One-stage revision is as effective as two-stage revision for chronic culture-negative periprosthetic joint infection after total hip and knee arthroplasty

Engineering mesoporous polydopamine-based potentiate STING pathway activation for advanced anti-biofilm therapy

The biofilm-induced "relatively immune-compromised zone" creates an immunosuppressive microenvironment that is a significant contributor to refractory infections in orthopedic endophytes. Consequently, the manipulation of immune cells to co-inhibit or co-activate signaling represents a crucial strategy for the management of biofilm. This study reports the incorporation of Mn2+ into mesoporous dopamine nanoparticles (Mnp) containing the stimulator of interferon genes (STING) pathway activator cGAMP (Mncp), and outer wrapping by M1-like macrophage cell membrane (m-Mncp). The cell membrane enhances the material's targeting ability for biofilm, allowing it to accumulate locally at the infectious focus. Furthermore, m-Mncp mechanically disrupts the biofilm through photothermal therapy and induces antigen exposure through photodynamic therapy-generated reactive oxygen species (ROS). Importantly, the modulation of immunosuppression and immune activation results in the augmentation of antigen-presenting cells (APCs) and the commencement of antigen presentation, thereby inducing biofilm-specific humoral immunity and memory responses. Additionally, this approach effectively suppresses the activation of myeloid-derived suppressor cells (MDSCs) while simultaneously boosting the activity of T cells. Our study showcases the efficacy of utilizing m-Mncp immunotherapy in conjunction with photothermal and photodynamic therapy to effectively mitigate residual and recurrent infections following the extraction of infected implants. As such, this research presents a viable alternative to traditional antibiotic treatments for biofilm that are challenging to manage.

Material-based treatment strategies against intraosseous implant biofilm infection

Implant-associated infections present a significant clinical obstacle for orthopedic practitioners, with bacterial biofilm formation serving as a pivotal factor in the initiation, progression, and management of such infections. Conventional approaches have proven inadequate in fully eradicating biofilm-related infections. Consequently, novel material-based therapeutic strategies have been developed, encompassing the utilization of antimicrobial agents, delivery vehicles, and synergistic antibacterial systems. In this review, we provide a succinct overview of recent advancements in anti-biofilm strategies, with the aim of offering insights that may aid in the treatment of intraosseous implant infections.

Unexpected positive culture (UPC) in adults revision spine surgery: a systematic review and meta-analysis of incidence, risk factors, and management

BACKGROUND

Without clear signs of infection, spinal implant failure is attributed to mechanical overloads and aseptic loosening. However, how low-grade infections contribute to seemingly aseptic implant failure is unclear.

PURPOSE

The systematic review examined unexpected positive cultures (UPCs) in revision spine surgery regarding prevalence, isolated pathogens, risk factors, and strategies to reduce infection among asymptomatic patients undergoing revision spine surgery.

METHODS

We followed the PRISMA guidelines and searched four main databases (PubMed, EMBASE, SCOPUS, Web of Science) comprehensively until January 2023 for articles reporting UPC after presumed aseptic adult revision spine surgery. The UPC rates were pooled, and risk factors were compared with the culture-negative control group and represented as odds ratio (OR) or mean difference (MD).

RESULTS

Fifteen studies of 1057 individuals were included in two groups: culture-positive or UPCs (n = 317) and culture-negative or control (n = 740). The overall UPC prevalence was 33.2% (317/1057, range: 0 to 53%, 95% CI = 30.2%-36.4%), and Cutibacterium acnes (43.0%, 95% CI = 37.4%-48.8%), Coagulase-negative Staphylococci (CoNS), (39.5%, 95% CI = 33.2%-46.2%), and Staphylococcus species in general (49.5%, 95%CI = 43.7%-55.4%) were reported the most common isolated microbes. 16.1% of the UPCs were polymicrobial. Risk factors associated with UPC rates were female sex (OR = 2.62, 95%CI = 1.76-3.90, P < 0.001), screw loosening (OR = 4.43, 95%CI = 1.31-15.02, P = 0.02), number of operated levels (MD = 0.77, 95%CI = 0.33-1.22, P = 0.0007), and shorter time since index surgery (MD = - 8.57 months, 95%CI = - 14.76, -2.39, P = 0.02).

CONCLUSIONS

One-third of patients undergoing spine revision surgery revealed UPC in this study. Each UPC pathogen interpretation and antibiotic use decision should be interpreted case by case.

LEVEL OF EVIDENCE

IV.

Periprosthetic Joint Infections of the Knee-Comparison of Different Treatment Algorithms

Background: Periprosthetic joint infection (PJI) following total knee arthroplasty is a serious complication lacking evidence-based diagnostic and treatment protocols, particularly in ruling out persisting infection before reimplantation. Methods: This retrospective analysis assessed the mid-term outcomes of 66 patients undergoing septic two-stage knee revision surgeries from 2007 to 2013, diagnosed as per the Musculoskeletal Infection Society criteria. After implant removal and antibiotic treatment, reimplantation decisions were based on either joint aspiration, blood counts, and clinical examination (group A) or an open biopsy (group B). Both groups underwent meticulous debridement and spacer exchange during the interim period. Results: Late re-infection occurred in 12.1% of all patients. In group A, 13.8% experienced late re-infection, with 14.3% in subgroup A1 and 13.3% in subgroup A2. In group B, 10% had a late re-infection. No significant difference in re-infection or complication rates was found between the groups. Conclusions: The study did not demonstrate the superiority of group B's approach of open biopsy over group A's joint aspiration, clinical examination, and blood counts in preventing re-infection or reducing complications.

Utilizing an antibiotic-eluting articulated cemented spacer in the two-stage management of infected total hip arthroplasty: a technical note

Two-stage revision is generally preferred to eradicate chronic periprosthetic infections after total hip arthroplasty (THA) because of its good infection control and promising results. During two-stage revision, a temporary antibiotic-impregnated cement spacer was initially used for the local delivery of antibiotics, thereby reducing the risk of infection recurrence. Many researchers have reported various techniques for fabricating cemented spacers; however, there is no established standard technique. We share our cost-effective and easily reproducible technique for creating an articulated cemented spacer for managing infected THA.

Innovations in the Isolation and Treatment of Biofilms in Periprosthetic Joint Infection: A Comprehensive Review of Current and Emerging Therapies in Bone and Joint Infection Management

Periprosthetic joint infections (PJIs) are a devastating complication of joint arthroplasty surgeries that are often complicated by biofilm formation. The development of biofilms makes PJI treatment challenging as they create a barrier against antibiotics and host immune responses. This review article provides an overview of the current understanding of biofilm formation, factors that contribute to their production, and the most common organisms involved in this process. This article focuses on the identification of biofilms, as well as current methodologies and emerging therapies in the management of biofilms in PJI.

Biofilm and How It Relates to Prosthetic Joint Infection

Prosthetic joint infection following total joint arthroplasty is a devastating complication, resulting in increased morbidity and mortality for the patient. The formation of a biofilm on implanted hardware contributes to the difficulty in successful identification and eradication of the infection. Antibiotic therapy and surgical intervention are necessary for addressing this condition; we present a discussion on different treatment options, including those that are not yet routinely utilized in the clinical setting or are under investigation, to highlight the present and future of PJI management.

Two-stage revision for periprosthetic joint infection after hip and knee arthroplasty

Aims

Histology is widely used for diagnosis of persistent infection during reimplantation in two-stage revision hip and knee arthroplasty, although data on its utility remain scarce. Therefore, this study aims to assess the predictive value of permanent sections at reimplantation in relation to reinfection risk, and to compare results of permanent and frozen sections.

