Aims. The purpose of this study was to determine whether intracellular Staphylococcus aureus is associated with recurrent infection in a rat model of open fracture. Methods. After stabilizing with Kirschner wire, we created a midshaft femur fracture in Sprague-Dawley rats and infected the wound with green fluorescent protein (GFP)-tagged S. aureus. After repeated debridement and negative swab culture was achieved, the isolation of GFP-containing cells from skin, bone marrow, and muscle was then performed. The composition and viability of intracellular S. aureus in isolated GFP-positive cells was assessed. We suppressed the host immune system and observed whether recurrent infection would occur. Finally, rats were assigned to one of six treatment groups (a combination of antibiotic treatment and implant removal/retention). The proportion of successful eradication was determined. Results. Green fluorescent protein-containing cells were successfully isolated after the swab culture was negative from skin (n = 0, 0%), muscle (n = 10, 100%), and bone marrow (n = 10, 100%) of a total of ten rats. The phagocytes were predominant in GFP-positive cells from muscle (73%) and bone marrow (81%) with a significantly higher viability of intracellular S. aureus (all p-values < 0.001). The recurrent infection occurred in up to 75% of rats after the immunosuppression. The proportion of successful eradication was not associated with implant retention or removal, and the efficacy of linezolid in eradicating intracellular S. aureus is significantly higher than that of vancomycin. Conclusion. Intracellular S. aureus is associated with recurrent infection in the rat model of open fracture. Usage of linezolid, a membrane-permeable antibiotic, is an effective strategy against intracellular S. aureus. Cite this article:Bone Joint Res. 2020;9(2):71–76

Background

Infection is one of the most severe comlications of the total arthroplasty. We sometimes encounter cases, which are very hard to finish repeated recurrence. Usage of steroids, immunosuppressants, and biologics would possibly effect to the incidence of the prosthetic infection and to the result of its treatment. Biologics have drastically decreased the number of the total arthoplasic patients, on the other hand, we must be more careful about the infectious conditions. For the infection two stage revision surgery; first removal and antibiotics cement spacer insertion then reimplantation later; is often chosen but sometimes one time antibiotics cement spacer cannot stop the infection and requires multi times spacer insertion. In those cases the dead spaces, poor blood supply and tight skin could be the cause of the recurrence. For these cases we had been performing musclo-cutaneal flap and successfully finish the infection.

Aims

Fracture-related infections (FRIs) are a devastating complication of fracture management. However, the impact of FRIs on mental health remains understudied. The aim of this study was a longitudinal evaluation of patients’ psychological state, and expectations for recovery comparing patients with recurrent FRI to those with primary FRI.

Aim. We reviewed a cohort of individuals with recurrent orthopaedic infection to describe the relative rates of microbial persistence vs re-infection at recurrence surgery. Method. A cohort of 125 individuals with recurrent infection (prosthetic joint infection, fracture-related infection and osteomyelitis) from two centres in the UK between 2007 and 2021. Electronic patient records were reviewed to identify culture results from surgical samples at index surgery and the next operation for recurrent infection. Antibiotic sensitivity results were recorded as sensitive, intermediate or resistant according to contemporary sensitivity testing guidelines. Results. Among patients with recurrent infection, 78/125 (62.4%) were male, with a median age 64 years (IQR 51–73y). 76 had prosthetic joint infection, and 49 had fracture related infection or osteomyelitis. Culture results at index procedure showed the most frequently isolated species were Staphylococci (Table 1). A single species was isolated in 75/125 (60%) and mixed species in 36/125 (28.8%). No organisms were cultured in 14/125 (11.2%). At re-operation 48/125 (38.4%) individuals had an organism from the same species or group as at the index operation. In 49/125 (39.2%), none of the organisms isolated at re-operation were grown at first operation. In 28/125 (22.4%), re-operative cultures yielded no growth. For each species isolated at the index procedure, the proportion with the same, different or no organisms isolated at the next procedure were reviewed (Table 1). Staphylococci (including S. aureus and coagulase-negative staphylococci) and Pseudomonas species showed the highest rate of persistence at the species level. Among coagulase-negative staphylococci, changes in antimicrobial sensitivity that make it unclear if these infections were truly persistent, or represented re-infection. Conclusions. Infection with different organisms was seen at similar rates (39.2% vs 38.4%) to persistent infection with the same species in this cohort. Staphylococcus aureus is the organism most likely to be persistently identified in recurrent infections

