Cementless femoral design concerns. Rationale for extensive porous coating

Abstract

In the early 1980s increased interest in proximally porous coated stems was sparked by first generation cemented stem failures in young patients and concerns with extensively porous coated cementless stems regarding thigh pain and stress shielding. As a result, various proximally porous coated stems were produced, each with differing clinical results. Using 5-year minimal followup as a cut off, the evolution of proximally porous coated stems during the years is presented and compared with the long term results obtained with extensively porous coated stems. Problems with some of the early proximally coated designs have been reported in the literature. Despite subsequent design modifications, the modern proximally coated stem has not eliminated thigh pain or stress shielding. Although some of the proximally porous coated stems have had good results, the question whether the push for proximally coated femoral stems resulted in significant clinical improvement versus the long term results of extensively porous coated stems remains.