Component selection for revision total hip arthroplasty is important for creating a stable hip, providing offset to maximize joint mechanics, and restoring appropriate leg lengths. On the femoral side, fully porous coated stems, modular tapered stems, and proximal femoral replacements can be used depending on the level of bone loss. For the acetabulum, smaller defects can be contained using second-generation porous coating hemispherical cups, whereas larger acetabular defects can be contained with cup cages, cages, or custom triflange implants. In addition, acetabular liners can improve stability through altered cup version, dual mobility, or constraint of the femoral head.

Keywords

Revision total hip arthroplasty

Fully porous coated stems

Modular components

Trabecular metal

Acetabular augments

Cages

Key points

Introduction

Component selection for revision total hip arthroplasty (THA) is dictated by choosing components that create a stable hip, restore appropriate leg lengths, and provide offset to maximize joint mechanics. Multiple factors go into the decision-making process for which components to use, including the amount of bone loss present and accounting for the components that are currently in place. For the femur, determining the geometry of the remaining bone helps to guide orthopedic surgeons to use fully porous coated stems for metaphyseal bone loss, modular stems that provide various stem versions, and proximal femoral replacements (PFRs) for reconstructions in which there is great proximal bone loss and no attachment for the abductors. Smaller acetabular defects can be contained by using hemispherical cups with second-generation porous coatings with or without metal augments or bone graft, whereas larger acetabular defects can be contained with cages or custom triflange implants. In addition, specific acetabular liners can be placed to alter the version of the cup by a set number of degrees, provide articulation through dual mobility liners, or constrain the femoral head. This article provides guidance as to which components to use in THA revisions.

Revision femoral components

Choosing femoral components in revision THA depends on the type of fixation needed to stabilize a prosthesis within a femur with bone loss. Although metaphyseal fixation is often used in primary THA stems with wedge and taper stems, most stems used in revision THA are designed for diaphyseal fixation, because the metaphysis can be weakened or even absent in the revision setting. If too much proximal femoral bone is missing, then a PFR may need to be used. The options for femoral components in revision THA are described later.