Aim. To assess whether recurrence of PJI and osteomyelitis impacts patient-reported quality of life (QoL). Method. We studied patients receiving surgical treatment for confirmed PJI or osteomyelitis in one of 26 centres in the UK. Patients completed the EQ-5D-3L questionnaire, directly after surgery, at day 14, day 42, day 120 and day 365 after surgery and were assessed for evidence of recurrence. Results. Of 621 patients with PJI, 99 had recurrent infection (15.9%). Patients with recurrence reported significantly lower QoL at one year after surgery compared to those without recurrence (EQ-5D-3L index score with recurrence: 0.368, SD0.344 vs. no recurrence: 0.592, SD0.315, p<0.001). Patients were grouped based on the timing of their recurrence: <42 days (n=27); 42–120 (n=28); or >120 days (n=44) post-surgery. At the time-point immediately preceding the diagnosis of recurrence, QoL was significantly lower than in corresponding patients without recurrence (recurrence <42 days, p<0.05; 42–120 days, p<0.001; >120 days, p<0.05). In 358 cases of osteomyelitis, 39 patients had recurrent infection (10.9%). Recurrence of osteomyelitis produced significantly lower QoL at one year after surgery compared to patients without recurrent infection (EQ-5D-3L for recurrence: 0.385, SD0.345 vs. no recurrence: 0.634, SD0.349, p<0.001). Patients with recurrence after 120 days (n=21) reported significantly lower QoL than those with no recurrence at the time-point immediately preceding the diagnosis of recurrence (p<0.01). In contrast to patients with PJI, patients with osteomyelitis who had recurrence diagnosed before 120 days (n=18) reported similar outcome scores to patients who did not have recurrence. Conclusion. Failure to eradicate infection greatly affects patient QoL. This study supports the monitoring of EQ-5D-3L among patients treated for bone and joint infections; patients with poorer QoL at follow up should prompt a low threshold for investigation to assess whether recurrence or continued infection is the underlying cause

Periprosthetic joint infections (PJI) are challenging complications following arthroplasty. Staphylococci are a frequent cause of PJI and known biofilm producers. Reoperations for PJI of the hip or knee between 2012 and 2015 performed at Sahlgrenska University Hospital were identified. Medical records were reviewed, and clinical parameters recorded for patients whose intraoperative bacterial isolates had been stored at the clinical laboratory. Staphylococcal strains isolated from reoperations due to first-time PJI were characterised by their ability to form biofilms using the microtiter plate test. The study group included 49 patients (70 bacterial strains) from first-time PJI, whereof 24 (49%) patients had recurrent infection. Strong biofilm production was significantly associated with recurrent infection. Patients infected with strong biofilm producers had a five-fold increased risk for recurrent infection. Strong biofilm production was significantly associated with increased antimicrobial resistance and PJI recurrence. This underscores the importance of determining biofilm production and susceptibility as part of routine diagnostics in PJI. Strong staphylococcal biofilm production may have implications on therapeutic choices and suggest more extensive surgery. Furthermore, despite the increased biofilm resistance to rifampicin, results from this study support its use in staphylococcal PJI

