible hemispheric external component with troncoconic internal thin thread of Protasul Titanium. It also has a polyethylene UHMW internal threaded element which adapts prosthesic femoral heads (28–32 mm of diameter).

The implant procedure is technically simple. First of all, the acetabulum is prepared by milling the cartilaginous surface with hemispheric mills. The external element is inserted pressthorn;t, later it is expanded with a troncoconic thread, the high density polyethylene is threaded inside the expanded component.

The aim of this comunication is to expose the clinical and radiological outcome of 50 patients whom a CLS Spotorno expansible cotyle were implanted with a mean clinical follow up of 14 years.

The indications are exposed considering the age, cotyle morphology and bone quality. The evaluation included both clinical and radiographic parameter. Test of Postel and Merle DñAubigne were assessed for this clinical outcome. Radiological evaluation included: Acetabular angle desviation, periprosthesic osteolysis, proximal and medial migration of the cotyle and polyethylene wear. The primary stability of the acetabular stems were found excellent. Good osteointegration and biocompatibility were demostrated by serial radiographic and funtional scores. We also present the surgical procedure, the complications and the conclusions of the study.