Culture-positive (CP) and culture-negative (CN) periprosthetic joint infections (PJI) remain a crucial area of research; however, current studies comparing these infections rely on unstandardized outcome reporting tools. Our study aimed to compare the outcomes of two-stage revision of CP and CN PJI using the standardized Musculoskeletal Infection Society (MSIS) outcome reporting tool. We retrospectively reviewed 138 patients who were diagnosed with PJI and indicated for two-stage revision total knee arthroplasty (rTKA). The majority of patients in both CP and CN cohorts achieved infection control without the need for reoperation (54.1% and 62.5%, respectively). There was a significant difference in the overall distribution of MSIS outcomes (p = 0.043), with a significantly greater rate of CN patients falling into Tier 1 (infection control without the use of suppressive antibiotics) (52.5% versus 29.6%, p = 0.011). There was also a significant difference in the distribution of septic versus aseptic reoperations after 2nd stage (p = 0.013), with more CP reoperations being septic and more CN reoperations being aseptic. The duration from first to second stage was significantly shorter in the CN cohort (p = 0.002). While overall infection control was similar between cohorts, these data suggest that the outcomes of two-stage rTKA are favorable in cases of CN PJI.

The efficacy of “Expanded Gram-Negative Antimicrobial Prophylaxis” (EGNAP) in preventing postoperative infections has been previously reported in total hip arthroplasty (THA). However, it remains unclear as to whether these benefits extend to total knee arthroplasty (TKA). This study investigated whether adding EGNAP to our institution’s preoperative antibiotic prophylaxis protocol would affect periprosthetic joint infection (PJI) risk in TKA patients. We retrospectively reviewed 10,666 elective, unilateral, primary TKA cases performed at a single-specialty tertiary academic hospital from 2018 to 2022. Before June 2021, all patients received 2 g of cefazolin for 24 h as part of the prophylactic antibiotic protocol. After June 2021, gentamicin or aztreonam (EGNAP) was added to the protocol for all TKA patients. Patients were grouped based on whether they received EGNAP or not (control group) before surgery. The groups were propensity score-matched in a 2:1 ratio. PJI and nephrotoxicity (using RIFLE criteria) risk was compared. After matching, the final study population consisted of 3007 patients in the non-EGNAP group and 1503 patients in the EGNAP group. There was no significant difference between the EGNAP and no EGNAP groups in the overall incidence of PJI (1.9% vs. 2.0%; p = 0.111) or the incidence of Gram-positive PJIs (0.3% vs. 0.8%; p = 0.103). The incidence of Gram-negative PJIs was 0.5% in the EGNAP group and 0.4% in the no EGNAP group, which was also not different between the groups (p = 0.692). There were no differences in nephrotoxicity between groups (p = 0.521). The addition of EGNAP to the antibiotic prophylactic protocol prior to TKA had no effect on overall or Gram-negative PJI risk in TKA patients. The findings of this study suggest that while EGNAP is safe to use and has minimal nephrotoxic effects, its prophylactic benefits do not extend to the primary TKA population. This may be attributed to the generally low rate of Gram-negative infections in TKA patients, where adding EGNAP does not provide a clear advantage in reducing the risk of such infections, unlike its potential benefits in primary THA population. This study investigates the effects of using prophylactic Gram-negative antibiotics prior to TKA and shows that though it is safe to use, Gram-negative bacterial coverage may have no impact on postoperative infection incidence.

Culture-positive (CP) and culture-negative (CN) periprosthetic joint infections (PJI) remain a crucial area of research; however, current studies comparing these infections rely on unstandardized outcome reporting tools. Our study aimed to compare the outcomes of CP and CN PJI using the standardized Musculoskeletal Infection Society (MSIS) outcome reporting tool. We retrospectively reviewed 138 patients who were diagnosed with PJI and indicated for two-stage revision total knee arthroplasty (rTKA). The majority of patients in both CP and CN cohorts achieved infection control without the need for reoperation (54.1% and 62.5%, respectively). There was a significant difference in the overall distribution of MSIS outcomes (p=0.043), with a significantly greater rate of CN patients falling into Tier 1 (infection control without the use of suppressive antibiotics) (52.5% versus 29.6%, p=0.011). There was also a significant difference in the distribution of septic versus aseptic reoperations after 2nd stage (p=0.013), with more CP reoperations being septic and more CN reoperations being aseptic. The duration from 1st to 2nd stage was significantly shorter in the CN cohort (p=0.002). While overall infection control was similar between cohorts, these data suggest that the outcomes of two-stage rTKA are favorable in cases of CN PJI.

Though opioids can be very effective for postoperative pain management after revision total hip arthroplasty (rTHA), many physicians have made an effort to decrease usage of these medications by focusing on alternative pain management strategies to reduce opioid dependence and unwanted side effects. This study sought to investigate trends in opioid consumption during hospitalization following rTHA from 2016 to 2021. We retrospectively reviewed all patients who received rTHA from January 2016 to April 2021. Baseline demographic variables including age, gender, race, body mass index, and American Society of Anesthesiologists classification were recorded. Additional information including patient-reported outcome measures (PROMs), postoperative outcomes, dosage, and type of opioid medication prescribed postoperatively were also collected. Opioid dosage and type were converted to milligram morphine equivalents (MMEs) per day of hospitalization and compared across the 6 years studied. Linear regression as well as t-tests were utilized to determine significant trends in MME consumption over time. In total, 1,096 patients met inclusion and exclusion criteria. The greatest daily average opioid consumption per patient was in 2017 (61.6 ± 155.4 MME per day) and the lowest was in 2021 (31.8 ± 105.8 MME per day). Linear regression analysis detected a downward trend of 4.97 MME per day each year, though these results were not statistically significant (R ²: 0.444, p = 0.089). t-Test analysis, however, did reveal a significant decrease in opioid consumption in the postprotocol cohort (38.41 ± 90.5 vs. 52.18 ± 120.2; p = 0.034). There was a significant increase in preoperative Hip Disability and Osteoarthritis Outcome Score, Joint Replacement scores (p = 0.007) over time as well as a significant decrease in preoperative visual analog scale pain scores (p = 0.012). The results of this study show that opioid consumption in 2021 was lower than in 2016 and 2017. This result emphasizes the effectiveness of protocols limiting opioid usage during hospitalization following rTHA. Moreover, the relatively consistent patient-reported outcome scores over time demonstrate that this decrease in opioid consumption per year does not impact patient-reported outcomes and satisfaction. Received: 04 October 2022 Accepted: 17 November 2023 Article published online: 19 January 2024 © 2024. Thieme. All rights reserved. Thieme Medical Publishers, Inc. 333 Seventh Avenue, 18th Floor, New York, NY 10001, USA