Intraoperative bacterial contamination in operations for joint replacement

No difference in bacterial contamination of hip capsule sutures and control sutures in hip arthroplasty surgery

BACKGROUND

Perioperative preventive measures are important to further reduce the rate of periprosthetic joint infections (PJI) in patients undergoing total hip arthroplasty (THA). During THA surgery, joint capsule sutures are commonly placed to optimize exposure and reinsertion of the capsule. Bacterial contamination of these sutures during the procedure poses a potential risk for postoperative infection. In this exploratory study, we assessed the contamination rate of capsule sutures compared to the contamination of the remains of exchanged control sutures at the time of closure.

METHODS

In 100 consecutive patients undergoing primary THA capsule sutures were exchanged by sterile sutures at the time of capsule closure. Both the original sutures and the remainder of the newly placed (control) sutures were retrieved, collected and cultured for ten days. Types of bacterial growth and contamination rates of both sutures were assessed.

RESULTS

Sutures from 98 patients were successfully collected and analyzed. Bacterial growth was observed in 7/98 (7.1%) of the capsule sutures versus 6/98 (6.1%) of the control sutures, with a difference of 1% [CI -6-8]. There was no clear pattern in differences in subtypes of bacteria between groups.

CONCLUSIONS

This study showed that around 7% of capsule sutures used in primary THA were contaminated with bacteria and as such exchange by new sutures at the time of capsule closure could be an appealing PJI preventive measure. However, since similar contamination rates were encountered with mainly non-virulent bacteria for both suture groups, the PJI preventive effect of this measure appears to be minimal.

Allogenic bone grafts and postoperative surgical site infection: are positive intraoperative swab cultures predictive for a higher infectious risk?

In spine surgery, allogenic bone grafts are often required to ensure bone fusion, however, the main concern regarding their use is the infection risk: therefore, an intraoperative swab for culture test is performed. The cost-effectiveness of these swabs and their influence on the patients' postoperative course have often been questioned. This study aims at determining whether positive spine allograft culture results are predictive of an increased risk of surgical site infection and whether they influence the surgeon's choices in postoperative management. The records of 340 patients who received allogenic bone graft during spinal fusion surgery in our institution were reviewed, for a total of 677 allografts. Each graft was swabbed intraoperatively. All patients were followed clinically for postoperative complications. Infection was diagnosed based on clinical data, blood tests and radiographic images, all assessed by an infectious disease specialist. Only 4 of the 677 allografts used (0.6%) resulted positive at the intraoperative swab culture. Three cultures were positive for Staphylococcus epidermidis and one culture for S. warneri. No clinical infection occurred in any of these patients. Twenty-eight of the 340 patients (8.2%) developed an infection, but none of them had a positive intraoperative swab culture. The most common microbiologic pathogen isolated from this cohort was S. aureus. According to our series, intraoperative swab culture results were not predictive for higher risk of infection and did not affect the clinical behavior of the surgeons in postoperative management.

Comparison of two different antiseptics regarding intracutaneous microbial load after preoperative skin cleansing in total knee and hip arthroplasties

Periprosthetic infections (PPIs) are a serious concern in total knee and hip arthroplasty, and they have an increasing incidence. To prevent PPI, preoperative skin disinfection, as a key element of antisepsis, represents an important part of infection prevention. However, no specific antiseptic agent is endorsed by the relevant guidelines. The purpose of this retrospective, not randomized study was to investigate the difference in the residual bacteria load between an approved antiseptic with an alcohol-based solution with additional benzalkonium chloride (BAC) and an alcohol-based solution with additional octenidine dihydrochloride (OCT) at two different time periods. In 200 consecutive patients with total knee or hip arthroplasty, skin samples from the surgical sites were collected after skin disinfection with BAC (100 g solution contain: propan-2-ol 63.0 g, benzalkonium chloride 0.025 g) or OCT (100 g solution contain: octenidine dihydrochloride 0.1 g, propan-1-ol, 30.0 g, propan-2-ol 45.0 g) (100 patients per group). Following the separation of cutis and subcutis and its processing, culture was performed on different agar plates in aerobic and anaerobic environments. In the case of bacteria detection, the microbial identification was determined by matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS), and the number of contaminated samples was compared between the groups. Additionally, multiple regression analysis was performed to examine the effect of the type of disinfectant, BMI, age, sex, rheumatoid arthritis, diabetes mellitus, skin disorders, smoking status, and localization of skin samples on positive bacteria detection. A total of 34 samples were positive for bacteria in the BAC group, while only 17 samples were positive in the OCT group (p = 0.005). Disinfectant type was the only significant parameter in the multiple regression analysis (p = 0.006). A significantly higher contamination rate of the subcutis was shown in the BAC group compared to the OCT group (19 vs. 9, p = 0,003). After the change from BAC to OCT in preoperative skin cleansing in the hip and knee areas, the number of positive cultures decreased by 50%, which might have been caused by a higher microbicidal activity of OCT. Therefore, the use of OCT in preoperative cleansing may reduce the risk of PPI in hip and knee surgery. Randomized controlled trials are required to confirm the effect and to evaluate if it reduces the risk of PPI.

Vancomycin lavage for the incidence of acute surgical site infection following primary total hip arthroplasty and total knee arthroplasty

BACKGROUND

Surgical site infection is a rare but serious complication associated with total joint arthroplasty (TJA). There are limited data on the effectiveness of intrawound irrigation with vancomycin solution (1000 mg/L; 2 L) before wound closure for preventing acute surgical site infection following primary total hip arthroplasty (THA) and total knee arthroplasty (TKA).

AIM

To investigate the effectiveness of prophylactic intraoperative application of vancomycin (1000 mg/L; 2 L) solution vs. plain irrigation in reducing the incidence of acute surgical site infection following primary THA and TKA.

METHODS

A retrospective review of 2725 consecutive patients undergoing THA or TKA from January 2012–December 2019 was performed. These patients received either intrawound irrigation with normal saline before wound closure between January 2012 and December 2015 (group 1, 1018 patients; 453 undergoing THA and 565 undergoing TKA) or intrawound irrigation with vancomycin solution (1000 mg/L) before wound closure between January 2016 and December 2019 (group 2, 1175 patients; 512 undergoing THA and 663 undergoing TKA). The outcomes were the incidences of postoperative surgical site infection and wound healing complications within 3 mo of primary TJA.

RESULTS

There were no significant demographic differences between the 2 groups. There was a significantly higher incidence of acute infection at the surgical site in patients who received intrawound irrigation with normal saline before wound closure than in those who received intrawound irrigation with vancomycin solution (1000 mg/L; 2 L) before wound closure (overall incidence of infection: group 1, 2.46% vs group 2, 0.09%, P < 0.001). There was no significant difference in the incidence of wound healing complications between the two groups.

CONCLUSION

Prophylactic irrigation with vancomycin solution (1000 mg/L; 2 L) significantly decreases the incidence of acute surgical site infection after primary TJA. This strategy is a safe, efficacious, and inexpensive method for reducing the incidence of acute surgical site infection after TJA.