Aims. Excision of chronic osteomyelitic bone creates a dead space which must be managed to avoid early recurrence of infection. Systemic antibiotics cannot penetrate this space in high concentrations, so local treatment has become an attractive adjunct to surgery. The aim of this study was to present the mid- to long-term results of local treatment with gentamicin in a bioabsorbable ceramic carrier. Methods. A prospective series of 100 patients with Cierny-Mader Types III and IV chronic ostemyelitis, affecting 105 bones, were treated with a single-stage procedure including debridement, deep tissue sampling, local and systemic antibiotics, stabilization, and immediate skin closure. Chronic osteomyelitis was confirmed using strict diagnostic criteria. The mean follow-up was 6.05 years (4.2 to 8.4). Results. At final follow-up, six patients (six bones) had recurrent infection; thus 94% were infection-free. Three infections recurred in the first year, two in the second year, and one 4.5 years postoperatively. Recurrence was not significantly related to the physiological class of the patient (1/20 Class A (5%) vs 5/80 Class B (6.25%); p = 0.833), nor was it significantly related to the aetiology of the infection, the organisms which were cultured or the presence of nonunion before surgery (1/10 with nonunion (10%) vs 5/90 without nonunion (5.6%); p = 0.570). Organisms with intermediate or high-grade resistance to gentamicin were significantly more likely in polymicrobial infections (9/21; 42.8%) compared with monobacterial osteomyelitis (7/79 (8.9%); p < 0.001). However, recurrence was not significantly more frequent when a resistant organism was present (1/16 for resistant cases (6.25%) vs 5/84 in those with a microbiologically sensitive infection (5.95%); p = 0.958). Conclusion. We found that a single-stage protocol, including the use of a high-delivery local antibiotic ceramic carrier, was effective over a period of several years. The method can be used in a wide range of patients, including those with significant comorbidities and an infected nonunion. Cite this article: Bone Joint J 2022;104-B(9):1095–1100

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/m. 2. (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

Aim. Mega-endoprosthesis over the last two decades have played a significant role in management of non-neoplastic cases for limb salvage for a variety of indications involving bone loss, infection, fracture and failed revision surgery. This is a retrospective case control study comparing outcomes of Mega-Endoprosthesis (MEP) in non-neoplastic cases with periprosthetic joint infections (PJI), with previous history of PJI and aseptic revision. Failure was defined as persistence/recurrence of infection, all cause revision, and antibiotic suppression during the follow up period. Secondary aims were identification of causative organisms, resistance profile and causative factors for revision surgery. Method. A total of 122 patients undergoing 133 MEPs were identified between January 2012 and December 2020. 60 procedures were categorised as group 1 (infection; 50%), 20 as group 2 (previous history of infection; 16.7%), and 53 controls (no infection; 44.2%). Mean age of the cohort was 70.97 years (37.16–94.17), with a mean follow-up of 44.5 months (0.2–179) including patients lost to follow up. Results. Overall failure rate was 71/133 53.3% (group 1 39/60 (55.56%), group 2 12/20 (60%) and controls 20/53 (37.7%)). Thirteen patients died in the first 2 years (five in group 1, one in group 2 & seven in controls). The most common postoperative infection was polymicrobial followed by Coagulase Negative Staphylococcus Species (CoNS) and Methicillin Sensitive Staphylococcus aureus (MSSA). Nineteen patients had polymicrobial PJI (Eighteen in group 1 and one in control). CoNS led to postoperative infection in Fifteen patients (six in group 1, five in group 2 and four in control group). MSSA was the pathogen in four patients (three in group-1 and one in the control group). The same organisms were responsible for recurrent infection in fourteen patients in group 1 and one patient in group 2. Limb salvage was achieved in 96.2% overall (95% group 1, 90% group 2, 100% control group). Conclusions. MEPs in the context of PJI have a significant risk of failure however they play an important role in limb salvage. Patients should be counselled appropriately prior to surgery

