Despite the availability of numerous tests, the diagnosis of periprosthetic infection (PJI) continues to be complex. Although several studies have suggested that coagulation-related markers, such as D-dimer and fibrinogen, may be promising tools in the diagnosis of prosthetic infections, their role is still controversial. The aim of this study is to evaluate the diagnostic accuracy of serum D-dimer and fibrinogen in patients with painful total knee replacement. 83 patients with painful total knee replacement and suspected peri-prosthetic infection were included. All patients underwent pre-operative blood tests to evaluate inflammation indices (ESR and CRP) and serum D-Dimer and Fibrinogen levels. The diagnostic performance of the tests was assessed using the ICM definition as the gold standard. The diagnostic accuracy of the D-dimer and fibrinogen was measured by assessing sensitivity, specificity and by calculating the area under the ROC curve.Aim
Method
Biofilm-related infections represent a recurrent problem in the orthopaedic setting. In recent years, great interest was directed towards the identification of novel molecules capable to interfere with pathogens adhesion and biofilm formation on implant surfaces. In this study, two stable forms of α-tocopherol, the hydrophobic acetate ester and the water-soluble phosphate ester, were tested Antimicrobial activity against microorganisms responsible of prosthetic and joints infections was assessed by broth microdilution method. In addition, α-tocopherol esters were evaluated for both their ability to hamper bacterial adhesion and biofilm formation on sandblasted titanium surfaces.Aim
Method
The induced membrane technique (IMT) or Masquelet technique is a two-step surgical procedure used to treat bony defects (traumatic or resulting from tumoral resections) and pseudo arthroses, even caused by infections. The relatively small case series reported, sometimes with variants to the original technique, make it difficult to assess the real value of the technique. Aim of this study was then to undertake a systematic review of the literature with a particular focus on bone union, infection eradication and complication rates. A systematic review was carried out following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses for Individual Patient Data (PRISMA-IPD) guidelines. PubMed and other medical databases were searched using “Masquelet technique” and “induced membrane technique” keywords. English, French or Italian written articles were included if dealing with IMT employed to long bones in adults and reporting at least 5 cases with a 12 months minimum follow-up. Clinical and bone defect features, aetiology, surgical data, complications, re-interventions, union and infection eradication rates were recorded into a database. Fischer's exact test and unpaired t-test were used for the statistical analysis on the individual patient's data.Aim
Method
Aim of this study is to present the first clinical trial on an antibiotic-loaded fast-resorbable hydrogel coating In this prospective, multi-centre, randomized, controlled, prospective study, a total of 260 patients were randomly assigned, in five European orthopaedic centres, to receive the antibiotic-loaded DAC coating or to a control group, without coating. Pre- and post-operative assessment of laboratory tests, wound healing, clinical scores and x-rays were performed at fixed time intervals.Aim
Method
Infection remains among the first reasons of failure of joint prosthesis. According to various preclinical reports, antibacterial coatings of implants may prevent bacterial adhesion and biofilm formation. Aim of this study is to present the first clinical trial on an antibiotic-loaded fast-resorbable hydrogel coating In this multi-center, randomized, prospective, study, a total of 380 patients, scheduled to undergo primary or revision total hip or knee joint replacement, using a cementless or a hybrid implant, were randomly assigned, in six European orthopedic centers, to receive the antibiotic-loaded DAC coating or to a control group, without coating. Pre- and post-operative assessment of clinical scores, wound healing, laboratory tests and x-ray were performed at fixed time intervals.Aim
Method
Implant-related infections, including peri-prosthetic joint infection (PJI) and infected osteosynthesis, are biofilm-related. Intra-operative diagnosis and pathogen identification is currently considered the diagnostic benchmark; however the presence of bacterial biofilm(s) may have a detrimental effect on pathogen detection with traditional microbiological techniques. Sonication and chemical biofilm debonding have been proposed to overcome, at least partially, this issue, however little is known about their possible economical impact. Aim of this study was to examine direct and indirect hospital costs connected with the routine use of anti-biofilm microbiological techniques applied to hip and knee PJIs. In a first part of the study, the “Turn Around Time (TAT)” and direct costs comparison between a system to find bacteria on removed prosthetic implantsAim
Method