Methods

We retrospectively collected data from 226 patients (90 hips, 136 knees) with periprosthetic joint infection who underwent two-stage revision between August 2011 and September 2021, with a minimum follow-up of one year. Histology was assessed via the SLIM classification. First, we analyzed whether patients with positive permanent sections at reimplantation had higher reinfection rates than patients with negative histology. Further, we compared permanent and frozen section results, and assessed the influence of anatomical regions (knee versus hip), low- versus high-grade infections, as well as first revision versus multiple prior revisions on the histological result at reimplantation. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), chi-squared tests, and Kaplan-Meier estimates were calculated.

Results

Overall, the reinfection rate was 18%. A total of 14 out of 82 patients (17%) with positive permanent sections at reimplantation experienced reinfection, compared to 26 of 144 patients (18%) with negative results (p = 0.996). Neither permanent sections nor fresh frozen sections were significantly associated with reinfection, with a sensitivity of 0.35, specificity of 0.63, PPV of 0.17, NPV of 0.81, and accuracy of 58%. Histology was not significantly associated with reinfection or survival time for any of the analyzed sub-groups. Permanent and frozen section results were in agreement for 91% of cases.

Conclusion

Permanent and fresh frozen sections at reimplantation in two-stage revision do not serve as a reliable predictor for reinfection.

Articulating Spacers in Total Hip Arthroplasty: Surgical Technique and Outcomes

Although one-stage exchange arthroplasty is gaining popularity, two-stage exchange arthroplasty remains the gold standard for the treatment of periprosthetic joint infections. Use of an articulating spacer for this procedure offers an avenue for maintaining hip motion and controlled weight-bearing, allowing local antibiotic elution. However, there is no uniform consensus on the optimal surgical protocol for using articulating spacers. This review describes the surgical technique for undertaking a first-stage exchange arthroplasty using an articulating spacer and discusses the pertinent literature on key concepts relating to periprosthetic joint infections in total hip arthroplasty to guide effective surgical decision making in these patients.

Do one-stage indications predict success following two-stage arthroplasty for chronic periprosthetic joint infection?

Introduction: The 2018 International Consensus Meeting (ICM) proposed criteria for one-stage exchange arthroplasty in treating periprosthetic joint infection (PJI). Our study aimed to determine what proportion of PJI patients met the 2018 ICM criteria and how this affected infection-free survivorship for patients. Methods: All chronic PJI patients treated with two-stage exchange within our institution between 2017-2020 were retrospectively reviewed. Included cases met 2011 Musculoskeletal Infection Society (MSIS) criteria for PJI and had a 2-year minimum follow-up. Treatment success was defined as Tier 1A in the 2019 MSIS working group definition. ICM one-stage criteria included non-immunocompromised host, absence of sepsis, adequate soft tissue for closure, known preoperative pathogen, and susceptibility. Immunocompromised host was analyzed as two separate definitions. Kaplan-Meier survivorship, Cox regression, and univariate analyses were performed. Results: A total of 293 chronic PJI patients were included. Overall, treatment failure occurred in 64 / 293 (21.8 %) patients. Only 13 % (n = 37 ) met ICM criteria definition no. 1 for one-stage exchange; 12 % (n = 33 ) met definition no. 2. In both definitions, infection-free survivorship at 2 years did not differ between patients who met and did not meet criteria (p > 0.05 ). Cox proportional hazard regression analyses demonstrated that the only variable predicting treatment failure was knee joint involvement (p = 0.01 ). Conclusions: We found that a very limited number of chronic PJI patients were suitable for a one-stage exchange. Furthermore, the supposition that healthier hosts with known pathogens (the basis of the ICM criteria) yield better PJI treatment outcomes was not observed. These results justify the ongoing multicenter randomized control trial comparing one-stage versus two-stage treatment for chronic PJI.

Systematic review and meta-analysis of single-stage vs two-stage revision for periprosthetic joint infection: a call for a prospective randomized trial

BACKGROUND

Periprosthetic joint infection (PJI) is a severe complication of joint arthroplasty that causes significant pain and economic loss. This study aimed to determine whether the current evidence supports single-stage revision for PJI based on reinfection and reoperation rates.

METHODS

We searched the PubMed, EBSCO, Medline, and Cochrane Library databases from inception to 30 May 2023 to identify studies that compared single-stage revision and two-stage revision for PJI. Data on reinfection and reoperation rates were pooled.

RESULTS

This meta-analysis included a total of 40 studies with 8711 patients. Overall, there was no significant difference between single- and two-stage revision regarding the postoperative reinfection rate and reoperation rate. Subgroup analysis by surgery period and different surgical sites revealed no difference between the two groups in the reinfection and reoperation rates.

CONCLUSIONS

Based on the available evidence, our study did not identify a significant difference in reinfection and reoperation rates between single- and two-stage revision for PJI. Given the limitations in inclusion/exclusion criteria and the observed heterogeneity, we acknowledge the complexity of drawing strong conclusions. Therefore, we suggest that the choice between single- and two-stage revision should be carefully considered on an individual basis, taking into account patient-specific factors and further research developments.

What Is the Most Effective Treatment for Periprosthetic Joint Infection After Total Joint Arthroplasty in Patients with Rheumatoid Arthritis?: A Systematic Review

BACKGROUND

Rheumatoid arthritis (RA) is a risk factor for periprosthetic joint infection (PJI) after total joint arthroplasty (TJA). The purpose of this study was to perform a systematic review comparing the failure rates of debridement, antibiotics, and implant retention (DAIR), one-stage exchange arthroplasty/revision (OSR), and 2-stage exchange arthroplasty/revision (TSR) for RA patients with PJI and identify risk factors in the RA population associated with increased treatment failure rate.

METHODS

PubMed, Ovid MEDLINE, and Ovid Embase databases were screened with the terms "rheumatoid arthritis," "total joint arthroplasty," "prosthetic joint infection," and "treatment for PJI" on August 29, 2021. Four hundred ninety-one studies were screened, of which 86 were evaluated. The primary outcome evaluated was failure of surgical treatment for PJI.

RESULTS

Ten retrospective cohort studies were included after full-text screening, yielding 401 patients with RA. Additional demographic and PJI management data were obtained for 149 patients. Patients with RA who underwent TSR demonstrated a lower failure rate (26.8%) than both DAIR (60.1%) and OSR (39.2%) (χ2 = 37.463, p < 0.00001). Patients with RA who underwent DAIR had a 2.27 (95% CI, 1.66-3.10) times higher risk of experiencing treatment failure than those who underwent TSR. Among risk factors, there was a significant difference in the C-reactive protein of patients who did vs. did not experience treatment failure (p = 0.02).

CONCLUSION

TSR has a higher rate of success in the management of PJI patients with RA compared with DAIR and OSR. The complete removal of the infected prosthesis and delayed reimplantation may lower the treatment failure rate.

LEVEL OF EVIDENCE

Level III. See Instructions for Authors for a complete description of levels of evidence.

Proceedings of the United Kingdom Periprosthetic Joint Infection Meeting 2022: Combined and Arthroplasty Sessions

Considerable variation in practice exists in the prevention, diagnosis, and treatment of periprosthetic joint infection (PJI), which is a devastating complication for patients and surgeons. The consensus principle has been increasingly embraced by the orthopaedic community to help guide practice, especially where high-level evidence remains unavailable. The third United Kingdom Periprosthetic Joint Infection (UK PJI) Meeting was held in Glasgow on April 1, 2022, with more than 180 delegates in attendance, representing orthopaedics, microbiology, infectious diseases, plastic surgery, anesthetics, and allied health professions, including pharmacy and arthroplasty nurses. The meeting comprised a combined session for all delegates, and separate breakout sessions for arthroplasty and fracture-related infection. Consensus questions for each session were prepared in advance by the UK PJI working group, based upon topics that were proposed at previous UK PJI Meetings, and delegates participated in an anonymized electronic voting process. We present the findings of the combined and arthroplasty sessions of the meeting in this article, and each consensus topic is discussed in relation to the contemporary literature.

