Project description:BackgroundMetaphyseal cones provide durable fixation in revision total knee arthroplasty (TKA). However, there is a paucity of data on the outcomes of a new porous cone design. As such, the goal of this study was to analyze the early survivorship in patients undergoing revision TKA with this cone.MethodsWe retrospectively reviewed 163 revision TKAs with a newly designed porous tibial cone from 2016 to 2018. Mean age was 67 years, and mean body mass index was 33 kg/m2. Minimum follow-up duration was 2 years. Most patients were revised for aseptic loosening (46%), 2-stage periprosthetic joint infection (PJI) reimplantation (28%), or instability (15%). Most were varus-valgus constrained (65%) or hinged (32%) constructs. The majority had hybrid tibial stem fixation (74%). A multivariate Cox regression analysis was used to identify risk factors for reoperation.ResultsSurvivorship free from re-revision for aseptic loosening, any nonmodular revision, and any reoperation was 100%, 96%, and 86% at 2 years, respectively. No patients were revised for aseptic loosening. Six (4%) tibial cones were removed for PJI, one of which was loose. There were 23 reoperations (14%), most commonly for PJI (10%). Multivariate analysis identified PJI reimplantation (hazard ratios [HR] = 4.2, P = .002), males (HR = 2.9, P = .02), and hinged constructs (HR = 2.7, P = .02) as significant risk factors for reoperation.ConclusionsIn a complex revision TKA cohort with a new highly porous tibial cone, in which most patients received hybrid stem fixation and nonlinked and linked constraint, there was 100% survival free from re-revision for aseptic loosening at 2 years. Longer term follow-up is required.
Project description:Failed total knee arthroplasties with large bone defects are increasing rapidly because of the growing population of young, active patients undergoing primary total knee arthroplasty. There are limited options when tibial metaphyseal bone loss is so extensive that a tibial component with augments and thickest available polyethylene cannot fill flexion and extension gaps once the femoral component is appropriately positioned. Previously, allograft or megaprostheses would be required. However, allografts require contouring and fixation and may not incorporate into surrounding bone. Most endoprostheses do not osseointegrate and are associated with high risk of failure. To our knowledge, we are the first to describe stacked porous titanium cones for reconstruction of massive tibial metaphyseal defects, a straightforward technique with standard revision implants highly likely to osseointegrate.
Project description:Tibial plateau fractures (TPFs) in older adults are increasing in incidence and now account for 8% of all fractures in patients over 60 years of age. Although primary fixation remains standard, the risk of fixation failure, loss of reduction, and the development of posttraumatic osteoarthritis are all markedly increased in this age group with higher rates of conversion to total knee arthroplasty (TKA) of 12%. When joint depression is severe with significant subchondral bone loss, up to half ultimately require TKA. TPFs with unicondylar depression can be managed primarily using tibial cones in acute TKA. In this study, we report the surgical technique for performing acute TKA using tibial cones for the primary management of TPFs in older adults and illustrate this technique with case examples.
Project description:BackgroundThe purpose of this study is to assess the short- and mid-term radiographic outcomes of a ream-then-broach metaphyseal cone design for revision total knee arthroplasty (rTKA).MethodsA retrospective, multicenter analysis of rTKA patients utilizing femoral and/or tibial metaphyseal cone placement from January 2017 to July 2022 was performed. Assessment of radiolucency was performed utilizing a novel "cones score" for radiolucency for tibial and femoral cones.ResultsSixty-four rTKAs (23 femoral and 59 tibial cones) with short-term follow-up (12-24 months) and 80 rTKA (24 femoral and 76 tibial cones) with mid-term follow-up (>24 months) were assessed. No intraoperative complications were reported. No cases of cone or stem aseptic loosening were observed. The cones scoring system had a significantly strong intraclass correlation between the 3 reviewers (P < .001). Of tibial cones, 96.6% and 96.1% had no change in cones scoring at short- and mid-term follow-ups, respectively. Of femoral cones, 87.0% and 100% had no change in cones scoring at short- and mid-term follow-ups, respectively. All tibial and femoral implants were deemed radiographically stable at last radiographic follow-up.ConclusionsThe utilization of a ream-then-broach metaphyseal cones demonstrated excellent radiographic stability at short- and mid-term follow-ups. The use of this method has minimal risk of intraoperative or short-term failures. Surgeons should be familiar with this type of cone implantation system.
Project description:IntroductionRevision total knee arthoplasty often requires modular implants to treat bone defects of varying severity. In some cases, it may not be clear which module size and implant combination (e.g. sleeve and stem) should be chosen for a specific defect. When balancing implant stability and osseointegration against stress-shielding, it is important to choose an appropriate implant combination in order to match the given level of bone loss. Therefore, the necessity of stems in less extensive tibial defects and the advantage of different stems (lengths and stiffnesses) in combination with large metaphyseal sleeves on implant fixation and bone flexibility using a modular tibial revision knee system, were analyzed.Materials and methodsFour different stem combinations for a tibial revision implant (Sigma TC3, DePuy) were compared to an intact bone. Standardized implantation with n = 4 synthetic tibial bones was performed after generating an Anderson Orthopaedic Research Institute (AORI) Type T1 bone defect. Axial torques around the longitudinal stem axis and varus-valgus torques were separately applied to the implant. Micromotions of bone and implant were tracked using a digital image correlation system to calculate relative micromotions at the implant-bone-interface and bone deformation.ResultsOverall, using stems reduced the proximal micromotions of tray and sleeve compared to no stem, while reducing bone deformation proximally at the same time, indicating some potential for proximal stress-shielding compared to no stem. The potential for increased proximal stress-shield due to reduced proximal deformation appeared to be greater when using the longer stems. The location of lowest relative micromotions was also more distal when using long stems as opposed to short stems. A short stem (especially a smaller diameter short stem which still achieves diaphyseal fixation) displayed less potential for stress-shielding, but greater bone deformation distal to the tip of the stem than in the natural model.DiscussionIn the case of tibial revision implants with metaphyseal sleeves in a simple fully contained Type I defect, the absence of a stem provides for more natural bone deformation. However, adding a stem reduces overall relative micromotions, while introducing some risk of proximal stress-shielding due to increased diaphyseal fixation. Increasing stem length intensifies this effect. Short stems offered a balance between reduced micromotions and more proximal bone deformation that reduced the potential for stress-shielding when compared to long stems. A short stem with slightly smaller diameter (simulating a less stiff stem which still has diaphyseal fixation) increased the proximal bone deformation, but also tended to increase the bone deformation even further at the distal stem's tip.ConclusionIn conclusion, further investigation should be conducted on fully contained Type I defects and the addition of a stem to offer better initial stability, taking into account stem length (i.e. shorter or more flexible stems) to support metaphyseal fixation and allowing bending found in intact bone. In addition, further study into more extensive tibial defects is required to determine if the stability/micromotion trends observed in this study with stems and sleeves in Type I defects still apply in cases of extensive proximal bone loss.
Project description:In Response To: Walker RH. Reply to: Tardive dyskinesia-like syndrome due to drugs that do not block dopamine receptors: rare or non-existent: literature review. Tremor Other Hyperkinet Mov. 2019; 9. doi: 10.7916/3rez-p096 Original Article: D'Abreu A, Friedman JH. Tardive dyskinesia-like syndrome due to drugs that do not block dopamine receptors: rare or non-existent: literature review. Tremor Other Hyperkinet Mov. 2018; 8. doi: 10.7916/D8FF58Z9.