A Novel Biodegradable Composite Polymer Material Based on PLGA and Silver Oxide Nanoparticles with Unique Physicochemical Properties and Biocompatibility with Mammalian Cells

A method for obtaining a stable colloidal solution of silver oxide nanoparticles has been developed using laser ablation. The method allows one to obtain nanoparticles with a monomodal size distribution and a concentration of more than 108 nanoparticles per mL. On the basis of the obtained nanoparticles and the PLGA polymer, a nanocomposite material was manufactured. The manufacturing technology allows one to obtain a nanocomposite material without significant defects. Nanoparticles are not evenly distributed in the material and form domains in the composite. Reactive oxygen species (hydrogen peroxide and hydroxyl radical) are intensively generated on the surfaces of the nanocomposite. Additionally, on the surface of the composite material, an intensive formation of protein long-lived active forms is observed. The ELISA method was used to demonstrate the generation of 8-oxoguanine in DNA on the developed nanocomposite material. It was found that the multiplication of microorganisms on the developed nanocomposite material is significantly decreased. At the same time, the nanocomposite does not inhibit proliferation of mammalian cells. The developed nanocomposite material can be used as an affordable and non-toxic nanomaterial to create bacteriostatic coatings that are safe for humans.

New Organosilicon Composite Based on Borosiloxane and Zinc Oxide Nanoparticles Inhibits Bacterial Growth, but Does Not Have a Toxic Effect on the Development of Animal Eukaryotic Cells

The present study a comprehensive analysis of the antibacterial properties of a composite material based on borosiloxane and zinc oxide nanoparticles (ZnO NPs). The effect of the polymer matrix and ZnO NPs on the generation of reactive oxygen species, hydroxyl radicals, and long-lived oxidized forms of biomolecules has been studied. All variants of the composites significantly inhibited the division of E. coli bacteria and caused them to detach from the substrate. It was revealed that the surfaces of a composite material based on borosiloxane and ZnO NPs do not inhibit the growth and division of mammalians cells. It is shown in the work that the positive effect of the incorporation of ZnO NPs into borosiloxane can reach 100% or more, provided that the viscoelastic properties of borosiloxane with nanoparticles are retained.

Should we be prepping the foot? Stockinette use and drape contamination during hip arthroplasty: An experimental study

BACKGROUND

Meticulous prepping and draping of the surgical field is paramount to reduce the risk of infection. A consistent technique for draping for hip arthroplasty is not well established. One technique for preparing the operative field utilises a sterile stockinette over an unprepped foot. This study aims to assess surgical site contamination when draping for hip arthroplasty without disinfecting the foot.

METHODS

Ultraviolet (UV) fluorescent powder was used as a surrogate for microbial presence on the foot. Powder was applied to a volunteer's foot to a level where antibacterial prep would stop. The leg was then draped according to three methods; directly with stockinette only, wrapping the foot without using an adhesive seal followed by stockinette, and wrapping the foot with the adhesive seal followed by stockinette. Proximal spread of powder after draping was assessed with UV light.

RESULTS

Contamination of the sterile field was found with all draping methods. Spread was particularly noted in the groin, posterior to the thigh and distal to mid-thigh. Wrapping the foot in a small drape without the adhesive seal prior to stockinette application was associated with significantly greater contamination when compared with use of the seal (p = 0.004).

CONCLUSION

Routine formal prepping of the foot during hip arthroplasty is recommended to reduce the risk of surgical site contamination. Surgeons who select not to prep the foot should make use of a small drape with occlusive, adhesive seal prior to stockinette application and consider applying a further U drape to the hip.

Does the Duration of Primary and First Revision Surgery Influence the Probability of First and Subsequent Implant Failures after Extremity Sarcoma Resection and Megaprosthetic Reconstruction?

Simple Summary

Tumor endoprostheses are a common type of reconstruction after the resection of an extremity bone sarcoma. However, in the long-term, first and subsequent implant failures leading to revision surgery are common. One potential risk factor for implant failure is the length of surgery. This study investigates the impact of the length of surgery on prosthetic survival in 568 patients with sarcoma. Patients who had a first implant failure had a longer surgery; however, there were no differences in the infection-free survival, but only in the probability of mechanical failure. Patients with a subsequent revision surgery for infection had a shorter duration of surgery during the first revision. In conclusion, a shorter surgery appears beneficial; however, longer surgeries are not clearly associated with infection. In revision surgery, a longer operating time, indicating a more thorough debridement, may be desirable.

Abstract

Complications in megaprosthetic reconstruction following sarcoma resection are quite common. While several risk factors for failure have been explored, there is a scarcity of studies investigating the effect of the duration of surgery. We performed a retrospective study of 568 sarcoma patients that underwent megaprosthetic reconstruction between 1993 and 2015. Differences in the length of surgery and implant survival were assessed with the Kaplan–Meier method, the log-rank test and multivariate Cox regressions using an optimal cut-off value determined by receiver operating curves analysis using Youden’s index. 230 patients developed a first and 112 patients a subsequent prosthetic failure. The median duration of initial surgery was 210 min. Patients who developed a first failure had a longer duration of the initial surgery (225 vs. 205 min, p = 0.0001). There were no differences in the probability of infection between patients with longer and shorter duration of initial surgery (12% vs. 13% at 5 years, p = 0.492); however, the probability of mechanical failure was higher in patients with longer initial surgery (38% vs. 23% at 5 years, p = 0.006). The median length of revision surgery for the first megaprosthetic failure was 101 min. Patients who underwent first revision for infection and did not develop a second failure had a longer median duration of the first revision surgery (150 min vs. 120 min, p = 0.016). A shorter length of the initial surgery appears beneficial, however, the notion that longer operating time increases the risk of deep infection could not be reproduced in our study. In revision surgery for infection, a longer operating time, possibly indicating a more thorough debridement, appears to be associated with a lower risk for subsequent revision.

Does intraoperative contamination during primary knee arthroplasty affect patient-reported outcomes for patients who are uninfected 1 year after surgery? A prospective cohort study of 714 patients

Background and purpose - It is well recognized that some knee arthroplasty (KA) patients present with prolonged postoperative inflammation and some develop persistent pain. It can reasonably be speculated that some of these problems develop because of low-grade infections with low virulence bacteria caused by intraoperative contamination. This prospective study was performed to investigate whether intraoperative contamination results in lower patient-reported outcomes (PRO) for patients who were clinically uninfected in the first year after surgery. Patients and methods - We combined data from 2 major prospective studies on patients undergoing primary KA at 2 Danish hospitals between September 2016 and January 2018. Pre- and postoperative (1.5, 3, 6, and 12 months) PROs and intraoperative microbiological cultures were obtained on a total of 714 patients who were included in the study. Based on the microbiological cultures, the patients were divided into 2 groups, contaminated and non-contaminated, and differences in PROs between the 2 groups were analyzed. Results - 84 of 714 (12%) patients were intraoperatively contaminated; none of the 714 patients developed clinical infection. The preoperative Oxford Knee Score was 24 and 23 for contaminated and non-contaminated patients, respectively, improving to 40 and 39 at 1 year (p = 0.8). 1-year AUC for Oxford Knee Score and absolute improvement at each postoperative time point for Forgotten Joint Score and EQ-5D-5L also were similar between contaminated and non-contaminated patients. Interpretation - Patient-reported outcomes from 714 patients do not indicate that intraoperative contamination affects the knee-specific or general health-related quality of life in primary KA patients who are clinically uninfected 1 year after surgery.

Intraoperative graft decontamination during ACL reconstruction surgery

Objective  To evaluate different decontaminants for tendon grafts, proposing an antiseptic protocol for contaminated grafts.

