Dyslipidaemia is associated with Cutibacterium acnes hip and knee prosthetic joint infection.

PURPOSE: Optimization of medical factors including diabetes and obesity is a cornerstone in the prevention of prosthetic joint infection (PJI). Dyslipidaemia is another component of metabolic syndrome which has not been thoroughly investigated as an individual, modifiable risk factor. This study examined the association of dyslipidaemia with PJI caused by the lipophilic microbe Cutibacterium acnes (C. acnes). METHODS: A retrospective chart review examined patients with positive C. acnes culture at hip or knee arthroplasty explantation. A control group with methicillin-sensitive Staphylococcus aureus (MSSA) positive cultures at explantation was matched for age, sex, and surgical site, as well as a second control group with no infection. A total of 80 patients were included, 16 with C. acnes, 32 with MSSA, and 32 with no infection. All patients had a lipid panel performed within one year of surgery. Lipid values and categories were compared using multinomial logistic regressions. RESULTS: High or borderline triglycerides (TG) (relative risk ratio (RRR) = 0.13; P = 0.013) and low high-density lipoprotein (HDL) (RRR = 0.13; P = 0.025) were significantly associated with C. acnes PJI compared to MSSA-PJI. High or borderline TG (RRR = 0.21; P = 0.041) and low HDL (RRR = 0.17; P = 0.043) were also associated with a greater probability of C. acnes infection compared to no infection. CONCLUSIONS: The presence of elevated TG and low HDL were both associated at a statistically significant level with C. acnes hip or knee PJI compared to controls with either MSSA PJI or no infection. This may represent a specific risk factor for C. acnes PJI that is modifiable.

Isothermal microcalorimetry improves accuracy and time to bacterial detection of periprosthetic joint infection after total joint arthroplasty.

Isothermal microcalorimetry (IMC) was evaluated compared to conventional cultures to determine the clinical performance for diagnosing periprosthetic joint infection (PJI) of hip/knee replacements. We prospectively collected three to five deep tissue samples per patient from 152 patients undergoing conversion or revision hip/knee arthroplasty from July 2020 to November 2022. Cultures and IMC for each sample were compared for concordance, median time to detection (TTD), and diagnostic performance based on 2013 Musculoskeletal Infection Society criteria. Secondary analyses involved patients on antibiotics at sampling. The 152 total patients had 592 tissue samples (mean 3.9 ± 0.3) with sample concordance between cultures and IMC of 90%. IMC demonstrated a sensitivity of 83%, specificity of 100%, negative predictive value (NPV) of 89%, and positive predictive value (PPV) of 100% for PJI. Cultures resulted in 69% sensitivity, 100% specificity, 81% NPV, and 100% PPV. The accuracy of IMC was 93% compared to 87% for cultures (P < 0.001). The median TTD of PJI by cultures was 51 (21-410) hours compared to 10 (0.5-148) hours for IMC (P < 0.001). For 39 patients on chronic antibiotics, sensitivity in PJI detection was 93%, specificity 100%, NPV 85%, and PPV 100% by IMC compared to 79% sensitivity, 100% specificity, 65% NPV, and 100% PPV for cultures. The accuracy was 95% for IMC compared to 85% for cultures (P < 0.001) with median TTD of 12 (0.5-127) hours compared to 52 (21-174) hours (P < 0.001). Utilizing IMC for PJI detection improves TTD by nearly 2 days while improving diagnostic accuracy compared to cultures, particularly in patients on chronic antibiotics.

Mycobacterium tuberculosis infectious monoarthritis in a paediatric patient.

Mycobacterium tuberculosis is uncommon in the USA, and when it is diagnosed, it is usually in adult patients with identifiable risk factors presenting with pulmonary manifestations of the disease. Paediatric tuberculosis is rare, and a minority of those cases can present with isolated extrapulmonary infection. When the musculoskeletal system is involved, there are often no constitutional symptoms, and it can resemble other infectious and inflammatory processes. Diagnosis is challenging, and delay leads to irreversible destructive osteoarticular changes. A prompt diagnosis requires a high index of suspicion. This report presents a case of successfully diagnosed paediatric M. tuberculosis monoarthritis of the knee to highlight these challenges.

Atypical mycobacterium infection following anterior cruciate ligament reconstruction.

A man in his 20s presented with instability of the right knee following an incident of fall from a height. He was clinicoradiologically diagnosed to have an anterior cruciate ligament (ACL) tear for which he underwent ACL reconstruction. Postoperatively, he was started on an accelerated ACL rehabilitation protocol. Six weeks postoperatively, he developed features of subclinical septic arthritis for which he underwent arthroscopic debridement. Intraoperative samples cultured Mycobacterium abscessus complex on MGIT 960 system. The patient subsequently had to undergo another debridement after 1 month as there were clinical signs of persisting infection. The graft was intact even on the second debridement and after removing the implants. This case reports a rare complication of ACL reconstruction with infection by atypical mycobacterium and the clinical outcome. It also emphasises that prompt surgical intervention can save the graft.