Trends in Revision Knee Arthroplasty for Prosthetic Joint Infection: A Single-Center Study of 384 Knees at a High-Volume Center Between 2008 and 2021

BACKGROUND

Prosthetic joint infection (PJI) is one of the most devastating complications after total knee arthroplasty (TKA), and comorbidities increase the risk. We examined whether a temporal change has occurred in the demographics, especially regarding comorbidities, of patients who have PJI and were treated at our institution over a 13-year study period. In addition, we assessed the surgical methods used and the microbiology of the PJIs.

METHODS

Revisions (n = 384, 377 patients) due to PJI of the knee performed at our institution between 2008 and September 2021 were identified. All included PJIs fulfilled the 2013 International Consensus Meeting diagnostic criteria. The surgeries were categorized into one of the following categories: debridement, antibiotics, and retention (DAIR), 1-stage revision, and 2-stage revision. Infections were classified as early, acute hematogenous, and chronic.

RESULTS

No changes in the median age of the patients nor comorbidity burden were observed during the study period. However, the proportion of 2-stage revisions decreased remarkably from 57.6% in 2008 to 2009 to 6.3% in 2020 to 2021. A DAIR was the most used treatment strategy, but the proportion of 1-stage revisions increased the most. In 2008 to 2009, 12.1% of the revisions were 1-stage, but in 2020 to 2021, the proportion was 43.8%. The most common pathogen was Staphylococcus aureus (27.8%).

CONCLUSION

The comorbidity burden remained at the same level with no trends. A DAIR was the most used strategy, but the proportion of 1-stage revisions rose to almost the same level. The incidence of PJI varied between the years, but remained relatively low.

Failed 2-Stage Revision Knee Arthroplasty for Periprosthetic Joint Infection-Patient Characteristics and Outcomes

BACKGROUND

Chronic prosthetic joint infection (PJI) is most frequently treated with 2-stage revision in conjunction with antibiotic treatment. The aims of this study were 1) to investigate the characteristics of patients who have recurrent infection following 2-stage revision for PJI and 2) to identify risk factors associated with treatment failure.

METHODS

A multicenter retrospective review of 90 total knee arthroplasty (TKA) patients who underwent 2-stage revision for treatment of PJI from March 1, 2003 to July 31, 2019, and had recurrent PJI was conducted. The minimum follow-up was 12 months (median follow up of 2.4 years). Microorganisms, subsequent revision, PJI control status, and final joint status were collected. The infection-free survival after initial 2-stage revision was plotted utilizing the Kaplan-Meier method.

RESULTS

Mean survival time to reinfection was 21.3 months (range, 0.3 to 160.5). There were 14 recurrent infections that were acute PJIs treated with debridement, antibiotics, and implant retention (DAIR), while 76 were chronic and treated with repeat 2-stage revision. The most common pathogen identified for both index and recurrent PJI was coagulase-negative Staphylococci. Pathogen persistence was observed in 14 (22.2%) of recurrent PJIs. In total, 61 (67.8%) patients possessed a prosthetic reimplantation at their most recent follow-up, and 29 (35.6%) patients required intervention following repeat 2-stage.

CONCLUSION

Overall, 31.1% of the patients obtained infection control after treatment of a failed 2-stage revision due to PJI. The high rate of pathogen persistence and the relatively low survival time to recurrence suggests a need to more closely monitor PJIs cases within 2 years.

Description of surgical treatment methods of hip and knee periprosthetic joint infections in the Chinese mainland: a national multi-centre survey

PURPOSE

Periprosthetic joint infection (PJI) is a serious hip and knee arthroplasty complication. Despite the increased incidence of primary joint replacements, there is no clear guideline for treating PJI in the Chinese mainland yet. We aim to measure the current situation and basis for surgical treatment methods of PJI in major orthopaedic hospitals in the Chinese mainland.

METHODS

We conducted a national survey on PJI treatment in Mainland China. Forty-one top arthroplasty centers were included, with 82.9% (34/41) response rate. The data were analyzed using Microsoft Excel version 20.0 and described as numbers and percentages.

RESULTS

For acute infections, prosthesis-preserving procedures (DAIR) are used in all centres. For hip and knee PJI, 20.5% (7/34) and 35% (12/34) of the centres used a one-stage exchange. If applied, this treatment will necessitate the previous patients' selection for a satisfactory outcome. All centres execute the two-stage exchange. Between phases, the majority of centres implant a cemented spacer. Revisions for infected hips included 21 (4.3%) cases of DAIR, 95 (19.9%) cases of single-stage exchange, 362 (75.2%) cases of two-stage exchange, and 2 (0.007%) cases of hip dissection. Revisions for infected knee comprised 88 (19.0%) cases of DAIR, 48 (10.3%) cases of single-stage exchange, 324 (69.8%) cases of two-stage exchange, and 5 (0.02%) cases of knee fusion.

CONCLUSIONS

The centers do not have a uniform PJI standard. Most patients have two-stage revision with a cemented spacer in China. These concepts can help establish treatment guidelines.

Comparable clinical outcomes of culture-negative and culture-positive periprosthetic joint infections: a systematic review and meta-analysis

PURPOSE

The aim of this study was to compare the clinical outcomes of culture-negative periprosthetic joint infection (CN PJI) with those of culture-positive periprosthetic joint infection (CP PJI).

METHODS

Data were obtained from Embase, Web of Science and EBSCO for all available studies comparing the clinical outcomes of CN PJI with those of CP PJI. The quality of the studies was scored using the Newcastle-Ottawa scale (NOS). Pooled odds ratios (ORs) and 95% confidence intervals (CIs) were used to assess clinical outcomes. Subgroup analyses were performed to explain heterogeneity among the included studies. Publication bias was estimated using Begg's funnel plot. Sensitivity analysis was performed to test the stability of pooled results.

RESULTS

Thirty studies with 1630 (38.7%) CN PJI and 2577 (61.3%) CP PJI were included in this meta-analysis. The pooled results of the included studies showed that overall failure rate in CN PJI group (19.0%, 309/1630) was significantly lower than that in CP PJI group (23.4%, 604/2577) (OR 0.63, 95% CI 0.47-0.84, P = 0.002). We performed the subgroup analysis based on the surgical strategies, the pooled results of nine studies for patients undergoing debridement, antibiotics and implant retention (DAIR) revealed that failure rate in CN PJI group (22.2%, 53/239) was significantly lower than that in CP PJI group (29.3%, 227/775) (OR 0.62, 95% CI 0.43-0.90, P = 0.01), the pooled results of four studies for patients undergoing one-stage revision revealed that failure rate between CN PJI group (11.5%, 11/96) and CP PJI group (7.6%, 27/355) had no significant difference (OR 1.57, 95% CI 0.75-3.26, P = 0.23), and the pooled results of 19 studies for patients undergoing two-stage revision revealed that failure rate in CN PJI group (16.1%, 171/1062) was significantly lower than that in CP PJI group (20.4%, 206/1010) (OR 0.52, 95% CI 0.34-0.79, P = 0.002).

CONCLUSIONS

CN PJI group had similar or better survival rate when compared with CP PJI group for patients who underwent DAIR, one-stage or two-stage revision. Negative culture was not a worse prognostic factor for PJI.

