Infecting microorganism is a strong predictor of treatment success for periprosthetic joint infection (PJI). The purpose of this study was to compare the infecting pathogens causing PJI at two large infection referral centers in the United States and in Europe. In this study, 898 consecutive cases of PJI were identified at the HELIOS ENDO-Klinik Hamburg in Europe and 772 cases were identified at the Rothman Institute in the United States. The incidence of organisms at the HELIOS ENDO-Klinik Hamburg versus the Rothman Institute was: coagulase-negative Staphylococcus (39.3 vs. 20.2%), S. aureus (13.0 vs. 31.0%), Streptococcus (6.5 vs. 5.8%), Enterococcus (7.0 vs. 3.9%), anaerobic (9.0 vs. 0.9%), fungal (0.3 vs. 2.3%), mycobacterial (0 vs. 0.6%), polymicrobial (3.4 vs. 7.4%), culture negative (16.1 vs. 15.8%), and other organisms (0.9 vs. 5.4%). The percentage of methicillin-resistant S. aureus was significantly higher at the American center than at the European center (48.1 vs. 12.8%; p < 0.0001). Our findings show higher virulence and resistance organisms are more prevalent at a referral center in the United States compared with one in Europe.

Aims: A variety of surgical approaches are used for total hip arthroplasty (THA), all with reported advantages and disadvantages. A number of common complications can occur following THA regardless of the approach used. The purpose of this study was to compare five commonly used surgical approaches with respect to the incidence of surgery-related complications. Patients and Methods: The electronic medical records of all patients who underwent primary elective THA at a single large-volume arthroplasty centre, between 2011 and 2016, with at least two years of follow-up, were reviewed. After exclusion, 3574 consecutive patients were included in the study. There were 1571 men (44.0%) and 2003 women (56.0%). Their mean age and body mass index (BMI) was 63.0 years (sd 11.8) and 29.1 kg/m² (sd 6.1), respectively. Data gathered included the age of the patient, BMI, the American Society of Anesthesiologists (ASA) score, estimated blood loss (EBL), length of stay (LOS), operating time, the presence of intra- or postoperative complications, type of complication, and the surgical approach. The approaches used during the study were posterior, anterior, direct lateral, anterolateral, and the northern approach. The complications that were recorded included prolonged wound drainage without infection, superficial infection, deep infection, dislocation, aseptic loosening, and periprosthetic fracture. Finally, the need for re-operation was recorded. Means were compared using analysis of variance (ANOVA) and Student’s t-tests where appropriate and proportions were compared using the chi-squared test. Results: A total of 248 patients had 263 complications related to the surgery, with an incidence of 6.94%. The anterior approach had the highest incidence of complications (8.5% (113/1329)) and the posterior approach had the lowest, at 5.85% (97/1657; p = 0.006). Most complications were due to deep infection (22.8%), periprosthetic fracture (22.4%), and prolonged wound drainage (21.3%). The rate of dislocation was 0.84% (14/1657) with the posterior approach and 1.28% (17/1329) with the anterior approach (p = 0.32). Conclusion: Overall, THA has a relatively low complication rate. However, the surgical approach plays a role in the incidence of complications. We found that the posterior approach had a significantly lower overall complication rate compared with the anterior approach, with an equal dislocation rate. Periprosthetic fracture and surgical site infection contributed most to the early complication rates. Cite this article: Bone Joint J 2019;101-B:646–651

While it is accepted accurate identification of infecting organisms is crucial in guiding treatment of periprosthetic joint infection (PJI), there remains no consensus regarding the best method for obtaining cultures. We compared the yield of intraoperative tissue samples versus swab cultures in diagnosing PJI. Tissue and swab cultures (three each) were collected prospectively during a consecutive series of 156 aseptic and septic revision arthroplasties from October 2011 to April 2012. The tissues and swabs were taken from standardized regions of the joint. After excluding 39 reimplantation procedures, we included 117 cases (74 hip, 43 knee; 30 septic, 87 aseptic) for analysis. We used a modified version of the Musculoskeletal Infection Society criteria for defining PJI, requiring three of five rather than four of six criteria. Tissue and swab cultures from septic and aseptic cases were used to calculate their sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) for identifying PJI. Tissue cultures were positive in a higher percentage of septic cases than swab cultures: 28 of 30 (93%) versus 21 of 30 (70%). Tissue cultures were positive in two of 87 aseptic cases (2%), while swab cultures were positive in 10 of 87 (12%). The sensitivity, specificity, PPV, and NPV were 93%, 98%, 93%, and 98%, respectively, for tissue cultures and 70%, 89%, 68%, and 90%, respectively, for swab cultures. Tissue cultures demonstrated higher sensitivity, specificity, PPV, and NPV for diagnosing PJI than swab cultures. Swab cultures had more false-negative and false-positive results than tissue cultures. Because swab cultures pose a higher risk of not identifying or incorrectly identifying infecting organisms in PJI, we believe their use in obtaining intraoperative culture specimens should be discouraged. Level II, diagnostic study. See Guidelines for Authors for a complete description of levels of evidence.