Methods  A total of 25 patients were tissue donors for the study. Each participant donated a 2.5-cm tendon sample, which was divided into 5 fragments with 5 mm each during anterior cruciate ligament (ACL) reconstruction surgery. The collected material was divided into 5 groups, totaling 125 samples. In total, four fragments of each patient were placed on the operating room floor for one minute for contamination, simulating the fall of the graft on the floor during surgery. The other fragment was immediately placed in a sterile container (group 1). One of the contaminated fragments was placed in the sterile container without being previously immersed in decontaminating solution (group 2). The remaining fragments were immersed for ten minutes in decontaminating solution: 0.5% chlorhexidine (group 3), 0.9% saline (group 4) and 0.55% ortho-phthalaldehyde (group 5), and, after this time, they were individually placed in a sterile container. The samples from the 5 groups were submitted to microbiological examination.

Results  Bacteria were detected in 26% of the total samples in the microbiological tests, and in group 1 there was no growth of microorganisms. In group 2, bacterial growth was observed in 16 samples. Considering the evaluation of test groups 3, 4 and 5, the percentage of decontamination was higher than the growth of microorganisms in the respective cultures.

Conclusion  The protocol suggested by the study showed that intraoperative graft decontamination is possible.

Bacterial Colonization of Irrigation Fluid during Aseptic Revision Knee Arthroplasty

Surgical risk factors for periprosthetic joint infection (PJI) after total knee arthroplasty (TKA) are the subjects of ongoing research. It is unclear if there are specific locations of the surgical area that might act as a pathogen source. Due to the fact that bacterial replication occurs preferably under humid conditions, it was our aim to investigate if irrigation fluid reservoirs on the surgical covers are subject to bacterial colonization. We prospectively observed 40 patients with scheduled aseptic 1-stage TKA revision. At time intervals of 30 min, irrigation samples were tested for microbiological colonization. Additionally, the suction tip was investigated at the end of surgery. Overall, a bacterial detection rate of 25% was found (57/232 samples). Analysis for any positive microbial detection revealed pathogen findings of irrigation fluid in 41.7% of samples after 30 min with a constant increase up to 77.8% after 90 min. Twenty-three percent of suction tips showed bacterial colonization. Coagulase-negative staphylococci, accounting for the majority of PJI, were the predominant pathogens. After an average follow-up of 17 months, no PJI was confirmed. Despite the substantial bacterial load of irrigation fluid, PJI rates were not elevated. Nevertheless, we recommend that irrigation fluid reservoirs should be prevented and not withdrawn by suction.

Comparison of infection in cemented, cementless and hybrid primary total knee arthroplasty: a network meta-analysis and systematic review of randomized clinical trials

BACKGROUND

Prosthetic joint infection (PJI) is a serious complication of joint replacement surgeries. Surgeons often take extra measures to reduce the risk of PJI. Whilst many studies have compared between cemented, cementless and hybrid fixation (femoral cementless, tibial cemented), most focus on survivorship, clinical and function outcome scores as primary endpoints. This meta-analysis aims to study the association between fixation methods and risk of PJI in primary total knee arthroplasty (TKA).

METHODS

A systematic review and network meta-analysis of randomized controlled trials (RCT) were performed according to Preferred Reporting Items for Systematic reviews and Meta-Analyses guidelines. Data from studies assessing prevalence of PJI in each fixation type were extracted and analysed.

RESULTS

Twelve RCT comprising a total of 1573 knees were included. Six RCT compared between cemented (n = 486 knees) and cementless (n = 440 knees) fixation, while six RCT compared between hybrid (n = 324 knees) and cementless (n = 323 knees) fixation. Network meta-analysis did not reveal any fixation type that significantly increased the infection rate in TKA. Rate of all infection was lowest in cemented TKA as compared to cementless (odds ratio (OR) 0.90, 95% confidence interval (CI) 0.35-2.28) and hybrid (OR 0.63, 95%CI 0.13-2.99) TKA. Rate of PJI requiring revision surgery was lowest in cementless TKA as compared to cemented (OR 0.89, 95%CI 0.30-2.41) and hybrid (OR 0.57, 95%CI 0.09-2.71) TKA. Rate of PJI not requiring revision surgery was lowest in cemented TKA as compared to hybrid (OR 0.56, 95%CI 0.06-6.10) and cementless (OR 0.55, 95% 0.14-5.63).

CONCLUSION

Unlike total hip arthroplasties, fixation method is not a predisposing risk factor for infections in TKA. However, this meta-analysis may not have sufficient statistical power to show a significant difference between fixation types. It is recommended that prophylactic precautions against other known risk factors for infection should still be clinically practiced.

LEVEL OF EVIDENCE

Level I, meta-analysis of randomized controlled trials.

Contamination Rate of Burnt Necrotic Tissue after Electrocoagulation in Total Knee Arthroplasty

Background

Periprosthetic joint infection (PJI) is one of the commonly found catastrophic complications after total knee arthroplasty (TKA). Preoperative antibiotic prophylaxis, proper skin cleansing, shortened operative time, and sterility of surgical field and equipment are essential to minimize the risk of PJI. Although bacterial contamination of electrocautery tips has been reported, contamination of residual product of electrocoagulation, burnt necrotic tissue (BNT), is not well known. Therefore, we aimed to assess the contamination rate of BNT and association between contaminated BNT and PJI, and risk factors.

Methods

BNTs from 183 patients who had undergone unilateral primary TKA at our institution were retrospectively analyzed. In each patient, three to five specimens of BNT were routinely collected in the operative field of primary TKA. Collecting time was defined as the duration from start of using the electrocautery device to the first collection of BNT.

Results

Culture was positive in eight of 183 patients (4.4%; contaminated BNT group), and the most commonly isolated organism was coagulase-negative Staphylococcus (62.5%). The average operative time was 103.1 ± 44.2 minutes in the contaminated BNT group and 79.0 ± 16.7 minutes in the non-contaminated BNT group (p = 0.17), and collecting time was 48.0 ± 44.3 minutes and 29.7 ± 17.0 minutes (p = 0.28), respectively. None of the patients with contaminated BNT developed PJI, whereas four patients with culture-negative BNT developed PJI within 2 postoperative years.

Conclusions

BNT in surgical field can become a reservoir of contaminating bacteria. However, contamination of BNT was not associated with PJI. Therefore, routine removal of all BNTs may be unnecessary.

Does the Method of Sterile Glove-Opening Influence Back Table Contamination? A Fluorescent Particle Study

BACKGROUND

Surgical site infections (SSI) may result from inadvertent intraoperative contamination events. This study investigated the method of opening surgical gloves onto the operative field (OF) and potential contamination rates.

METHODS

Twenty surgical glove packets were coated with a commercially available fluorescent particle powder. Two methods of glove openings (10 surgical glove packets in each cohort) were investigated: direct drop (DD) onto the OF vs opening and direct hand-off (DH) to a sterile intermediary (SI). Ultraviolet black light was used to quantify fluorescent particles for dispensed glove packets and the OF in both cohorts. The gloves of the SI were inspected in the DH cohort. A previously used contamination scale for fluorescent particle model contamination was employed: 0: no detectable fluorescent particle specks, 1: 1-5 specks, 2: 5-10 specks, 3: 11-100 specks, 4: >100 specks.