Single-stage revision for chronic periprosthetic joint infection after knee and hip arthroplasties: indications and treatments

Single-stage revision for chronic periprosthetic joint infection has been introduced 40 years ago. This option is gaining more and more attention as well as popularity. It is a reliable treatment for the chronic periprosthetic joint infection after knee and hip arthroplasties when implemented by an experienced multi-disciplinary team. However, its indications and corresponding treatments remain controversial. This review focused on the indications and specific treatments related to the option, with an attempt to help surgeons to use this method with more favorable outcomes.

One-stage revision using intra-articular carbapenem infusion effectively treats chronic periprosthetic joint infection caused by Gram-negative organisms

Gram-negative periprosthetic joint infection (PJI) has been poorly studied despite its rapidly increasing incidence. Treatment with one-stage revision using intra-articular (IA) infusion of antibiotics may offer a reasonable alternative with a distinct advantage of providing a means of delivering the drug in high concentrations. Carbapenems are regarded as the last line of defense against severe Gram-negative or polymicrobial infection. This study presents the results of one-stage revision using intra-articular carbapenem infusion for treating Gram-negative PJI, and analyzes the characteristics of bacteria distribution and drug sensitivity. We retrospectively reviewed 32 patients (22 hips and 11 knees) who underwent single-stage revision combined with IA carbapenem infusion between November 2013 and March 2020. The IA and intravenous (IV) carbapenem infusions were administered for a single Gram-negative infection, and IV vancomycin combined with IA carbapenems and vancomycin was applied for polymicrobial infection including Gram-negative bacteria. The bacterial community distribution, drug sensitivity, infection control rate, functional recovery, and complications were evaluated. Reinfection or death caused by PJI was regarded as a treatment failure. Gram-negative PJI was mainly caused by Escherichia coli (8/34), Enterobacter cloacae (7/34), and Klebsiella pneumoniae (5/34). Seven cases (7/32) involved polymicrobial PJIs. The resistance rates of penicillin, cephalosporin, quinolones, and sulfonamides were > 10%, and all penicillin and partial cephalosporins (first and second generation) were > 30%. Of 32 cases, treatment failed to eradicate infection in only three cases (9.4%), at a mean follow-up of 55.1 months (SD 25 to 90). The mean postoperative Harris Hip Score and Hospital for Special Surgery knee score at the most recent follow-up were 81 (62 to 91) and 79 (56 to 89), respectively. One patient developed a fistula, and another presented with a local rash on an infected joint. The use of IA carbapenem delivered alongside one-stage revision effectively controlled Gram-negative infection and obtained acceptable clinical outcomes with few complications. Notably, first- and second-generation cephalosporins and penicillin should be administrated with caution, due to a high incidence of resistance.

Successful eradication rate following one-stage septic knee and hip exchange in selected pre-operative culture-negative periprosthetic joint infections

PURPOSE

The main requirement for performing the one-stage septic exchange is the pre-operative identification of the pathogen and its susceptibility. The purpose of this study is to evaluate the success rate with special focus on reinfection in a cohort of patients who underwent one-stage septic knee or hip revision for pre-operative culture-negative PJI.

METHODS

We retrospectively analyzed 640 patients treated by one-stage revision for chronic knee or hip PJI between January 1, 2016, and December 31, 2018. Only cases with pre-operative culture-negative PJI, with culture-negative synovial aspirations and one negative open biopsy, were analyzed. We evaluated the septic and aseptic complication and the rate of complication-free survival defined as the time from the date of first operation and the date of complication events.

RESULTS

A total of 22 patients fulfilled the inclusion and were enrolled. The mean age of the group was 73.2 ± 9.8 years, with a median ASA score of 3 (range 3-4). After mean follow-up of 3.6 ± 2.6 years, 86.4% (19 out of 22) of patients reported no complications. Two patients (9.1%) after one-stage hip required revision arthroplasty due to septic failure, while one patient (4.5%) with one-stage knee had revision for femoral component aseptic loosening.

CONCLUSION

Our analysis suggests that the absence of pre-operative pathogen detection may not be contraindication to the one-stage revision in selected patients. The one-stage exchange might be considered in patients with pre-operative negative cultures in presence of ASA > 3 and multiple comorbidities that are not able to tolerate multiple surgeries.

One- or two-stage reimplantation for infected total knee prosthesis?

A prosthetic joint infection (PJI) is possibly the most significant potential complication of total knee arthroplasty (TKA) and is associated with substantial morbidity and socioeconomic burden. It is a devastating complication for both the patient and the surgeon alike. A two-stage revision approach for infected TKA has been the standard for surgical management; however, there is growing interest in single-stage revision surgery due to fewer procedures, reduced inpatient hospital stay and reduced costs to healthcare systems. A one-stage exchange is indicated when there is no sign of systemic sepsis and in cases where a microorganism has been isolated. It involves removal of the old prosthesis, debridement of all infected tissue, a copious washout and re-draping, and finally, re-implantation of a new prosthesis. The two-stage approach involves the use of an antibiotic spacer before the second stage is carried out. The length of time between the stages is discussed. Patients with a PJI should be managed by a multidisciplinary team. We recommend these patients are managed in specialist arthroplasty centres by high volume revision arthroplasty specialists.

Single-Stage Revision Reverse Shoulder Arthroplasty: Preoperative Planning, Surgical Technique, and Mixed Reality Execution

Revision shoulder arthroplasty is increasing with the number of primary shoulder replacements rising globally. Complex primary and revisions of shoulder arthroplasties pose specific challenges for the surgeon, which must be addressed preoperatively and intraoperatively. This article aimed to present strategies for the management of revision of shoulder arthroplasties through a single-stage approach. Preoperatively, patient factors, such as age, comorbidities, and bone quality, should be considered. The use of planning software can aid in accurately evaluating implants in situ and predict bony anatomy that will remain after explantation during the revision surgery. The planning from such software can then be executed with the help of mixed reality technology to allow accurate implant placement. Single-stage revision is performed in two steps (debridement as first step, implantation and reconstruction as the second step), guided by the following principles: adequate debridement while preserving key soft tissue attachments (i.e., rotator cuff, pectoralis major, latissimus dorsi, deltoid), restoration of glenoid joint line using bone grafting, restoration of humeral length, reconstruction and/or reattachment of soft tissues, and strict compliance with the postoperative antibiotic regimen. Preliminary results of single-stage revision shoulder arthroplasty show improvement in patient outcomes (mean 1 year), successful treatment of infection for those diagnosed with periprosthetic joint infection, and improved cost-benefit parameters for the healthcare system.

One and a Half-Stage Revision With Prosthetic Articulating Spacer for Definitive Management of Knee Periprosthetic Joint Infection

This paper is a comprehensive review that describes indications, contraindications, clinical outcomes, and pearls and pitfalls of 1.5-stage revision total knee arthroplasty (TKA) utilizing a primary TKA femoral component, all-polyethylene tibial component, and hand-crafted antibiotic cement for the management of chronic periprosthetic joint infection. The 1.5-stage exchange TKA details placement of an articulating spacer for an indefinite period, prolonging revision until reinfection, deterioration of functional status, or construct failure. A 1.5-stage revision TKA technique is a viable option for treatment of chronic periprosthetic knee infections. The inherent advantages of decreased health-care costs, decreased morbidity and mortality, and improved emotional ease from having a single procedure is attractive, especially if reinfection rates are determined to be equivocal to 2-stage revision.

