Purpose Open debridement with prosthesis retention (ODPR) has been considered as a reasonable treatment option for acute periprosthetic joint infection (PJI) following total knee arthroplasty (TKA). However, multiple recent studies have challenged this contention. This study was undertaken to determine the success rate of ODPR, whether the success rate was affected by the ODPR timing or by the microorganisms. Method We retrospectively reviewed 52 cases of ODPR performed in four institutions to treat acute PJI which met the definition of PJI by the International Consensus Group on PJI. We recorded patient demographics; time from index TKA and symptom duration; the microorganisms involved; and whether the infection was controlled or not. Results The overall success rate of ODPR was 71 %, and early postoperative infection and acute hematogenous infection had a success rate of 82 and 55 %, respectively. Success rate was associated with a shorter symptom duration in patients with acute hematogenous infections (p = 0.040). However, success was not influenced by the type (p = 0.992) or virulence of the causative microorganisms (p = 0.706). Conclusion ODPR should be considered as a viable treatment option for acute PJI following TKA. The promptness of ODPR is of paramount importance for success of ODPR, rather than the causative organism type or virulence.

This dataset contains raw size measurements and derived shape parameters for six ash samples of the 2011 Grímsvötn eruption, Iceland (G1, G3, G4, G6, G7, & G8). All size measurements were made on backscattered electron SEM images using ImageJ image analysis software. Size measurements have units of pixels, and the dimensions of each pixels (in microns) is given for each sample. This dataset forms part of the supplementary material for the publication Liu, E.J., Cashman, K.V., Rust, A.C., & Gislason, S., (2015), The role of bubbles in generating fine ash during hydromagmatic eruptions', Geology.

The role of irrigation and debridement (I&D) in the treatment of periprosthetic joint infections (PJI) of the knee remains controversial. Our purpose was to identify the success rate and factors determining outcome of I&D in those patients. Clinical characteristics of 78 patients with PJI of the knee treated with I&D were retrospectively reviewed. Implant retention at final follow-up was achieved in 43 patients (55.1%). Logistic regression analysis revealed that duration of symptoms > 5 days and thyroid disease were independent predictors of I&D failure. Patients with methicillin-resistant staphylococcal infections had a success rate of 45.5% and significantly lower odds of success compared to patients with negative cultures. In selected patients, I&D is a reasonable option in the context of acute PJI of the knee.

Background: Periprosthetic shoulder infections can be difficult to diagnose. The purpose of this study was to investigate the utility of arthroscopic tissue culture for the diagnosis of infection following shoulder arthroplasty. Our hypothesis was that culture of arthroscopic biopsy tissue is a more reliable method than fluoroscopically guided shoulder aspiration for diagnosing such infection. Methods: A retrospective review identified patients who had undergone culture of arthroscopic biopsy tissue during the evaluation of a possible chronic periprosthetic shoulder infection. The culture results of the arthroscopic biopsies were compared with those of fluoroscopically guided glenohumeral aspiration and open tissue biopsy samples obtained at the time of revision surgery. Results: Nineteen patients had undergone arthroscopic biopsy to evaluate a painful shoulder arthroplasty for infection. All subsequently underwent revision surgery, and 41% of those with culture results at that time had a positive result, which included Propionibacterium acnes in each case. All arthroscopic biopsy culture results were consistent with the culture results obtained during the revision surgery, yielding 100% sensitivity, specificity, positive predictive value, and negative predictive value. In contrast, fluoroscopically guided glenohumeral aspiration yielded a sensitivity of 16.7%, specificity of 100%, positive predictive value of 100%, and negative predictive value of 58.3%. Conclusions: Arthroscopic tissue biopsy is a reliable method for diagnosing periprosthetic shoulder infection and identifying the causative organism.

