Periprosthetic joint infections at a teaching hospital in 1990-2007

Total hip arthroplasty with monobloc press-fit acetabular components and large-diameter bearings for atypical acetabula is safe: a consecutive case series of 125 hips with mean follow-up of 9 years

BACKGROUND

Large-diameter head (LDH) total hip arthroplasty (THA) with a monobloc acetabular component improves hip stability. However, obtaining initial press-fit stability is quite challenging in atypical acetabula. The purpose of this study was to assess primary and secondary fixation of monobloc cups in atypical acetabula.

METHODS

In this consecutive case series, the local arthroplasty database was used to retrospectively identify patients with secondary osteoarthritis who underwent primary hip replacement with press-fit only LDH monobloc acetabular components between 2005 and 2018 and who had a minimum of 2 years of follow-up. Radiographic evaluation was performed at last follow-up, and patient-reported outcome measures (PROMs) were assessed with the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), the Forgotten Joint Score (FJS), and the Patient's Joint Perception (PJP) question.

RESULTS

One hundred and six LDH THAs and 19 hip resurfacings were included in the study. Preoperative diagnoses included hip dysplasia (36.8%), Legg-Calve-Perthes disease (32.0%), osteoarthritis with acetabular deficiency (17.6%), periacetabular osteotomy (8.0%), arthrodesis (4.0%), and osteopetrosis (1.6%). After a mean follow-up of 9.2 years, no aseptic loosening of the acetabular component was recorded nor observed on radiologic review. There were 13 (10.4%) revisions unrelated to the acetabular component fixation. The mean WOMAC and FJS scores were 9.2 and 80.9, respectively. In response to the PJP question, 49.4% of the patients perceived their hip as natural, 19.1% as an artificial joint with no restriction, 31.5% as an artificial joint with restriction, and none as a non-functional joint.

CONCLUSION

Primary press-fit fixation of monobloc acetabular components with LDH implanted in atypical acetabula led to secondary fixation in all cases with low revision and complication rates and great functional outcomes. With careful surgical technique and experience, systematic use of supplemental screw fixation is not essential in THA with atypical acetabula.

Incidence of periprosthetic joint infection after primary total hip arthroplasty is underestimated: a synthesis of meta-analysis and bibliometric analysis

The American Musculoskeletal Society updated the diagnostic criteria for periprosthetic joint infection (PJI) in 2011 and 2018. However, the overall incidence of PJI since the introduction of these new standards has not been assessed. In order to fill this knowledge gap, a single-group meta-analysis was conducted using articles obtained from several databases, focusing on the incidence of PJI after primary total hip arthroplasty (THA). Our study revealed a significant difference in the incidence of PJI reported by different national or regional databases. Moreover, most cases of PJI were found to be underestimated. This highlights the crucial need for standardized diagnostic criteria and monitoring methods to accurately identify and track cases of PJI. Furthermore, a bibliometric analysis was conducted to provide a comprehensive overview of the current state of research on PJI after THA. This analysis explored the most productive countries, organizations, journals, and individuals in this research area. Additionally, it identified the research trends and hotspots of the last decade, highlighting the advancements and areas of focus in this field. By conducting these analyses, the study aims to contribute to the understanding of PJI after THA and provide valuable insights for clinicians, researchers, and policymakers involved in the management of this condition.

Evaluation of bioactive glass scaffolds incorporating SrO or ZnO for bone repair: In vitro bioactivity and antibacterial activity

A series of bioactive glass scaffolds doped with SrO or ZnO (0, 5, and 10 mol%) were synthesized by the foam replica and melting method. The thermodynamic evolution, phase composition, microstructure, ion release, in vitro bioactivity, and oxygen density of the scaffolds were characterized. The proliferation of murine long bone osteocyte Y4 cells was studied by cell culture. The survival rate of the BGs evaluated the antibacterial activity and Escherichia coli strains in co-culture. The results indicated that the process window decreases with the increase of dopants. All the samples have a pore structure size of 200-400 μm. When the scaffolds were immersed in simulated body fluid for 28 days, hydroxyapatite formation was not affected, but the degradation process was retarded. The glass network packing and ionic radii variations of the substitution ions control surface degradation, glass dissolution, and ion release. MTT results revealed that 5Sr-BG had a significant effect on promoting cell proliferation and none of the BGs were cytotoxicity. Sr-BGs and Zn-BGs exhibited significantly inhibited growth against E. coli bacterial strains. Generally, these results showed the 5Sr-BG scaffold with high vitro bioactivity, cell proliferation, and antibacterial property is an important candidate material for bone tissue regeneration and repair.