Prevalence, interpretation, and management of unexpected positive cultures in revision TKA: a systematic review

PURPOSE

Unexpected positive intraoperative cultures (UPIC) found in revision total knee arthroplasty (TKA) are difficult to interpret. Management goes along with risks for both over- and undertreating a potential periprosthetic joint infection (PJI). The objective of this systematic review was to determine the prevalence of UPIC in revision TKA surgery, evaluate the diagnostic workup process and the postoperative treatment, and assess outcome regarding re-revision rates.

METHODS

Evidence was gathered from Medline (PubMed) and Embase published from January 2000 until April 2021. Nine studies with data of UPIC in revision TKA and outcome after at least 2 years of follow-up were identified.

RESULTS

The calculated prevalence of UPIC in aseptic knee revision surgery was 8.32%. However, the diagnostical approach differs as well as the used criteria to confirm PJI in presumed aseptic revision surgery. The work-up generally consists of a serum C-reactive protein and Erythrocyte Sedimentation Rate, joint fluid aspiration for culture and white blood cell count and formula, and radiographic imaging. Collection of intraoperative cultures is widely used, but inconsistent in sample amount and incubation time. Once a single UPIC is found, surgeons tend to treat it in different ways. Regarding re-revision rates, the weighted arithmetic mean in the included studies was 18.45% in the unsuspected PJI group compared to 2.94% in the aseptic group. There also seems to be a trend towards higher re-revision rates when a higher number of intraoperative cultures are positive.

CONCLUSION

The interpretation of UPIC in revision TKA is of utmost importance since the decision whether to treat a UPIC as an unsuspected PJI has a major impact on implant survival and re-revision rate. Different criteria are used to differentiate between unsuspected PJI and contamination in true aseptic failure, and the heterogeneity amongst the included papers impedes to state a clear recommendation, integrating not only quantitative findings, but also qualitative data such as virulence of the identified microorganism.

LEVEL OF EVIDENCE

Systematic review, III.

What Is the Normal Trajectory of C-Reactive Protein, Erythrocyte Sedimentation Rate, Plasma Fibrinogen and D-Dimer after Two-Stage Exchange for Periprosthetic Joint Infection?

Objective

C‐reactive protein (CRP), erythrocyte sedimentation rate (ESR), plasma fibrinogen and D‐Dimer are used as diagnostic biomarkers of prosthetic joint infection (PJI) after total joint arthroplasty (TJA). The purpose of the study was to investigate the normal trajectory of CRP, ESR, plasma fibrinogen and D‐Dimer at different time points after two‐stage exchange arthroplasty for PJI.

Methods

We studied 53 patients undergoing two‐stage exchange for PJI at five time points: preoperatively (T0), duration of hospital stays (T1), 30 days (T2), 30–90 days (T3), and 90–180 days (T4) after surgery. The medical records of all patients were well documented and carefully reviewed. The Shapiro–Wilk test was utilized to compare the normal distribution for continuous variables, and the nonnormally distributed data were used for Friedmann's one‐way repeat measures analysis of variances. Post hoc Dunnett's test was used to compare each pair of data to find differences from baseline.

Results

Compare with T0 point, the levels of CRP and ESR increased significantly and reached peak values at T1 point (all P < 0.001), with median values of 56.40 mg/L (range, 5.54–161.0 mg/L) and 49.00 mm/h (range, 13.00–113.0 mm/h), respectively. In addition, the levels of plasma fibrinogen and D‐Dimer increased significantly and reached peak values at T1 point (all P < 0.001), with median values of 4.13g/L (range, 2.27–6.80 mg/L) and 4.00 mg/L (range, 0.19–14.01 mg/L), respectively. CRP and ESR rapidly declined at the T2 point with significantly compared with T0 point (P = 0.001 and P < 0.001). The levels of CRP, ESR, plasma fibrinogen and D‐Dimer returned to preoperative levels of 5.23 mg/L (range, 1.01–21.70 mg/L), 19.00 mm/h (range, 6.00–60.00 mm/h), 3.38g/L (range, 1.71–5.10 g/L) and 2.33 mm/h (range, 0.19–6.87 mg/L) at T4 point, and there was no significant difference compared with T0 point (all P > 0.05).

Conclusions

The study demonstrated the normal trajectory of CRP, ESR, plasma fibrinogen and D‐Dimer at five time points in patients who underwent two‐stage exchange for PJI. Thus, the results have the possibility of providing signs of infection after the patient receives two‐stage exchange arthroplasty for PJI, which can benefit from early treatment.

Machine learning models accurately predict recurrent infection following revision total knee arthroplasty for periprosthetic joint infection

PURPOSE

This study aimed to develop and validate machine-learning models for the prediction of recurrent infection in patients following revision total knee arthroplasty for periprosthetic joint infection.

METHODS

A total of 618 consecutive patients underwent revision total knee arthroplasty for periprosthetic joint infection. The patient cohort included 165 patients with confirmed recurrent periprosthetic joint infection (PJI). Potential risk factors including patient demographics and surgical characteristics served as input to three machine-learning models which were developed to predict recurrent periprosthetic joint. The machine-learning models were assessed by discrimination, calibration and decision curve analysis.

RESULTS

The factors most significantly associated with recurrent PJI in patients following revision total knee arthroplasty for PJI included irrigation and debridement with/without modular component exchange (p < 0.001), > 4 prior open surgeries (p < 0.001), metastatic disease (p < 0.001), drug abuse (p < 0.001), HIV/AIDS (p < 0.01), presence of Enterococcus species (p < 0.01) and obesity (p < 0.01). The machine-learning models all achieved excellent performance across discrimination (AUC range 0.81-0.84).

CONCLUSION

This study developed three machine-learning models for the prediction of recurrent infections in patients following revision total knee arthroplasty for periprosthetic joint infection. The strongest predictors were previous irrigation and debridement with or without modular component exchange and prior open surgeries. The study findings show excellent model performance, highlighting the potential of these computational tools in quantifying increased risks of recurrent PJI to optimize patient outcomes.

LEVEL OF EVIDENCE

IV.

Current treatments for biofilm-associated periprosthetic joint infection and new potential strategies

Periprosthetic joint infection (PJI) remains a devastating complication after total joint arthroplasty. Bacteria involved in these infections are notorious for adhering to foreign implanted surfaces and generating a biofilm matrix. These biofilms protect the bacteria from antibiotic treatment and the immune system making eradication difficult. Current treatment strategies including debridement, antibiotics, and implant retention, and one- and two-stage revisions still present a relatively high overall failure rate. One of the main shortcomings that has been associated with this high failure rate is the lack of a robust approach to treating bacterial biofilm. Therefore, in this review, we will highlight new strategies that have the potential to combat PJI by targeting biofilm integrity, therefore giving antibiotics and the immune system access to the internal network of the biofilm structure. This combination antibiofilm/antibiotic therapy may be a new strategy for PJI treatment while promoting implant retention.

Surgical Management for Chronic Destructive Septic Hip Arthritis: Debridement, Antibiotics, and Single-Stage Replacement is as Effective as Two-Stage Arthroplasty

Objective

To compare the surgical outcomes of debridement, antibiotics, and single‐stage total hip replacement (DASR) vs two‐stage arthroplasty (two‐stage arthroplasty) for chronic destructive septic hip arthritis (SHA).

Methods

Cases of chronic destructive SHA treated by DASR or two‐stage arthroplasty in our department from January 2008 to October 2021 were retrospectively reviewed. Patient demographic information, perioperative inflammation markers, intraoperative blood loss, microbial culture, and metagenomic new generation sequencing results were recorded. The perioperative complications, hospital stay, hospitalization cost, infection recurrence rate, and Harris Hip Score (HHS) at the last follow‐up were compared between the two groups.