Background: Infection is a major complication after total joint arthroplasty. The urinary tract is a possible source of surgical site contamination, but the role of asymptomatic bacteriuria (ASB) before elective surgery and the subsequent risk of infection is poorly understood. Methods: Candidates for total hip or total knee arthroplasty were reviewed in a multicenter cohort study. A urine sample was cultured in all patients, and those with ASB were identified. Preoperative antibiotic treatment was decided on an individual basis, and it was not mandatory or randomized. The primary outcome was prosthetic joint infection (PJI) in the first postoperative year. Results: A total of 2497 patients were enrolled. The prevalence of ASB was 12.1% (303 of 2497), 16.3% in women and 5.0% in men (odds ratio, 3.67; 95% confidence interval, 2.65-5.09; P < .001). The overall PJI rate was 1.7%. The infection rate was significantly higher in the ASB group than in the non-ASB group (4.3% vs 1.4%; odds ratio, 3.23; 95% confidence interval, 1.67-6.27; P = .001). In the ASB group, there was no significant difference in PJI rate between treated (3.9%) and untreated (4.7%) patients. The ASB group had a significantly higher proportion of PJI due to gram-negative microorganisms than the non-ASB group, but these did not correlate to isolates from urine cultures. Conclusions: ASB was an independent risk factor for PJI, particularly that due to gram-negative microorganisms. Preoperative antibiotic treatment did not show any benefit and cannot be recommended.

Background: Propionibacterium acnes is a clinically relevant pathogen with total shoulder arthroplasty. The purpose of this study was to determine the sensitivity of frozen section histology in identifying patients with Propionibacterium acnes infection during revision total shoulder arthroplasty and investigate various diagnostic thresholds of acute inflammation that may improve frozen section performance. Methods: We reviewed the results of forty-five patients who underwent revision total shoulder arthroplasty. Patients were divided into the non-infection group (n = 15), the Propionibacterium acnes infection group (n = 18), and the other infection group (n = 12). Routine preoperative testing was performed and intraoperative tissue culture and frozen section histology were collected for each patient. The histologic diagnosis was determined by one pathologist for each of the four different thresholds. The absolute maximum polymorphonuclear leukocyte concentration was used to construct a receiver operating characteristics curve to determine a new potential optimal threshold. Results: Using the current thresholds for grading frozen section histology, the sensitivity was lower for the Propionibacterium acnes infection group (50%) compared with the other infection group (67%). The specificity of frozen section was 100%. Using a receiver operating characteristics curve, an optimized threshold was found at a total of ten polymorphonuclear leukocytes in five high-power fields (400×). Using this threshold, the sensitivity of frozen section for Propionibacterium acnes was increased to 72%, and the specificity remained at 100%. Conclusions: Using current histopathology grading systems, frozen sections were specific but showed low sensitivity with respect to the Propionibacterium acnes infection. A new threshold value of a total of ten or more polymorphonuclear leukocytes in five high-power fields may increase the sensitivity of frozen section, with minimal impact on specificity.

Negative results on culture still pose a real challenge in the diagnosis of periprosthetic joint infection. There are numerous reasons for the inability to isolate the infecting organism from the affected joint, the most important of which is the administration of antibiotics prior to obtaining culture samples. For patients suspected of having a periprosthetic joint infection, antibiotics should not be given until the diagnosis is confirmed or aspiration of the joint should be delayed for at least two weeks after the last dose of antibiotics. Other strategies that can be used to enhance the likelihood of obtaining a positive result on culture include expeditious transport of culture samples, placement of a tissue or fluid sample in the appropriate medium, implant sonication, and prolonging the incubation period of the samples to two or three weeks. In patients in whom the prerevision aspiration has not yielded an infecting organism, yet the clinical picture is consistent with periprosthetic joint infection, a minimum of three to five tissue culture samples are recommended at the time of revision surgery. Biomarkers and molecular techniques, such as polymerase chain reaction identification of bacterial DNA, may play an increasing role in the future in the diagnosis of periprosthetic joint infection, when standardized techniques have not identified an infecting organism.

Background: Infection after shoulder arthroplasty can be a devastating complication, and subacute and chronic low-grade infections have proven difficult to diagnose. Serum marker analyses commonly used to diagnose periprosthetic infection are often inconclusive. The purpose of this study was to evaluate the effectiveness of serum interleukin-6 (IL-6) as a marker of periprosthetic shoulder infection. Methods: A prospective cohort study of thirty-four patients who had previously undergone shoulder arthroplasty and required revision surgery was conducted. The serum levels of IL-6 and C-reactive protein (CRP), the erythrocyte sedimentation rate (ESR), and the white blood-cell count (WBC) were measured. The definitive diagnosis of an infection was determined by growth of bacteria on culture of intraoperative specimens. Two-sample Wilcoxon rank-sum (Mann-Whitney) tests were used to determine the presence of a significant difference in the ESR and WBC between patients with and those without infection, while the Fisher exact test was used to assess differences in IL-6 and CRP levels between those groups. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of each marker were also calculated. Results: There was no significant difference in the IL-6 level, WBC, ESR, or CRP level between patients with and those without infection. With a normal serum IL-6 level defined as <10 pg/mL, this test had a sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of 0.14, 0.95, 0.67, 0.61, and 0.62, respectively. Conclusions: IL-6 analysis may have utility as a confirmatory test but is not an effective screening tool for periprosthetic shoulder infection. This finding is in contrast to the observation, in previous studies, that IL-6 is more sensitive than traditional serum markers for periprosthetic infection.

