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

Aim. Antimicrobial suppression has shown to significantly improve treatment success of streptococcal periprosthetic joint infection (PJI) compared to 12-week standard antimicrobial therapy, however, only short-term follow-up was investigated. In this study we assessed the impact of suppression on the long-term outcome of streptococcal PJI. Method. Consecutive patients with streptococcal PJI (defined by EBJIS criteria) treated 2009–2021 were prospectively included and allocated into standard and suppression (> 6 months) treatment group. Infection-free survival was assessed with Kaplan-Meier-method and compared between the groups with log rank test. Rates of infection-free, streptococcal infection-free and relapse-free status as well as tolerability of suppression were assessed. Results. Sixty-three PJI episodes (36 knee, 26 hip and one shoulder prosthesis) of patients with a median age of 70 (35–87) years were included. Twenty-seven (43%) were females. Predominant pathogens were S. agalactiae (n=20), S. dysgalactiae (n=18) and S. mitis/oralis (n=13). The main surgical procedures used were two-stage exchange (n=35) and prosthesis retention (n=21). Standard 12-week treatment was administered in 33 patients and suppression in 30 patients, of whom 10 had ongoing suppression and 20 had discontinued antibiotics at time of follow-up. Used oral antibiotics for suppression were amoxicillin (n=29), doxycycline (n=5) and clindamycin (n=2); 6 patients changed antibiotic substance due to side effects. The median follow-up time was 3.9 (0.3–13.3) years. Infection-free survival after 7.5 years was 38% with standard treatment and 62% with suppression (p=0.038). Of all failures, 52% (14/27) were due to streptococci. Suppression was effective in preventing streptococcal infection for the duration of antimicrobial treatment, however, after discontinuation relapses or new infections due to streptococci occurred in 5/20 (25%) patients and infection with any Streptococcus spp. was observed in 9/19 (47%) failures with standard treatment, 5/6 (83%) failures after discontinuing suppression and none during suppression. All failures in patients with ongoing suppression were caused by gram-negative rods. Conclusion. At long-term follow-up, the success rate was superior with suppression compared to standard treatment. Most failures after stopping suppression were caused by streptococci, whereas failures under suppression were caused by aerobic gram-negative rods

Aim. To analyse the prevalence of culture negative periprosthetic joint infections (PJI) when adequate culture techniques are applied, and to evaluate the outcome of patients who were treated with antibiotics for a culture negative PJI versus those in whom treatment was withheld. Method. A multicenter observational study in which acute and chronic PJIs diagnosed between 2013 and 2018 were analyzed. Culture negative PJIs were diagnosed according to the MSIS, ICM and EBJIS definitions. Results. Out of the 1553 acute PJIs, none were culture negative. Out of the 1556 chronic PJIs, 70 were culture negative (4.7%) and included for further analysis. A total of 36 were treated with antibiotics (51%). After two years of follow-up, no infections occurred in patients in whom antibiotic treatment was withheld, but prosthesis extraction by any cause was observed more often in the no antibiotic group compared to the antibiotic group (32.4% versus 8.3%, P 0.012), especially in the absence of metallosis. Antibiotic treatment was the only independent predictor of prosthesis retention in the multivariate analysis (95% CI 0.15, 0.03 – 0.70). Conclusions. When adequate culture techniques are applied, the incidence of culture negative PJIs is low. If diagnosed, antibiotic treatment should be administered

Aim. Optimal strategies for surgical and antimicrobial management of Candida periprosthetic joint infections (PJI) are unclear. We present a retrospective case series of patients diagnosed with PJI caused by Candida spp. Method. Patients treated at our institution with Candida PJI from 01/2017 to 04/2018 were retrospectively included with isolation of Candida spp. in synovial fluid, intraoperative tissue or sonication fluid culture. PJI was defined by the proposed European Bone and Joint Infection Society (EBJIS) criteria. Treatment failure was defined as relapse or persistence of infection. Results. We included 9 patients (4 men and 5 women, mean age 75 years) involving 4 knee and 5 hip joint prosthesis. Risk factors for Candida PJI were prior PJI (n=4), diabetes mellitus (n=3), chronic kidney disease (n=3), obesity (n=3), negative-pressure wound therapy (n=3), rheumatoid arthritis (n=1) and chronic decubitus (n=1). Two patients had no risk factors for Candida PJI identified. Infection was acquired postoperatively (n=7), hematogenously (n=1) or contiguously through communicating vesico-articular sinus (n=1). The causative pathogen was C. albicans in 5, C. parapsilosis in 3, C. tropicalis in 1 patient, isolated from periprosthetic tissue samples (n=7), sonication fluid (n=3) and blood cultures (n=2); bacterial co-pathogens were isolated in 8 patients. Histopathological analysis revealed low-grade inflammation in all 6 patients, in whom it was performed. All patients were treated with oral fluconazole for 3 months, two initially received intravenous caspofungin and three received suppression with oral fluconazole for additional 9 months (total treatment 12 months). Liposomal amphotericin B (300–700 mg per 40 g bone cement) was admixed to spacer cement in 3 patients. Debridement and prosthesis retention was performed in one patient with tumor prosthesis after bone resection due to osteochondrosarcoma. In the remaining 8 patients the prosthesis was removed, with one-stage reimplantation in 1 patient and two-stage reimplantation in 3 patients (after 6 weeks, 3 months and 7 months); two patients are currently awaiting reimplantation, one died due to reason not related to PJI and another underwent knee arthrodesis. Among 5 patients with prosthesis in place, relapse occurred in one patient with prosthesis retention. Another patient experienced new PJI of the exchanged prosthesis caused by Staphylococcus aureus. Conclusions. All Candida PJI presented as chronic infection with low-grade inflammation. Treatment with prostheses retention failed, whereas in 4 patients who underwent two-stage exchange and long-term antifungal suppression, no relapse or persistence of infection was observed. All patients received oral fluconazole for ≥3 months

