Infection in prosthetic material

Surgical site infection (SSI) occurs when a wound created as part of a surgical procedure becomes infected. SSI is one of the most common healthcare-associated infections and occurs in approximately 5% of patients undergoing a surgical procedure. SSI may lead to patients suffering considerable morbidity or mortality and have significant cost implications. The aetiology involves the interplay of host, environmental and pathogen factors all of which should be addressed in seeking to reduce the risk of developing an infection. The presence of prosthetic material reduces the number of bacteria necessary for an infection to develop and can give rise to treatment and diagnostic difficulties. The responsible organisms are most commonly Staphylococcus aureus and S. epidermidis. Diagnosis is frequently problematic and antibiotic treatment alone is often ineffective due to biofilm formation necessitating removal of prosthesis in many cases. Prevention of infection is by far the most important aspect of prosthetic implant surgery. Patient optimization is equally important as the cutting edge research into biological prostheses in reducing the incidence of prosthetic infection in future practice

Complications of Resection Arthroplasty in Two-Stage Revision for the Treatment of Periprosthetic Hip Joint Infection

Little data is available regarding complications associated with resection arthroplasty in the treatment of hip periprosthetic joint infection (PJI). We assessed complications during and after two-stage revision using resection arthroplasty. In this retrospective study, 93 patients undergoing resection arthroplasty for hip PJI were included. Patients were assigned to a prosthesis-free interval of ≤10 weeks (group 1; 49 patients) or >10 weeks (group 2; 44 patients). The complication rates between groups were compared using the chi-squared test. The revision-free and infection-free survival was estimated using a Kaplan-Meier survival analysis. Seventy-one patients (76%) experienced at least one local complication (overall 146 complications). Common complications were blood loss during reimplantation (n = 25) or during explantation (n = 23), persistent infection (n = 16), leg length discrepancy (n = 13) and reinfection (n = 9). Patients in group 1 experienced less complications after reimplantation (p = 0.012). With increasing severity of acetabular bone defects, higher incidence of complications (p = 0.008), periprosthetic bone fractures (p = 0.05) and blood loss (p = 0.039) was observed. The infection-free survival rate at 24 months was 93.9% in group 1 and 85.9% in group 2. The indication for resection arthroplasty needs to be evaluated carefully, considering the high rate of complications and reduced mobility, particularly if longer prosthesis-free intervals are used

Enterococcal periprosthetic joint infection: clinical and microbiological findings from an 8-year retrospective cohort study

BACKGROUND: Treatment of enterococcal periprosthetic joint infections (PJI) is challenging due to non-standardized management strategies and lack of biofilm-active antibiotics. The optimal surgical and antimicrobial therapy are unknown. Therefore, we evaluated characteristics and outcome of enterococcal PJI. METHODS: Consecutive patients with enterococcal PJI from two specialized orthopedic institutions were retrospectively analyzed. Both institutions are following the same diagnostic and treatment concepts. The probability of relapse-free survival was estimated using Kaplan-Meier survival curves and compared by log-rank test. Treatment success was defined by absence of relapse or persistence of PJI due to enterococci or death related to enterococcal PJI. Clinical success was defined by the infection-free status, no subsequent surgical intervention for persistent or perioperative infection after re-implantation and no PJI-related death within 3 months. RESULTS: Included were 75 enterococcal PJI episodes, involving 41 hip, 30 knee, 2 elbow and 2 shoulder prostheses. PJI occurred postoperatively in 61 episodes (81%), hematogenously in 13 (17%) and by contiguous spread in one. E. faecalis grew in 64 episodes, E. faecium in 10 and E. casseliflavus in one episode(s). Additional microorganism(s) were isolated in 38 patients (51%). Enterococci were susceptible to vancomycin in 73 of 75 isolates (97%), to daptomycin in all 75 isolates, and to fosfomycin in 21 of 22 isolates (96%). The outcome data was available for 66 patients (88%). The treatment success after 3 years was 83.7% (95% confidence interval [CI]; 76.1-96.7%) and the clinical success was 67.5% (95% CI; 57.3-80.8%). In 11 patients (17%), a new PJI episode caused by a different pathogen occurred. All failures occurred within 3 years after surgery. CONCLUSION: About half of enterococcal PJI were polymicrobial infections. The treatment success was high (84%). All treatment failures occurred within the first 3 years after revision surgery. Interestingly, 17% of patients experienced a new PJI caused by another pathogen at a later stage

Prosthetic joint infections

Objectives: To review the available literature on prosthetic joint infections and provide recommendations on management particularly the importance of identifying the causative organism and starting the most appropriate antimicrobial therapy. Methods: The medical literature was searched using PubMed, employing the key words prosthetic joint infections. There appears to be no UK consensus guidelines on the management of prosthetic joint infections or the use of prophylactic antibiotics to prevent them. There is however a number of key documents and trust policies which deal with the subject extensively. We also made use of ‘The Sanford Guide to Antimicrobial therapy 2012’ for the latest recommendations on the correct antimicrobial therapy. Conclusion: Although diagnosis is often difficult, there are a number of investigations which can help us identify the organism. We recommend that the local prevalence of such infections is studied together with identification of the commonest organisms. Work is already underway between the infectious disease team and orthopaedic surgeons to devise locally adapted protocols for the identification and management of such infections. They should work in close liaison to implement the correct treatment which often involves a combination of both surgical and antimicrobial therapy.peer-reviewe

