Silver-coated modular Megaendoprostheses in salvage revision arthroplasty after periimplant infection with extensive bone loss – a pilot study of 34 patients

Abstract

BackgroundHip and knee replacements in patients with bone defects after infection correlates with high rates of reinfection. In this vulnerable patient population, the prevention of reinfection is to be considered superordinate to the functionality and defect bridging. The use of silver coating of aseptic implants as an infection prophylaxis is already proven; however, the significance of these coatings in septic reimplantation of large implants is still not sufficiently investigated.MethodsIn a retrospective analysis, 34 patients who have been treated with a modular mega-endoprosthesis after a cured bone infection of the lower limb (femur or tibia) have been evaluated. One group with 14 patients (NSCG: non silver- coated group) was supplied with the non silver- coated implants: MML München- Lübeck™ modular endoprosthesis system (AQ Implants, Ahrensburg, Germany) or MUTARS® Modular Universal Tumor And Revision System (Implantcast GmbH, Buxtehude, Germany). The other group with 20 patients (SCG: silver- coated group) was supplied with the silver- coated system of MUTARS®. In addition to the clinical findings and the patients’ histories, specifically the reinfection rates, the patients’ mobility was assessed using the New Mobility Score (NMS, by Parker and Palmer).ResultsThe median follow-up period was 72 months, ranging from 6 to 267 months. The dropout rate was 5.8%. The reinfection rate after healed reinfection in SCG was 40% (8/20), in NSCG 57% (8/14), p = 0.34; α =0.05. The time for reinfection was, on average, 14 months (1–72 months) in SCG and 8 months (1–48 months) in the NSCG (p = 0.61; α =0.05). The two groups showed no differences in the NMS.ConclusionWith this retrospective analysis, it can be determined that the rate of reinfection of modular mega-endoprostheses on the hip and knee joint after healed periprosthetic joint infection (PJI) can be reduced by the use of silver coated implants. The time until reinfection can also be delayed by utilizing silver coated implants. Due to the low number of cases of this highly specific patient population, no statistical significance could be determined. A positive effect, however, can be assumed through the use of silver coatings in mega-endoprostheses after an infectious situation.

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.…”

Prevention of Prosthetic Joint Infection: From Traditional Approaches towards Quality Improvement and Data Mining

“…A recent systematic review reported a tendency to a lower PJI rate with silver-coated hip megaprostheses primarily used in tumor indications [179]. These implants have also been used after PJI in patients with extensive bone loss [180]. However, the overall evidence in favor of using silver-coated implants is still insufficient [181].…”

An Evolution of Shoulder Periprosthetic Infections Management: MicroDTTect, Bioactive Glass and Tantalum Cones Employment

“…In a retrospective analysis of 34 patients, Zajonz et al [ 30 ] demonstrated that the rate of reinfection of modular mega-endoprostheses on hip and knee joints can be reduced by the use of silver-coated implants. Reinfection time can also be delayed by utilizing silver-coated implants.…”