The use of 2-octyl cyanoacrylate as an adjuvant to wound closure in total knee arthroplasty

PURPOSE

The efficacy of the use of 2-octyl cyanoacrylate (OCA) as an adjuvant to wound closure in preventing wound complications after total knee arthroplasty (TKA) is rarely reported. This study was aimed to determine whether the use of OCA as a supplement to conventional wound closure reduces the incidence of wound complications following TKA.

PATIENTS AND METHODS

This retrospective study reviewed 1106 consecutive patients who underwent TKA for symptomatic end-stage osteoarthritis (OA) between 2012 and 2017. The first 562 patients who did not receive OCA were grouped into the Control group, and the subsequent 544 patients who received OCA as an adjuvant to wound closure were grouped into the OCA group. All patients were followed up for at least 2 years. The main outcome was the development of operative site complications, including aseptic and infectious complications. Aseptic wound complications were wound leakage, hematoma, wound dehiscence and delayed wound healing, and infectious complication was mainly referred to the superficial infection.

RESULTS

No significant difference with regard to hematoma was observed between groups (3.0% vs. 3.7%, P = 0.617, φ = - 0.02). The incidences were significantly higher in the Control group versus the OCA group in regard to wound leakage (9.4% vs. 2.0%, P = 0.000, φ = 0.16), wound dehiscence (5.7% vs. 1.3%, P = 0.000, φ = 0.12), delayed wound healing (4.4% vs. 1.5%, P = 0.004, φ = 0.09) and superficial infection (2.0% vs. 0.4%, P = 0.022, φ = 0.07). No serious adverse events (AEs) occurred.

CONCLUSIONS

The present study showed that the addition of OCA reduced the incidence of wound leakage, wound dehiscence, delayed wound healing and superficial infection after TKA compared to conventional wound closure. Based on the outcomes above, we decide to use OCA routinely for wound closure after TKA.

LEVEL OF EVIDENCE

III, retrospective, cohort study.

Suppressing Antibacterial Resistance: Chemical Binding of Monolayer Quaternary Ammonium Salts to Polymethyl Methacrylate in an Aqueous Solution and its Clinical Efficacy

Antibacterial resistance (ABR) poses an enormous threat to human health. ABR mainly develops due to bacteria being constantly exposed to diluted levels of disinfectants. Here, we propose a method for suppressing ABR through the chemical binding of disinfectants to polymethyl methacrylate (PMMA) device surfaces in solutions of 5%, 10%, and 20% disinfectant concentrations. PMMA discs were fabricated from a commercial orthodontic acrylic resin system (Ortho-Jet) and quaternary ammonium salts (QAS), 3-(trimethoxysilyl)-propyldimethyloctadecyl ammonium chloride (42% in methanol), were used as the disinfectant. The PMMA surfaces were activated in 3 M sulfuric acid at 80 °C for 5 h for the esterification of hydrolyzed QAS to PMMA. Fourier transform infrared difference spectra confirmed that the carboxy-terminated PMMA was chemically bound to the QAS. In vitro cell viability tests using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide assays revealed that 5%QAS-c-PMMA was more biocompatible than 10%QAS-c-PMMA and 20%QAS-c-PMMA. The results of antibacterial tests and clinical trials demonstrated the excellent antibacterial power of 5%QAS-c-PMMA. This method is the first solution-based approach to successfully avoid disinfectant leakage and subsequent ABR, as revealed by mass spectrometry studies of the solution obtained by agitating the disinfectant-bound PMMA for 28 days.

Epidemiology and Outcome Determinants of Staphylococcus aureus Bacteremia Revisited: A Population-Based Study

PURPOSE

Staphylococcus aureus bacteremia (SAB) is associated with significant morbidity and mortality. We sought to re-define the burden, epidemiology and mortality-associated risk factors of SAB in a large Canadian health region.

METHODS

Residents (> 18 years) experiencing SAB from 2012 to 2014 were assessed. Incidence rates were calculated using civic census results. Factors associated with 30-day mortality were determined through multivariate logistic regression. Incidence and risk factors for SAB were compared to 2000-2006 data.

