In an effort to improve mobility and alleviate pain from degenerative and connective tissue joint disease, an increasing number of individuals are undergoing prosthetic joint replacement in the United States. Joint replacement is a highly effective intervention, resulting in improved quality of life and increased independence [1]. By 2030, it is predicted that approximately 4 million total hip and knee arthroplasties will be performed yearly in the United States [2]. One of the major complications associated with this procedure is prosthetic joint infection (PJI), occurring at a rate of 1-2% [3-7]. In 2011, the Musculoskeletal Infectious Society created a unifying definition for prosthetic joint infection [8]. The following year, the Infectious Disease Society of America published practice guidelines that focused on the diagnosis and management of PJI. These guidelines focused on the management of commonly encountered organisms associated with PJI, including staphylococci, streptococci and select aerobic Gram-negative bacteria. However, with the exception of Propionibacterium acnes, management of other anaerobic organisms was not addressed in these guidelines [1]. Although making up approximately 3-6% of PJI [9,10], anaerobic microorganisms cause devastating complications, and similar to the more common organisms associated with PJI, these bacteria also result in significant morbidity, poor outcomes and increased health-care costs. Data on diagnosis and management of anaerobic PJI is mostly derived from case reports, along with a few cohort studies [3]. There is a paucity of published data outlining factors associated with risks, diagnosis and management of anaerobic PJI. We therefore reviewed available literature on anaerobic PJI by systematically searching the PubMed database, and collected data from secondary searches to determine information on pathogenesis, demographic data, clinical features, diagnosis and management. We focused our search on five commonly encountered anaerobic organisms associated with PJI. Since anaerobic PJI has also been linked to dental procedures, we also reviewed information on the use of dental procedures and prophylaxis, when available.

This study aims to identify the long-term outcomes of total knee arthroplasty (TKA) treated for deep infection. 3270 consecutive primary and 175 revision TKAs were followed prospectively. There were 39 deep infections (1.16%): 29 primary (0.9%) and 10 revision (5.7%) cases. Two-stage resection and re-implantation procedure was performed in 13 primary cases with 10/13 (77%) successfully resolved. Early (<1 month) Irrigation and Debridement (I&D) was performed in 16 primary cases with 100% success. Late (>4 months) I&D was performed in 6 cases with 5/6 (83.3%) successful. Infection following revision TKA resulted in poor outcomes with both two-stage (2/4 successful) and I&D (2/6 successful). Deep infection after primary TKA can be successfully resolved with I&D and appropriate antibiotic treatment in the early postoperative course.

Background. The purpose of this study was to determine the risk of prosthetic joint infection (PJI) as a complication of routine genitourinary (GU) procedures in patients with total hip arthroplasty (THA) or total knee arthroplasty (TKA) and to study the impact of antibiotic prophylaxis administered prior to these procedures. Methods. We conducted a prospective, single-center, case-control study between December 1, 2001 and May 31, 2006. Case patients were hospitalized with total hip or knee PJI. Control subjects underwent a THA or TKA and were hospitalized during the same period on the same orthopedic floor without a PJI. Data regarding demographic features and potential risk factors were collected. The outcome measure was the odds ratio (OR) of PJI after GU procedures performed within 2 years of admission. Results. A total of 339 case patients and 339 control subjects were enrolled in the study. Of these, 52 cases (15%) and 55 controls (16%) had undergone a GU procedure in the preceding 2 years. There was no increased risk of PJI for patients undergoing a GU procedure with or without antibiotic prophylaxis (adjusted OR [aOR] = 1.0, 95% confidence interval [CI] = 0.2–4.5, P = .95 and aOR = 1.0, 95% CI = 0.6–1.7, P = .99, respectively). Results were similar in a subset of patients with a joint age less than 6 months, less than 1 year, or greater than 1 year. Conclusions. Genitourinary procedures were not risk factors for subsequent PJI. The use of antibiotic prophylaxis before GU procedures did not decrease the risk of subsequent PJI in our study.

Background. Prosthetic joint infections (PJIs) significantly complicate joint arthroplasties. Propionibacterium acnes is an increasingly recognized PJI pathogen, yet limited clinical and therapeutic data exist. We sought to examine characteristics of P. acnes shoulder PJIs and compare surgical and nonsurgical management outcomes. Methods. A retrospective analysis of P. acnes shoulder PJIs was conducted at an academic center in Baltimore, Maryland from 2000 to 2013. Results. Of 24 cases of P. acnes shoulder PJIs, 92% were diagnosed after extended culture implementation; 42% in the delayed and 46% in the late postsurgical period. Joint pain and diminished function were the predominant presenting clinical signs. Erythrocyte sedimentation rate and C-reactive protein elevations occurred in 47% and 44%, respectively. All tested isolates were susceptible to β-lactams, moxifloxacin, vancomycin, and rifampin. Clindamycin resistance was identified in 6%. Of the antibiotic-only treated cases, 67% had a favorable clinical outcome compared with 71% (P = 1.0) of cases with a combined antibiotic-surgical approach. Favorable outcome with and without rifampin therapy was 73% and 60% (P = .61), respectively. Conclusions. Propionibacterium acnes PJI diagnoses increased with extended culture. Inflammatory markers were elevated in a minority of cases. Isolates maintained broad antimicrobial susceptibility. Compared to combined antibiotic-surgical approaches, antibiotic-only approaches were similarly successful in selected cases.

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.

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.