Tumorprothesen in der endoprothetischen Revisionschirurgie der unteren Extremität – Ergebnisse von 25 Patienten nach Versorgung mit einem modularen Tumor- und Revisionssystem (MUTARS®)

Abstract

With extended life expectancy, the number of primary joint arthroplasties has also increased. Revision surgery is also more often necessary, due to aseptic or septic loosening of the prosthesis or periprosthetic fracture. Large bone defects often occur in these patients and several non-modular, conventional implants are available to handle this difficult situation. Custom made implants offer an individually designed and defect-adapted shape with perfect covering of the lesion, but may delay the operation. The Modular Universal Tumor And Revision System (MUTARS®) offers the possibility to vary the length and angle of the femoral neck and the antetorsion angle. Thus, it permits intraoperative adaption to the individual patient's defect. The aim of our study is to present clinical, functional results and the rate of complications in a cohort of patients undergoing revision surgery for failed endoprosthetic replacement or failed trauma surgery, using the Modular Universal Tumor And Revision System with short-to midterm follow-up. Between August 2005 and September 2014, 25 patients (17 female, 8 male) with an average age of 72 years (min. 56, max. 92 years) were included in a retrospective study using the MUTARS® system. The patients underwent surgical revision of osseous defects that were not susceptible to conventional care. The mean follow-up was 16 months (min. 12, max. 72 months). The indications which led to revision surgery were as follows: loosened metal-on-metal prosthesis with an acetabular defect caused by a metal-induced granuloma (n = 1), pseudoarthrosis after implantation of femur nail (n = 2), cut-out of a femur nail (n = 1), aseptic loosening of an implanted endoprosthesis (n = 4), septic loosening of an implanted endoprosthesis (n = 1), periprosthetic fracture (n = 6) and periprosthetic infection after two stage revision surgery (infection consolidated Girdlestone situation) (n = 10). All patients were followed up at regular intervals, both clinically and radiologically. Apart from comorbidities, clinical and functional parameters were measured, including the Harris Hip Score. An outcome analysis was also performed with respect to peri- and postoperative complications. Serial plain X-rays were followed-up. In all patients, stable reconstruction without the use of an allograft was possible. In total, 23 patients underwent surgery by using a proximal femur prosthesis; three patients also received a custom made acetabular component. One patient was treated by using a distal femur and one patient was treated by implantation of a total femur prosthesis. The average length of hospital stay was 25 days (min.11, max. 47 days). The Harris Hip Score improved from 28 points preoperatively to 81 points after surgery.In total we recorded 24 % of complications after surgery. Two patients suffered recurrent periprosthetic infection and the prosthesis had to be revised in a further two stage exchange; one patient had a tractus gap and was revised by surgery. Two patients suffered periprosthetic fracture due to trauma...

Infection risk analysis of 101 silver-coated endoprostheses

“…2 However, within each selected patient population and anatomical localization, silver-coated implants have consistently shown lower infection rates in comparison to other implants 18,[25][26] and our results corroborate these findings in the setting of an independent institution with longer follow-up from previous smaller patient series. 4,5,20,22,23 The overall 12 % infection rate of the presented study is almost identical to the previously published series of mixed primary resections with revision arthroplasty where Glehr et al 27 reported an infection rate of 12.5 % among 32 patients who had been treated with MUTARS® silver-coated endoprostheses and Wafa et al 18 reported an overall postoperative infection rate of 11.8 % in the silver-coated group of 85 Agluna-Stanmore Implants. Likewise, Schmolders et al 4 had to perform revision operations due to infection in 10 % of their implanted silver-coated MUTARS® endoprostheses after a median follow-up of 24 months for primary or metastatic oncological patients.…”

“…Furthermore, the results in revision arthroplasty patients are difficult to analyse within or between different centres due to different diagnostic methods of infection (e.g., sonication), perioperative antibiotic regiments, number of previous surgical procedures and pre-existing infections. All these limitations were also present in all other recent studies of this topic [1][2][3][4][5][6][19][20][21][22][23][24] where the infection-rate variability of silver-coated implants was larger between different patient populations (primary resection, metastases, revision, previous infection) and anatomical localizations than between different implant types (silver-coated vs. non-coated). 2 However, within each selected patient population and anatomical localization, silver-coated implants have consistently shown lower infection rates in comparison to other implants 18,[25][26] and our results corroborate these findings in the setting of an independent institution with longer follow-up from previous smaller patient series.…”

“…15,16 The antimicrobial efficacy of silver-coated endoprostheses has not yet been confirmed in randomized controlled studies, but several retrospective studies analysed different implants, 17,18 among them the widely used MUTARS® system (= Modular Universal Tumour And Revision System, Implantcast GmbH). [1][2][3][4]6,[19][20][21][22][23][24] These studies were either conducted by the main developmental hospital of this manufacturer (University Hospital Münster, Münster, Germany) 1,3,6,15,21,24 or in smaller centres with patient series of 25-40 patients and < 2 years follow-up. 4,5,20,22,23 So far no study has been published by an independent institution with the entire cohort of a hundred silver-coated MUTARS® implants and over 3 years of mean follow-up.…”

Novel concept of a modular hip implant could contribute to less implant failure in THA: a hypothesis

“…Until now, modularity in THA is mainly applied in revision and tumor arthroplasty [ 15 – 18 ]. In primary THA modular implants are barely used because of the high risk of breakage [ 11 , 19 – 21 ].…”

Editorial für die Zeitschrift für Orthopädie und Unfallchirurgie

“…Modularen Revisionsschaftsystemen nicht gut versorgbar ist. Durch die Arbeitsgruppe von Schmolders et al [5] wurde daher die Anwendung eines modularen tumorendoprothetischen Systems (MUTARS) in der femoralen Revisionsendoprothetik untersucht. Es zeigte sich aufgrund der einfachen Handhabung intraoperativ mit modularer Adaptation an die vorliegende Defektsituation (vom proximalen Femurersatz bis zum totalen Femur) eine für diese komplexen Fälle akzeptable Komplikationsrate von insgesamt 24 %.…”