Twenty-year results of the cementless Corail stem.

The concept of an extensive hydroxyapatite (HA) coating for the fixation of a tapered femoral stem (Corail®) was introduced 25 years ago in the hope that we could achieve durable biological fixation while preserving normal periprosthetic bone activity. The value of uncemented fixation using HA-coated implants is now widely admitted. However, the characteristics of implant coating and more specifically its extent still remain a subject of debate or even controversy. This prospective study conducted over a 20-year period has greatly contributed to demonstrating the reliability of the Corail® prosthesis, in terms of functional abilities, radiographic evidence and global survivorship. A full HA coating applied on a straight and proximally flared stem induces substantial short-, mid- and long-term benefits without any deleterious effects reported. Modifications of the bone pattern have been strictly limited: slight resorption at the calcar level, absence of cortical hypertrophy and alleged stress shielding. The radiological "silence" is one of the paramount facts clearly demonstrated.