RESULTS

The DD cohort had a median OF contamination of 4 (range, 3-4) vs 3 for the DH trials (range, 1-3; P = .001). Likewise, the median glove contamination was higher in the DD cohort, 3 (range, 2-4) vs 1 for DH (range, 0-3; P = .007). Minimal contamination was found on the hands of the SI. Total fluorescent contamination rates, including the gloves of SI in the DH cohort, revealed greater overall contamination in DD (median, 3.5; range, 2-4) vs DH cohort (median, 1; range, 0-3); (P < .001).

CONCLUSION

Using a fluorescent particle model, there is a greater burden of potential contamination from dispensed glove packets and OF with DD vs DH. The DH method did not show significant fluorescent particle contamination on the SI gloves. These data support the use of the opening of gloves via DH over the DD method in total joint arthroplasty to decrease the risk of potential contamination.

Contamination rate of the surgical gowns during total hip arthroplasty

INTRODUCTION

Surgical instrument contamination during total joint replacement is a matter of major concern. Available recommendations suggest changing suction tips, gloves and avoiding light handle manipulation during the procedure. There is a paucity of data regarding surgical gown contamination. The aim of the present study was to evaluate the contamination rate of surgical gowns (SGs) during total hip arthroplasty (THA) and secondarily compare it with other orthopedic procedures.

MATERIALS AND METHODS

One hundred and forty surgical gowns (from 70 surgeries) were screened for bacterial contamination using thioglycolate (a high-sensitivity culture broth). The THA contamination rate was compared with those of knee and spine procedures. Controls were obtained at the beginning of every surgery and from the culture broth. The procedure's duration and the level of training of the surgeon were evaluated as potential risk factors for contamination.

RESULTS

Bacterial contamination was identified on 12% of surgical gowns (22% of surgical procedures). The contamination rate during THA was 4.1% (2% in primary THA and 8.3% in revisions) vs 21.67% during other surgeries (spine and knee) (OR 6.15, p = 0.012). There were no contaminated SGs during THAs performed in ≤ 2 h (0/33 SGs) vs 7.5% (3/40) for THAs that took ≥ 2 h (p = 0.25).

CONCLUSION

There was a high rate of SG contamination during orthopedic procedures that was higher during non-arthroplasty procedures and prolonged THAs. There were no contaminated surgical gowns in THAs under 120 min, efforts should point keeping primary THAs under this cutoff time. As a general recommendation, SGs should be changed every time there is concern about potential contamination.

Periprosthetic joint infection in aseptic total hip arthroplasty revision

PURPOSE

There is no consensus regarding systematic screening for infection in aseptic revision total hip arthroplasty (THA). The rationale for systematic intra-operative samples is to increase the sensitivity of latent infections detection, which may require specific treatment. However, the incidence of occult infection in revision THAs is not precisely known. As such, the aim of the study was to evaluate the incidence of occult infection in presumed aseptic revision THAs and identify associated risk factors.

METHOD

Bacteriological samples from 523 aseptic THA revisions performed for five years were analyzed. Revisions performed for periprosthetic joint infection (PJI) or clinical suspicion of PJI were excluded. Microbiological cultures were performed using tissue samples in 505 cases (97%), synovial fluid in blood culture vials in 158 (30%), and in dry tubes in 263 (50%). Implants were sent for sonication in 12 cases (2.6%). The mean number of microbiological samples per patient was 3.6 (range, 1-15). Histology samples were collected for 300 patients (57%).

RESULTS

The incidence of occult infection was 7% (36 cases) and contamination 8% (42 cases). Among occult infections, the primary reasons for revision were dislocation (42%), aseptic loosening (25%), fracture (19%), and others (14%). The infection rate in the dislocation group was significantly higher than that of other reasons for revision (p < 0.001). Among the patients determined with PJI, the revision THA was performed less than a year after primary in 19 (53%).

CONCLUSION

The incidence of occult PJI justifies systematic intraoperative sampling. A short time between primary arthroplasty and revision or an early postoperative dislocation is a factor to suspect infections.

[Total endoprosthetic replacement of femur, humerus and tibia]

Improvements in diagnostics and effectiveness of chemotherapy have resulted in most patients with primary malignant bone tumours being candidates for limb salvage surgery. Herewith, the use of modern modular tumour endoprostheses allows for the replacement of all big joints and even entire long bones such as the femur, humerus and tibia. In this article, we focus on individual prerequisites for and challenges with performing a total endoprosthetic reconstruction of the above-mentioned anatomic structures. Additionally, data from the literature with regards to functional outcome, problems and complications are presented.

Donning Gloves Before Surgical Gown Eliminates Sleeve Contamination

BACKGROUND

There are numerous studies in the literature that have recognized the importance of the glove-gown interface as a potential source of intraoperative bacterial contamination. It has been demonstrated that the methods with which one dons their surgical gown and gloves can alter the level of gown contamination. We hypothesize that donning undergloves before the surgical gown will decrease if not eliminate sleeve contamination.

METHODS

We performed a comparative study to assess the differences in gown contamination between three different gown and glove donning techniques. Participants ranged in experience level from intern to attending. Each participant covered their hands with ultraviolet light disclosing lotion and then donned surgical gown and gloves with their preferred technique and with the proposed technique in a randomly assigned order. The gowns were then removed and analyzed under ultraviolet light for distance and quantity of sleeve contamination.

RESULTS

The gloves-first technique demonstrated zero contamination in all samples. This is significantly less than both closed and open staff-assisted techniques (P < .0001). All samples of closed and open techniques demonstrated some level of contamination. The distance of contamination on the right sleeve is significantly greater than the left sleeve (P < .0001).

DISCUSSION

The gloves-first technique demonstrates zero sleeve contamination throughout all samples, regardless of the experience level. We strongly recommend considering the use of this glove and gown donning technique as opposed to the currently accepted closed and open techniques in an effort to reduce gown contamination.

Rate of surface contamination in the operating suite during revision total joint arthroplasty

Background

This study estimated operating room surface contamination rates during aseptic vs septic total joint arthroplasty and evaluated the similarity between clinically infecting organisms and those isolated from contaminated surfaces.

Methods

Patients undergoing total hip and knee revision arthroplasties were identified, and surface and tissue samples were collected. Cases were classified aseptic or septic based on Musculoskeletal Infection Society criteria for prosthetic joint infection. Positive surface cultures were compared with intraoperative tissue cultures. Positive cultures were speciated and tested for antimicrobial sensitivity.

Results

Samples were collected from 31 aseptic and 18 septic cases. Patients had similar demographics and time to explantation. Surface contamination rates for septic revisions were greater than those for aseptic revisions (77% vs 13%). During septic revisions, when intraoperative tissue cultures were positive, the surgical field was contaminated in 14 of 15 cases. The kappa correlation statistic for positive surgical cultures matching the surface sample was 0.9 (95% confidence interval: 0.78-1).

Conclusions

Septic revisions had a significantly higher rate of surgical field contamination than aseptic revisions. Cultures suggest that bacteria contaminating the septic revision surgical field likely originated from the infected joint. Although this observation seems obvious, it is an important piece of information when discussing best practices during a single-stage exchange revision. Further clinical studies will demonstrate the use of a preparation and reset period during a single-stage revision to remove contaminated surfaces.