Peter Fabian and Martin Dameris provide a concise yet comprehensive overview of established scientific knowledge about ozone in the atmosphere. They present both ozone changes and trends in the stratosphere, as well as the effects of overabundance in the troposphere including the phenomenon of photosmog.Aspects such as photochemistry, atmospheric dynamics and global ozone distribution as well as various techniques for ozone measurement are treated. The authors outline the various causes for ozone depletion, the effects of ozone pollution and the relation to climate change.The book provides a handy reference guide for researchers active in atmospheric ozone research and a useful introduction for advanced students specializing in this field. Non-specialists interested in this field will also profit from reading the book.Peter Fabian can look back on a life-long active career in ozone research, having first gained international recognition for his measurements of the global distribution of halogenated hydrocarbons. He also pioneered photosmog investigations in the metropolitan areas of Munich, Berlin, Athens and Santiago de Chile, and his KROFEX facility provided controlled ozone fumigation of adult tree canopies for biologists to investigate the effects of ozone increases on forests. Besides having published a broad range of scientific articles, he has also been the author or editor of numerous books. From 2002 to 2005 he served the European Geosciences Union (EGU) as their first and Founding President.Martin Dameris is a prominent atmospheric modeler whose interests include the impacts of all kinds of natural and man-made disturbances on the atmospheric system. His scientific work focuses on the connections between ozone and climate changes. For many years he has been an active contributor to the WMO scientific ozone depletion assessments, which have been used to monitor the depletion and recovery of the ozone layer in accordance with the Montreal Protocol.

Object Surgical site infection (SSI) is a serious and costly complication of spinal surgery. There have been several conflicting reports on the use of intrawound vancomycin powder in decreasing SSI in spine surgery. The purpose of this study is to answer the question: “Does intrawound vancomycin powder reduce the rate of SSIs in spine surgery?” Methods A comprehensive search of multiple electronic databases and bibliographies was conducted to identify clinical studies that evaluated the rates of SSI with and without the use of intrawound vancomycin powder in spine surgery. Independent reviewers extracted data and graded the quality of each paper that met inclusion criteria. A random effects meta-analysis was then performed. Results The search identified 9 retrospective cohort studies (Level III evidence) and 1 randomized controlled trial (Level II evidence). There were 2574 cases and 106 infections in the control group (4.1%) and 2518 cases and 33 infections (1.3%) in the treatment group, yielding a pooled absolute risk reduction and relative risk reduction of 2.8% and 68%, respectively. The meta-analysis revealed the use of vancomycin powder to be protective in preventing SSI (relative risk = 0.34, 95% confidence interval 0.17–0.66, p = 0.021). The number needed to treat to prevent 1 SSI was 36. A subgroup analysis found that patients who had implants had a reduced risk of SSI with vancomycin powder (p = 0.023), compared with those who had noninstrumented spinal operations (p = 0.226). Conclusions This meta-analysis suggests that the use of vancomycin powder may be protective against SSI in open spinal surgery; however, the exact population in which it should be used is not clear. This benefit may be most appreciated in higher-risk populations or in facilities with a high baseline rate of infection.

