What's New in Adult Reconstructive Knee Surgery

The Rothman Institute, Thomas Jefferson University, 925 Chestnut Street, 5th floor, Philadelphia, PA 19107, USA.
The Journal of Bone and Joint Surgery (Impact Factor: 5.28). 01/2012; 94(2):182-8. DOI: 10.2106/JBJS.K.01262
Source: PubMed
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Available from: Carl A Deirmengian, Jan 19, 2015
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    • "First, we recognize that this model oversimplifies the actual procedures performed in orthopaedic surgery in humans. For example, in total knee arthroplasty, the cartilage is removed, and an implant is placed on both the tibial and femoral side and a variety of implant materials in addition to titanium are used (e.g., cobalt-chrome and polyethylene plastic) [33]. However, we believe that this model does reproduce the in vivo behavior of orthopaedic implant infections, which are characterized by the chronic and persistent bacterial infection of the implant and the surrounding bone and joint tissue [17]–[19]. "
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    ABSTRACT: Recent advances in non-invasive optical, radiographic and μCT imaging provide an opportunity to monitor biological processes longitudinally in an anatomical context. One particularly relevant application for combining these modalities is to study orthopaedic implant infections. These infections are characterized by the formation of persistent bacterial biofilms on the implanted materials, causing inflammation, periprosthetic osteolysis, osteomyelitis, and bone damage, resulting in implant loosening and failure. An orthopaedic implant infection model was used in which a titanium Kirshner-wire was surgically placed in femurs of LysEGFP mice, which possess EGFP-fluorescent neutrophils, and a bioluminescent S. aureus strain (Xen29; 1×10(3) CFUs) was inoculated in the knee joint before closure. In vivo bioluminescent, fluorescent, X-ray and μCT imaging were performed on various postoperative days. The bacterial bioluminescent signals of the S. aureus-infected mice peaked on day 19, before decreasing to a basal level of light, which remained measurable for the entire 48 day experiment. Neutrophil EGFP-fluorescent signals of the S. aureus-infected mice were statistically greater than uninfected mice on days 2 and 5, but afterwards the signals for both groups approached background levels of detection. To visualize the three-dimensional location of the bacterial infection and neutrophil infiltration, a diffuse optical tomography reconstruction algorithm was used to co-register the bioluminescent and fluorescent signals with μCT images. To quantify the anatomical bone changes on the μCT images, the outer bone volume of the distal femurs were measured using a semi-automated contour based segmentation process. The outer bone volume increased through day 48, indicating that bone damage continued during the implant infection. Bioluminescent and fluorescent optical imaging was combined with X-ray and μCT imaging to provide noninvasive and longitudinal measurements of the dynamic changes in bacterial burden, neutrophil recruitment and bone damage in a mouse orthopaedic implant infection model.
    PLoS ONE 10/2012; 7(10):e47397. DOI:10.1371/journal.pone.0047397 · 3.23 Impact Factor
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    ABSTRACT: Introduction Total knee replacement (TKR) is the procedure that best lends itself to the use of computer navigator assistance in orthopedic surgery. The special anatomy of the knee, the easy access to bony structures for the placement of arrays, the demanding final results as to component angles, the mandatory correction of the final axis of the limb, and, of course, commercial interest, have fostered the use of navigator assisted surgery in TKRs to the extent that it has become the preferred technique amongst the new procedures available in our specially. Current situation Many reports and studies of this technique have been published in the literature and there is a wide range of articles that show comparative X-ray results seen between TKRs carried out with and without navigator assistance. In all studies it is shown, rather repetitively, that navigator assistance provides safety, precision, and reproducibility when performing bone cuts. Although it is not yet known if the better final position of the limb and better angulations between the implant and the corresponding bone weill result in better clinical results in the medium and long term. Limitations of the technique Navigator assistance during surgery has its limitations. The learning curve is long depends on technological advances, and a minimum knowledge of IT is necessary. There is still very little experience with severe deformities or revision surgery. And final ligament stability is sometimes of the new navigation systems are gradually making this technique easier to use and increasing the knowledge the surgeon has of the preoperative situation of the knee, of the surgical steps that are necessary during t he operation and of the final result of the procedure. The aim of this study is to offer a general perspecptive of the situation of navigator assisted TKR, from a practical and up-todate viewpoint.
    Revista de Ortopedia y Traumatología 01/2006; 50:33–40. DOI:10.1016/S0482-5985(06)74993-8
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