Fracture related infections (FRI) are debilitating complications of musculoskeletal trauma surgery that can result in permanent functional loss or amputation. This study aims to determine risk factors associated with FRI treatment failure, allowing clinicians to optimise them prior to treatment and identify patients at higher risk. A major trauma centre database was retrospectively reviewed over a six-year period. Of the 102 patients identified with a FRI (66 male, 36 female), 29.4% (n=30) had acute infections (onset <6 weeks post-injury), 34.3% (n=35) had an open fracture. Open fractures were classified using Gustilo-Anderson (GA) classification (type 2:n=6, type 3A:n=16, type 3B:n=10, type 3C:n=3). Patients with periprosthetic infections of the hip and knee joint, those without prior fracture fixation, soft tissue infections, diabetic foot ulcers, pressure sore infections, patients who died within one month of injury, <12 months follow-up were excluded. FRI treatment failure was defined as either infection recurrence, non-union, or amputation. Lifestyle, clinical, and intra-operative data were documented via retrospective review of medical records. Factors with a P-value of p<0.05 in univariate analysis were included in a stepwise multivariate logistic regression model. FRI treatment failure was encountered in 35.3% (n=36). The most common FRI site was the femoral shaft (16.7%; n=17), and 15.7% (n=16) presented with signs of systemic sepsis. 20.6% (n=21) had recurrent infection, 9.8% (n=10) had non-union, and 4.9% (n=5) required an amputation. The mean age at injury was 49.71 years old. Regarding cardiovascular risk factors, 37 patients were current smokers (36.3%), 31 patients were diabetics (30.4%), and 32 patients (31.4%) were obese (BMI≥30.0). Average follow-up time was 2.37 (range: 1.04-5.14) years. Risk factors for FRI treatment failure were BMI>30, GA type 3c, and implant retention. Given that FRI treatment in 35.3% (36/102) ended up in failure, clinicians need to take into account the predictive variables analysed in this study, and implement a multidisciplinary team approach to optimise these factors. This study could aid clinicians to redirect efforts to improve high risk patient management, and prompt future studies to trial adjuvant technologies for patients at higher risk of failure

Aim. Excision of chronic osteomyelitis (cOM) creates a dead space which must be managed to avoid early recurrence of infection. Systemic antimicrobials cannot penetrate this space in high concentration so local therapy has become an attractive adjunct to surgery. This study presents the mid- long-term results of local therapy with gentamicin in a bioabsorbable ceramic carrier. Method. A prospective series of 100 patients with Cierny & Mader Types III and IV cOM, affecting 105 bones, were treated with a single stage procedure, including debridement, deep tissue sampling, local and systemic antimicrobials, stabilization and immediate skin closure. cOM was confirmed with strict diagnostic criteria. Patients were followed up for a mean of 6.05 years (range 4.2–8.4 years). Results. At final follow-up, 6 patients had evidence of recurrent infection (94% infection-free). 3 infections recurred in the first year, with 2 in the second year and one at 4.5 years after surgery. Recurrence was not dependent on host physiological class (1/20 Class A; 5% vs 5/80 Class B; 6.25%. p=0.833). Nor was it related to aetiology of the infection, microbial culture or the presence of an infected non-union before surgery (1/10 with non-union; 10% vs 5/90 without non-union; 5.6%. p=0.57). Organisms which demonstrated intermediate or high-grade resistance to gentamicin were more likely in polymicrobial infections (9/21; 42.8%) compared to single isolate osteomyelitis (7/79; 8.9%)(p<0.001). However, recurrence was not more frequent when a resistant organism was present (1/16; 6.25% for resistant cases vs 5/84; 5.95% in sensitive culture infection) (p=0.96). Conclusions. This study shows that the single stage protocol, including a high delivery local antibiotic ceramic, was effective over several years. The method can be applied to a wide range of patients, including those with significant comorbidities and infected non-union

