Aim. Debridement Antibiotics and Implant Retention(DAIR) is a procedure to treat a periprosthetic joint infection(PJI) after Total Hip Arthroplasty(THA) or Total Knee Arthroplasty(TKA). The timing between the primary procedure and the DAIR is likely a determinant for its successful outcome. There are few retrospective studies correlating timing of a DAIR with success (1,2). However, the optimal timing of a DAIR and the chance of success still remains unclear. We aimed to assess the risk of re-revision within one year after a DAIR procedure and to evaluate the timing of the DAIR in primary THA and TKA. An estimation of the chance of a successful DAIR will help clinicians and patients in their decision-making process in case of an acute postoperative PJI. Method. We used data from the Dutch Arthroplasty Register(LROI) and selected all primary THA and TKA in the period 2007–2016 who underwent a DAIR within 12 weeks after primary procedure. A DAIR was defined as a revision for infection in which only modular parts were exchanged. A DAIR was successful if not followed by a re-revision within 1 year after DAIR. The analyses were separated for THA and TKA procedures. Results. 207 DAIRs were performed <4 weeks after THA of which 41(20%) received a re-revision within 1 year; 87 DAIRs were performed between 4–8 weeks of which 15(17%) were re-revised and 11 DAIRs were performed >8 weeks and 2(18%) received a re-revision. 126 DAIRs were performed <4 weeks after TKA of which 27(21%) received a re-revision within 1 year; 68 DAIRs were performed between 4–8 weeks of which 14(21%) were re-revised and 15 DAIRs were performed >8 weeks and 3(20%) received a re-revision. Conclusions. There was no difference in 1-year re-revision rate after a DAIR procedure by timing of DAIR procedure for total hip and knee arthroplasty based on Dutch registry data

Aim. Analysis of microbiological spectrum and resistance patterns as well as the clinical outcome of patients who underwent a Debridement, antibiotics and implant retention (DAIR) procedure in the early phase following failed two-stage exchange arthroplasty of the knee and hip. Method. Of 312 patients treated with two-stage exchange arthroplasty between January 2011 and December 2019, 16 (5.1%) patients (9 knee, 7 hip) underwent a DAIR procedure within 6 months following second stage. We retrospectively analyzed the microbiological results as well as changes in the microbiological spectrum and antibiotic resistance patterns between stages of two-stage exchange arthroplasties and DAIR procedures. Patient's re-revision rates after a minimum follow-up of 12 months following DAIR procedure were evaluated. Moreover, differences between knee and hip and between infected primary total joint replacement (TJRs) and infected revision TJRs as well as patient's host factors and microbiological results regarding the outcome of DAIR were analyzed. Results. In 7/16 (43.8%) patients the first and second stage procedure was culture positive, in 5/16 (31.2%) patients the first and second stage procedure was culture negative and in 4/16 (25%) patients the first stage procedure was culture positive, and the second stage procedure was culture negative. Moreover, 6 (37.5%) out of 16 DAIR procedures showed a positive microbiological result. In 5/7 (71.4%) patients with culture positive second stage procedure a different microorganism compared to first stage procedure was detected. In 6/6 (100%) patients with culture positive DAIR procedure, the isolated microorganisms were not detected during first or second stage procedure. An additional re-revision surgery was necessary in 4/16 (25%) patients after a median time of 31 months (range, 12 to 138 months) at a mean follow up of 63.1 ± 32 months following DAIR procedure. Highest re-revision rates were found in patients with culture positive second stage procedures (3/7 [42.9%]) and patients with culture positive DAIR procedures (2/6 [33.3%]). Conclusions. DAIR procedure seems to be a useful early treatment option following failed two-stage exchange arthroplasty. The re-revision rates were independent of different combinations of culture positive and culture negative first and second stage procedures. The high number of changes in the microbiological spectrum needs to be considered in the treatment of PJI