RESULTS

780 residents experienced 840 episodes of SAB (MRSA; 20%). Incidence rates increased from 23.5 to 32.0 cases/100,000 from 2012 to 2014; [IRR 1.15 (95% CI 1.07-1.23); p < 0.001]. Compared to a decade ago, incidence of SAB has increased [IRR 1.28 (95% CI 1.21-1.36); p < 0.001] despite minimal change in nosocomial SAB. MRSA proportion did not change through the study (p = 0.3), but did increase relative to a decade ago (20.0% vs 11.0%, p < 0.001). Thirty-day mortality rates were 30.6% and 21.3% for MRSA and MSSA, respectively (p = 0.01), similar to rates from 2000 to 2006. Several clinical, demographic, and biochemical factors were independently associated with SAB mortality.

CONCLUSIONS

SAB is common within our population resulting in significant mortality. Incidence rates of SAB are increasing in our health region; however, 30-day mortality rates remain stable.

Comparison of the elution properties of commercially available gentamicin and bone cement containing vancomycin with 'home-made' preparations

AIMS

Vancomycin is commonly added to acrylic bone cement during revision arthroplasty surgery. Proprietary cement preparations containing vancomycin are available, but are significantly more expensive. We investigated whether the elution of antibiotic from 'home-made' cement containing vancomycin was comparable with more expensive commercially available vancomycin impregnated cement.

MATERIALS AND METHODS

A total of 18 cement discs containing either proprietary CopalG+V; or 'home-made' CopalR+G with vancomycin added by hand, were made. Each disc contained the same amount of antibiotic (0.5 g gentamycin, 2 g vancomycin) and was immersed in ammonium acetate buffer in a sealed container. Fluid from each container was sampled at eight time points over a two-week period. The concentrations of gentamicin and vancomycin in the fluid were analysed using high performance liquid chromatography mass spectrometry.

RESULTS

The highest peak concentrations of antibiotic were observed from the 'home-made' cements containing vancomycin, added as in the operating theatre. The overall elution of antibiotic was, fivefold (vancomycin) and twofold (gentamicin) greater from the 'home-made' mix compared with the commercially mixed cement. The use of a vacuum during mixing had no significant effect on antibiotic elution in any of the samples.

CONCLUSION

These findings suggest that the addition of 2 g vancomycin powder to gentamicin-impregnated bone cement by hand significantly increases the elution of both antibiotics compared with commercially prepared cements containing vancomycin. We found no significant advantages of using expensive commercially produced vancomycin-impregnated cement and recommend the addition of vancomycin powder by hand in the operating theatre. Cite this article: Bone Joint J 2017;99-B:73-7.

Superficial wound infection does not cause inferior clinical outcome after TKA

PURPOSE

Superficial wound infections do not lead to chronic prosthetic joint infection. Therefore, it has been hypothesized that a superficial infection of a surgical wound following a successfully treated TKA does not lead to a lower functional outcome at long-term follow-up. This may be due to early diagnosis and proper treatment without interrupting the rehabilitation programme. The purpose of this study was to support the hypothesis by comparing the functional outcome and health-related quality of life (HRQoL) of superficial infections treated successfully after primary total knee arthroplasty (TKA).

METHODS

In a 3000 prospective TKA cohort, 45 superficial infections were compared to a control group of 629 TKA without complications. The functional outcome, health quality, expectations and revision rate were compared between the study and control groups.

RESULTS

The groups were comparable in terms of demographic values and preoperative scores. The mean follow-up was 74.57 months (SD ± 7.1). No statistical differences were observed relative to functional outcomes at the final follow-up as measured with the Knee Society Score (156.9 vs 168.4; n.s) and range of motion (0.2-114.4 vs 0.7-112.3; n.s). For the HRQoL, no differences in the physical (40.0 vs 40.6; n.s) and mental (43.2 vs 45.8; n.s) SF-36 scores were found. Neither were there differences in post-operative expectations and the revision rate.

CONCLUSIONS

In a long-term follow-up, a different clinical outcome and HRQoL were not obtained after a successfully treated superficial infection following a TKA when compared to a TKA without complications. Based on the findings of the study, additional complications are not anticipated after a successfully treated superficial wound infection in TKA. Therefore, a different follow-up to that of a non-complicated TKA is not recommended when the early post-operative superficial wound infection has been appropriately treated. A superficial infection successfully treated in the acute post-operative period should be considered solved at long-term follow-up.

LEVEL OF EVIDENCE

Therapeutic study, Level III.