Aim. This retrospective study evaluated the outcome of treatment for unhealed fracture-related infections (FRI). Methods. We identified a consecutive, single-centre cohort of patients having treatment for an FRI Consensus confirmed FRI. All fractures were unhealed at the time of treatment. Patients were followed up for at least one year. Successful outcome was a healed fracture without recurrent infection. Lack of union, persistent infection and/or unplanned reoperation defined failure. Results. Demographics: 183 patients (184 FRIs) with mean age 52.1 years (range 17-96) were treated and followed up for a mean of 2.8 years (range 1-9.4). Mean duration of FRI was 1.1 years with 65 (35.5 %) presenting within 6 months of injury. 118 patients had established infected non-union. FRI was most frequent in the tibia (74), femur (48) and humerus (24). 171 patients were BACH Complex. 75.5% of FRIs were culture positive, with Staph. aureus being the most frequent organism. Polymicrobial infection and Gram negative cultures were common (25.5% and 33.6%). Treatment: 98.3% of surgeries were performed in one stage with just 3 planned 2-stage procedures (2 endoprosthetic replacements and 1 free fibular flap). No bone graft was used in any surgery and all wounds were closed at first operation. 48 cases (26%) required flap coverage (29 free flaps and 19 local flaps). Local antibiotics were used in 124 cases (67.4%) of primary surgeries. All patients had sampling, debridement, systemic antibiotics and wound closure. 40 (21.7%) had DAIR, 31 (16.8%) had new internal fixation and 105 (57.1%) had external fixation (including 79 Ilizarov fixators). Outcomes: After primary surgery, 84.6% of all patients were infection-free and 77.2% had united. After further surgery, 98.8% were infection-free and 98.1% had united. External fixation techniques achieved infection eradication in 89.1% compared to 71.7% with any internal fixation (p=0.005). Primary internal fixation achieved union in 81.7% compared to 74.3% with external fixation (p=0.27). Secondary surgery after external fixation was mainly docking site fixation. Conclusion. Unhealed FRIs present a difficult challenge for treatment. This large series demonstrated that single-stage treatment, without bone grafting, gave acceptable results with few reoperations. Primary external fixation gave more certainty of infection eradication but required more reoperations to secure union. However, this difference in reoperation was not statistically significant. We strongly advocate managing these patients with a multidisciplinary team which can treat all aspects of the condition

Abstract. Introduction. The prevalence of recurrent infection following two-stage exchange arthroplasty following failure of a total knee arthroplasty (TKA) has been reported to be 10% to 25%. There is limited literature available on repeat two stage revisions for TKA infection with only small cohorts and variable success rates. Methodology. A retrospective cohort study investigating the outcome of two stage revision arthroplasty for treatment of TKA infection was conducted with the aim of identifying factors linked to recurrence of infection. A consecutive cohort of all microbiology intra-operative periprosthetic knee samples from a single revision arthroplasty centre between January 2010 and December 2016 was identified. The final cohort consisted of 658 samples taken during 64 patients undergoing two stage revision knee surgery for infection. Patient demographics, medical and orthopaedic history data including post-operative outcomes and subsequent treatment was obtained from the electronic records system and medical notes. Results. 65.6% of the cohort (N=42) had successful eradication of their infection. For the twenty-two patients that had failure of their two stage revision, twenty patients had samples available from further surgical intervention. Sixteen patients (80%) had different organisms isolated when they had repeat surgical samples taken when compared to their first stage samples. Overall, for subsequent treatments there was a success rate of 75% if the same organism was identified and 62.5% if there were new isolated organisms. Conclusion. These findings may have implications for the treatment strategies chosen for re-infection after two stage TKA revisions if new causative organisms are isolated