Purpose. The success rate of surgical debridement and prostheses retention for acute periprosthetic joint infection (PJI) is controversial. This study aims to report our experience in managing acute PJI following total knee arthroplasty (TKA) with surgical debridement and prostheses retention, and to identify the prognostic factors that may influence the surgical outcomes. Methods. A retrospective review from our prospective joint replacement register in Queen Mary Hospital, Hong Kong, of patients who were managed with surgical debridement and prosthesis retention for acute PJI after TKA between 1998 and 2013 was performed. The diagnosis of acute PJI was based on the 2011 Musculoskeletal Infection Society (MSIS) PJI diagnostic criteria. Both the early post-operative infections and the late haematogenous infections were included (Tsukayama type 2 and 3). Surgical outcomes were defined as successful if patients’ clinical symptoms had been relieved; inflammatory marker levels including C-Reactive Protein (CRP), Erythrocyte Sedimentation Rate (ESR) and White Blood Cell (WBC) count had returned to normal; X-rays showed no prosthetic loosening; and no lifelong antibiotic suppression was required. Outcomes were defined as failed if patients required any further surgeries (e.g., re-debridement, one or two-stage revision), or needed lifelong antibiotic suppression. All Patients’ perioperative data, i.e., age, primary diagnosis, pre-operative CRP, ESR, WBC, haemoglobin, albumin, glucose level, time lag from symptoms onset to debridement, synovial fluid total cell count and bacteriology were traced and recorded. SPSS 22.0 was used to calculate and compare the statistical differences between surgically successful group and failed group regarding the factors above. Results. 34 patients with 35 TKAs were included. There were 19 female and 15 male. The primary diagnoses included 29 osteoarthritis (OA) and 5 rheumatoid arthritis (RA). 8 had history of diabetes mellitus (DM). 25 knees received primary TKA and 10 knees received revision TKA, including 6 revisions for PJI and 4 for aseptic loosening. 12 belonged to Tsukayama type 2 (early post-operative infection) and 23 belonged to Tsukayama type 3 (late haematogenous infection). During a mean follow-up time of 45.9±44.2 months, 12 were successfully treated while 23 failed, including 15 required re-operations and 8 needed lifelong antibiotic suppression. The success rate of debridement was 34.2%. Statistical analyses showed no significant differences between the two groups on patients’ age, time lag from symptoms onset to debridement, pre-operative CRP, ESR, WBC, haemoglobin, albumin, glucose level or synovial fluid total cell count. (Table 1) Patients’ primary diagnosis, previous revision surgeries or staphylococcal infections had no significant impacts on the surgical outcome, either. Debridement with polyethylene insert exchange, however, had a significantly higher success rate than debridement alone. (Table 2). Conclusions. We concluded that debridement with prosthesis retention has a low success rate for acute periprosthetic infection in TKA. No significant prognostic factors could be identified, except that debridement with polyethylene insert exchange has higher success rate than debridement alone