Culture examination is still considered the gold standard for diagnosis of bone and joint infections, including prosthetic ones, even if in up to 20–30% of cases, particularly prosthetic joint infections, it fails to yield microbial growth. To overcome this limitation, determination of markers of inflammation and or infection directly in joint fluid has been proposed. Aim of this study was to evaluate the applicability of measurement of lecukocyte esterase (LE), C-reactive protein (CRP) and glucose in synovial fluid for diagnosis of bone and joint infections. Synovial fluids from 80 patients were aseptically collected and sent to laboratory for microbiological cultures. After centrifugation at 3000 rpm for 10 minutes, pellet was used for cultures, while the surnatant was used for determination of LE, CRP and glucose. LE and glucose were evaluated by means of enzymatic colorimetric strips developed for urinanalysis. One drop of synovial fluid was placed on the LE and on the glucose pads and the results were read after about 120 seconds. A LE test graded + or ++, and a glucose test equal to trace or negative were considered suggestive for infection. CRP was measured by an automated turbidimetric method. On the basis of clinical findings, microbiological, haematological and histological analyses patients were retrospectively divided into 2 groups. Group 1 comprised 19 infected patients (12 males, 7 females age: 70.6 ± 10.3 yrs, range: 47 – 88 yrs) while Group 2 included 61 aseptic patients (32 males and 29 females, age: 61.5 ± 16.3 yrs, range: 15 – 84). Sensitivity of the three tests was 89.5%. 84% and 73,7% for LE, CRP and glucose, respectively. Specificity was 98.4%, 88.5% and 70% for LE, CRP and glucose, respectively. Positive and negative predictive values were 94.4% and 96.8% for LE, 69.6% and 94.6% for CRP and 77.8% and 89.6% for glucose test. When LE was combined with CRP, sensitivity increased to 94.7%, while no differences were observed for LE combined with glucose. Leukocyte esterase has proven to be a rapid, simple and inexpensive test to rule in or out bone and joint infections. Combination of its measurement with that of CRP increased sensitivity. In conclusion, the combination of leukocyte esterase and CRP may represent a simple and useful tool for diagnosis of bone and joint infections.
Post operative prosthetic joint infection (PJI) is the most common cause of failure of total joint arthroplasty, requiring revision surgery, but a gold standard for the diagnosis and the treatment of PIJ is still lacking [1]. SuPAR, the soluble urokinase plasminogen activation receptor, has been recently described as a powerful diagnostic and prognostic tool, able not only to detect sepsis but also to discriminate different grade of sepsis severity [2,3] This study aimed to examine the diagnostic value of SuPAR in post operative PJI, in order to explore the possible application of this new biomarker in the early diagnosis of PJI. The level of SuPAR have been measured in PJI patients and controls (patients undergoing prosthesis revision without infection), and correlated with pro and anti inflammatory markers (CRP C-reactive protein, IL-6, IL-1 TNFα, IL-10, IL-12, IL-8, IL1ra and the chemokine CCL2). Statistical analysis of Receiver Operating Characteristic (ROC) curves and Area Under the Curve (AUC) was performed As described in Figure 1, serum SuPAR displayed a strongly significative increase in PJI patients compared to not infected controls, and a significative positive correlation with C-reactive protein, IL-6, IL-1 and TNFα and the chemokine CCL2. SuPAR displayed a very good AUC, significantly higher than CRP and IL-6 AUC This study clearly show that the measure of Serum level of SuPAR provide a extremely important benefit because it is a precise indicator of bacterial infection, and the addition of SuPAR serum level measurement to classical inflammatory markers can strongly improve the diagnosis of prosthesis joint infection The authors acknowledge ViroGates, Denmark for providing suPARNOSTIC Standard Kit. The authors would also acknowledge the Italian Ministero dell’ Istruzione, Università e Ricerca (MIUR) and Italian Ministero della Salute for providing funds for this research project.
The best surgical modality for treating chronic periprosthetic shoulder infections has not been established, with a lack of randomised comparative studies. This systematic review compares the infection eradication rate and functional outcomes after single- or two-stage shoulder exchange arthroplasty, to permanent spacer implant or resection arthroplasty. Full-text papers and those with an abstract in English published from January 2000 to June 2014, identified through international databases, were reviewed. Those reporting the success rate of infection eradication after a single-stage exchange, two-stage exchange, resection arthroplasty or permanent spacer implant were included, with a minimum follow-up of 6 months and sample size of 5 patients. Eight original articles reporting the results after resection arthroplasty (n = 83), 6 on single-stage exchange (n = 75), 13 on two-stage exchange (n = 142) and 8 papers on permanent spacer (n = 68) were included. The average infection eradication rate was 86.7% at a mean follow-up of 39.8 months (SD 20.8) after resection arthroplasty, 94.7% at 46.8 months (SD 17.6) after a single-stage exchange, 90.8% at 37.9 months (SD 12.8) after two-stage exchange, and 95.6% at 31.0 months (SD 9.8) following a permanent spacer implant. The difference was not statistically significant. Regarding functional outcome, patients treated with single-stage exchange had statistically significant better postoperative Constant scores (mean 51, SD 13) than patients undergoing a two-stage exchange (mean 44, SD 9), resection arthroplasty (mean 32, SD 7) or a permanent spacer implant (mean 31, SD 9) (p=0.029). However, when considering studies comparing pre- and post-operative Constant scores, the difference was not statistically significant. This systematic review failed to demonstrate a clear difference in infection eradication and functional improvement between all four treatment modalities for established periprosthetic shoulder infection. The relatively low number of patients and the methodological limitations of the studies available point out the need for well designed multi-center trials to further assess the best treatment option of peri-prosthetic shoulder infection.