Aim. Local antibiotic treatment for bone and joint infections offers direct delivery of high concentrations of antibiotics with reduced systemic exposure and favourable safety profile. However, the possibility of prolonged release of antibiotics at sub-therapeutic levels creates concern about the possible development of antimicrobial resistance. We investigated patients with recurrent bone and joint infection for evidence of antimicrobial resistance emerging from the use of local antibiotics. Method. 125 patients with recurrent infection (prosthetic joint infection, fracture related infection and osteomyelitis) in the UK between 2007 and 2021 were identified. Electronic patient records (including operative notes, pathology results and prescriptions) were reviewed to extract site of infection, date of surgery, the use of local antibiotics, culture results, empiric and definitive antibiotic therapy. All antibiotic sensitivity results were recorded as sensitive, intermediate or resistant according to contemporary guidelines (BSAC and EUCAST). Results. Local antibiotics were used in 74/125 (59.2%) of patients. Agents used were Gentamicin 53/125 (42.4%), Tobramycin 18/125 (14.4%), and vancomycin in 19/125 (15.2%). Combined gentamicin and vancomycin usage was seen in 16/125 patients (12.8%). Gentamicin non-sensitivity was common in this cohort with frequent aminoglycoside use. At index procedure, a Gentamicin non-sensitive organism was cultured in 51/125 patients (40.8%). At re-operation this proportion was lower: 40/125 (32%). There was no statistically significant difference in the rate of Gentamicin resistance at reoperation comparing patients who previously received local aminoglycosides with those who had not (21/71, 29.8% vs 19/54, 35.2% p=0.6, chi-squared test). In 48/125 (38.4%) of patients, the same species was isolated during the index and recurrence surgery. We identified 7 cases with new aminoglycoside resistance arising at the second procedure. In 2/7 – S. aureus and E. faecalis - aminoglycoside resistance was the only change in antimicrobial sensitivity. In 5/7, there were at least 2 additional changes in observed antimicrobial sensitivity. 3/74 (4%) of cases who initially received local aminoglycoside cultured organisms with aminoglycoside resistance at recurrence. 4/51 (7.8%) of those who did not receive local or systemic aminoglycoside at index surgery cultured resistant organisms (chi square 0.82; p=0.365). Conclusions. As a group, patients whose treatment for orthopaedic infection included local antibiotics did not exhibit higher rates of specific antimicrobial resistance compared with those not treated with local antibiotics. However we did identify cases where Gram positive bacteria developed aminoglycoside resistance regardless of their initial antimicrobial therapy. This should be considered in antimicrobial choice during surgery for recurrence

Aims. Two-stage exchange revision total hip arthroplasty (THA) performed in case of periprosthetic joint infection (PJI) has been considered for many years as being the gold standard for the treatment of chronic infection. However, over the past decade, there have been concerns about its safety and its effectiveness. The purposes of our study were to investigate our practice, collecting the overall spacer complications, and then to analyze their risk factors. Methods. We retrospectively included 125 patients with chronic hip PJI who underwent a staged THA revision performed between January 2013 and December 2019. All spacer complications were systematically collected, and risk factors were analyzed. Statistical evaluations were performed using the Student's t-test, Mann-Whitney U test, and Fisher's exact test. Results. Our staged exchange practice shows poor results, which means a 42% mechanical spacer failure rate, and a 20% recurrent infection rate over the two years average follow-up period. Moreover, we found a high rate of spacer dislocation (23%) and a low rate of spacer fracture (8%) compared to the previous literature. Our findings stress that the majority of spacer complications and failures is reflecting a population with high comorbid burden, highlighted by the American Society of Anesthesiology grade, Charlson Comorbidity Index, and Lee score associations, as well as the cardiac, pulmonary, kidney, or hepatic chronic conditions. Conclusion. Our experience of a two-stage hip exchange revision noted important complication rates associated with high failure rates of polymethylmethacrylate spacers. These findings must be interpreted in the light of the patient’s comorbidity profiles, as the elective population for staged exchange has an increasing comorbid burden leading to poor results. In order to provide better results for this specific population, our conclusion suggests that comparative strategy studies are required to improve our therapeutic indication. Cite this article: Bone Jt Open 2022;3(6):485–494

Introduction. The burden of prosthetic joint infection (PJI) in total knee arthroplasty (TKA) has been rising in line with the number of primary operations performed. Current estimates suggest an infection rate of 1–2.4%. Two-stage revision has traditionally been considered the gold standard of treatment; however, some studies suggest comparable results can be achieved with single-stage procedures. The potential advantages include less time in hospital, a single anaesthetic, reduced costs, and greater patient satisfaction. Methods. We reviewed data for 72 patients (47 males, 25 females), with a mean age of 71 years (range, 49 to 94), who underwent single-stage revision TKA for confirmed PJI between 2006 and 2016. A standardized debridement protocol was performed with immediate single-stage exchange. All cases were discussed preoperatively at multidisciplinary team (MDT) meetings, which included input from a senior musculoskeletal microbiologist. Patients were not excluded for previous revisions, culture-negative PJI, or the presence of a sinus. Results. The average length of follow-up was 8 years (range, 2 to 13). In total, 65 patients (90.3%) were infection free at most recent follow-up, with seven reinfections (9.7%). Three of these patients with recurrent infections underwent arthrodesis, two underwent re-revision, and two received long-term antibiotics following debridement and implant retention (DAIR). No amputations were undertaken. Conclusions. Single-stage revision for the infected TKA, according to a strict debridement protocol with MDT input, demonstrates reinfection rates comparable with two-stage revision procedures. This is the largest single-surgeon series to date, with extensive follow-up, and supports a growing evidence base for one-stage exchange