Aims. Fracture-Related Infection (FRI) is a severe complication caused by microbial infection of bone. It is imperative to gain more insight into the potentials and limitations of Debridement, Antibiotics and Implant Retention (DAIR) to improve future FRI treatment. The aims of this study were to: 1) determine how time to surgery affects the success rate of DAIR procedures of the lower leg performed within 12 weeks after the initial fracture fixation operation and 2) evaluate whether appropriate systemic antimicrobial therapy affects the success rate of a DAIR procedure. Methods. This multinational retrospective cohort study included patients of at least 18-years of age who developed an FRI of the lower leg within 12 weeks after the initial fracture fixation operation, between January 1st 2015 to July 1st 2020. DAIR success was defined by the absence of recurrence of infection, preservation of the affected limb and retention of implants during the initial treatment. The antimicrobial regimen was considered appropriate if the pathogen(s) was susceptible to the given treatment at the correct dose as per guideline. Logistic regression modelling was used to assess factors that could contribute to the DAIR success rate. Results. A total of 120 patients were included, of whom 70 DAIR patients and 50 non-DAIR patients. Within a median follow-up of 35.5 months, 21.4% of DAIR patients developed a recurrent FRI compared to 12.0% of non-DAIR patients. The DAIR procedure was successful in 45 patients (64.3%). According to the Willenegger and Roth classification, DAIR success was achieved in 66.7% (n=16/24) of patients with an early infection (<2 weeks), 64.4% (n=29/45) of patients with a delayed infection (2–10 weeks) and 0.0% (0/1) of patients with a late infection (>10 weeks). Univariate analysis showed that the duration of infection was not associated with DAIR success in this cohort (p=0.136; OR: 0.977; 95%CI: [0.947–1.007]). However, an appropriate antimicrobial regimen was associated with success of DAIR (p=0.029; OR: 3.231; 95%CI: [1.138–9.506]). Conclusions. Although the results should be interpreted with caution, an increased duration of infection was not associated with a decreased success rate of a DAIR procedure in patients with FRI of the lower leg. The results of this study highlight the multifactorial contribution to the success of a DAIR procedure and emphasize the importance of adequate antimicrobial treatment. Therefore, time to surgery should not be the only key-factor when considering a DAIR procedure to treat FRI

Periprosthetic joint infection is a serious complication of primary total hip replacement (THR) with significant associated morbidity. In acute infection, Debridement, Antibiotics and Implant Retention (DAIR) may be considered. Current national guidelines recommend a DAIR should be performed by “an experienced arthroplasty surgeon┕ but do not specify the need for this to be a revision arthroplasty surgeon. We investigated outcomes in our NHS Trust of DAIR procedures performed by revision and non-revision arthroplasty surgeons. Infection registry data and patient records were analysed for all DAIR procedures of infected primary THRs between 2017 and 2021. Data collected included details of the primary surgery, the presentation with infection, the DAIR procedure and any subsequent complications including return to theatre at any time point. Routinely collected pre- and post-operative patient reported outcome measures (PROMs) were reviewed. 54 periprosthetic joint infections of primary THRs received a DAIR procedure. 41 DAIRs were performed by a revision surgeon and 13 by non-revision surgeons. There was no significant difference in time from primary THR to presentation with infection, time from presentation to DAIR or pre-operative C-reactive protein between the two groups. In 21 (38.9%) patients the DAIR procedure was classed as a treatment failure; 17 patients (31.5%) returned to theatre for further revision surgery, one (2.4%) died related to infection and three (5.6%) had persistent infection but did not receive further surgery. Treatment failure was significantly higher in the non-revision surgeon group (9/13 (69.2%)) than in the revision surgeon group (12/41 (29.3%)) (p = 0.02). Overall, improvement in PROMs after DAIR was seen at both six and 12 months. The overall success rate of DAIR was 61.1% and there was a sustained improvement in PROMs after surgery. However, there was a significant difference in failure rates between revision surgeons and non-revision surgeons

Abstract. Background. Infections are rare and poorly studied complications of unicompartmental knee athroplasty (UKA) surgery. They are significantly less common compared to infections after total knee arthroplasties (TKAs). Optimal management of periprosthetic joint infections (PJIs) after a UKA is not clearly defined in the literature. We present the results of a multicentre retrospective series of UKA PJIs treated with Debridement, Antibiotics and Implant Retention (DAIR). Methodology. Patients presenting between January 2016 and December 2019 with early UKA infection were identified at three specialist centres using the Musculoskeletal Infection Society (MSIS) criteria. All patients underwent a standardized treatment protocol consisting of the DAIR procedure and antibiotic therapy comprising two weeks of intravenous (IV) antibiotics followed by six weeks of oral therapy. The main outcome measure was overall survivorship free from reoperation for infection. Results. A total of 3225 UKAs (2793 (86.2%) medial and 432 (13.8%) lateral UKAs) were performed between January 2016 and December 2019. Nineteen patients had early infections necessitating DAIR. The mean follow-up period was 32.5 months. DAIR showed an overall survivorship free from septic reoperation of 84.2%, with an overall survivorship free from all-cause reoperation of 78.95%. The most common bacteria were Coagulase-negative Staphylococci, Staphylococcus aureus and Group B Streptococci. Three patients required a second DAIR procedure but remained free from re-infection at follow-up obviating the need for more demanding, staged revision surgery. Conclusions. In infected UKAs, the DAIR procedure produces a high rate of success, with a high survivorship of the implant