A novel hybrid type (custom-made plus off-the-shelf) total femoral PROSTALAC

INTRODUCTION

Treatment of periprosthetic joint infection following revision-Total Hip Arthroplasty is more problematic when there is poor bone quality and severe bone loss. Migration of revision prosthesis with a long stem to the knee joint in infected cases makes treatment more complex. In these cases, total femoral replacement is the only treatment option and eradication of infection is mandatory before the replacement. In 2-staged reconstruction treatment, there is a need for a PROSTALAC to replace the whole femur.

METHODS

We describe here a novel hybrid type (custom-made plus off-the-shelf) total femoral PROSTALAC for cases in need of whole femoral bone and femoral component removal for the treatment of periprosthetic joint infection in total hip arthroplasty.

RESULT

Both sides of the PROSTALAC have anatomical joint surfaces, so the articulation with the acetabulum proximally is expected to be more stable. The off-the-shelf anatomic joint surface of the PROSTALAC distally allows articulation compatible with a proximal tibial off-the-shelf spacer.

CONCLUSIONS

This simple hybrid-type total femoral PROSTALAC can be adjusted to femoral length, has anatomical joint surfaces that produce a more stable articulation, and can articulate with an off-the-shelf proximal tibial spacer.

Modified Girdlestone arthroplasty and hip arthrodesis using the Ilizarov external fixator as a salvage method in the management of severely infected total hip replacement

BACKGROUND

Resection arthroplasty or hip arthrodesis after total hip replacement (THR) can be used to salvage the limb in case with deep infection and severe bone loss. The Ilizarov fixator provides stability, axial correction, weight-bearing and good fusion rates.

MATERIALS AND METHODS

We retrospectively assessed the outcomes of 37 patients with severe periprosthetic infection after THR treated between 1999 and 2011. The treatment included implant removal, debridement and a modified Girdestone arthroplasty (29 cases) or hip arthrodesis (seven cases) using the Ilizarov fixator. The Ilizarov fixation continued from 45 to 50 days in the modified arthroplasty group and 90 days in the arthrodesis group. One case was treated using the conventional resection arthroplasty bilaterally.

RESULTS

Eighteen months after treatment, infection control was seen in 97.3% cases. Six hips were fused as one patient died in this group. Limb length discrepancy (LLD) averaged 5.5 cm. The Harris hip score ranged from 35 to 92 points. Hip joint motion ranged from 10° to 30° in the modified arthroplasty group. All subjects could walk independently or using support aids. No subluxation or LLD progression was observed.

CONCLUSION

The modified Girdlestone arthroplasty and hip arthrodesis using the Ilizarov apparatus results in sufficient ability for ambulation and good infection control in cases of failed THR associated with severe infection.

Burden of Surgical Site Infections Associated with Arthroplasty and the Contribution of Staphylococcus aureus

BACKGROUND

Patients undergoing arthroplasty are at considerable risk of experiencing post-operative complications, including surgical site infections (SSIs). In addition to potential economic consequences, SSIs can have a negative impact on patient outcomes and may potentially be life-threatening. Staphylococcus aureus has been consistently shown as the leading cause of SSIs associated with orthopedic surgery, with an important contribution from methicillin-resistant S. aureus (MRSA). This study evaluated the global burden of SSIs among patients undergoing orthopedic surgical procedures, and specifically those undergoing knee and hip arthroplasties.

METHODS

An extensive search of PubMed and recent conference proceedings was conducted. English articles published between 2003 and 2013 pertaining to SSI epidemiology, patient outcomes, and healthcare resource utilization and costs were reviewed.

RESULTS

Overall, 81 studies were included, mainly from North America and Europe. Median SSI and S. aureus SSI rates, calculated as percentage of all arthroplasty procedures, were 1.7% (range: 0.25%-4.4%; 15 studies) and 0.6% (range: 0.1%-23%), respectively. Median SSI rates were 1.3% (range: 0.05%-19%; 22 studies) after knee arthroplasty, and 2.1% (range: 0.05%-28%; 24 studies) after hip arthroplasty. S. aureus SSI rates ranged from 0.2%-2.4% and 0.18%-3.8% for patients undergoing knee and hip arthroplasty, respectively. The percentage of S. aureus SSIs because of MRSA varied widely within each patient category. SSI-related mortality data (14 studies) showed that in-hospital mortality rates were low (1.2%-2.5%), but increased with time after index arthroplasty procedure (up to 56% over 1 y). Studies assessing healthcare resource utilization (n = 21) revealed that developing post-orthopedic SSIs resulted in a two- to three-fold increase in length of hospital stay (LOS) compared with non-infected patients (median LOS: 18.9 d vs. 6 d for non-SSI patients). Patients with SSIs because of methicillin-resistant staphylococci incurred greater mean LOS compared with SSIs because of methicillin-sensitive organisms. Readmission rates reported in 11 studies indicate a greater likelihood in the presence of SSIs; comparison across studies was not feasible because of differences in data reporting. Consistent with increased healthcare resource utilization (LOS and readmission) associated with SSIs, cost studies (n = 23) revealed that the presence of SSIs was associated with up to three-fold cost increase compared with the absence of SSI across all orthopedic patient categories assessed.