Background: The perioperative diagnosis of infection in the setting of revision elbow arthroplasty may be difficult to establish. Intraoperative pathology with histology for identification of acute inflammatory changes has been reported to be of value in revision surgery after failed hip or knee arthroplasty. The purpose of this study was to study the role of intraoperative histology in the diagnosis of infection in patients undergoing revision elbow arthroplasty. Methods: From 2000 to 2007, 296 consecutive revision elbow procedures were performed at our institution. Both intraoperative histology and operative samples for culture were obtained at the time of 227 of these procedures, which form the basis of this study. Results: Histology was read as consistent with acute inflammation in patients undergoing thirty-three procedures (14.5%). Intraoperative cultures were positive in thirty-nine procedures (17.2%). Intraoperative histology was considered true positive (both histology and cultures positive) in twenty arthroplasties (8.8%), true negative (both histology and cultures were negative) in 175 arthroplasties (77.1%), false positive (the histology was positive but the culture was negative) in thirteen arthroplasties (5.7%), and false negative (the histology was negative but the culture was positive) in nineteen arthroplasties (8.4%). With regard to intraoperative histology, the sensitivity was 51.3%, the specificity was 93.1%, and the accuracy was 85.9%. The positive predictive value was 60.6% and the negative predictive value was 90.2%. Conclusions: In our study, intraoperative histology had a high specificity and negative predictive value, but a low sensitivity and positive predictive value for predicting infection in the setting of revision elbow arthroplasty. Intraoperative histology should be used in conjunction with other studies to definitively establish the diagnosis of infection in the setting of revision elbow arthroplasty.

Abstract These guidelines are intended for use by infectious disease specialists, orthopedists, and other healthcare professionals who care for patients with prosthetic joint infection (PJI). They include evidence-based and opinion-based recommendations for the diagnosis and management of patients with PJI treated with debridement and retention of the prosthesis, resection arthroplasty with or without subsequent staged reimplantation, 1-stage reimplantation, and amputation.

Study Design. Retrospective analysis. Objective. The objective of this study was to describe the microbiology of surgical site infection (SSI) in spine surgery and relationship with surgical management characteristics. Summary of Background Data. SSI is an important complication of spine surgery that results in significant morbidity. A comprehensive and contemporary understanding of the microbiology of postoperative spine infections is valuable to direct empiric antimicrobial treatment and prophylaxis and other infection prevention strategies. Methods. All cases of spinal surgery associated with SSI between July 2005 and November 2010 were identified by the hospital infection control surveillance program using Centers for Disease Control National Health Safety Network criteria. Surgical characteristics and microbiologic data for each case were gathered by direct medical record review. Results. Of 7529 operative spine cases performed between July 2005 and November 2010, 239 cases of SSI were identified. The most commonly isolated pathogen was Staphylococcus aureus (45.2%), followed by Staphylococcus epidermidis (31.4%). Methicillin-resistant organisms accounted for 34.3% of all SSIs and were more common in revision than in primary surgical procedures (47.4% vs. 28.0%, P = 0.003). Gram-negative organisms were identified in 30.5% of the cases. Spine surgical procedures involving the sacrum were significantly associated with gram-negative organisms (P < 0.001) and polymicrobial infections (P = 0.020). Infections due to gram-negative organisms (P = 0.002) and Enterococcus spp. (P = 0.038) were less common in surgical procedures involving the cervical spine. Cefazolin-resistant gram-negative organisms accounted for 61.6% of all gram-negative infections and 18.8% of all SSIs. Conclusion. Although gram-positive organisms predominated, gram-negative organisms accounted for a sizeable portion of SSI, particularly among lower lumbar and sacral spine surgical procedures. Nearly half of infections in revision surgery were due to a methicillin-resistant organism. These findings may help guide choice of empiric antibiotics while awaiting culture data and antimicrobial prophylaxis strategies in specific spine surgical procedures.

Negative culture result is frequently encountered in periprosthetic joint infection, but its clinical feature has not been well studied. In this study, clinical characteristics and treatment outcome were compared in two patient groups: (1) 40 periprosthetic joint infections with negative culture results (culture-negative group) and (2) 135 patients with positive culture results (culture-positive group). In comparison of two groups, the culture-negative group showed significantly higher incidence of prior antibiotic use (p = 0.005), higher incidence of prior resection surgery (p < 0.001) and lower ESR (p = 0.02) than the culture-positive group. The success rate of infection control was higher in the culture-negative group (p = 0.006), which suggests that culture negativity may not necessarily be a negative prognostic factor for periprosthetic joint infection.