Aim. To date, the value of culture results after a debridement, antibiotics and implant retention (DAIR) for early (suspected) prosthetic joint infection (PJI) as risk indicators in terms of prosthesis retention is not clear. At one year follow-up, the relative risk of prosthesis removal was determined for culture-positive and culture-negative DAIRs after primary total hip or knee arthroplasty. The secondary aim was to explore differences in patient characteristics, infection characteristics and outcomes between these two groups. Methods. A retrospective regional registry study was performed in a group of 359 patients (positive cultures: n = 299, negative cultures n = 60) undergoing DAIR for high suspicion of early PJI in the period from 2014 to 2019. Differences in patient characteristics, deceased patients and number of subsequent DAIRs between the positive and negative DAIR groups were analyzed using independent t-tests, Mann-Whitney, Pearson's Chi-square tests and Fisher's Exact tests. Results. Overall implant survival rate following DAIR was 89%. The relative risk for prosthesis removal was 7.4 times higher (95% confidence interval (CI) 1.0–53.1) in the positive DAIR group (37/299, 12.4%) compared to the negative DAIR group (1/60, 1.7%). The positive group had a higher body mass index (p = 0.034), rate of wound leakage of >10 days (p = 0.016) and more subsequent DAIRs (p = 0.006). Conclusion. Since implant survival results after DAIR are favorable, the threshold to perform a DAIR procedure in early PJI should be low in order to retain the prosthesis. A DAIR procedure in case of negative cultures does not seem to have unfavorable results in terms of prosthesis retention

Background. Acute soft tissue defects (wound dehiscence or necrosis) after a total knee arthroplasty (TKA) may be the cause of the devasting complication of deep infection. When a medium (4–6cm) defect is present, in patellar or infra-patellar localization, a medial hemi-gastrocnemius flap is widely used to cover it, because of its low morbidity and high functional results. Normally, this coverage is not associated to a debridement, antibiotics and implant retention surgery (DAIR). When facing this situation, we should consider associating to the coverage treatment, like muscle flap, a DAIR procedure, in order to treat the possible acute infection, even when the diagnosis of infection is not clear. We could not find any studies comparing the benefice of this association in the same surgical act to isolated treatment of soft tissue defects. Our hypothesis was that when a TKA surgical wound defect is present, the risk of an acute infection is elevated and the patient would benefit from a muscle flap with DAIR procedure and polyethylene exchange. Methods. We performed a retrospective study to compare TKA infection clearance in patients with DAIR and flap in the same surgical act against those who received an isolated flap procedure for soft tissue coverage after an acute surgical wound defect. Patients were identified from a prospectively collated TKA database. Between 2005 and 2021, 19 patients met our inclusion criteria. A medial hemi-gastrocnemius flap was performed in 15 patients (78%). Healing or TKA infection clearance was defined as the presence of the original prosthesis after soft tissue coverage intervention, no need of DAIR after soft tissue coverage or no suppressive antibiotic treatment. Results. We obtained two groups. The first one, included those patients who had received the association of DAIR with polyethylene exchange and Flap (n=12). The other group included those who had received an isolated flap (n=7). We did not find differences in comorbidities and risk factors between both groups. In the combination treatment group 66,6% patients healed after treatment. In the other group, these favourable results decrease to 42,9%. Even though results were better in the combination treatment group, no significant differences were found. Conclusion. Although no significant statistical differences were found, probably due to small sample, the association of DAIR with polyethylene exchange and muscle flap is recommended in the coverage over an acute dehiscence or necrosis after TKA. More studies, with bigger sample are needed to extrapolate results in general population