CONCLUSIONS

SSIs are associated with increased morbidity, mortality rates, healthcare resource utilization, and costs. Despite the relatively low SSI incidence following orthopedic surgery and specifically arthroplasty, preventive methods, specifically those targeting S. aureus, would serve to minimize costs and improve patient outcomes.

Plastic surgeons' self-reported operative infection rates at a Canadian academic hospital

BACKGROUND

Surgical site infection rates are of great interest to patients, surgeons, hospitals and third-party payers. While previous studies have reported hospital-acquired infection rates that are nonspecific to all surgical services, there remain no overall reported infection rates focusing specifically on plastic surgery in the literature.

OBJECTIVE

To estimate the reported surgical site infection rate in plastic surgery procedures over a 10-year period at an academic hospital in Canada.

METHODS

A review was conducted on reported plastic surgery surgical site infection rates from 2003 to 2013, based on procedures performed in the main operating room. For comparison, prospective infection surveillance data over an eight-year period (2005 to 2013) for nonplastic surgery procedures were reviewed to estimate the overall operative surgical site infection rates.

RESULTS

A total of 12,183 plastic surgery operations were performed from 2003 to 2013, with 96 surgical site infections reported, corresponding to a net operative infection rate of 0.79%. There was a 0.49% surgeon-reported infection rate for implant-based procedures. For non-plastic surgery procedures, surgical site infection rates ranged from 0.04% for cataract surgery to 13.36% for high-risk abdominal hysterectomies.

DISCUSSION

The plastic surgery infection rate at the study institution was found to be <1%. This rate was equal to, or somewhat less than, surgical site infection rates. However, these results do not report patterns of infection rates germane to procedures, season, age groups or sex. To provide more in-depth knowledge of this topic, multicentre studies should be conducted.

In vitro assessment of nanosilver-functionalized PMMA bone cement on primary human mesenchymal stem cells and osteoblasts

Peri-prosthetic infections caused by multidrug resistant bacteria have become a serious problem in surgery and orthopedics. The aim is to introduce biomaterials that avoid implant-related infections caused by multiresistant bacteria. The efficacy of silver nanoparticles (AgNP) against a broad spectrum of bacteria and against multiresistant pathogens has been repeatedly described. In the present study polymethylmethacrylate (PMMA) bone cement functionalized with AgNP and/or gentamicin were tested regarding their biocompatibility with bone forming cells. Therefore, influences on viability, cell number and differentiation of primary human mesenchymal stem cells (MSCs) and MSCs cultured in osteogenic differentiation media (MSC-OM) caused by the implant materials were studied. Furthermore, the growth behavior and the morphology of the cells on the testing material were observed. Finally, we examined the induction of cell stress, regarding antioxidative defense and endoplasmatic reticulum stress. We demonstrated similar cytocompatibility of PMMA loaded with AgNP compared to plain PMMA or PMMA loaded with gentamicin. There was no decrease in cell number, viability and osteogenic differentiation and no induction of cell stress for all three PMMA variants after 21 days. Addition of gentamicin to AgNP-loaded PMMA led to a slight decrease in osteogenic differentiation. Also an increase in cell stress was detectable for PMMA loaded with gentamicin and AgNP. In conclusion, supplementation of PMMA bone cement with gentamicin, AgNP, and both results in bone implants with an antibacterial potency and suitable cytocompatibility in MSCs and MSC-OM.

