Timing of debridement, antibiotics, and implant retention (DAIR) for early post-surgical hip and knee prosthetic joint infection (PJI) does not affect 1-year re-revision rates: data from the Dutch Arthroplasty Register

Diagnostics in Late Periprosthetic Infections-Challenges and Solutions

The rising number of arthroplasties is combined with a rising number of periprosthetic joint infections, which leads to life-concerning consequences for the patients, including extended antibiotic treatment, further surgery and increased mortality. The heterogeneity of the symptoms and inflammatory response of the patients due to, e.g., age and comorbidities and the absence of a single diagnostic test with 100% accuracy make it very challenging to choose the right parameters to confirm or deny a periprosthetic joint infection and to establish a standardized definition. In recent years, additional diagnostic possibilities have emerged primarily through the increasing availability of new diagnostic methods, such as genetic techniques. The aim of the review is to provide an overview of the current state of knowledge about the various tests, including the latest developments. The combination of different tests increases the accuracy of the diagnosis. Each physician or clinical department must select the tests from the available methods that can be best implemented for them in organizational and technical terms. Serological parameters and the cultivation of the samples from aspiration or biopsy should be combined with additional synovial tests to create an accurate figure for the failure of the prosthesis, while imaging procedures are used to obtain additional information for the planned therapeutic procedure.

Diagnosis and Management of Infected Total Ankle Replacements

As the number of primary total ankle replacements increases for treatment of end-stage ankle arthritis, failures are also expected to rise. Periprosthetic joint infection is among the causes of failures and has been reported to be as high as 5%. Diagnosis is usually made by a combination of clinical examination findings, imaging, laboratory, and microbiological workup. Management is generally separated into limb salvage or amputation. Limb salvage can be challenging and may involve a single versus staged approach. Options include revision arthroplasty or arthrodesis procedures (ankle versus tibiotalocalcaneal), and a multidisciplinary approach is sought to eradicate infection before definitive management.

DAIR in treating chronic PJI after total knee arthroplasty using continuous local antibiotic perfusion therapy: a case series study

BACKGROUND

Antimicrobial agents are administered via intramedullary antibiotic perfusion (iMAP)/intrasoft tissue antibiotic perfusion (iSAP) to infected lesions to control osteoarticular and soft tissue infections. Continuous local antibiotic perfusion (CLAP) has been reported to be useful. This study aimed to investigate the outcomes of DAIR combined with CLAP for chronic PJI after total knee arthroplasty performed at our hospital.

SUBJECTS AND METHODS

Six patients (male; one case, female; five cases, mean age 79.5 years (70-94)) underwent CLAP for chronic PJI after TKA at our hospital between July 2020 and June 2022. They were followable for at least one year after surgery. Seven months (17-219), with a mean follow-up of 24.3 months (12-36). In addition to direct debridement and insert exchange, systemic antimicrobial treatment, and CLAP with gentamicin were performed using NPWT. We investigated the organisms causing the inflammation, the duration of iMAP/iSAP implantation, the maximum daily dose of GM, the maximum GM blood concentration, and the presence or absence of GM-induced adverse events.

RESULT

Two of six patients had a recurrence of infection at five weeks and five months after initial CLAP and required repeat CLAP treatment, but all patients could preserve their components. The organisms responsible for the flare-ups were MSSA in three cases: ESBL-producing E. coli, mixed MSSA and streptococcal infection, Klebsiella pneumonia in one case each, and unknown pathogens in one case. CLAP therapy for all patients was administered eight times in 6 cases: iMAP, mean: 10.0 days (5-16); iSAP, mean: 19.3 days (15-28); GM dose, mean: 162.5 mg/day (80-240); and GM blood concentration, mean: 1.4 µg/mL (0.2-5.0). Adverse events included one case of reversible acute kidney injury during CLAP in a patient with recurrent infection. DAIR with CLAP for chronic post-TKA infection can be a useful treatment option to preserve components and allow the infection to subside, provided the implant is not markedly loosened.

Piezoelectric ultrasonic debridement as new tool for biofilm removal from orthopedic implants: A study in vitro

Pulse lavage (PL) debridement is the standard treatment used in Debridement, Antibiotics and Implant Retention (DAIR) for bacterial biofilm removal during acute and early postoperative cases of periprosthetic joint infection (PJI). The failure rate of DAIR is still high due to the inadequacy of PL in removing the biofilm. Ultrasound-based techniques are a well-established tool for PJI diagnosis due to their ability to completely eradicate the biofilm from implant surfaces. Hence, this study investigates the efficiency of a piezoelectric ultrasonic scalpel (PUS) in removing bacterial biofilm from different orthopedic implant materials in vitro and compares the results with PL. Biofilms of methicillin-resistant Staphylococcus aureus strains were grown on titanium alloy (Ti6Al4V ELI), stainless steel (AISI 316L), and ultrahigh molecular weight polyethylene (UHMWPE) disks for 24 h. The disks of each material were divided into three groups: (i) a control group (no lavage/debridement), (ii) a group treated with PL, (iii) a group treated with PUS. The disks were then sonicated for viable cell count to measure the residual biofilm content. Compared to the initial cell count (105  CFU/mL for each material), PL showed a two-log reduction of CFU/mL (p < 0.001 for each material), while for PUS a four-log reduction was found (p < 0.001 for each material). The comparison between the two lavage/debridement displayed a two-log reduction of CFU/mL (p < 0.001 for each material) of PUS compared with PL. Its increased efficiency compared with PL promotes the use of PUS in removing bacterial biofilm from orthopedic implants, suggesting its implementation to improve the success rate of DAIR.