Infection following total knee arthroplasty (TKA) can cause significant morbidity to the patient and be associated with significant costs and burdens to the healthcare system. Wound complications often initiate the cascade that can eventually lead to deep infection and implant failure. Galat et al. reported that wound complications following TKA requiring surgical treatment were associated with 2-year cumulative risks of major reoperation and deep infection of 5.3% and 6.0%, respectively. Consequently, developing a systematic approach to the management of wound problems following TKA can potentially minimise subsequent complications. Unlike the hip, the vascular supply to the soft tissue envelope to the knee is less robust and more sensitive to the trauma of surgery. Therefore, proper soft tissue handling and wound closure at the time of surgery can minimise potential wound drainage and breakdown postoperatively. Kim et al. showed, using a meta-analysis of the literature, that primary skin closure with staples demonstrated lower wound complications, decreased closure times, and lower resource utilization compared to sutures. However, a running subcuticular closure enables the most robust skin perfusion following TKA. Finally, the use of hydrofiber surgical dressings following surgery was associated with increased patient comfort and satisfaction and reduced the incidence of superficial surgical site infection. A wound complication following TKA needs to be managed systematically and aggressively. A determination of whether the extent of the involvement is superficial or deep is critical. Antibiotics should not be started without first excluding the possibility of a deep infection. Weiss and Krackow recommended return to the operating room for wound drainage persisting beyond 7 days. While incisional negative pressure wound therapy can occasionally salvage the “at risk” draining wound following TKA, its utilization should be limited only to the time immediately following surgery and should not delay formal surgical debridement, if indicated. Finally, early wound flap coverage and co-management of wound complications with plastic surgery is associated with increased rates of prosthesis retention and limb salvage

Infection following total knee arthroplasty (TKA) can cause significant morbidity to the patient and be associated with significant costs and burdens to the health care system. Wound complications often initiate the cascade that can eventually lead to deep infection and implant failure. Galat et al. reported that wound complications following TKA requiring surgical treatment were associated with a 2-year cumulative risk of major reoperation and deep infection of 5.3% and 6.0%, respectively. Consequently, developing a systematic approach to the management of wound problems following TKA can potentially minimise subsequent complications. Unlike the hip, the vascular supply to the soft tissue envelope to the knee is less robust and more sensitive to the trauma of surgery. Therefore, proper soft tissue handling and wound closure at the time of surgery can minimise potential wound drainage and breakdown post-operatively. Kim et al. showed, using a meta-analysis of the literature, that primary skin closure with staples demonstrated lower wound complications, decreased closure times, and lower resource utilization compared to sutures. However, a running subcuticular closure enables the most robust skin perfusion following TKA. Finally, the use of hydrofiber surgical dressings following surgery was associated with increased patient comfort and satisfaction and reduced the incidence of superficial surgical site infection. A wound complication following TKA needs to be managed systematically and aggressively. A determination of whether the extent of the involvement is superficial or deep is critical. Antibiotics should not be started without first excluding the possibility of a deep infection. Weiss and Krackow recommended return to the operating room for wound drainage persisting beyond 7 days. While incisional negative pressure wound therapy can occasionally salvage the “at risk” draining wound following TKA, its utilization should be limited only to the time immediately following surgery and should not delay formal surgical debridement, if indicated. Finally, early wound flap coverage and co-management of wound complications with plastics surgery is associated with increased rates of prosthesis retention and limb salvage

Aim. Gram-negative aerobic bacteria account for 10%-17% of periprosthetic joint infection (PJI). Due to its biofilm-activity, ciprofloxacin plays a key role in the treatment of gram-negative PJI. However, data about treatment outcome of these infections are conflicting. With this retrospective study we aim at evaluating characteristics and outcome of gram-negative PJI. Method. We retrospectively included consecutive patients with gram-negative PJI treated at our institution from 01/2013 to 03/2018. Diagnosis of PJI was defined by the proposed European Bone and Joint Infection Society (EBJIS) criteria. Growth of gram-negative aerobic bacteria was required in synovial fluid, periprosthetic tissue or sonication fluid. Clinical success (infection-free status) was defined as fulfillment of all of the following criteria: (i) unremarkable surgical site and no subsequent surgery (ii) no PJI related mortality and (iii) no long-term antimicrobial suppression therapy of >6 months. Results. A total of 76 patients with gram-negative PJI involving 45 hips, 26 knees, 3 elbows and 2 shoulders were analyzed. The median patient age was 76 years (range, 41–92 years). The route of infection was perioperative in 52 cases, hematogenous in 17 cases and contiguous in 5 cases. The most common isolated pathogens were Escherichia coli (n=31), Klebsiella species (n=17), Proteus species (n=13), Enterobacter species (n=11) and Pseudomonas aeruginosa (n=9). Ciprofloxacin resistance was detected in 20 of 90 (23%) gram-negative pathogens. 21 patients were treated with two-stage revision, 17 with prosthesis retention, 16 with permanent prosthesis removal, 14 with multi-stage exchange and 6 with one-stage revision. In 55 of 71 (77%) patients, ciprofloxacin was included in the treatment regimen. Median follow-up was 10.8 months (range, 1.6–60.7 months) and infection was eradicated in 29 of 47 patients (62%). Among 18 failures, 13 (72%) experienced a new PJI due to another pathogen (n=11) or had negative cultures (n=2), one patient died. The failures occurred after a median of 13.3 months (range, 3.9–28.8 months). All 4 patients with relapse caused by the same pathogen were resistant to ciprofloxacin. Ciprofloxacin-resistance was associated with worse outcome compared to ciprofloxacin-susceptible bacteria (5/13 (38%) vs. 23/33 (70%), p=0.09). Conclusions. The overall outcome of gram-negative PJI was poor (62%). However, most infections were caused by a new pathogen or were culture-negative and occurred after 13.3 months. Ciprofloxacin resistance of the causative pathogen was associated with treatment failure. The reason for the high rate of new PJI is unclear and should be meticulously investigated to improve the outcome