Prevalence and quantification of contamination of knitted cotton outer gloves during hip and knee arthroplasty surgery

INTRODUCTION

Knitted cotton outer gloves offer protection against surgical glove perforation and provide improved grip on instruments. These gloves absorb blood and other fluids during surgery, and may therefore also accumulate contaminating bacteria. To date, there is no published data on microbial contamination of such gloves during surgery.

METHODS

Knitted cotton outer gloves used in primary and revision hip and knee arthroplasty from two Swiss hospitals were analysed by quantitative bacteriology. Samples were subjected to sonication and vortexing, followed by membrane filtration of the sonicate. Membranes were incubated under aerobic and anaerobic culture conditions, respectively, for 21 days. Total microbial load for each pair of gloves was determined by colony-forming units (CFU) count. Strain identification was performed with MALDI-TOF.

RESULTS

A total of 43 pairs of gloves were collected from continuous series of surgeries. Under aerobic culture conditions, total CFU counts ranged 0-1103, 25 (58%) samples remaining sterile, and 4 (9%) yielding > 100 CFU. Under anaerobic culture conditions, total CFU counts ranged 0-3579, 22 (51%) samples remaining sterile, 6 (14%) yielding > 100 CFU. The only covariate significantly associated with the level of contamination was the provider hospital (p < 0.0001 for aerobic and p = 0.007 for anaerobic cultures). Strain identification revealed only skin commensals, mainly coagulase-negative staphylococci and Propionibacterium spp.

CONCLUSION

While contamination of surgical latex gloves is a well-known issue, no study has examined so far contamination of knitted cotton outer gloves. No or very low microbial contamination could be identified in the majority of the knitted cotton outer gloves assayed. However, a relevant proportion showed contamination far higher than estimated minimal thresholds for implant-associated infection. Clinical relevance of these findings remains to be established.

The Impact of Supplemental Intraoperative Air Decontamination on the Outcome of Total Joint Arthroplasty: A Pilot Analysis

BACKGROUND

During the early era of arthroplasty, the concept of ultraclean operating room (OR) was introduced based on the principle that the number of airborne particles in the OR directly influences incidence of device-related infections. The hypothesis of this pilot study was that use of an innovative UV-C air decontamination technology would lead to a reduction in the incidence of periprosthetic joint infection (PJI) following total joint arthroplasty.

METHODS

A retrospective, observational, surveillance study was conducted with a consecutive series of patients who underwent total joint arthroplasty (n = 496) between January 2016 and August 2017. All perioperative and postoperative care protocols were identical for both groups, only study variable was that in 231 arthroplasty patients (OR B), an innovative supplemental UV-C air decontamination technology was used, whereas in the remaining 265 patients, arthroplasty was performed with standard turbulent HVAC (OR A).

RESULTS

There was no significant difference between patient groups regarding age, body mass index, diabetes diagnosis, smoking status, length of surgery, or revision status. The rate of PJI was documented to be 1.9% in the turbulent air group, and no infections were documented in the cohorts operated under UV-C air decontamination, which was statistically significant (P < .044).

CONCLUSION

While PJI is multifactorial in nature, the present retrospective pilot study suggests that use of an intraoperative supplemental air decontamination significantly reduced the overall risk of PJI. The findings of this study are encouraging and should be examined in a larger-scale, prospective, multicenter study.

[Advances in total femur replacement]

Objective

To summarize the advances of total femur replacement in recent years.

Methods

The literature related to total femur replacement was reviewed, and the indications, techniques, prosthesis design, complications, rehabilitation, and function were summarized.

Results

The indication of total femur replacement is a wide involvement of the femur, skip lesions and a huge bone defect in revision. Watson-Jone is the main incision in the proximal, and then the full length of the thigh to the patella. Vascular and nerve bundle, abduction muscles are well protected, and combined or costumed prosthesis are replaced. The prosthesis design progresses, showing a diversified prostheses. Complication is frequent and varied. Rehabilitation in early stage is physical therapy, weight training is evolutionary. The main function evaluation system is Musculoskeletal Tumor Society (MSTS) score.

Conclusion

Total femur replacement is effective in limb salvage. Large sample size and long-term follow-up study should be carried out to unify indications and functional exercise standards and reduce postoperative complications.

Prevention and detection of prosthetic temporomandibular joint infections-update

Prosthetic joint infections are not only distressing complications for patients and surgeons, but also have an enormous financial impact on healthcare systems. The reported incidence of prosthetic joint infection is likely underestimated due to difficulties in their diagnosis. This unfortunate complication has challenged joint replacement surgeons for years, despite all the advances made in this surgical discipline. Since eradication of these infections can be very difficult, prevention remains the primary objective. Identifying recipient risk factors, adopting a proper surgical technique, appropriate wound care, optimizing the operating room environment, and appropriate postoperative care have become some of the core elements that can help to minimize the overall incidence of this complication. The purpose of this article is to provide the temporomandibular joint replacement surgeon with an update on the prevention and detection of prosthetic joint infections based on a review of the most recent information published in the orthopedic and surgical literature.

Preventing infection in shoulder surgery

Although rare, infection after shoulder surgery can represent a devastating complication. Infection can negatively affect clinical outcomes, and eradication often requires a protracted treatment course. Staphylococcus aureus, Staphylococcus epidermidis, and Cutibacterium acnes are among the most frequently isolated pathogens. Perioperative measures can be implemented to reduce infection risk. Here we review various perioperative practices and their efficacy at reducing infection after shoulder surgery.

Bacterial Contamination of a Marking Pen in Anterior Cruciate Ligament Reconstruction

Background:

A sterile surgical marking pen is commonly used during anterior cruciate ligament reconstruction (ACLR) to outline the proposed skin incision and then to mark the graft during preparation. Once in contact with the skin, the pen is a potential source of bacterial transmission and subsequent infections after ACLR.

Purpose/Hypothesis:

The purpose of this study was to assess whether the skin marking pen is a fomite for contamination during arthroscopic ACLR. We hypothesized that there would be a difference in the rate of culture-positive pens between control pens and the study pens used to delineate the proposed skin incision.

Study Design:

Controlled laboratory study.

Methods:

Twenty surgical marking pens were collected prospectively from patients undergoing ACLR over a 12-month period. All patients underwent standard preoperative sterile preparation and draping procedures. Proposed incisions were marked with a new sterile pen, and the pen tip was immediately sent for a 5-day inoculation in broth and agar. Negative controls (unopened new pen) and positive controls (used to mark the skin incisions preoperatively) were also cultured. Additionally, blank culture dishes were observed during the growth process. All pens were removed from the surgical field before incision, and new marking pens were used when needed during the procedure.

Results:

Three of the 20 study pens (15%) demonstrated positive growth. All 3 pens grew species of Staphylococcus. None of the negative controls demonstrated growth, 6 of the 12 positive controls showed growth, and none of the blank dishes exhibited growth.

Conclusion:

This study found a 15% rate of surgical marking pen contamination by Staphylococcus during ACLR. It is recommended that the skin marking pen not be used for any further steps of the surgical case and be discarded once used.

Clinical Relevance:

Infections after ACLR are rare but may result in significant morbidity, and all measures to reduce them should be pursued. Surgeons performing ACLR should dispose of the surgical marking pen after skin marking and before intraoperative use such as graft markup.

