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.

Study design: Retrospective review of a prospectively collected database. Objective: Our objective was to assess the rates of postoperative wound infection associated with spine surgery. Summary of background data: Although wound infection after spine surgery remains a common source of morbidity, estimates of its rates of occurrence remain relatively limited. The Scoliosis Research Society prospectively collects morbidity and mortality data from its members, including the occurrence of wound infection. Methods: The Scoliosis Research Society morbidity and mortality database was queried for all reported spine surgery cases from 2004 to 2007. Cases were stratified based on factors including diagnosis, adult (≥ 21 years) versus pediatric (<21 years), primary versus revision, use of implants, and whether a minimally invasive approach was used. Superficial, deep, and total infection rates were calculated. RESULTS.: In total, 108,419 cases were identified, with an overall total infection rate of 2.1% (superficial = 0.8%, deep = 1.3%). Based on primary diagnosis, total postoperative wound infection rate for adults ranged from 1.4% for degenerative disease to 4.2% for kyphosis. Postoperative wound infection rates for pediatric patients ranged from 0.9% for degenerative disease to 5.4% for kyphosis. Rate of infection was further stratified based on subtype of degenerative disease, type of scoliosis, and type of kyphosis for both adult and pediatric patients. Factors associated with increased rate of infection included revision surgery (P < 0.001), performance of spinal fusion (P < 0.001), and use of implants (P < 0.001). Compared with a traditional open approach, use of a minimally invasive approach was associated with a lower rate of infection for lumbar discectomy (0.4% vs. 1.1%; P < 0.001) and for transforaminal lumbar interbody fusion (1.3% vs. 2.9%; P = 0.005). Conclusion: Our data suggest that postsurgical infection, even among skilled spine surgeons, is an inherent potential complication. These data provide general benchmarks of infection rates as a basis for ongoing efforts to improve safety of care.

Background Clinical characteristics and control of the infection of patients with culture-negative (CN) prosthetic joint infection (PJI) have not been well assessed. Prior use of antimicrobial therapy has been speculated but not proven as a risk factor for CNPJI. Questions/purposes We therefore determined whether prior use of antimicrobial therapy, prior PJI, and postoperative wound healing complications were associated with CN PJI. Methods We performed a retrospective case-control study of 135 patients with CN PJI treated between January 1, 1985, and December 31, 2000 matched with 135 patients with culture-positive (CP) PJIs (control patients) during the study period. The time to failure of therapy compared between cases and control patients using a Kaplan-Meier analysis. Results The use of prior antimicrobial therapy and postoperative wound drainage after index arthroplasty were associated with increased odds of PJI being culture-negative (odds ratio, 4.7; 95% CI, 2.8-8.1 and odds ratio, 3.5; 95% CI, 1.5-8.1, respectively). The percent (± SE) cumulative incidence free of treatment failure at 2 years followup was similar for CN and CP PJI: 75% (± 4%) and 79% (± 4%), respectively. Conclusions Prior antimicrobial therapy and postoperative wound drainage were associated with an increased risk of negative cultures among patients with PJI. Physicians should critically evaluate the need for antimicrobial therapy before establishing a microbiologic diagnosis of PJI in patients with suspected PJI.

Eradicating poverty is one of the highest priorities of development policies. Besides the necessary improvement of peoples livelihoods, the reduction of poverty is believed to have a positive effect on the stability of the rainforest margins. Better-off households are furthermore less vulnerable to shocks caused by natural hazards.