This study evaluates the long-term survival of spinal implants after surgical site infection (SSI) and the risk factors associated with treatment failure. A Kaplan-Meier survival analysis was carried out on 43 patients who had undergone a posterior spinal fusion with instrumentation between January 2006 and December 2008, and who consecutively developed an acute deep surgical site infection. All were appropriately treated by surgical debridement with a tailored antibiotic program based on culture results for a minimum of eight weeks. A ‘terminal event’ or failure of treatment was defined as implant removal or death related to the SSI. The mean follow-up was 26 months (1.03 to 50.9). A total of ten patients (23.3%) had a terminal event. The rate of survival after the first debridement was 90.7% (95% confidence interval (CI) 82.95 to 98.24) at six months, 85.4% (95% CI 74.64 to 96.18) at one year, and 73.2% (95% CI 58.70 to 87.78) at two, three and four years. Four of nine patients required re-instrumentation after implant removal, and two of the four had a recurrent infection at the surgical site. There was one recurrence after implant removal without re-instrumentation. Multivariate analysis revealed a significant risk of treatment failure in patients who developed sepsis (hazard ratio (HR) 12.5 (95% confidence interval (CI) 2.6 to 59.9); p < 0.001) or who had > three fused segments (HR 4.5 (95% CI 1.25 to 24.05); p = 0.03). Implant survival is seriously compromised even after properly treated surgical site infection, but progressively decreases over the first 24 months. Cite this article: Bone Joint J 2013;95-B:1121–6.

Background: An intraoperative culture sample obtained during revision elbow arthroplasty that is unexpectedly positive poses a dilemma for the surgeon. The purpose of our study was to determine the prevalence of positive cultures during revision elbow arthroplasty when infection is not suspected preoperatively, and the long-term implications of these positive cultures. Methods: Two hundred and thirteen consecutive revision elbow arthroplasties were performed at our institution between 2000 and 2007. Of these, sixteen patients had unexpected positive intraoperative cultures. Results: The majority of cultures grew either Staphylococcus epidermidis or Propionibacterium acnes. Twelve patients had more than two years of follow-up. One of the twelve patients was treated as for an infection because of unexplained early implant loosening and the isolation of Staphylococcus epidermidis. Ten of the twelve elbows were treated as “contaminants” and did not receive long-term antibiotic treatment. Nine of these ten remained infection-free at the time of the final follow-up, while the remaining one developed an infection with a different organism. Conclusions: In our series, there was a 7.5% chance of encountering an unexpected positive result on intraoperative culture at the time of revision elbow arthroplasty. The majority of patients were successfully treated without antibiotics with a low rate of failure. A minority were considered as infections, typically presenting with unexplained early loosening and isolation of an organism on solid culture medium.

BACKGROUND: Up to 2% of THAs are complicated by infection, leading to dissatisfied patients with poor function and major social and economic consequences. The challenges are control of infection, restoration of full function, and prevention of recurrence. Irrigation and débridement with or without exchange of modular components remains an attractive alternative to two-stage reimplantation in acutely infected THAs but with variable results from previous studies. QUESTIONS/PURPOSES: We therefore determined the rate at which aggressive early débridement with exchange of modular components controlled acutely infected cemented THAs. METHODS: We retrospectively studied all 26 patients presenting with acutely infected cemented THAs (16 primaries, 10 revisions) occurring within 6 weeks of the index operation or of hematogenous spread from a confirmed source of infection elsewhere between 1999 and 2006. Microbiology confirmed bacterial colonization in all patients, with 18 early postoperative infections and eight acute hematogenous infections. Patients underwent aggressive débridement with open complete synovectomy, exchange of all mobile parts, débridement of all aspects of the joint, irrigation with antiseptic solutions, and pulsatile lavage. Minimum followup was 5 years (mean, 6.6 years; range, 5-11 years). RESULTS: Eight patients had multiple washouts with control of infection in four at latest followup. Five patients underwent two-stage revisions and one patient was placed on long-term antibiotic suppression. Twenty patients returned to their expected functional level with no radiographic evidence of prosthetic failure. At minimum 5-year followup, we had a 77% infection control rate. CONCLUSIONS: Our data confirm current literature and suggest there may be a role for aggressive early débridement in controlling acute postoperative and hematogenous infections after cemented THA. LEVEL OF EVIDENCE: Level IV, therapeutic study. See Instructions for Authors for a complete description of levels of evidence.