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.