Aims. Fracture-related infection (FRI) is commonly classified based on the time of onset of symptoms. Early infections (< two weeks) are treated with debridement, antibiotics, and implant retention (DAIR). For late infections (> ten weeks), guidelines recommend implant removal due to tolerant biofilms. For delayed infections (two to ten weeks), recommendations are unclear. In this study we compared infection clearance and bone healing in early and delayed FRI treated with DAIR in a rabbit model. Methods. Staphylococcus aureus was inoculated into a humeral osteotomy in 17 rabbits after plate osteosynthesis. Infection developed for one week (early group, n = 6) or four weeks (delayed group, n = 6) before DAIR (systemic antibiotics: two weeks, nafcillin + rifampin; four weeks, levofloxacin + rifampin). A control group (n = 5) received revision surgery after four weeks without antibiotics. Bacteriology of humerus, soft-tissue, and implants was performed seven weeks after revision surgery. Bone healing was assessed using a modified radiological union scale in tibial fractures (mRUST). Results. Greater bacterial burden in the early group compared to the delayed and control groups at revision surgery indicates a retraction of the infection from one to four weeks. Infection was cleared in all animals in the early and delayed groups at euthanasia, but not in the control group. Osteotomies healed in the early group, but bone healing was significantly compromised in the delayed and control groups. Conclusion. The duration of the infection from one to four weeks does not impact the success of infection clearance in this model. Bone healing, however, is impaired as the duration of the infection increases. Cite this article: Bone Joint Res 2024;13(3):127–135

Introduction. In recent years, many studies demonstrated the efficacy of an early switch to oral antibiotics after surgical treatment in orthopaedic related infections. However, large analyses on periprosthetic joint infections (PJIs) are lacking. Material and Methods. We conducted a retrospective observational multicenter study in patients diagnosed with an early postoperative PJI (i.e less than 3 months after the index arthroplasty) treated with debridement, antibiotics and implant retention (DAIR). Patients from Europe and the USA were included. These two cohorts served as a quasi-randomised trial since an early oral antibiotic switch is routine practice in Europe versus a long duration of intravenous (IV) antibiotic treatment in the USA. Failure was defined as the clinical need for: i) a second DAIR, ii) implant removal, iii) suppressive antibiotic treatment or iv) infection related death. Results. A total of 668 patients were included. 277 received IV antibiotics for <14 days, 232 were given IV antibiotics between 14 - 27 days and 159 received IV antibiotics for >27 days. The overall 1-year failure rate within the 3 groups was 41.5%, 44.4% and 42.1%, respectively (P 0.80), and mainly comprised the need for a second DAIR. The results did not change when analyzing patients with or without obesity, the causative microorganism or the type of oral antibiotics. Conclusion. In early postoperative PJIs, a longer duration of IV antibiotic treatment is not associated with a lower failure rate of a DAIR procedure

Aims. Although low-intensity pulsed ultrasound (LIPUS) combined with disinfectants has been shown to effectively eliminate portions of biofilm in vitro, its efficacy in vivo remains uncertain. Our objective was to assess the antibiofilm potential and safety of LIPUS combined with 0.35% povidone-iodine (PI) in a rat debridement, antibiotics, and implant retention (DAIR) model of periprosthetic joint infection (PJI). Methods. A total of 56 male Sprague-Dawley rats were established in acute PJI models by intra-articular injection of bacteria. The rats were divided into four groups: a Control group, a 0.35% PI group, a LIPUS and saline group, and a LIPUS and 0.35% PI group. All rats underwent DAIR, except for Control, which underwent a sham procedure. General status, serum biochemical markers, weightbearing analysis, radiographs, micro-CT analysis, scanning electron microscopy of the prostheses, microbiological analysis, macroscope, and histopathology evaluation were performed 14 days after DAIR. Results. The group with LIPUS and 0.35% PI exhibited decreased levels of serum biochemical markers, improved weightbearing scores, reduced reactive bone changes, absence of viable bacteria, and decreased inflammation compared to the Control group. Despite the greater antibiofilm activity observed in the PI group compared to the LIPUS and saline group, none of the monotherapies were successful in preventing reactive bone changes or eliminating the infection. Conclusion. In the rat model of PJI treated with DAIR, LIPUS combined with 0.35% PI demonstrated stronger antibiofilm potential than monotherapy, without impairing any local soft-tissue. Cite this article: Bone Joint Res 2024;13(7):332–341