Risk factors for periprosthetic joint infection after total joint arthroplasty: a systematic review and meta-analysis

Many of the mooted risk factors associated with periprosthetic joint infection (PJI) after total joint arthroplasty (TJA) remain controversial and are not well characterized. Online and manual searches were performed using Medline, Embase, Chinese National Knowledge Infrastructure and the Cochrane Central Database from January 1980 to March 2014). For inclusion, studies had to meet the quality assessment criteria of the CONSORT statement, and be concerned with evaluation of risk factors for PJI after TJA. Two reviewers extracted the relevant data independently and any disagreements were resolved by consensus. Fourteen studies were included in this meta-analysis. The following significant risk factors for PJI were identified: body mass index (both continuous and dichotomous variables); diabetes mellitus; corticosteroid therapy; hypoalbuminaemia; history of rheumatoid arthritis; blood transfusion; presence of a wound drain; wound dehiscence; superficial surgical site infection; coagulopathy; malignancy, immunodepression; National Nosocomial Infections Surveillance Score ≥2; other nosocomial infection; prolonged operative time; and previous surgery. Factors that were not significantly associated with PJI were: cirrhosis; hypothyroidism; urinary tract infection; illicit drug abuse; alcohol abuse; hypercholesterolaemia; hypertension, ischaemic heart disease; peptic ulcer disease; hemiplegia or paraplegia; dementia; and operation performed by a staff surgeon (vs a trainee). Strategies to prevent PJI after TJA should focus, in particular, on those patients at greatest risk of infection according to their individual risk factors.

Silver nanoparticles do not alter human osteoclastogenesis but induce cellular uptake

Based on the increasing number of multi-drug resistant bacteria in periprosthetic infections, improvement of the antibacterial activity of commonly used biomaterials must be achieved. The broad-spectrum, high antimicrobial efficacy has made silver nanoparticles a promising new antibacterial agent. However, there is still a serious lack of knowledge concerning the impact of nanosilver on bone cells.

For this reason a study was conducted to evaluate the influence of silver nanoparticles on osteoclastogenesis of human peripheral blood mononuclear cells. Upon incubation with subtoxic concentrations of nanosilver the cells did not exhibit changes in osteoclast differentiation and podosomal structures. However, the osteoclasts were able to uptake the nanoparticles, accumulating them in endo-lysosomal compartments. Furthermore, nanosilver exposure led to an increase in oxidative stress and a decrease in clathrin-dependent endocytosis on the mRNA level.

In conclusion, our results indicate nanosilver-induced cell stress at higher concentrations. For this reason antibacterial benefits and possible health risks should be weighed in more detail in further studies.

Preventing surgical site infections: a randomized, open-label trial of nasal mupirocin ointment and nasal povidone-iodine solution

BACKGROUND

Treatment of Staphylococcus aureus colonization before surgery reduces risk of surgical site infection (SSI). The regimen of nasal mupirocin ointment and topical chlorhexidine gluconate is effective, but cost and patient compliance may be a barrier. Nasal povidone-iodine solution may provide an alternative to mupirocin.

METHODS

We conducted an investigator-initiated, open-label, randomized trial comparing SSI after arthroplasty or spine fusion in patients receiving topical chlorhexidine wipes in combination with either twice daily application of nasal mupirocin ointment during the 5 days before surgery or 2 applications of povidone-iodine solution into each nostril within 2 hours of surgical incision. The primary study end point was deep SSI within the 3 months after surgery.

RESULTS

In the modified intent-to-treat analysis, a deep SSI developed after 14 of 855 surgical procedures in the mupirocin group and 6 of 842 surgical procedures in the povidone-iodine group (P = .1); S. aureus deep SSI developed after 5 surgical procedures in the mupirocin group and 1 surgical procedure in the povidone-iodine group (P = .2). In the per protocol analysis, S. aureus deep SSI developed in 5 of 763 surgical procedures in the mupirocin group and 0 of 776 surgical procedures in the povidone-iodine group (P = .03).

CONCLUSIONS

Nasal povidone-iodine may be considered as an alternative to mupirocin in a multifaceted approach to reduce SSI.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT01313182.

Is there an association between periprosthetic joint infection and low vitamin D levels?

PURPOSE

Vitamin D is increasingly being recognized as an important mediator of immune function and may have a preventive role in the pathogenesis of periprosthetic joint infection. To the best of our knowledge, no other study has examined possible associations between periprosthetic joint infection and vitamin D deficiency. We investigated the rate of vitamin D deficiency in patients treated for periprosthetic joint infection and whether vitamin D deficiency is independent of other risk factors for vitamin D deficiency in patients with periprosthetic joint infection.