Early and/or prolonged wound discharge after total knee arthroplasty often raises the question whether this is a sign of an early infection or if the prolonged discharge leads to a secondary deep wound infection from migrating skin bacteria. Confronted with the dilemma of what to do with early PWC our department implemented a new treatment protocol in 2002 to deal with early PWC after TKA in order to standardize decision-making. The aim of this study was to report our long-term results using this protocol on a prospective cohort primary TKA and revision TKA performed for other reasons than infection. This report focuses on the results of DAIR (debridement, antibiotics and implant retention) performed for early PPJI and/or early wound complications without clinical signs of infection. After implementing our treatment algorithm regarding postoperative wound complications in early 2002, we initiated a quality registration including every primary and non infected revision TKA performed. Between January 2002 and August 2012 1439 consecutive primary knee arthroplasties were performed at our institution. During the same period a total of 120 knee revisions for reasons not related to infection were performed. All patients undergoing DAIR within three months of the index procedure where divided into two groups: successful and unsuccessful. Successful DAIR didn't require any more surgery and the implant could be retained with a minimum follow up time of two years. Unsuccessful DAIR required at least one more surgical intervention. Treatment with DAIR was successful in 47 of 62 patients operated with primary and revision TKA as index operation. Those patients had no signs of infection and no antimicrobial therapy after a minimum of one year follow up time. The remaining 15 patients were in need of further surgery. Positive cultures could be obtained in 41 of 62 patients including those operated for aseptic revision arthroplasty. Staphylococcus aureus was by far the most common isolated organism with 24 isolations and the sole causative pathogen in 15 cases. When looking at all patients even including those with aseptic revision TKA we could see that the algorithm resulted in 57 of 62 patients (91,9%) ending up with a working knee prosthesis at the final follow up. In 47 (75,8%) cases prosthesis retention could be achieved with only a single DAIR procedure. We therefore conclude that the algorithm applied at our centre leads to satisfactory results

Infection is a potentially disastrous complication of total knee arthroplasty (TKA). Although advances in surgical technique and antibiotic prophylaxis have reduced the incidence of infection to approximately 1% in primary TKA, there is still a substantial number of patients. Treatment options include antibiotic suppression, irrigation and debridement with component retention (with or without polyethylene exchange), one-stage or two-stage revision, resection arthroplasty and rarely arthrodesis or amputation. Salvage of prostheses has always been associated with low rates of success. It was reported a success rate of 27% for open debridement. It is suitable for selective cases where infection occurs within the first 4–6 weeks of primary TKA or in the setting of acute hematogenous gram positive infection with stable implants. With the advances in arthroscopic technique, arthroscopy after TKA has become an accepted method to assess and manage the complications of TKA. Arthroscopic treatment for infected TKA was reported and the successful rate was similar or better than open debridement in selected situations. We used arthroscopic debridement combined with continuous antibiotic irrigation and suction to treat acute presentation of infected TKA with acceptable result. From 2010∼2013, we has performed arthroscopic debridement and continuous antibiotic irrigation system for seven patients with infected TKA. All of the seven patients had no open wounds nor sinuses and no radiological evidence of prosthetic instability or evidence of osteomyelitis. Most of the surgical intervention was performed within two weeks from the onset of symptoms. Arthroscopic debridement was performed with a shaver using a multiportal technique (anterolateral, anteromedial, superolateral, superomedial, posterolateral, posteromedial) and a continuous antibiotic irrigation system was used to dilutes concentration of the causative microorganism and keep high local bactericidal concentration of antibiotics. We evaluated the efficacy by using follow up of the C-reactve protein (CRP) test, erythrocyte sedimentation rate (ESR) test and physical examination. Successful treatment was defined as prosthesis retention without recurrent infection by the final follow-up. Six of seven infected TKA were cured without recurrence at a mean follow-up of 23 months (range, 6–41 months). One case with rheumatoid arthritis under long-term steroid therapy had recurred after episode of upper respiratory tract infection for 3 times. However, the infection was controlled by arthroscopic debridement and retention of the prosthesis was achieved. We emphasize the importance of posterior portal to ensure adequate arthroscopic debridement. It is imperative to make early diagnosis and treatment for infected TKA. We should make more effort to preserve the prosthesis in acute infection(within 2 weeks). With the advantage of minimal morbidity, arthroscopic treatement shoulder be an alternative to open debridement