Results

A total of 28 patients were included in the study, including 11 patients who received DASR and 17 patients who received two‐stage arthroplasty. There was no significant difference in demographic information, preoperative serum inflammatory markers, synovial fluid white blood cell count, or percentage of polymorphonuclear leukocytes between the two groups. The DASR group demonstrated significantly lower intraoperative blood loss [(368.2 ± 253.3) mL vs (638.2 ± 170.0) mL, p = 0.002], hospital stay [(22.6 ± 8.1) days vs (43.5 ± 13.2) days, p < 0.0001], and hospitalization expenses [(81,269 ± 11,496) RMB vs (137,524 ± 25,516) RMB, p < 0.0001] than the two‐stage arthroplasty group. In the DASR group, one patient had dislocation as a complication. There were no cases with recurrence of infection. In the two‐stage arthroplasty group, there was one case complicated with spacer fracture, one case with spacer dislocation, and one case with deep vein thrombosis of the lower limbs. There were no cases with recurrence of infection. There were no significant differences in the readmission rate, complication rate, or HHS at the last follow‐up between the two groups.

Conclusions

Both DASR and two‐stage arthroplasty achieved a satisfactory infection cure rate and functional recovery for chronic destructive SHA, and DASR demonstrated significantly lower intraoperative blood loss, hospital stay, and hospitalization costs than two‐stage arthroplasty. For appropriately indicated patients, if microbial data are available and a standardized debridement protocol is strictly followed, DASR can be a treatment option.

Microbiological Advantages of Open Incisional Biopsies for the Diagnosis of Suspected Periprosthetic Joint Infections

Background: Periprosthetic joint infection (PJI) represents a serious complication following total hip (THA) and knee arthroplasty (TKA). When preoperative synovial fluid cultures remain inconclusive, open incisional joint biopsy (OIB) can support causative microorganism identification. Objective: This study investigates the potential benefit of OIB in THA and TKA patients with suspected PJI and ambigious diagnostic results following synovial fluid aspiration. Methods: We retrospectively assessed all patients treated from 2016 to 2020 with suspected PJI. Comparing the microbiology of OIB and the following revision surgery, we calculated sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and the number needed to treat (NNT). Results: We examined the diagnostic validity of OIB in 38 patients (20 female) with a median age of 66.5 years. In THA patients (n = 10), sensitivity was 75%, specificity was 66.67%, PPV was 60%, NPV was 80%, and NNT was 2.5. In TKA patients (n = 28), sensitivity was 62.5%, specificity was 95.24%, PPV was 83.33%, NPV was 86.96%, and NNT was 1.42. Conclusions: Our results indicate that OIB represents an adequate diagnostic tool when previously assessed microbiological results remain inconclusive. Particularly in TKA patients, OIB showed an exceptionally high specificity, PPV, and NPV, whereas the predictive validity of the diagnosis of PJI in THA patients remained low.

Is a preoperative pathogen detection a prerequisite before undergoing one-stage exchange for prosthetic joint infection of the hip?

BACKGROUND

A preoperative pathogen detection is considered a prerequisite before undergoing one-stage exchange for prosthetic joint infection (PJI) according to most guidelines. This study compares patients with and without preoperative pathogen detection undergoing one-stage exchange for PJI of the hip. The authors put up the hypothesis that a preoperative pathogen detection is no prerequisite in selected cases undergoing one-stage exchange.

METHODS

30 consecutive patients with PJI of the hip, treated with one-stage exchange, between 2011 and 2021, were retrospectively included. Mean age was 70 years and mean follow-up 2.1 ± 1.8 years. PJI was defined according to the European Bone and Joint Infection Society. One-stage exchange was performed in (1) chronic PJI longer than 4 weeks, (2) well-retained bone condition, (3) absence of multiple prior revisions for PJI (≤ 2) with absence of difficult-to-treat pathogens in the past, and (4) necessity/preference for early mobility due to comorbidities/age.

RESULTS

One-stage exchange was performed in 20 patients with and in 10 without a preoperative pathogen detection. Age (71 years, 68 years, p = 0.519), sex (50% and 30% males, p = 0.440), American Society of Anesthesiologists Score (2.2, 2.4, p = 0.502), and Charlson Comorbidity Index (3, 4, p = 0.530) did not differ among the two groups. No significant differences were noted concerning preoperative CRP (15 mg/l, 43 mg/l, p = 0.228), synovial cell count (15.990/nl, 5.308/nl, p = 0.887), radiological signs of loosening (55%, 50%, p = 0.999), and intraoperative histopathology. Except a higher rate of coagulase-negative staphylococci (70%, 20%, p = 0.019) in patients with a preoperative pathogen detection, no significant differences in pathogen spectrum were identified among groups. Revision for PJI recurrence was performed in one patient with an initial preoperative pathogen detection (3.3%). Additional revisions were performed for dislocation in two and postoperative hematoma in one patient. Revision rate for both septic and aseptic causes (p = 0.999), stay in hospital (16 and 15 days, p = 0.373) and modified Harris Hip Score (60, 71, p = 0.350) did not differ between groups.

CONCLUSION

Patients with and without a preoperative pathogen detection did not show significant differences concerning baseline characteristics, clinical and functional outcomes at 2 years. An absent preoperative pathogen detection is no absolute contraindication for one-stage exchange in chronic PJI, if involving good bone quality and absence of multiple prior revisions.

Debridement, antibiotics, and implant retention in non-oncological femoral megaprosthesis infections: minimum 5 year follow-up

PURPOSE

Megaprostheses are increasingly utilised outside of the oncological setting, and remain at significant risk of periprosthetic joint infection (PJI). Debridement, antibiotic, and implant retention (DAIR) is an established treatment for PJI, however its use in non-oncological patients with femoral megaprostheses has not been widely reported. There are significant differences in patient physiology, treatment goals, and associated risks between these patient cohorts.

METHODS

We identified 14 patients who underwent DAIR for a PJI of their femoral megaprostheses, between 2000 and 2014, whom had their index procedure secondary to non-oncological indications. Patients were managed as part of a multidisciplinary team, with our standardised surgical technique including exchange of all mobile parts, and subsequent antibiotic therapy for a minimum of 3 months. Patients were followed up for a minimum of 5 years.

RESULTS

Patients included six proximal femoral replacements, five distal femoral replacements, and three total femoral replacements. No patients were lost to follow-up. There were six males and eight females, with a mean age of 67.2 years, and mean ASA of 2.3. Nine patients (64.3%) successfully cleared their infection following DAIR at a minimum of 5 year follow-up. Five patients (35.7%) required further revision surgery, with four patients cleared of infection. No patients who underwent DAIR alone suffered complications as a result of the procedure.

CONCLUSIONS

The use of DAIR in these complex patients can lead to successful outcomes, but the risk of further revision remains high. The success rate (64.3%) remains on par with other studies evaluating DAIR in megaprostheses and in primary arthroplasty. This study indicates judicious use of DAIR can be an appropriate part of the treatment algorithm.

LEVEL OF EVIDENCE

II.

High revision rates following repeat septic revision after failed one-stage exchange for periprosthetic joint infection in total knee arthroplasty

AIMS

The outcome of repeat septic revision after a failed one-stage exchange for periprosthetic joint infection (PJI) in total knee arthroplasty (TKA) remains unknown. The aim of this study was to report the infection-free and all-cause revision-free survival of repeat septic revision after a failed one-stage exchange, and to determine whether the Musculoskeletal Infection Society (MSIS) stage is associated with subsequent infection-related failure.

