Unexpected positive cultures in revision total knee arthroplasty after unicompartmental knee arthroplasty.

PURPOSE: Unexpected positive cultures are defined as a single positive culture in intraoperative samples taken during revision surgery after prosthetic joint infection was preoperatively ruled out. This study aims to determine the prevalence of unexpected positive cultures (UPC) in revision total knee arthroplasty (TKA) after unicompartmental knee arthroplasty (UKA). As a secondary objective, this study aims to compare the re-intervention rate in this specific group, between UPC and non-UPC patients. The hypothesis is that the UPC prevalence in patients who undergo a revision TKA after UKA is not higher than in other TKA revision cases and this does not increase the risk of re-intervention. METHODS: This is a retrospective study where all patients who underwent a UKA revision from January 2016 to February 2023 in a high-volume arthroplasty centre, were analyzed. Unexpected positive culture prevalence in this group of patients was obtained. RESULTS: During the included period, 270 UKA revision surgeries were performed. Eight cases had at least two positive cultures and were therefore excluded. The final analysis included 262 patients. Of these, 8 (3.05%) patients presented UPCs and the isolated microorganisms were low-virulence organisms. None of the UPC patients received any treatment. No statistical differences were found between UPC and non-UPC groups in the analyzed variables. CONCLUSION: The prevalence of unexpected positive cultures in patients following revision of unicompartmental knee arthroplasty is lower than in patients who undergo a revision of total knee arthroplasty. In UKA patients a UPC does not seem to increase the risk of a re-intervention, so it can be safely ignored if ICM criteria are not met.

Unexpected positive cultures in patients with arthrofibrosis following total hip and total knee arthroplasty.

PURPOSE: It has been suggested that low-grade infections could be the cause of arthrofibrosis. However, this hypothesis has not been conclusively proven. The aim of this study is to assess the incidence of unexpected positive cultures (UPC) in patients undergoing revision total joint arthroplasty for a diagnosis of arthrofibrosis. METHODS: A retrospective single-centre review was performed. All patients who underwent an aseptic revision due to histologically confirmed arthrofibrosis (based on the synovial-like interface membrane (SLIM) criteria) were included. The incidence of UPC was then calculated. RESULTS: A total of 147 patients were included. Of these, 100 underwent a total knee arthroplasty (TKA) procedure and 46 a total hip arthroplasty (THA) surgery. One patient had a periprosthetic joint infection and was therefore excluded. Of the 146 included patients, 6 had confirmed UPC (4.08%). The following bacteria were identified: Anaerococcus octavius, Staphylococcus epidermidis, Enterobacter cloacae, Staphylococcus hominis, Streptococcus pluranimalium, Staphylococcus pettenkoferi. CONCLUSIONS: Our results suggest that the incidence of UPC in patients with arthrofibrosis is low. It is lower than that of UPC in patients that undergo a revision for other causes. There is no proven relationship between histologically confirmed arthrofibrosis following total joint arthroplasty and prosthetic joint infection.

A secure blood-saving protocol for Jehovah's Witnesses in primary total hip replacement.

OBJECTIVES: The study aimed to analyze the efficacy of the blood management protocol developed by our team for patients who are Jehovah's Witnesses (JW) presenting for primary total hip replacement (THR). PATIENTS AND METHODS: Thirty JW patients (6 males, 24 females; mean age: 70.1±9.8 years; range, 65 to 81 years) and 30 age- and sex-matched controls (6 males, 24 females; mean age: 68.7±9.1 years; range, 62 to 79 years) who underwent primary THR at our institution between January 2018 and June 2020 were retrospectively evaluated. While the surgical technique of THR was not different among the groups, blood loss management differed between the groups. Patients in the control group were given 1 g of intravenous tranexamic acid (TXA) 15 min before the surgical incision. In addition to the same TXA protocol, intraoperative cell salvage with a continuous autologous transfusion system was used for JW patients. The estimated blood loss (EBL) was determined using Meunier's formula. Hemoglobin (Hgb) decline, EBL on the first and third postoperative days, allogenic blood transfusion (ABT) requirement, and complications were analyzed between groups. RESULTS: There were no significant differences between groups regarding demographic and clinical characteristics (p>0.05), ABT requirement (p>0.999), and Hgb decline in the first and third postoperative days (p=0.540 and p=0.836, respectively). Furthermore, both groups did not significantly differ between EBL in the first and third postoperative days (p=0.396 and p=0.616, respectively) and the length of hospital stay (p=0.547). Similar complication rates were noted for both groups. Hemoglobin level assessments revealed that values on the first and third postoperative days were significantly lower than the baseline Hgb value in both cohorts (p<0.001). CONCLUSION: A combination of intravenous administration of 1 g of TXA, meticulous hemostasis, and intraoperative use of cell saver constitutes a reasonable strategy for achieving the goal of transfusion-free primary THR with predictable levels of blood loss that are similar to non-JW patients.