Objectives: To examine one health system's response to the essential care of its hip fracture population during the COVID-19 pandemic and report on its effect on patient outcomes. Design: Prospective cohort study. Setting: Seven musculoskeletal care centers within New York City and Long Island. Patients/Participants: One hundred thirty-eight recent and 115 historical hip fracture patients. Intervention: Patients with hip fractures occurring between February 1, 2020, and April 15, 2020, or between February 1, 2019, and April 15, 2019, were prospectively enrolled in an orthopaedic trauma registry and chart reviewed for demographic and hospital quality measures. Patients with recent hip fractures were identified as COVID positive (C+), COVID suspected (Cs), or COVID negative (C−). Main Outcome Measurements: Hospital quality measures, inpatient complications, and mortality rates. Results: Seventeen (12.2%) patients were confirmed C+ by testing, and another 14 (10.1%) were suspected (Cs) of having had the virus but were never tested. The C+ cohort, when compared with Cs and C− cohorts, had an increased mortality rate (35.3% vs. 7.1% vs. 0.9%), increased length of hospital stay, a greater major complication rate, and a greater incidence of ventilator need postoperatively. Conclusions: COVID-19 had a devastating effect on the care of patients with hip fracture during the pandemic. Although practice patterns generally remained unchanged, treating physicians need to understand the increased morbidity and mortality in patients with hip fracture complicated by COVID-19. Level of Evidence: Prognostic Level III. See Instructions for Authors for a complete description of Levels of Evidence.

Periprosthetic joint infection (PJI) is one of the most devastating and costly complications following total joint arthroplasty (TJA). Diagnosis and management of PJI is challenging for surgeons. There is no "gold standard" for diagnosis of PJI, making distinction between septic and aseptic failures difficult. Additionally, some of the greatest difficulties and controversies involve choosing the optimal method to treat the infected joint. Currently, there is significant debate as to the ideal treatment strategy for PJI, and this has led to considerable international variation in both surgical and nonsurgical management of PJI. In this review, we will discuss diagnosis and management of PJI following TJA and highlight some recent advances in this field.

Background: The volume of total knee arthroplasties, including revisions, in young patients is expected to rise. The objective of this study was to compare the reasons for revision and re-revision total knee arthroplasties between younger and older patients, to determine the survivorship of revision total knee arthroplasties, and to identify risk factors associated with failure of revision in patients fifty years of age or younger. Methods: Perioperative data were collected for all total knee arthroplasty revisions performed from August 1999 to December 2009. A cohort of eighty-four patients who were fifty years of age or younger and a cohort of eighty-four patients who were sixty to seventy years of age were matched for the date of surgery, sex, and body mass index (BMI). The etiology of failure of the index total knee arthroplasty and all subsequent revision total knee arthroplasties was determined. Kaplan-Meier survival curves were used to evaluate the timing of the primary failure and the survivorship of revision knee procedures. Finally, multivariate Cox regression was used to calculate risk ratios for the influence of age, sex, BMI, and the reason for the initial revision on survival of the revision total knee arthroplasty. Results: The most common reason for the initial revision was aseptic loosening (27%; 95% confidence interval [CI] = 19% to 38%) in the younger cohort and infection (30%; 95% CI = 21% to 40%) in the older cohort. Of the twenty-five second revisions in younger patients, 32% (95% CI = 17% to 52%) were for infection, whereas 50% (95% CI = 32% to 68%) of the twenty-six second revisions in the older cohort were for infection. Cumulative six-year survival rates were 71.0% (95% CI = 60.7% to 83.0%) and 66.1% (95% CI = 54.5% to 80.2%) for revisions in the younger and older cohorts, respectively. Infection and a BMI of ≥40 kg/m2 posed the greatest risk of failure of revision procedures, with risk ratios of 2.731 (p = 0.006) and 2.934 (p = 0.009), respectively. Conclusions: The survivorship of knee revisions in younger patients is a cause of concern, and the higher rates of aseptic failure in these patients may be related to unique demands that they place on the reconstruction. Improvement in implant fixation and treatment of infection when these patients undergo revision total knee arthroplasty is needed. Level of Evidence: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.