Aim. The number of periprosthetic joint infections (PJI) is increasing due to ageing population and increasing numbers of arthroplasty procedures and treatment is costly. Aim of the study was to analyze the direct healthcare costs of PJI in Europe for total hip arthroplasties (THA) and total knee arthroplasties (TKA). Method. A systematic review in PubMed with search of direct costs of PJI in European countries was performed. Thereby the term cost* AND (infection OR PJI) AND (prosthesis OR knee OR hip OR “TKA” OR “THA” OR arthroplast*) was combined with each European country to detect relevant publications. Publications with definition of performed procedure and joint localization were included into further analysis. The mean value of direct healthcare cost was calculated for the respective joint and the respective operation performed. Results. Screening revealed 1,274 eligible publications. After review of abstracts and full-texts n=11 manuscripts were included into final analysis (Figure 1). The mean combined direct hospital costs for revision for PJI after TKA and THA was 26,311€. Mean costs for revision procedures for PJI after TKA were 24,617€. Direct costs for TKA-PJI treated with debridement, antibiotics and implant retention (DAIR) were on average 10,121€. For two-stage revisions in knee arthroplasties total average costs were 30,829€. Referring to revision surgery for PJI in THA, the mean hospital costs in Europe were 28,005€. For a DAIR procedure direct healthcare costs of 5,528€ were identified. Two-stage revision cost on average 31,217€. Conclusions. PJIs are associated with significant direct healthcare costs. The financial burden of up to 30,000 € per case underlines the impact of the disease for European health care system. However, the number of detailed reports on PJI costs is limited and the quality of the literature is limited. There is a strong need for more detailed financial data on the costs of PJI treatment. For any tables or figures, please contact the authors directly

Aims. Arthroplasty surgery of the knee and hip is performed in two to three million patients annually. Periprosthetic joint infections occur in 4% of these patients. Debridement, antibiotics, and implant retention (DAIR) surgery aimed at cleaning the infected prosthesis often fails, subsequently requiring invasive revision of the complete prosthetic reconstruction. Infection-specific imaging may help to guide DAIR. In this study, we evaluated a bacteria-specific hybrid tracer (. 99m. Tc-UBI. 29-41. -Cy5) and its ability to visualize the bacterial load on femoral implants using clinical-grade image guidance methods. Methods. 99m. Tc-UBI. 29-41. -Cy5 specificity for Stapylococcus aureus was assessed in vitro using fluorescence confocal imaging. Topical administration was used to highlight the location of S. aureus cultured on femoral prostheses using fluorescence imaging and freehand single photon emission CT (fhSPECT) scans. Gamma counting and fhSPECT were used to quantify the bacterial load and monitor cleaning with chlorhexidine. Microbiological culturing helped to relate the imaging findings with the number of (remaining) bacteria. Results. Bacteria could be effectively stained in vitro and on prostheses, irrespective of the presence of biofilm. Infected prostheses revealed bacterial presence on the transition zone between the head and neck, and in the screw hole. Qualitative 2D fluorescence images could be complemented with quantitative 3D fhSPECT scans. Despite thorough chlorhexidine treatments, 28% to 44% of the signal remained present in the locations of the infection that were identified using imaging, which included 500 to 2,000 viable bacteria. Conclusion. The hybrid tracer . 99m. Tc-UBI. 29-41. -Cy5 allowed effective bacterial staining. Qualitative real-time fluorescence guidance could be effectively combined with nuclear imaging that enables quantitative monitoring of the effectiveness of cleaning strategies. Cite this article: Bone Joint Res 2023;12(1):72–79

Aim. Debridement, antibiotics and implant retention (DAIR) are considered as an optimal curative treatment option for prosthetic joint infection (PJI) when the biofilm is still immature and radical debridement is achievable. There are two main groups of patients suitable for DAIR. Those with an early acute PJI and patients with acute hematogenous PJI. However, there is also a third group of early PJI resulting from a wound healing problem or leaking hematoma. These may be either high or low grade depending on the microorganisms that infected the artificial joint “per continuitatem”. Methods. We retrospectively analysed 100 successive DAIR procedures on prosthetic hip and knee joints performed between January 2010 and January 2022, from total of 21000 primary arthroplasties implanted within the same time period. We only included PJI in primary total replacements with no previous surgeries on the affected joint. Patients data (demographics, biochemical, microbiological, histopathological results, and outcomes) were collected from hospital bone and joint infection registry. The aim of surgery was radical debridement and the mobile parts exchange. The standardized antibiotic regime based on antibiofilm antibiotics. Results. The mean age of patients was 70 years (60% women, 43 hips, 57 knees) with a mean follow-up of 3 years. 45 cases were early acute or related to wound healing problems, 55 were hematogenous PJI. 25 patients received preoperative antibiotics. 6 of these were culture negative. The mean symptom duration was 7 days. Mean age of the prosthesis was 30 days for early, and 1064 days for the hematogenous group. Conclusions. In our cohort the success rate of DAIR is 94% which indicates that the protocol is highly successful in PJI with short-lasting symptoms and “debridable” joints. Antibiotic protocol violation and duration of symptoms may have a role in failures