Disseminated Erysipelothrix rhusiopathiae with Secondary Prosthetic Hip Joint Infection: A Case of Successful Identification and Management in a Regional Hospital.

CASE: This article reports a case of a 72-year-old man with bilateral total hip joint replacements who suffered cuts to his hands while butchering a wild boar. He presented to the emergency department with fevers and unilateral hip pain. Erysipelothrix rhusiopathiae (E. rhusiopathiae) was isolated on hip aspirate and blood cultures. E. rhusiopathiae is a well-recognized zoonotic infection in humans, particularly in at-risk hosts, most commonly infecting swine. Infection is spread by ingestion or through skin abrasion. CONCLUSION: This illustrates an example of successful operative and perioperative management of prosthetic joint infection secondary to E. rhusiopathiae, particularly microbiological identification, within a multispecialty team of physicians and surgeons.

Defensive antibacterial coating in revision total hip arthroplasty: new concept and early experience.

BACKGROUND: Infections remains the most feared complication in total hip arthroplasty (THA). New strategies of PJI prevention includes coating of conventional implants. Defensive Antibacterial Coating (DAC), an antibacterial hydrogel coating made of hyaluronan, poly-D and L-lactide can protect biomaterials as an effective barrier at the time of implantation. In addition, it can be used with topical antibiotics to prevent early colonisation of the implant. SCOPE: This manuscript describes the detailed function of the DAC in general as well as an analysis of its use in revision THA in a series of 28 patients in a short-term follow-up.Its use in patients undergoing cementless re-implantation after 2-staged procedures in THA is described in detail within the manuscript. CONCLUSION: DAC found to be effective in terms of infection control and safety in our patient cohort and has been expanded for cementless 1-staged revisions in PJI of the hip in our institution.

Complication rates are low with the use of Stimulan calcium sulphate based antibiotic delivery system in the management of patients with hip-related PJI: early results of a consecutive case series.

BACKGROUND: Effective management of prosthetic joint infection (PJI) requires prolonged, sustained delivery of antibiotics to the effective joint space. Calcium sulphate antibiotic delivery systems have been used in this setting, however, potentially serious complications including symptomatic hypercalcaemia have been described. There is relatively little prospective data on the results with the use of these compounds. METHODS: A prospective study was performed between October 2016 and June 2018. 29 patients who underwent revision total hip arthroplasty (THA) for confirmed PJI were treated with Stimulan calcium sulphate antibiotic delivery system. Laboratory blood tests including serum calcium levels, C-reactive protein (CRP) and white cell count (WBC) were monitored for 6 weeks post-surgery. Wounds were assessed for discharge and radiographs for dissolution and for signs of heterotopic ossification. RESULTS: The mean age was 67 years and mean ASA score III. There was no significant increase between the preoperative serum calcium and those at 2 and 6 weeks. The CRP and white cell count were significantly reduced at 6 weeks. Full dissolution occurred by 6 weeks post-op. 1 patient (3.4%) had a prolonged wound discharge. CONCLUSIONS: Stimulan is a valid option for management of patients with PJI following total hip arthroplasty. Complication rates are low following its use.