Antibiotic Prophylaxis and Prevention of Surgical Site Infection in Shoulder and Elbow Surgery

Infection after orthopedic procedures is a devastating and serious complication associated with significant clinical and financial challenges to the health care system and unfortunate patient. The time and resource-intensive nature of treating infection after orthopedic procedures has turned attention toward enhancing prevention and establishing quality improvement measures. Prevention strategies throughout the perioperative period include host optimization, risk mitigation, reducing bacterial burden and proper wound management. Understanding the most common offending organisms of the shoulder, Propionibacterium acnes and coagulase negative Staphylococcus species, and their hypothesized mechanism of infection is crucial to selecting appropriate preventative measures.

A Case Report of Dual Incision Technique for Total Femur Arthroplasty as a Salvage Procedure in Infected Non-Unions

Introduction

Total femur arthroplasty (TFA) is a rare salvage limb procedure which serves as an effective alternative to limb amputation. Most commonly, it is indicated for oncologic orthopedic cases, and very few cases of a purely traumatic history for TFA have been documented. The decision to perform this complex procedure involves paying careful attention to reconstructive needs and functional expectations of the patient. Alternatives to this procedure are quite detrimental and include hip disarticulation and above-the-knee amputation.

Case Report

A 66-year-old woman with a history of hypertension, and parkinsonism was brought into the outpatient department of a tertiary care hospital. She has undergone a procedure for proximal femur nailing on her left hip in 2013 due to a trauma-related fracture. However, after the development of a series of complications, she underwent revision surgery on her left hip 6 times by different surgeons. This included surgeries for implant removal and fixation of a custom-made bipolar hemi-replacement hip, followed by a cemented bipolar hip hemi- replacement with plating and cerclage wires followed by infection, the treatment of which entailed implant removal and placement of an antibiotic cement. This was followed by a long stem constrained cemented total hip arthroplasty which also failed. The surgeon then made the decision to perform a TFA. 12-month follow-up post-operatively showed neither peri-prosthetic infection or inflammation nor any leg length discrepancy. The functional outcome on lower extremity function scale showed improvement from 0 pre-operatively to 31 at 12-month follow- up.

Conclusion

TFA serves as a viable technique for salvage of the lower extremity in cases of infected non-unions. However, a thorough evaluation of the particular case in the hand should be made before reaching a conclusion.

Environment of care: Is it time to reassess microbial contamination of the operating room air as a risk factor for surgical site infection in total joint arthroplasty?

In the modern operating room (OR), traditional surgical mask, frequent air exchanges, and architectural barriers are viewed as effective in reducing airborne microbial populations. Intraoperative sampling of airborne particulates is rarely performed in the OR because of technical difficulties associated with sampling methodologies and a common belief that airborne contamination is infrequently associated with surgical site infections (SSIs). Recent studies suggest that viable airborne particulates are readily disseminated throughout the OR, placing patients at risk for postoperative SSI. In 2017, virtually all surgical disciplines are engaged in the implantation of selective biomedical devices, and these implants have been documented to be at high risk for intraoperative contamination. Approximately 1.2 million arthroplasties are performed annually in the United States, and that number is expected to increase to 3.8 million by the year 2030. The incidence of periprosthetic joint infection is perceived to be low (<2.5%); however, the personal and fiscal morbidity is significant. Although the pharmaceutic and computer industries enforce stringent air quality standards on their manufacturing processes, there is currently no U.S. standard for acceptable air quality within the OR environment. This review documents the contribution of air contamination to the etiology of periprosthetic joint infection, and evidence for selective innovative strategies to reduce the risk of intraoperative microbial aerosols.

Disinfection and healing effects of 222-nm UVC light on methicillin-resistant Staphylococcus aureus infection in mouse wounds

UVC radiation is known to be highly germicidal. However, exposure to 254-nm-UVC light causes DNA lesions such as cyclobutane pyrimidine dimers (CPD) in human cells, and can induce skin cancer after long-term repeated exposures. It has been reported that short wavelength UVC is absorbed by proteins in the membrane and cytosol, and fails to reach the nucleus of human cells. Hence, irradiation with 222-nm UVC might be an optimum combination of effective disinfection and biological safety to human cells. In this study, the biological effectiveness of 222-nm UVC was investigated using a mouse model of a skin wound infected with methicillin-resistant Staphylococcus aureus (MRSA). Irradiation with 222-nm UVC significantly reduced bacterial numbers on the skin surface compared with non-irradiated skin. Bacterial counts in wounds evaluated on days 3, 5, 8 and 12 after irradiation demonstrated that the bactericidal effect of 222-nm UVC was equal to or more effective than 254-nm UVC. Histological analysis revealed that migration of keratinocytes which is essential for the wound healing process was impaired in wounds irradiated with 254-nm UVC, but was unaffected in 222-nm UVC irradiated wounds. No CPD-expressing cells were detected in either epidermis or dermis of wounds irradiated with 222-nm UVC, whereas CPD-expressing cells were found in both epidermis and dermis irradiation with 254-nm UVC. These results suggest that 222-nm UVC light may be a safe and effective way to reduce the rate of surgical site and other wound infections.

Distribution characteristics of Staphylococcus spp. in different phases of periprosthetic joint infection: A review

Periprosthetic joint infection (PJI) is a devastating condition and Staphylococcus spp. are the predominant pathogens responsible, particularly coagulase-negative staphylococci (CoNS) and Staphylococcus aureus. The aim of the present systematic review was to evaluate the distribution characteristics of specific Staphylococcus spp. in different PJI phases, reveal the effect of pathogens' feature on their distribution and suggest recommendations for antibiotic treatment of Staphylococcal PJI. The present systematic review was performed using PubMed and EMBASE databases with the aim to identify existing literature that presented the spectrum of Staphylococcus spp. that occur in PJI. Once inclusion and exclusion criteria were applied, 20 cohort studies involving 3,344 cases in 3,199 patients were included. The predominant pathogen involved in PJI was indicated to be CoNS (31.2%), followed by S. aureus (28.8%). This trend was more apparent in hip replacement procedures. In addition, almost equal proportions of CoNS and S. aureus (28.6 and 30.0%, respectively) were indicated in the delayed phase. CoNS (36.6%) were the predominant identified organism in the early phase, whereas S. aureus (38.3%) occurred primarily in the late phase. In PJI caused by S. aureus, the number of cases of methicillin-sensitive Staphylococcus aureus (MSSA) was ~2.5-fold greater than that of methicillin-resistant Staphylococcus aureus (MRSA). MRSA occurred predominantly in the early phase, whereas MSSA was largely observed in the delayed and late phases. With regards to antibiotic treatment, the feature of various pathogens and the phases of PJI were the primary considerations. The present review provides useful information for clinical practice and scientific research of PJI.

Calcium Phosphate Bioceramics: A Review of Their History, Structure, Properties, Coating Technologies and Biomedical Applications

Calcium phosphate (CaP) bioceramics are widely used in the field of bone regeneration, both in orthopedics and in dentistry, due to their good biocompatibility, osseointegration and osteoconduction. The aim of this article is to review the history, structure, properties and clinical applications of these materials, whether they are in the form of bone cements, paste, scaffolds, or coatings. Major analytical techniques for characterization of CaPs, in vitro and in vivo tests, and the requirements of the US Food and Drug Administration (FDA) and international standards from CaP coatings on orthopedic and dental endosseous implants, are also summarized, along with the possible effect of sterilization on these materials. CaP coating technologies are summarized, with a focus on electrochemical processes. Theories on the formation of transient precursor phases in biomineralization, the dissolution and reprecipitation as bone of CaPs are discussed. A wide variety of CaPs are presented, from the individual phases to nano-CaP, biphasic and triphasic CaP formulations, composite CaP coatings and cements, functionally graded materials (FGMs), and antibacterial CaPs. We conclude by foreseeing the future of CaPs.