Mechanical complications and infection control comparison of custom-made and prefabricated articular hip spacers in the treatment of periprosthetic infection

OBJECTIVES

The purpose of our study was to compare the complication rate and the outcomes of custom-made spacers (C-spacers) and prefabricated articular spacers (P-spacers) in the treatment of periprosthetic infection.

PATIENTS AND METHODS

In this retrospective study, 78 patients (44 females, 34 males; mean age: 68.5±9.48 years; range, 47 to 82 years) with articular spacers implanted in our institution were analyzed between January 2009 and December 2019. We recorded implant results as per mechanical complications, infection control, the interval from surgery to definitive hip replacement, and the rate of achieving recovery of joint function after stage two arthroplasty.

RESULTS

There were 29 revised spacers; 18 of them were C-spacers and 11 were P-spacers (p=0.0383). A total of 16 dislocations were recorded, of which six were dislocations of C-spacers, and 10 were dislocations of P-spacers (p=0.0082). Additionally, we registered four spacer breakages, all of which occurred in C-spacers (p=0.295). C-spacers failed early, at an mean interval of 2.2 weeks after implantation, and P-spacers failed later, with an mean of 9.3 weeks after implantation (p=0.0187). A total of nine reinfection complications of spacers were registered; only one infection of P-spacers, and eight infections related to C-spacers (p=0.2583). Definitive revision total hip arthroplasty (rTHA) after spacer explantation and successful treatment of the infection occurred in 63 cases out of 78 patients. Definitive rTHA occurred after the use of C-spacers in 41 (78%) patients and after the use of C-spacers in 22 (84%) patients (p=0.7816). C-spacers had a mean interval from spacer implantation to definitive rTHA of 6.56±6.03 months, and P-spacers had a mean interval of 4±1.93 months (p=0.0164).

CONCLUSION

Custom-made spacers were shown to have lower mechanical complication rates than prefabricated ones but more infection complications. Prefabricated spacers had more dislocations and fewer breakages. Custom-made spacer mechanical failures occurred earlier compared to prefabricated ones.

Outcomes of Concurrent Endocarditis and Periprosthetic Joint Infection: A Retrospective Case Series of 16 Patients

Introduction

Concurrent diagnosis of periprosthetic joint infection (PJI) of total hip arthroplasty (THA) or total knee arthroplasty (TKA) with infectious endocarditis is a devastating clinical scenario infrequently documented in the literature. To date, no studies have fully described the orthopedic and infectious outcomes of patients with these concurrent diagnoses. The purpose of this study was to conduct a case series of patients with these diagnoses and document the orthopedic and infectious outcomes so that surgeons may effectively counsel patients regarding the gravity of the condition and the expected course of treatment.

Methods

This study is a retrospective case series using patient data from five hospitals within an academic healthcare system in the northeastern United States. Cases of concurrent endocarditis and THA or TKA PJI with a minimum of one-year follow-up were identified from January 2000 to January 2021. Basic statistics such as means, standard deviations, and percentages were used to identify trends within our series. Kaplan-Meier survivorship curves with log-rank tests were performed to determine if there were any differences in two-year mortality and joint survival (defined as needing explant) between patients who had cardiac surgery prior to surgical management for their PJI and those who had surgical management for PJI prior to cardiac surgery.

Results

A total of 18 joints in 16 patients with endocarditis and concurrent TKA or THA PJI were identified. All PJIs were managed surgically, with 14/18 (77.77%) of joint infections initially being managed by debridement, antibiotics, and implant retention (DAIR) and 4/18 (22.22%) of joint infections initially being managed by explant. Within the first six months of PJI diagnosis, 25% (4/16) of patients died of complications related to their infection, and one additional patient died of bacteremia just over a year after the initial PJI diagnosis. Of the 18 PJIs, 72.23% (13/18) had treatment failure, defined as any outcome equal to or worse than requiring chronic suppressive antibiotics for the infection. Due to low statistical power, we were not able to identify any differences in two-year mortality from PJI diagnosis (p=0.311) or joint survival (in terms of requiring explant) (p=0.420) depending on whether cardiac surgery or DAIR was performed first.

Conclusions

Concurrent infectious endocarditis and prosthetic joint infection is associated with high morbidity and mortality. Patients with these concurrent infections should be counseled that not only the associated mortality rate is high, but also the surgical treatment of their PJI has a high rate of treatment failure, including an explant following an initial DAIR, an explant with retained spacer, or a requirement of lifelong antibiotic suppression.