METHODS

We retrospectively reviewed all repeat septic revision TKAs which were undertaken after a failed one-stage exchange between 2004 and 2017. A total of 33 repeat septic revisions (29 one-stage and four two-stage) met the inclusion criteria. The mean follow-up from repeat septic revision was 68.2 months (8.0 months to 16.1 years). The proportion of patients who had a subsequent infection-related failure and all-cause revision was reported and Kaplan-Meier survival for these endpoints was determined. Patients were categorized according to the MSIS staging system, and the association with subsequent infection was analyzed.

RESULTS

At the most recent follow-up, 17 repeat septic revisions (52%) had a subsequent infection-related failure and the five-year infection-free survival was 59% (95% confidence interval (CI) 39 to 74). A total of 19 underwent a subsequent all-cause revision (58%) and the five-year all-cause revision-free survival was 47% (95% CI 28 to 64). The most common indication for the first subsequent aseptic revision was loosening. The MSIS stage of the host status (p = 0.663) and limb status (p = 1.000) were not significantly associated with subsequent infection-related failure.

CONCLUSION

Repeat septic revision after a failed one-stage exchange TKA for PJI is associated with a high rate of subsequent infection-related failure and all-cause revision. Patients should be counselled appropriately to manage expectations. The host and limb status according to the MSIS staging system were not associated with subsequent infection-related failure. Cite this article: Bone Joint J 2022;104-B(3):386-393.

Results of 'two-in-one' single-stage revision total knee arthroplasty for infection with associated bone loss : prospective five-year follow up

Aims

Periprosthetic joint infection (PJI) occurs in approximately 1% to 2% of total knee arthroplasties (TKA) presenting multiple challenges, such as difficulty in diagnosis, technical complexity, and financial costs. Two-stage exchange is the gold standard for treating PJI but emerging evidence suggests 'two-in-one' single-stage revision as an alternative, delivering comparable outcomes, reduced morbidity, and cost-effectiveness. This study investigates five-year results of modified single-stage revision for treatment of PJI following TKA with bone loss.

Methods

Patients were identified from prospective data on all TKA patients with PJI following the primary procedure. Inclusion criteria were: revision for PJI with bone loss requiring reconstruction, and a minimum five years’ follow-up. Patients were followed up for recurrent infection and assessment of function. Tools used to assess function were Oxford Knee Score (OKS) and American Knee Society Score (AKSS).

Results

A total of 24 patients were included with a mean age of 72.7 years (SD 7.6), mean BMI of 33.3 kg/m² (SD 5.7), and median ASA grade of 2 (interquartile range 2 to 4). Mean time from primary to revision was 3.0 years (10 months to 8.3 years). At revision, six patients had discharging sinus and three patients had negative cultures from tissue samples or aspirates. Two patients developed recurrence of infection: one was treated successfully with antibiotic suppression and one underwent debridement, antibiotics, and implant retention. Mean AKSS scores at two years showed significant improvement from baseline (27.1 (SD 10.2 ) vs 80.3 (SD 14.8); p < 0.001). There was no significant change in mean AKSS scores between two and five years (80.3 (SD 14.8 ) vs 74.1 (SD 19.8); p = 0.109). Five-year OKS scores were not significantly different compared to two-year scores (36.17 (SD 3.7) vs 33.0 (SD 8.5); p = 0.081).

Conclusion

‘Two-in-one’ single-stage revision is effective for treating PJI following TKA with bone loss, providing patients with sustained improvements in outcomes and infection clearance up to five years post-procedure.

Cite this article: Bone Jt Open 2022;3(2):107–113.

Failure Analysis in Multiple TKA Revisions-Periprosthetic Infections Remain Surgeons' Nemesis

BACKGROUND

The aim of this study was to categorize reasons for failure and to analyze the survivorship of multiple total knee arthroplasty (TKA) revisions.

METHODS

The study retrospectively evaluated all multiple TKA revisions performed between 2005 and 2015 at the authors' institutions. Sixty-three patients (35 female, 28 male, age 64 ± 10 years, follow-up 55 ± 36 months) underwent a total of 157 re-revision TKA surgeries (range 2-5). The revision indications were divided up into main diagnoses. Survivorship was evaluated by mixed model analysis.

RESULTS

The main overall reason for re-revision was periprosthetic joint infection (PJI) (48%), followed by instability (12%), polyethylene wear (11%), malpositioning (8%), and aseptic loosening (8%). Survivorship shortened with an increasing number of revision surgeries (p = 0.003). While PJI was in 38% of all cases, the reason for the first revision, incidence increased constantly with the number of revisions (48% at second revision, 55% at third revision, 86% at fourth revision, and 100% at fifth revision, p = 0.022). If periprosthetic infection caused the first revision, patients showed an average of two more septic revisions at follow-up than patients with an aseptic first revision indication (p < 0.001). In 36% of cases, the reason for follow-up surgery in case of periprosthetic infection was again PJI.

CONCLUSION

The probability of survival of the implanted knee arthroplasty is significantly reduced with each subsequent revision. Periprosthetic infection is the main cause of multiple revisions.

Favourable outcomes of repeat one-stage exchange for periprosthetic joint infection of the hip

AIMS

One-stage exchange for periprosthetic joint infection (PJI) in total hip arthroplasty (THA) is gaining popularity. The outcome for a repeat one-stage revision THA after a failed one-stage exchange for infection remains unknown. The aim of this study was to report the infection-free and all-cause revision-free survival of repeat one-stage exchange, and to investigate the association between the Musculoskeletal Infection Society (MSIS) staging system and further infection-related failure.

METHODS

We retrospectively reviewed all repeat one-stage revision THAs performed after failed one-stage exchange THA for infection between January 2008 and December 2016. The final cohort included 32 patients. The mean follow-up after repeat one-stage exchange was 5.3 years (1.2 to 13.0). The patients with a further infection-related failure and/or all-cause revision were reported, and Kaplan-Meier survival for these endpoints determined. Patients were categorized according to the MSIS system, and its association with further infection was analyzed.

RESULTS

A total of eight repeat septic revisions (25%) developed a further infection-related failure, and the five-year infection-free survival was 81% (95% confidence interval (CI) 57 to 92). Nine (28%) underwent a further all-cause revision and the five-year all-cause revision-free survival was 74% (95% CI 52 to 88). Neither the MSIS classification of the host status (p = 0.423) nor the limb status (p = 0.366) was significantly associated with further infection-related failure.

CONCLUSION

Repeat one-stage exchange for PJI in THA is associated with a favourable five-year infection-free and all-cause revision-free survival. Notably, the rate of infection control is encouraging when compared with the reported rates after repeat two-stage exchange. The results can be used to counsel patients and help clinicians make informed decisions about treatment. With the available number of patients, further infection-related failure was not associated with the MSIS host or limb status. Cite this article: Bone Joint J 2022;104-B(1):27-33.

[Strategic approach in periprosthetic joint infections]

With rising numbers of revisions of total arthroplasty procedures of the lower extremities, the annual number of cases of implant-associated infection are also increasing. The conventional two-stage replacement strategy often leads to increased morbidity and mortality of patients; however, in the literature a one-stage exchange procedure shows equally good results if the indications are strictly defined. In addition to the correct diagnostics, the patient history, the inserted implant, the state of health and when applicable the pathogens present play an important role. If, among other factors, the pathogen is uncomplicated combined with a good bone and soft tissue situation and without a large number of previous operations, a single stage replacement of the endoprosthesis may be a suitable option. Despite existing controversies in the literature, this treatment approach seems to demonstrate a reduced hospitalization, reduced costs and improved patient satisfaction with the same re-revision rate. This review article explains the strategic approach to chronic infections of endoprostheses of the lower extremities based on clinical examples and a review of the current literature.