METHODS

Serum 25-hydroxyvitamin D (25OHD) levels of every patient scheduled to receive a total prosthesis either of the hip, knee, or shoulder in the orthopaedic department of the Johannes-Guttenberg-University Hospital in Mainz, Germany (109 patients), were measured after admission. Furthermore, serum 25OHD levels were measured for every patient presenting with periprosthetic joint infection (n = 50) or aseptic loosening of the prosthesis (n = 31) scheduled to undergo revision surgery. The prevalence of normal (> 30 ng/ml), insufficient (20-30 ng/ml), and deficient (<20 ng/ml) 25OHD levels was determined.

RESULTS

All tested patient subgroups showed low vitamin D levels. Statistical analysis found no significant difference in vitamin D levels comparing patients with prosthesis and patients with aseptic prosthesis loosening (p = 0.58). Significant differences in 25OHD levels were found comparing patients with periprosthetic joint infection and patients scheduled for primary arthroplasty (p < 0.001). In addition, we found a significant difference (p < 0,001) in 25OHD levels of patients with periprosthetic joint infection compared with patients with aseptic prosthesis loosening.

CONCLUSION

We found a high frequency of vitamin D deficiency in patients being treated by primary arthroplasty and those with aseptic joint prosthetic loosening and periprosthetic joint infection. Vitamin D deficiency was severe in patients with periprosthetic joint infection.

Biocompatibility of silver nanoparticles and silver ions in primary human mesenchymal stem cells and osteoblasts

The prevention of implant-related infections is an important issue in medical research. The aim is to exploit the strong antimicrobial effect of silver nanoparticles (AgNP) to develop new antibacterial coatings for implants. However, there is still a serious lack of information on the influence of AgNP on bone metabolism. In the present study we have evaluated the influence of AgNP on cell stress, viability, proliferation and differentiation of primary human mesenchymal stem cells (MSC) and osteoblasts (OB). Finally, cellular uptake of the AgNP was examined. After 21 days impairment of cell viability of MSC and OB occurred at a concentration of 10 μg/g of AgNP. Cytotoxicity and inhibition of proliferation was highly time and dose dependent. No influence on cell differentiation, but an increase in cell stress, was observed. Uptake of AgNP into MSC and OB could be confirmed. In summary, these results demonstrate AgNP-mediated cytotoxicity at higher concentrations. Therefore, a therapeutical window for the application of AgNP in medical products might exist. However, the antibacterial benefits and potential health risks of AgNP need to be weighed in further studies.

Does perioperative systemic infection or fever increase surgical infection risks after internal fixation of femur and tibia fractures in an intensive care polytrauma unit?

BACKGROUND

We hypothesized that internal fixation procedures performed on trauma intensive care unit (ICU) patients with systemic infections, some also febrile, would be at increased risk for deep infection.

METHODS

A total of 128 patients (mean age, 37.4 years; mean Injury Severity Score [ISS], 34.7) admitted to the ICU with 179 femur or tibia fractures developed systemic infections. Systemic infections included sepsis, pneumonia, urinary tract infections, abdominal infections, and wound infections remote to the fracture. Of the fractures, 33 open and 146 closed underwent 150 intramedullary and 29 plate fixation procedures. Data were gathered regarding antibiotic use, systemic infection timing in relation to the date of fixation, and whether fever (>38.2°C) was present within 24 hours of fixation. Patients were followed up for a mean of 491 days.

RESULTS

Twenty-eight procedures were performed a mean of 4.7 days after the diagnosis of a systemic infection, and 151 were performed a mean of 9.3 days before the diagnosis. Forty-five procedures were performed in patients who were febrile within 24 hours. Of the 179 procedures, 10 (5.6%) developed a deep infection. Four patients' implant infection was potentially hematogenously seeded with the same organism as their systemic infection. Neither the timing of the systemic infection in relation to the fixation procedure nor the presence of fever within 24 hours of fixation, days of preoperative antibiotics, location of the fracture, type of fixation (intramedullary nail vs. plate fixation), or type of systemic infection was significantly associated with the development of an infection. The only significant risk factor for developing an orthopedic infection was an open fracture (p < 0.001).

CONCLUSION

Internal fixation performed in ICU patients with fever or in close conjunction to the diagnosis of systemic infection led to a 5.6% infection rate, which compares favorably with historic infection rates for fixation of open or closed tibia and femur fractures.

LEVEL OF EVIDENCE

Therapeutic, level IV.