Aim. Reconstruction of composite soft-tissue defects with extensor apparatus deficiency in patients with periprosthetic joint infection (PJI) of the knee is challenging. We present a single-centre multidisciplinary orthoplastic treatment concept based on a retrospective outcome analysis over 20 years. Method. One-hundred sixty-seven patients had PJI after total knee arthroplasty. Plastic surgical reconstruction of a concomitant perigenicular soft-tissue defect was indicated in 49 patients. Of these, seven presented with extensor apparatus deficiency. Results. One patient underwent primary arthrodesis and six patients underwent autologous reconstruction of the extensor apparatus. The principle to reconstruct missing tissue ‘like with like’ was thereby favoured: Two patients with a wide soft-tissue defect received a free anterolateral thigh flap with fascia lata; one patient with a smaller soft-tissue defect received a free sensate, extended lateral arm flap with triceps tendon; and three patients received a pedicled medial sural artery perforator gastrocnemius flap, of which one with Achilles tendon. Despite good functional results 1 year later, long-term follow-up revealed that two patients had to undergo knee arthrodesis because of recurrent infection and one patient was lost to follow-up. In parts, results have been published under doi: 10.7150/jbji.47018. Conclusions. A treatment concept and its rationale, based on a single-centre experience, is presented. It differentiates between various types of soft-tissue defects and shows reconstructive options following the concept to reconstruct ‘like with like’. Despite good results 1 year postoperatively, PJI of the knee with extensor apparatus deficiency remains a dreaded combination with a poor long-term outcome

Introduction. Two-stage reimplantation for prosthetic joint infection (PJI) of the hip is the standard of care with a 5–10% recurrence at a minimum two-year follow-up. Compiling outcomes data for this standard of care is necessary in order to characterize long-term reinfection risk and the culpable microbiology. The purpose of this study was to determine the long-term success of two-stage reimplantation and identify the factors that affected the success. Methods. We performed a systematic review of randomized control trials, cohort studies, and case series through May 2019, searching Embase, Medline via PubMed, and Cochrane Library for the concept of two-stage reimplantation for the treatment of hip and knee PJIs, yielding 464 unique citations for abstract review, of which 135 were reviewed in full. Our parameters of interest included: reinfection and mortality events following successful reimplantation, the timing of these events, and the microbiology of index and recurrent infections. Results. Meeting our criteria were 59 studies with 4,494 patients (1,842 hips) who had completed reimplantation. Among successfully reimplanted hips, 4.76% (95% CI, 2.00–8.41) were reinfected by 24 months, 6.84% (4.92–9.02) were reinfected by final follow-up, 1.6% (0.32–3.52) were reinfected with an identical organism(s) with identical resistance, and 2.55% (0.77–5.03) were reinfected with a novel organism(s) or novel resistance. In 24 studies with reinfected patients and sufficient data, 8 studies reported an average interval from reimplantation to reinfection greater than 24 months, and 14 reported at least 1 patient with a reinfection event greater than 48 months following reimplantation. Conclusion. The results from this review determined that the host of an index PJI faces ongoing risk of recurrent infection years into the post-operative period despite initial eradication and that novel microbiology is the cause of a significant proportion of failures. For any tables or figures, please contact the authors directly

