Segmental defects of the acetabulum are often encountered in revision surgery. Many times these can be handled with hemispherical cups. However when larger defects are encountered particularly involving the dome and/or posterior wall structural support for the cup is often needed. In the past structural allograft was used but for the last 12 years at our institution trabecular metal augments have been used in the place of structural allograft in all cases. This talk will focus on technique and mid-term results using augments in association with an uncemented revision shell. The technique can be broken down into 6 steps outlined below: 1. Exposure, 2. Reaming, 3. Trialing, 4. Augment Inserted, 5. Cup Insertion/Stabilization, 6. Trial Reduction/Liner Cementation. A recent study was undertaken to assess the mid-term results of this technique. We prospectively followed the first 56 patients in whom these augments were utilised in combination with a trabecular metal acetabular component in our unit. Details of this study will be presented. The median follow up of the surviving patients was 110 months (range 88–128 months). Survivorship of the augments at 10 years was 92.2% (95% CI: 97.0–80.5%). In one case the augment was revised for infection and in 3 for loosening. In 1 of the revised cases there was a pre-operative pelvic discontinuity, the other 2 discontinuities in the series were not revised and remain asymptomatic. Conclusions. The results of the acetabular trabecular metal augments continue to be encouraging in the medium to long term with low rates of revision or loosening in this complex group of patients

In revision total hip arthroplasty (THA), acetabular reconstruction while dealing with severe bone loss is a challenge. The porous tantalum revision acetabular shells have been in use for the past decade. Several reports have documented successful use at early to mid-term follow up. There is, however, very little literature around the long-term survival and quality of life outcome with the use of these shells. We reviewed the results of 46 acetabular revisions with Paprosky 2 and 3 acetabular bone defects reconstructed with a hemispheric, tantalum acetabular shell and multiple supplementary screws. There were 31 females. Average age at revision was 64 years (range 23–85 years). The mean and median follow up was 11 years (range 10–12 years, SD 1). Morselised femoral allograft was used in 34 hips to fill contained cavitary defectes. Bulk femoral allografting was performed in 2 hips. At a minimum follow-up of 10 (range 10–12) years, the survivorship of the porous tantalum acetabular shell, with revision of the shell as end point was 96%. The minimum 10-year survivorship with hip revision for any reason as end point was 92%. We noted excellent pain relief (mean WOMAC pain 92.6) and good functional outcome (mean WOMAC function 90.3, mean UCLA 5); and generic quality of life measures (mean SF-12 physical component 48.3; mean SF-12 mental component 56.7). Patient satisfaction with pain relief, function and return to recreational activities were noted to be excellent. Cementless acetabular revision with the tantalum acetabular shell demonstrated excellent clinical and quality of life outcomes at minimum 10-year follow-up. As far as we are aware this is the first report of minimum 10-year follow up of use of this technique for revision hip arthroplasty

Revision total hip replacements are likely to have higher complication rates than primary procedures due to the poor quality of the original bone. This may be constrained to achieve adequate fixation strength to prevent future “aseptic loosening” [1]. A thin, slightly flexible, acetabular component with a three dimensional, titanium foam in-growth surface has been developed to compensate for inferior bone quality and decreased contact area between the host bone and implant by better distributing loads across the remaining acetabulum in a revision situation. This is assumed to result in more uniform bone apposition to the implant by minimizing stress concentrations at the implant/bone contact points that may be associated with a thicker, stiffer acetabular component, resulting in improved implant performance.[2] To assemble the liner to the shell, the use of PMMA bone cement is recommended at the interface between the polyethylene insert and the acetabular shell as a locking mechanism configuration may not be ideal due to the flexibility in the shell [3]. The purpose of this study was to quantify the mechanical integrity of a thin acetabular shell with a cemented liner in a laboratory bench-top total hip revision condition. Two-point loading in an unsupported cavity was created in a polyurethane foam block to mimic the contact of the anterior and posterior columns in an acetabulum with superior and inferior defects. This simulates the deformation in an acetabular shell when loaded anatomically [4]. The application has been extended to evaluate the fatigue performance of the Titanium metal foam Revision Non-Modular Shell Sequentially Cross Linked PE All-Poly Inserts and its influence on liner fixation