Aim. Antimicrobial peptides occur naturally in our intrinsic immune system. PLG0206 is a novel, engineered, 24-amino acid peptide which has broad-spectrum antimicrobial activity, including in biofilm and against multi-drug resistant pathogens (1,2). This is the first clinical study to evaluate the safety and tolerability of PLG0206 when administered via an irrigation solution in patients with periprosthetic joint infections (PJI) following total knee arthroplasty (TKA) during debridement, antibiotics, and implant retention (DAIR). Secondary objectives were to evaluate pharmacokinetics (PK), biomarkers and initial clinical efficacy at one year post-DAIR procedure. Method. This prospective, multicenter, open-label, interventional study assessed two dose levels of PLG0206. Fourteen patients underwent revision for PJI after TKA. At the end of debridement, they received a single intra-articular irrigation of PLG0206 into the wound cavity lasting 15 minutes at concentrations of 3 mg/mL (n=7) or 10 mg/mL (n=7). Patients received post-operative care and intravenous/oral antimicrobial therapy as per their institutional guidelines. Patients were monitored for safety and signs of relapse or persistent infection for 12 months post study drug administration and PK and blood biomarkers were assessed. Results. All patients completed their final study assessment at Day 365. Over the 1-year follow-up, only one recurrence (7%) was noted at Day 169 in the low-dose cohort. Following dosing, nine patients (64.3%) had limited systemic exposure; maximum plasma concentration occurred 1-hour post-administration and declined rapidly to undetectable levels by 24 hours following treatment in all patients. The incidence of drug related treatment-emergent adverse events (TEAEs) was low. Two patients, both in the higher dose cohort, experienced a transient drug related TEAE; one of hypertransaminasaemia and one of neuralgia. Both events were moderate in severity and resolved within two weeks of onset. Conclusions. A single 15-minute irrigation of PLG0206 into the wound cavity of patients undergoing a DAIR procedure for PJI following TKA, is safe and well tolerated by patients. This new antimicrobial peptide offers a promising therapeutic option in musculoskeletal infection. The initial clinical efficacy is encouraging but now needs to be investigated in a much larger clinical trial

Aim. The time to onset of symptoms after fracture fixation is still commonly used to classify fracture-related infections (FRI). Early infections (<2 weeks) can often be treated with debridement, systemic antibiotics, irrigation, and implant preservation (DAIR). Late infections (>10 weeks) typically require implant removal as mature, antibiotic-tolerant biofilms have formed. However, the recommendations for delayed infections (2–10 weeks) are not clearly defined. Here, infection healing and bone healing in early and delayed FRI is investigated in a rabbit model with a standardized DAIR procedure. Method. Staphylococcus aureus was inoculated into 17 rabbits after plate osteosynthesis in a humerus osteotomy. The infection developed either one week (early group, n=6) or four weeks (delayed group, n=6) before a standardized DAIR procedure and microbiological analysis were performed. Systemic antibiotics were administered for six weeks (two weeks: Nafcillin+Rifampin, four weeks: Levofloxacin+Rifampin). A control group (n=5) also underwent a revision operation (debridement and irrigation) after four weeks, but received no antibiotic treatment. Rabbits were euthanized seven weeks after the revision operation. Bone healing was assessed using a modified radiographic union score for tibial fractures (mRUST). After euthanasia, a quantitative microbiological examination of the entire humerus, adjacent soft tissues, and implants was performed. Results. All animals were infected at the time of revision surgery, with the bacterial load in the early group (especially in soft tissues) being greater than in the delayed group and control group. This indicates infiltration of bacteria into areas that are more difficult to reach after four weeks of debridement. The infection was eradicated in all animals in both the early and delayed groups at euthanasia, but not in the control group (CFU median (IQR): 2.1×10. 7. (1.3×10. 7. -2.6×10. 7. ). The osteotomy healed in the early group, while bone healing was significantly impaired in both the delayed group and control group (mRUST median (IQR): early group: 16 (14–16), delayed group: 7.5 (6–10), control: 7 (5.5–9); early vs. delayed: p=0.0411, early vs. control p=0.0065). Conclusion. The maturation of the infection between the first and fourth week does not affect the success of infection eradication in this rabbit FRI model. However, bone healing appears to be impaired with increasing duration of infection

