Total knee arthroplasty is an excellent operation and the results have been well documented for both cemented and cementless techniques. It is generally accepted that the results for cemented total knee outpace the results for cementless total knees. Despite this there remains great interest in developing systems and techniques that might allow predictable biologic fixation for knee arthroplasty. There is a long list of requirements that must be met to predictably allow bone ingrowth. These include viable bone, optimal pore size, optimal pore depth, optimal porosity, minimal gaps between bone and implant and minimal micromotion. Implant design is critical but it is proposed that operative techniques can help with some of these issues. We will discuss these operative issues during the surgical demo. These technique issues include: replication of normal posterior slope of the tibia, irrigation of all cuts to avoid thermal necrosis, and application of autologous bone chips to interface - “bone slurry”. These are obviously not all of the issues to consider but we feel they are some of the more important factors related to the cementless technique. The surgeon also has to be mindful of all of the other techniques that are essential to primary total knee arthroplasty. This demo will also utilise an ultracongruent bearing and with Vitamin E polyethylene.
The number of complex revision total hip arthroplasties (THA) is predicted to rise. The identification of acetabular bone defects prior to revision THA has important implications on technique and complexity of acetabular reconstruction. Paprosky et al. proposed a classification system including 3 main types with up to 3 subtypes focused on the integrity of the superior rim of the acetabulum and medial wall. However, the classification system is complex and its reliability has been questioned. The purpose of this study was to evaluate the effectiveness of different radiologic imaging modalities (plain radiographs, 2-D CT, 3-D CT reconstructions) in classifying acetabular defects in revision hip arthroplasty cases and their value of at different levels of orthopaedic training. Patients treated with revision total hip arthroplasty for acetabular bone defects between 2002–2012 were identified and 22 cases selected that had plain radiographs, 2-D CT and 3-D reconstructions available. Bone defects were classified independently by two fellowship-trained adult reconstruction surgeons. Representative sections were chosen and compiled into a timed presentation. Thirty-five residents from PGY-1 to PGY-5 and 4 attending orthopaedic surgeons were recruited for this study and received a 15-minute introduction to the classification system. Chi square analysis was utilized to examine the influence of image modality and level of training on the correct classification of acetabular bone loss using the Paprosky classification system with alpha=0.05.Introduction
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