500 penile prostheses implanted by a surgeon in Italy in the last 30 years

OBJECTIVES: The aim of our study was to report our experience with patients affected by Erectile Dysfunction (ED) and undergoing penile prosthetic implantation (PPI) in a single center by a single surgeon. MATERIAL AND METHODS: We retrospectively evaluated the clinical outcome of 500 patients (mean age: 51.5 years, range: 20-86 years) affected by ED and referred to our private andrological center from January 1984 to December 2013 who underwent penile prosthesis implantation, including the reported level of patient satisfaction. RESULTS: 182 silicone, 180 malleable, 18 monocomponent hydraulic and 120 multicomponents hydraulic prostheses were implanted by the same experienced surgeon. All patients were hospitalized for the procedure. All patients were evaluated immediately, 1 month (496 patients) and, for the great majority, every year after implantation. One hundred twenty five patients were lost to follow-up. Twenty two patients underwent revision surgery for complications in the postoperative period. The most serious postoperative complications were mechanical problems (45 patients, 9.0%) and infection (15 patients, 3%). Forty two (8.4%) prostheses were explanted. Overall, 80% (400/500) of patients were able to have sexual intercourse and were fully satisfied with the results. CONCLUSIONS: In our experience prosthetic surgery should be considered a good solution for men affected by ED and not responsive to other therapeutic solutions. Prosthetic surgery can be performed not only in large public hospitals but also in smaller private facilities

Prophylactic antibiotic regimens in tumour surgery (PARITY): protocol for a multicentre randomised controlled study.

IntroductionLimb salvage with endoprosthetic reconstruction is the standard of care for the management of lower-extremity bone tumours in skeletally mature patients. The risk of deep postoperative infection in these procedures is high and the outcomes can be devastating. The most effective prophylactic antibiotic regimen remains unknown, and current clinical practice is highly varied. This trial will evaluate the effect of varying postoperative prophylactic antibiotic regimens on the incidence of deep infection following surgical excision and endoprosthetic reconstruction of lower-extremity bone tumours.Methods and analysisThis is a multicentre, blinded, randomised controlled trial, using a parallel two-arm design. 920 patients 15 years of age or older from 12 tertiary care centres across Canada and the USA who are undergoing surgical excision and endoprosthetic reconstruction of a primary bone tumour will receive either short (24 h) or long (5 days) duration postoperative antibiotics. Exclusion criteria include prior surgery or infection within the planned operative field, known colonisation with methicillin-resistant Staphylococcus aureus or vancomycin-resistant Enterococcus at enrolment, or allergy to the study antibiotics. The primary outcome will be rates of deep postoperative infections in each arm. Secondary outcomes will include type and frequency of antibiotic-related adverse events, patient functional outcomes and quality-of-life scores, reoperation and mortality. Randomisation will be blocked, with block sizes known only to the methods centre responsible for randomisation, and stratified by location of tumour and study centre. Patients, care givers and a Central Adjudication Committee will be blinded to treatment allocation. The analysis to compare groups will be performed using Cox regression and log-rank tests to compare survival functions at α=0.05.Ethics and disseminationThis study has ethics approval from the McMaster University/Hamilton Health Sciences Research Ethics Board (REB# 12-009). Successful completion will significantly impact on clinical practice and enhance patients' lives. More broadly, this trial will develop a network of collaboration from which further high-quality trials in Orthopaedic Oncology will follow

A systematic review of the evidence for single stage and two stage revision of infected knee replacement

BACKGROUND: Periprosthetic infection about the knee is a devastating complication that may affect between 1% and 5% of knee replacement. With over 79 000 knee replacements being implanted each year in the UK, periprosthetic infection (PJI) is set to become an important burden of disease and cost to the healthcare economy. One of the important controversies in treatment of PJI is whether a single stage revision operation is superior to a two-stage procedure. This study sought to systematically evaluate the published evidence to determine which technique had lowest reinfection rates. METHODS: A systematic review of the literature was undertaken using the MEDLINE and EMBASE databases with the aim to identify existing studies that present the outcomes of each surgical technique. Reinfection rate was the primary outcome measure. Studies of specific subsets of patients such as resistant organisms were excluded. RESULTS: 63 studies were identified that met the inclusion criteria. The majority of which (58) were reports of two-stage revision. Reinfection rated varied between 0% and 41% in two-stage studies, and 0% and 11% in single stage studies. No clinical trials were identified and the majority of studies were observational studies. CONCLUSIONS: Evidence for both one-stage and two-stage revision is largely of low quality. The evidence basis for two-stage revision is significantly larger, and further work into direct comparison between the two techniques should be undertaken as a priority

Outlook Magazine, Winter 2015

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