Aims. The aims of this study were to determine the incidence and factors for developing periprosthetic joint infection (PJI) following hemiarthroplasty (HA) for hip fracture, and to evaluate treatment outcome and identify factors associated with treatment outcome. Methods. A retrospective review was performed of consecutive patients treated for HA PJI at a tertiary referral centre with a mean 4.5 years’ follow-up (1.6 weeks to 12.9 years). Surgeries performed included debridement, antibiotics, and implant retention (DAIR) and single-stage revision. The effect of different factors on developing infection and treatment outcome was determined. Results. A total of 1,984 HAs were performed during the study period, and 44 sustained a PJI (2.2%). Multiple logistic regression analysis revealed that a higher CCI score (odds ratio (OR) 1.56 (95% confidence interval (CI) 1.117 to 2.187); p = 0.003), peripheral vascular disease (OR 11.34 (95% CI 1.897 to 67.810); p = 0.008), cerebrovascular disease (OR 65.32 (95% CI 22.783 to 187.278); p < 0.001), diabetes (OR 4.82 (95% CI 1.903 to 12.218); p < 0.001), moderate-to-severe renal disease (OR 5.84 (95% CI 1.116 to 30.589); p = 0.037), cancer without metastasis (OR 6.42 (95% CI 1.643 to 25.006); p = 0.007), and metastatic solid tumour (OR 15.64 (95% CI 1.499 to 163.087); p = 0.022) were associated with increasing PJI risk. Upon final follow-up, 17 patients (38.6%) failed initial treatment and required further surgery for HA PJI. One-year mortality was 22.7%. Factors associated with treatment outcome included lower preoperative Hgb level (97.9 g/l (SD 11.4) vs 107.0 g/l (SD 16.1); p = 0.009), elevated CRP level (99.1 mg/l (SD 63.4) vs 56.6 mg/l (SD 47.1); p = 0.030), and type of surgery. There was lower chance of success with DAIR (42.3%) compared to revision HA (66.7%) or revision with conversion to total hip arthroplasty (100%). Early-onset PJI (≤ six weeks) was associated with a higher likelihood of treatment failure (OR 3.5 (95% CI 1.2 to 10.6); p = 0.007) along with patients treated by a non-arthroplasty surgeon (OR 2.5 (95% CI 1.2 to 5.3); p = 0.014). Conclusion. HA PJI initially treated with DAIR is associated with poor chances of success and its value is limited. We strongly recommend consideration of a single-stage revision arthroplasty with cemented components. Cite this article: Bone Jt Open 2022;3(12):924–932

Aim. To describe the management of PJI due to S. aureus in CRIOAcs in 2019 and to particularly focus on the evaluation of the efficacy of DAIR regarding control of infection and risk factors for failure up to 12 months. Method. Thirteen CRIOAcs were selected to participate to the study. Data concerning the management of all the PJI in the year 2019 were retrospectively collected and registered in eCRFs. Inclusion criteria were: ≥ 18 years old patients with S. aureus ± other bacteria (in per surgical procedure sample); knee or hip PJI and with clinical signs of infection. Patients treated with bacteriophages were excluded. All eligible patients were notified by an information letter. Patients treated by the DAIR procedure were selected, and rate of control of infection (no inflammatory local signs or no new surgical procedure or no S. aureus in case of puncture) was analyzed using Kaplan Meier method and risk factors for failure at 12 months were assessed using Cox regression model. Results. A total of 978 PJI were managed in the 9 CRIOAcs, including 238 hip and knee PJI due to S. aureus and 79 to S. aureus plus another bacteria. Among all of them, 154 were managed with DAIR, and 100 fulfilled inclusion criteria, notifying no opposition to their data collection. The median age was 73.0 years; 57% were male, the median Charlson score was 4.0; 66% had hip PJI. A total of 45 failure were observed during the period studied. At 12 months, the control rate was 58. 7% [36.5–75.4], 49.3% [34.3–62.7] in in early and late PJI respectively according to Tsukuyama classification and 49.6% [30.5–66.1], 54.1% [37.7 – 68.0] in early and delayed/late PJI respectively according to Zimmerli classification, 56.6% [39.5–70.5] in case of mobile part exchange, 53.4% [35.3–68.5] for MRSA PJI and 63.4% [50.5–73. 8] in patients treated with rifampicin. No rifampicin intake was the only significative risk factor for failure in univariate analysis (HR=0.31 (0.17–0.57), p=0.0002), and remained significant after adjustment on Charlson score (aHR=0.34 (0.18–0.64), p=0.0008). Conclusions. The DAIR procedure is frequently performed in patients with acute and late PJI, and is associated with a high rate of failure, especially for patients who cannot receive rifampin. There is a strong rational to assess the use of bacteriophages during the DAIR, as bacteriophages have antibiofilm activity in vitro, and could improve the efficacy of the DAIR to control the disease