The Neurostimulation Appropriateness Consensus Committee (NACC) Recommendations for Infection Prevention and Management

INTRODUCTION

The use of neurostimulation for pain has been an established therapy for many decades and is a major tool in the arsenal to treat neuropathic pain syndromes. Level I evidence has recently been presented to substantiate the therapy, but this is balanced against the risk of complications of an interventional technique.

METHODS

The Neurostimulation Appropriateness Consensus Committee (NACC) of the International Neuromodulation Society convened an international panel of well published and diverse physicians to examine the best practices for infection mitigation and management in patients undergoing neurostimulation. The NACC recommendations are based on evidence scoring and peer-reviewed literature. Where evidence is lacking the panel added expert opinion to establish recommendations.

RESULTS

The NACC has made recommendations to improve care by reducing infection and managing this complication when it occurs. These evidence-based recommendations should be considered best practices in the clinical implantation of neurostimulation devices.

CONCLUSION

Adhering to established standards can improve patient care and reduce the morbidity and mortality of infectious complications in patients receiving neurostimulation.

Method of intraoperative tissue sampling for culture has an effect on contamination risk

PURPOSE

This prospective study was designed to determine whether exposure of intraoperative tissue samples to the operating room environment affects subsequent culture results.

METHODS

A prospective study conducted on 125 patients undergoing primary total knee arthroplasty was conducted from August 2013 to December 2015. During surgery, three samples from the infrapatellar fat pad were obtained. The first sample was obtained using clean instruments and placed directly into a specimen cup (direct). The second sample was obtained using clean instruments, placed in the palm of an assistant, then placed in the hands of the scrub nurse, and finally transferred into a specimen cup (glove). The third sample was obtained with clean instruments, placed on a gauze pad on the back table, and transferred to a specimen cup at the time of skin closure (table).

RESULTS

There were two (1.6 %) positive cultures in the direct transfer group, none (0.0 %) in the glove contact group, and eight (6.4 %) in the exposed (table) group; there was a statistically significant difference between the glove contact and table samples (p = 0.01). The organisms isolated were coagulase-negative Staphylococcus in five samples, Proprionibacterium acnes in two samples, Staphylococcus epidermidis in one sample, Pediococcus pentosaceus in one sample, and Corynebacterium in one sample.

CONCLUSIONS

Contamination of tissue samples obtained for culture can occur if samples are exposed to the operating room environment. To prevent potential contamination, samples obtained for culture should be retrieved using clean instruments, transferred to a culture bottle directly, and transported to the microbiology laboratory as soon as possible.

LEVEL OF EVIDENCE

II.

Iodine-impregnated incision drape and bacterial recolonization in simulated total knee arthroplasty

Background and purpose - Iodine-impregnated incision drapes (IIIDs) are used to prevent surgical site infection (SSI). However, there is some evidence to suggest a potential increase in SSI risk as a result of IIID use, possibly from promotion of skin recolonization. A greater number of viable bacteria in the surgical field of an arthroplasty, and surgery in general, may increase the infection risk. We investigated whether IIID use increases bacterial recolonization compared to no drape use under conditions of simulated total knee arthroplasty (TKA). Methods - 20 patients scheduled for TKA were recruited. Each patient had 1 knee randomized for draping with IIID, while the contralateral knee was left bare. The patients thus served as their own control. The operating room conditions and perioperative procedures of a TKA were simulated. Cylinder samples were collected from the skin of each knee prior to disinfection, and again on 2 occasions after skin preparation-75 min apart. Quantities of bacteria were estimated using a spread plate technique under aerobic conditions. Results - We found similar quantities of bacteria on the intervention and control knees immediately after skin disinfection and after 75 min of simulated surgery. These quantities had not increased at the end of surgery when compared to baseline, so no recolonization was detected on the draped knees or on the bare knees. Interpretation - The use of IIIDs did not increase bacterial recolonization in simulated TKA. This study does not support the hypothesis that IIIDs promote bacterial recolonization and postoperative infection risk.

Risk of Contamination in Assembled vs Disassembled Instruments in Hip Arthroplasty Surgery

BACKGROUND

Periprosthetic joint infection (PJI) is one of the most common causes of revision total hip arthroplasty (THA) and associated with higher costs, prolonged pain, and worse clinical outcomes. Many factors have been linked to increased infection rates, one being the operative equipment and instrumentation used during the surgical procedure. With few arthroplasty instruments designed for complete disassembly and increasingly complex instrument designs, this study seeks to understand the effect that instrument disassembly plays on infection using disassembled and assembled standard femoral broach handles (BHs).

METHODS

Two BHs, not designed for disassembly, were modified and then contaminated in the disassembled state with Geobacillus stearothermophilus vegetative-form bacteria and spores. Using both flash and standard sterilization cycles, the BHs were steam sterilized in the disassembled or assembled state and then analyzed for remaining bacteria and spores.

RESULTS

At all target locations after either a flash sterilization cycle or a standard sterilization cycle, complete eradication of both the vegetative-form and spore-form of G stearothermophilus was achieved.

CONCLUSION

This study demonstrates that adequate decontamination of the tested BHs can be achieved after steam sterilization in either the disassembled or assembled state, without an increased risk of infection transmission.

Quantification Analysis of the Intraoperative Bacterial Contamination Rate and Level in Osteochondral Autografts

BACKGROUND

Inadvertent contamination of osteochondral (OC) autografts during harvesting and preparation can lead to significant complications and can cause the operating team to weigh the infection risk after reimplantation against discarding the OC fragment. The most commonly reported contamination mechanism is the accidental dropping of an OC fragment; however, associated contamination levels remain unclear. The rate and level of contamination during standard harvesting and preparation are also unknown.

PURPOSE

To quantitatively evaluate the rate and level of bacterial contamination of OC autografts during harvesting and preparation compared with those of accidently dropped autografts.

STUDY DESIGN

Controlled laboratory study.

METHODS

Under sterile conditions, 138 fresh OC specimens were harvested and retrieved from 23 primary total knee arthroplasties (TKAs). Six OC fragments were retrieved from each TKA: 3 were used as controls, and 3 were dropped onto the operating room floor. Each specimen was incubated to allow for aerobic and anaerobic growth, and the number of colony-forming units (CFUs) per gram was calculated.

RESULTS

Contamination rates (positive cultures) for the control and dropped groups were 29% (n = 20/69) and 42% (n = 29/69), respectively. The difference in the contamination rate between groups was not statistically significant (P = .109). The most common organisms identified were Staphylococcus aureus (40%) in the control group and Staphylococcus epidermidis (24.1%) and Bacillus species (20.7%) in the dropped group. The contamination level (CFUs/g) for both groups was low. The median (range) CFUs/g among the contaminated specimens in the dropped and control groups were 27 (1-120) and 3 (1-15), respectively (P < .0001).

