Fig. 4.

Photograph of a POP. Manufactured from a titanium alloy, its shape is tubular and solid and retains features in common with a hip arthroplasty stem with a plasma-sprayed coating. Osseointegration occurs over a few centimeters near the abutment; the remainder of the proximal aspect of the implant is for alignment only. The goal of this limited integration, analogous to uncemented total hip implants that integrate mainly at the proximal femoral metaphyseal flare, is to avoid stress-shielding. The abutment is smooth niobium oxide, with the goal of inhibiting skin adhesion to the implant. Attachment to the external implant features a dual cone adapter, and immediate implant retention is achieved through press-fit implantation. (Reproduced, with modification, from: Allyn G, Bloebaum RD, Epperson RT, Nielsen MB, Dodd KA, Williams DL. Ability of a wash regimen to remove biofilm from the exposed surface of materials used in osseointegrated implants. J Orthop Res. 2019 Jan;37[1]:248-57. Epub 2018 Nov 19. This article is a U.S. Government work and is in the public domain in the USA.)