Aims. Pelvic discontinuity is a rare but increasingly common complication of total hip arthroplasty (THA). This single-centre study evaluated the performance of custom-made triflange acetabular components in acetabular reconstruction with pelvic discontinuity by determining: 1) revision and overall implant survival rates; 2) discontinuity healing rate; and 3) Harris Hip Score (HHS). Methods. Retrospectively collected data of 38 patients (39 hips) with pelvic discontinuity treated with revision THA using a custom-made triflange acetabular component were analyzed. Minimum follow-up was two years (mean 5.1 years (2 to 11)). Results. There were eight subsequent surgical interventions. Two failures (5%) of the triflange acetabular components were both revised because of deep infection. There were seven (18%) patients with dislocation, and five (13%) of these were treated with a constraint liner. One patient had a debridement, antibiotics, and implant retention (DAIR) procedure. In 34 (92%) hips the custom-made triflange component was considered stable, with a healed pelvic discontinuity with no aseptic loosening at midterm follow-up. Mean HHS was 80.5 (48 to 96). Conclusion. The performance of the custom triflange implant in this study is encouraging, with high rates of discontinuity healing and osteointegration of the acetabular implant with no aseptic loosening at midterm follow-up. However, complications are not uncommon, particularly instability which we successfully addressed with constrained liners. Cite this article: Bone Jt Open 2022;3(11):867–876

Aim. The purpose of this study is to report the overall infection control rate and prognostic factors associated with acute, hematogenous and chronic PJIs treated with DAIR. Methods. All DAIR procedures performed at 2 institutions from 2009 to 2018 (n=104) were reviewed and numerous data were recorded, including demographics, preoperative laboratory tests, Charleston Comorbidity Index, surgical information and organism culture results. Treatment success was defined according to the criteria reported by Diaz-Ledezma. A multivariable analysis was utilized to identify prognostic factors associated with treatment and a Kaplan-Meier survival analysis was used to depict infection control rate as a function of time. Results. The overall treatment success rate in the current cohort of patients was 67.3% at a median 38.6 (23.5–90.7) months follow-up. Patients with a duration of infectious symptoms greater than 10 days were more likely to fail (P=0.035, odds ratio 8.492, 95% confidence interval 1.159–62.212). There was no difference among acute, hematogenous and chronic infections in terms of failure rate even when time was considered (p=0.161). Conclusion. With careful patient selection, DAIR is a reasonable treatment option for PJI and its use in the setting of chronic infection does not appear to be a contraindication. Performing the DAIR procedure within 10 days of the presentation of symptoms had higher rates of treatment success

Aims. The aim of this meta-analysis is to assess the association between exchange of modular parts in debridement, antibiotics, and implant retention (DAIR) procedure and outcomes for hip and knee periprosthetic joint infection (PJI). Methods. We conducted a systematic search on PubMed, Embase, Web of Science, and Cochrane library from inception until May 2021. Random effects meta-analyses and meta-regression was used to estimate, on a study level, the success rate of DAIR related to component exchange. Risk of bias was appraised using the (AQUILA) checklist. Results. We included 65 studies comprising 6,630 patients. The pooled overall success after DAIR for PJI was 67% (95% confidence interval (CI) 63% to 70%). This was 70% (95% CI 65% to 75%) for DAIR for hip PJI and 63% (95% CI 58% to 69%) for knee PJI. In studies before 2004 (n = 27), our meta-regression analysis showed a 3.5% increase in success rates for each 10% increase in component exchange in DAIR for hip PJI and a 3.1% increase for each 10% increase in component exchange for knee PJI. When restricted to studies after 2004 (n = 37), this association changed: for DAIR for hip PJI a decrease in successful outcome by 0.5% for each 10% increase in component exchange and for DAIR for knee PJI this was a 0.01% increase in successful outcome for each 10% increase in component exchange. Conclusion. This systematic review and meta-regression found no benefit of modular component exchange on reduction of PJI failure. This limited effect should be weighed against the risks for the patient and cost on a case-by-case basis. The association between exchange of modular components and outcome changed before and after 2004. This suggests the effect seen after 2004 may reflect a more rigorous, evidence-based, approach to the infected implant compared to the years before. Level of Evidence: Level III. Cite this article: Bone Jt Open 2021;2(10):806–812