Prosthetic implants, periprosthetic and osteoarticular tissues are specimens of choice for diagnosis of bone and joint infections including prosthetic joint infections (PJIs). However, it is widely known that cultures from prostheses and tissues may fail to yield microbial growth in up to one third of patients. In the recent past, treatment of prosthetic implants have been optimized in order to improve sensitivity of microbiological cultures, while less attention has been addressed to tissue samples. For these latter homogenization is considered the best procedure, but it is quite laborious, time-consuming and it is not always performed in all laboratories. Dithiothreitol (DTT) has been proposed as an alternative treatment to sonication for microbiological diagnosis of PJIs. In this study, we evaluated the applicability of MicroDTTect treatment, a closed system developed for transport and treatment of tissues and prosthetic implants with DTT. For evaluation of applicability of MicroDTTect to tissue specimens, samples (tissues and, in case of PJI, prosthetic implants) from 40 patients (12 PJIs and 5 osteomyelitis and 23 not-infected) were evaluated. MicroDTTect system consists of a sterile plastic bag containing a reservoir which allows for release of a 0.1% (v:v) DTT solution, once the sample is placed into the bag. Comparison of MicroDTTect treatment of prostheses with sonication included samples from 30 patients (14 with aseptic loosening of the prosthesis and 16 with PJIs). Of two tissue samples from the same region, one was placed into MicroDTTect bag and the other was collected in a sterile container with addition of sterile saline. After agitation and centrifugation of the eluate, aliquots of the pellets were plated on agar plates and inoculated into broths which were incubated for 48 hrs and 15 days, respectively. Treatment of prosthetic implants with MicroDTTect showed a higher specificity and sensitivity than sonication (specificity 92.8% vs 85.7%; sensitivity: 87.5% vs 75.0 % DTT vs sonication). When used for tissue treatment, MicroDTTect showed a sensitivity of 82.3% and a specificity of 97% which were higher than that observed when saline was used (sensitivity: 64.7%; specificity 91%). Treatment of tissues and prosthetic implants with MicroDTTect may be a practicable strategy to improve microbiological diagnosis of osteoarticular infections, reducing sample manipulation and therefore limiting sample contamination. Moreover, use of MicroDTTect does not require dedicated instrumentation, and is time and cost saving.
The role of biofilm in pathogenesis of several chronic human infections is widely accepted, as this structure leads pathogens to persist among the human body, being protected from the action of antibacterial molecules and drugs (1). It has been estimated that up to 65% of bacterial infections are caused by microorganisms growing in biofilms (2). Moreover, biofilm is involved in device-related orthopaedic bacterial infections, which are unaffected by vaccines and antibiotic therapies, constituting a serious problem for the human health care. The aim of the present work was to evaluate the anti-biofilm action of a selected and patented lactobacillus strain (MD1) supernatant, both on the in-formation- biofilm and on mature biofilm produced by pathogenic bacteria. MD1 was grown in BHI for 48 h at 37°C. After incubation, the sample was centrifuged for 5’ for 14,000 × g and the supernatant previously filtered and treated in order to obtain the anti-biofilm compounds (Special Supernatant – SS) was collected. Staphylococcus aureus and Pseudomonas aeruginosa strains were grown in BHI for 24h at 37°C. The anti-biofilm ability of the tested SS – lactobacillus strain was evaluated by a spectrophotometric method according to Christensen at al., following the incubation of pathogens and the “mature biofilm” with the lactobacillus supernatant. Confocal Laser Scanning Microscopy was used to confirm the data obtained from Crystal Violet Assay. After the incubation of the SS with pathogens and mature biofilm, the formation of biofilm was inhibited and a significant disruption of the mature biofilm was observed. Interestingly, the same properties were observed also when the SS pH was neutralized to pH 6.5. In particular, the reduction of biofilm production and the disruption of mature biofilm was about 50–70% for all microorganisms. The SS lactobacillus strain MD1 exhibited a relevant antibiofilm action against mature and in-formation-biofilm produced by S. aureus and P. aeruginosa strains tested in the study. Moreover, the antibiofilm action has been observed to be pH-independent, as when the supernatant was neutralized to pH 6.5, the reduction of pathogenic biofilm has been still observed. These promising results highlighted the possibility to use this SS-lactobacillus anti-biofilm property to develop a cost-effective and safety treatment able to reduce the impact of pathogenic biofilm on device-related orthopaedic bacterial infections.
