Purpose. The aim of this study was to compare the clinical outcomes of the revision TKA in which
Metaphyseal bone loss, due to loosening, osteolysis or infection, is common with revision total knee arthroplasty (TKA). Small defects can be treated with screws and cement, bone graft, and non-porous metal wedges or blocks. Large defects can be treated with bulk structural allograft, impaction grafting, or highly porous metal cones. The AORI classification of bone loss in revision TKA is very helpful with pre-operative planning. Type 1 defects do not require augments or graft—use revision components with stems. Type 2A defects should be treated with non-porous metal wedges or blocks. Type 2B and 3 defects require a bulk structural allograft or porous metal cone. Highly-porous metal metaphyseal cones are a unique solution for large bone defects. Both femoral (full or partial) and tibial (full, stepped, or cone+plate) cones are available. These cones substitute for bone loss, improve metaphyseal fixation, help correct malalignment, restore joint line, and permit use of a short cemented stem. The technique for these cones involve preparing the remaining bone with a high speed burr and rasp, followed by press-fit of the cone into the remaining metaphysis. The interface is sealed with bone graft and putty. The fixation and osteoconductive properties of the outer surface allow ingrowth and biologic fixation. The revision knee component is then implanted, with antibiotic-cement, into the porous cone inner surface, which provides superior fixation compared to cementing into deficient metaphyseal bone. There are several manufacturers that provide porous cones for knee revision, but the tantalum-“trabecular metal” cones have the largest and longest clinical follow-up. The advantages of the
Restoration of bone loss is a major challenge of revision TKA surgery. It is critical to achieve of a stable construct to support implants and achieve successful results. Major bone defects of the femoral and/or tibia (AORI type IIB/III) have been reconstructed using impaction grafting, structural allografts or tumor prostheses. The major concerns with structural allograft are graft resorption, mechanical failure, tissue availability, disease transmission, considerable surgical skill required and prolonged operative time. Porous tantalum metaphyseal cones, are becoming the established method of choice to correct large bone defects with several recent studies demonstrating promising results. The high coefficient of friction of these implants provides structural support for femoral and tibial components. The high degree of porosity has excellent potential for bone ingrowth and long-term biologic fixation. Several published series, although with relatively small cohorts of patients, have reported good short-term results with
Total knee arthroplasty in the setting of osseous defects has multiple management options. However, the optimal treatment strategy remains controversial. The purpose of this study is to report the clinical and radiographic results of
Little information exists regarding optimal tibial stem usage in revision total knee arthroplasty (rTKA) utilising a tibial
The “keel” is the relatively short part of the undersurface of the tibial component that extends into the medullary canal. Most knee replacement systems have the capacity to attach modular stem extensions for enhanced intra-medullary fixation for revision. Diaphyseal length, large diameter stems may also guide positioning of trial components and are ideal for accurate surgical technique, even if fully cemented stems are eventually implanted. Smaller diameter non-modular stem extensions may be used for fully cemented fixation. They do not however guide component position very accurately and do not make sense for uncemented fixation. Revision surgery is different from primary surgery and enhanced fixation with some type of intramedullary fixation is highly appropriate, especially if constrained devices might be required. Options for enhanced intramedullary fixation are: 1. Fully cemented metaphyseal or shorter stems; 2. Diaphyseal engaging press fit stems; and 3. Very short fully cemented stems with