Aim. This study investigated the effect of the choice of antibiotic regime on outcome of patients treated for fracture-related infection (FRI) at 3 centres, in the UK and the Netherlands between 2015 and 2019. Method. All patients with FRI, confirmed by the FRI Consensus Definition. 1. and treated surgically, were included. Data were collected on patient characteristics, microbial cultures, antibiograms, empiric and definitive systemic antibiotic regimes and local antibiotic use. All patients were followed up for at least one year. The primary outcome was eradication of infection. The chosen antibiotic regimes were compared to the recent guidelines from the FRI Consensus Group. 2. , to assess the correlation with outcome. Results. 433 FRIs were treated in patients with mean age 49.7 years (range 14–84). Patients were followed up for a mean of 26 months (range 12–72). A microbiological diagnosis was obtained in 353 patients (18.5% culture negative rate), with 46% monomicrobial and 35.5% polymicrobial. Staph aureus was present in 51.3% of monomicrobial and 55.2% of polymicrobial infections. Negative cultures were much less likely in FRI within 10 weeks of injury (p=0.00001). Treatment failure with recurrent infection occurred in 13.6% of patients. Failure was more likely in culture positive cases (Polymicrobial; p=0.016, monomicrobial 0.039). Definitive antibiotic regimes were fully compliant with the FRI Guideline in 107 cases (24.7%). In 294 cases (68%) antibiotic regimes outside the guidelines were used. Non-compliance was often due to differences in recommended dosing or overtreatment with extra antimicrobials. 32 cases (7.4%) could not be assessed against the FRI Guidelines as the organisms or regimes were not represented in the guide. Failure rate with FRI Guideline compliant regimes was 12.1% and with non-compliant, 13.2% (p=0.87). Failure in unclassifiable cases was 21.9%. The use of local antibiotics reduced the recurrence rate from 18.3% without local antibiotics to 10.3% with local antibiotics (p=0.022). Conclusions. This study demonstrated that there can be considerable variability in the choice of antimicrobial regimes in FRI. Some deviations from the FRI Guideline did not result in poorer outcomes. These smaller differences in antimicrobial choice may not be major determinants of outcome

Aim. Periprosthetic joint infection (PJI) is a feared complication of total joint arthroplasty of hip (THA) or knee (TKA). Debridement, antibiotic treatment, and implant retention (DAIR) is an effective treatment of early PJI. In the Netherlands, cefazolin resistance in early PJI after primary arthroplasty is low. Little is known about causative micro-organisms and resistance patterns in PJI after revision arthroplasty. No recommendations for empirical treatment are described in the current guidelines. The aim of this study is to describe the characteristics of PJI after revision arthroplasty and to evaluate whether the used empirical treatment regimens are adequate, based on microbiology data. Method. In this retrospective study we included patients with early PJI after aseptic revision of THA or TKA, treated with DAIR between 2012 and 2020. Success rate was defined as implant retention and no persistent or recurrent infection during one year follow-up. Results. We identified 96 patients with PJI. PJI was most frequently caused by Staphylococcus spp. (n=73), Gram-negative bacilli (n=31) or Enterococcus spp. (n=13). Polymicrobial infection was diagnosed in 38 PJIs. Mismatches were present in 72 (75%) of the PJIs (95% CI: 0.66–0.84). Table 1 shows the number of mismatches per empirical treatment regimen. Figure 1 shows the responsible micro-organisms for the mismatches. Success rate of PJI treatment was significant reduced for patients with mismatching compared to matching empirical therapy: 62% vs. 95% respectively (OR: 0.09, 95% CI: 0.01–0.68, p=0.004). If vancomycin would have been the empirical treatment, mismatches would have been reduced to 31 (32%) (95% CI: 0.23–0.42). With vancomycin-ciprofloxacin combination therapy the mismatches would have been reduced to 1% (95% CI: −0.01–0.03). Conclusions. There is a high number of mismatches in empirical treatment in early PJI after revision arthroplasty, which have significant influence on the outcome. Based on our data cefazolin should not be recommended as empirical treatment for this specific group. Our data shows that review of local data is necessary to improve treatment strategies, that eventually might improve outcome. Besides changing Gram-positive coverage, a prospective study is needed to assess the benefits of broader spectrum empiric antimicrobial treatment taken into account toxicity and other side effects such as antimicrobial resistance. For any tables or figures, please contact the authors directly