CONCLUSION

A relatively high rate of OC autograft contamination can be expected during harvesting and preparation (29%) or after accidentally dropping a specimen (42%). Although the types of organisms isolated differed between specimens contaminated during harvesting and preparation and dropped specimens, the quantification of the autograft contamination level revealed a very low CFUs/g in both cases.

CLINICAL RELEVANCE

The intraoperative autograft contamination level is very low. Hence, in cases of grafts with a known contamination incident, saving and reimplanting them after proper decontamination is recommended over discarding them or using an allograft.

Prevention of Surgical Site Infections in Joint Replacement Surgery

Prosthetic joint infections (PJI), although rare, represent a serious complication of total joint arthroplasty as they pose not only a direct financial burden to the patient but also an indirect burden related to psychosocial impact that PJI incur on the patient. Treatment of PJI is complex and requires a combined surgical and medical approach. Patients are often subjected to multiple surgical procedures and prolonged courses of antimicrobial therapy. Therefore, all efforts should be directed toward maximizing the prophylactic measures in the peri-operative and post-operative phases in order to prevent the occurrence of surgical site infections. This article explores primarily the prophylactic measures that target the host and the operative theater environment. Implementation of such preventive measures requires a multi-disciplinary approach and is crucial for a successful outcome of the total joint arthroplasty.

Current concepts in total femoral replacement

Total femoral replacement (TFR) is a salvage arthroplasty procedure used as an alternative to lower limb amputation. Since its initial description in the mid-20^th century, this procedure has been used in a variety of oncologic and non-oncologic indications. The most compelling advantage of TFR is the achievement of immediate fixation which permits early mobilization. It is anticipated that TFR will be increasingly performed as the rate of revision arthroplasty rises worldwide. The existing literature is mainly composed of a rather heterogeneous mix of retrospective case series and a wide assortment of case reports. Numerous TFR prostheses are currently available and the surgeon must understand the unique implications of each implant design. Long-term functional outcomes are dependent on adherence to proper technique and an appropriate physical therapy program for postoperative rehabilitation. Revision TFR is mainly performed for periprosthetic infection and the severe femoral bone loss associated with aseptic revisions. Depending on the likelihood of attaining infection clearance, it may sometimes be advisable to proceed directly to hip disarticulation without attempting salvage of the TFR. Other reported complications of TFR include hip joint instability, limb length discrepancy, device failure, component loosening, patellar maltracking and delayed wound healing. Further research is needed to better characterize the long-term functional outcomes and complications associated with this complex procedure.

Regional Intraosseous Administration of Prophylactic Antibiotics is More Effective Than Systemic Administration in a Mouse Model of TKA

BACKGROUND

In human TKA studies, intraosseous regional administration (IORA) of prophylactic antibiotics achieves local tissue antibiotic concentrations 10 times greater than systemic administration. However, it is unclear if such high concentrations provide more effective prophylaxis.

QUESTIONS/PURPOSES

We asked: (1) What prophylaxis dosage and route (intravenous [IV] versus IORA of prophylactic antibiotics) produce less in vivo bacterial burden compared with no-antibiotic controls? (2) Compared with controls, what prophylaxis dosage and route yield fewer colony-forming units (CFUs) in euthanized animals in a model of TKA? (3) Is prophylactic IORA of antibiotics more effective than same-dose IV antibiotic administration in reducing CFUs?

METHODS

Mice (six to nine per group) were block randomized to one of six prophylaxis regimens: control, systemic cefazolin (C100IV), IORA of cefazolin (C100IORA), systemic vancomycin (V110IV), low-dose systemic vancomycin (V25IV), and low-dose IORA of vancomycin (V25IORA). Surgery involved placement of an intraarticular knee prosthesis, followed by an inoculum of bioluminescent Staphylococcus aureus strain Xen36. Biophotonic imaging assessed in vivo bacterial loads, and after 4 days bacterial load was quantified using culture-based techniques. Comparisons were made for each prophylactic regimen to controls and between same-dose IV and IORA of prophylactic antibiotic regimens.

RESULTS

Mice treated with systemic high-dose vancomycin, IORA of vancomycin, or IORA of cefazolin had lower in vivo Staphylococcus aureus burdens (median area under curve, Control: 5.0 × 10(6); V110IV: 1.5 × 10(6), difference of medians 3.5 × 10(6), p = 0.003; V25IV: 1.94 × 10(6), difference 3.07 × 10(6), p = 0.49; V25IORA: 1.51 × 10(6), difference 3.5 × 10(6), p = 0.0011; C100IORA: 1.55 × 10(6), difference 3.46 × 10(6), p = 0.0016; C100IV: 2.35 × 10(6), difference 2.66 × 10(6), p = 0.23.) Similar findings were seen with culture-based techniques on recovered implants. IORA of prophylactic antibiotics was more effective than same-dose IV administration in reducing bacterial load on recovered implants (median CFUs < 7.0 × 10(0) vs 2.83 × 10(2), p = 0.0183).

CONCLUSIONS

IORA of prophylactic cefazolin and vancomycin was more effective than the same dose of antibiotic given systemically. The effectiveness of vancomycin in particular was enhanced by IORA of prophylactic antibiotics despite using a lower dose.

CLINICAL RELEVANCE

Our study supports previous studies of IORA of prophylactic antibiotics in humans and suggests this novel form of administration has the potential to enhance the effectiveness of prophylaxis in TKA. Because of concerns regarding antibiotic stewardship, IORA of prophylactic vancomycin may be more appropriately restricted to patients having TKA who are at greater risk of infection, and clinical trials are in progress.

Postoperative Deep Infection After Cemented Versus Cementless Total Hip Arthroplasty: A Meta-Analysis

Periprosthetic joint infection (PJI) is a serious complication of total hip arthroplasty (THA). The objective of this meta-analysis was to compare the PJI rate between cemented and cementless THAs. Eight clinical studies (2 randomized controlled trials and 6 observational studies) were available for the analysis. Meta-analysis (with a fixed-effects model) and subgroup analysis were performed by research design and meta-regression was performed by continuous moderator. The overall incidence of PJI was 0.4% (357/84,200). The incidence was 0.5% (310/67,531) in cemented group, and 0.3% (47/16,669) in cementless group (P=0.008). The meta-analysis revealed that the use of cement in THA was associated with an increased risk of PJI (odds ratio 1.53; 95% confidence interval 1.120 to 2.100; P=0.008).

Bacterial Contamination in Tips of Electrocautery Devices During Total Hip Arthroplasty

Surgical equipment can become contaminated during surgery. It is unknown if electrocautery tips can become contaminated in clean orthopedic procedures despite the produced heat. Therefore, we conducted a prospective study to address this concern. The tips from 25 primary and 25 aseptic revision THAs were collected and an additional 5 sterile tips served as negative controls. Aerobic and anaerobic cultures were incubated for a minimum of 3 days. There were 3 positive cultures (6%); one in primary THA (4%) with Lactobacillus and Enterococcus faecalis; two among revisions (8%), one with E. faecalis and another one with alpha hemolytic streptococci and coagulase negative Staphylococcus. The mean exposure time of the contaminated tips was 132.3 minutes. Patients were followed for 90 days postoperatively and none of them developed surgical site infection. This is the first study to demonstrate that electrosurgical devices can become contaminated during THA in laminar flow equipped operating rooms.