COVID-19 Collateral Damage: Management of Periprosthetic Joint Infection in Malaysia

Background and objective

Periprosthetic joint infection (PJI) is one of the dreaded complications in patients after arthroplasty surgeries, owing to the risk of morbidity and arduous investigations and management associated with it. Nevertheless, as Malaysia is currently battling against the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-induced coronavirus disease 2019 (COVID-19) pandemic head-on, the treatment for other non-life-threatening diseases including PJI has taken a backseat. In this study, we present a case series of 11 patients with PJI who were managed surgically at the largest tertiary hospital in Malaysia and we hope to shed some light on the difficulties we have encountered during this trying period.

Patients and methods

Patients with PJIs who underwent surgical intervention during the ongoing COVID-19 pandemic (March 1, 2020, to June 30, 2021) were reviewed and included in this study. The demographic profile of the patients, presenting complaints, prosthesis topography, biochemical investigative findings, surgical interventions, and short-term outcomes were summarized.

Results

A total of 11 patients were treated surgically at Hospital Kuala Lumpur for PJI. Among them, five patients are still awaiting their second-stage surgeries despite the completion of their antibiotic regimes, and they are fit for the procedure.

Conclusion

The COVID-19 pandemic has wreaked havoc on the treatment of patients with PJI. In a setting with scarce resources, surgeons should strongly consider single-stage revision surgeries for the treatment of patients with PJI.

Elution and Biomechanical Properties of Meropenem-Loaded Bone Cement

Objective

To investigate the biomechanical and elution properties of meropenem‐loaded bone cement.

Methods

Bone cement (Palacos LV) with 5% (2 g/4 0g), 10% (4 g/40 g), and 15% (6 g/40 g) meropenem; 5% (2 g/40 g) and 10% (4 g/40 g) vancomycin; and blank bone cement were prepared in a total of six groups named A2, A4, A6, B2, B4, and A0 (antibiotic‐free). 36 cylinder specimens (6‐mm diameter and 12‐mm height) of all six groups were molded for a compression test. After the compression test, because of mechanical properties below the ISO standard requirements, groups B2, B4 were not subjected to a bending test. So a total of 24 rectangular strip specimens (10‐mm width, 75‐mm length, and 3.3‐mm thickness) for groups A2, A4, A6 and A0 were molded for the bending test. Between‐group differences of compressive strength, bending strength and bending modulus were analyzed. The meropenem standard was prepared as a series of standard solutions to calculate the standard curve. At a constant temperature of 37 °C, separately, meropenem‐loaded bone cement cylinder specimens (12 mm in diameter and 17 mm in length) of A2, A4 and A6 were serially immersed in saline solution without stirring. The eluent drug concentration at 24, 48, 72 h and 6, 12, 24 days was measured and the drug concentration‐time curve of meropenem was constructed.

Results

With the exception of groups B2 and B4, all cements compressive strength values were well above the minimum requirement of the ISO 5833 standard (70 MPa). The compressive strength and bending strength values of group A4 were higher than those of group A0 (P < 0.05), but no difference was found between the A0, A2 and A6 groups (P > 0.05). There were no intergroup differences of bending modulus between the A0, A2, A4 and A6 groups (P > 0.05). A standard curve of meropenem was obtained and a regression equation was constructed: Y = 15.0265 X + 13.5218, r = 1.00. At 37 °C, the release of meropenem was rapid during the first 48 h for all A2, A4, A6 samples, and subsequent release continued to decrease.

Conclusion

When adding up to 15% (6 g/40 g) meropenem to the bone cement, the biomechanical properties were not reduced, and bone cement with 10% (4 g/40 g) meropenem had the best performance. At a constant temperature of 37°C, meropenem can be released from bone cement for up to 24 days.

Cost-effectiveness of Single vs Double Debridement and Implant Retention for Acute Periprosthetic Joint Infections in Total Knee Arthroplasty: A Markov Model

Background

Periprosthetic joint infection (PJI) is a common cause of revision total knee surgery. Although debridement and implant retention (DAIR) has lower success rates in the chronic setting, it is an accepted treatment of acute PJI, whether postoperatively or with late hematogenous seeding. There are two broad DAIR strategies: single debridement and planned double debridement. The purpose of this study is to evaluate the cost-effectiveness of single vs double DAIR for acute PJI in total knee arthroplasty.

Methods

A decision tree using single or double DAIR as the treatment strategy for acute PJI was constructed. Quality-adjusted life years and costs associated with the two treatment arms were calculated. Treatment success rates, failure rates, and mortality rates were derived from the literature. Medical costs were derived from both the literature and Medicare data. A cost-effectiveness plane was constructed from multiple Monte Carlo trials. A sensitivity analysis identified parameters most influencing the optimal strategy decision.

Results

Double DAIR was the optimal treatment strategy both in terms of the health utility state (82% of trials) and medical cost (97% of trials). Strategy tables demonstrated that as long as the success rate of double debridement is 10% or greater than the success rate of a single debridement, the two-stage protocol is cost-effective.

Conclusions

A double DAIR protocol is more cost-effective than single DAIR from a societal perspective.

[Septic revision arthroplasty: how to confirm diagnosis, plan surgery and manage follow-up treatment]

BACKGROUND

Septic revision arthroplasty represents an interdisciplinary challenge in terms of diagnosis as well as surgical and follow-up treatment.

DIAGNOSIS

The implementation of a standardized diagnostic algorithm including anamnesis, clinic, imaging, blood sampling and joint aspiration is essential. Depending on the duration of the symptoms acute (< 3 weeks) and chronic (> 3 weeks) infections are distinguished.

THERAPY

While acute infections show an immature biofilm and can usually be addressed surgically via debridement and changing the mobile parts, chronic infections almost always require a complete change of the implant. This can be done in one or two stages, depending on the general condition of the patient, the pathogen, its resistances as well as the wound conditions. The surgical revision is always followed by a resistance-based antibiotic treatment.

Detailed Revision Risk Analysis after Single- vs. Two-Stage Revision Total Knee Arthroplasty in Periprosthetic Joint Infection: A Retrospective Tertiary Center Analysis

Periprosthetic joint infection (PJI) remains one of the most common causes of revision knee arthroplasty. Controversy continues to surround the proper operative technique of PJI in knee arthroplasty with single- or two-stage replacement. Significant variations are seen in the eradication rates of PJI and in implant survival rates. This detailed retrospective analysis of a single tertiary center is intended to provide further data and insight comparing single- and two-stage revision surgery. A retrospective analysis of all revision total knee arthroplasty (TKA) surgeries from 2013 to 2019 was performed and screened with respect to single- or two-stage TKA revisions. Single- and two-stage revisions were analyzed with regard to implant survival, revision rate, microbiological spectrum, and other typical demographic characteristics. A total of 63 patients were included, with 15 patients undergoing single-stage revision and 48 patients undergoing two-stage revision. The mean follow-up time was 40.7 to 43.7 months. Statistically, no difference was found between both groups in overall survival (54.4% vs. 70.1%, p = 0.68) and implant survival with respect to reinfection (71.4% vs. 82.4%, p = 0.48). Further, high reinfection rates were found for patients with difficult-to-treat organisms and low- to semi-constrained implant types, in comparison to constrained implant types. A statistically comparable revision rate for recurrence of infection could be shown for both groups, although a tendency to higher reinfection rate for single-stage change was evident. The revision rate in this single-center study was comparably high, which could be caused by the high comorbidity and high proportion of difficult-to-treat bacteria in patients at a tertiary center. In this patient population, the expectation of implant survival should be critically discussed with patients.