The fate of fungal periprosthetic joint infection after total knee arthroplasty.

PURPOSE: To demonstrate the clinical outcomes of patients with fungal periprosthetic joint infections (PJIs) after two-stage exchange arthroplasty combined with antifungal therapy. METHODS: We retrospectively reviewed the outcomes of 41 patients with fungal PJIs after primary total knee arthroplasty (TKA) in a single centre from January 1999 to October 2017. During the first stage of resection arthroplasty, antifungal-impregnated cement spacers (AICSs) were implanted in all patients. After systemic antifungal treatment during the interval between the two surgeries, delayed reimplantation as part of a two-stage exchange protocol was performed when patients were clinically stable. We defined treatment success as a well-functioning arthroplasty without any signs of PJI after a minimum follow-up of two years without antimicrobial suppression. Successful treatment was confirmed by repeat negative cultures as well as a return of inflammatory markers to normal levels. RESULTS: The treatment success rate was 63.4% at the final follow-up. Thirty-six of 41 patients (87.8%) met the criteria for second-stage revision after confirmation of complete infection control. The mean prosthesis-free interval was 6.6 months (range, 2.0-30.0 months). During follow-up after two-stage exchange arthroplasty, ten patients (27.7% of 36 patients) unfortunately experienced recurrence or relapse of infection after an average of 31.3 months (range, 2.7-135.6 months). The rate of survivorship free from reinfection was 94.4% at six months, 84.8% at one year, and 73.6% at two years. Cox proportional hazard regression analysis demonstrated that the prosthesis-free interval (HR = 1.016, p = 0.037) and mean length of antifungal treatment (HR = 0.226, p = 0.046) were potential risk factors for failure. CONCLUSION: Fungal PJIs led to devastating clinical outcomes despite even two-stage revision arthroplasty with the use of AICSs and antifungal medications.

High Rate of Intramedullary Canal Culture Positivity in Total Knee Arthroplasty Resection for Prosthetic Joint Infection.

BACKGROUND: Periprosthetic infection is a devastating complication following total knee arthroplasty. A 2-stage protocol often includes an interim antibiotic spacer with intramedullary (IM) dowels. However, the necessity of IM dowels has recently been challenged. Specifically, the data supporting bacterial colonization of the IM canal are limited and controversial. The purpose of this study was to identify the rate of positive IM cultures during resection arthroplasty in periprosthetic knee infection. METHODS: A total of 66 IM diaphyseal cultures were taken during resection arthroplasty from 34 patients diagnosed with periprosthetic knee infection. These IM cultures were taken from the femoral and tibial canals using separate sterile instruments. All patients had infected primary total knee arthroplasty implants at the time of resection. RESULTS: Thirty one percent (n = 21) of IM canal cultures in this study were positive from either the tibial or the femoral diaphysis at the time of resection arthroplasty. There were 18 of 21 (86%) of the positive IM canal cultures with concordant intraoperative joint cultures where the IM cultures matched the intraarticular cultures. CONCLUSION: With a 31% positive IM canal culture rate, this study confirms the logic of using IM dowels with an antibiotic spacer to treat periprosthetic knee infection. Since the failure of a 2-stage reimplantation is catastrophic, any attempt to provide additional local antibiotic delivery seems warranted. Since nearly one-third of our patients had positive IM cultures, this simple addition to an antibiotic spacer has the potential to improve 2-stage results. Claims supporting the elimination of IM dowels during resection arthroplasty seem ill-advised.

Early diagnosis and treatment of acute brucellosis knee arthritis complicated by acute osteomyelitis: two cases report.

BACKGROUND: Brucellosis is an endemic systemic infectious disease, the most common complication is bone and joint involvement. Sacroiliac joint and spinal joint are the most frequently involved sites in adults, but knee joint infection is rare, and acute infectious knee arthritis complicated by acute osteomyelitis is even extremely uncommon in adults. Here, we report two cases of acute septic knee arthritis complicated by acute osteomyelitis caused by Brucella melitensis (B. melitensis). CASE PRESENTATION: Both patients had a history of traveling in animal husbandry areas within three months. On clinical examination, their right knee joint was tender, swollen, had limited movement and an effusion was present. Imaging examination showed effusion and synovial thickening of the right knee joint, as well as subchondral bone edema of the distal femur and proximal tibia. Laboratory examination showed that the serum agglutination test (SAT) in both patients were positive (1: 640 and 1: 320) without leukocytosis, although the proportion of lymphocytes, erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) significantly increased. Both patients underwent knee joint aspiration. Real-time polymerase chain reaction (Real-time PCR) analysis of synovial fluid showed that there was B. melitensis, and blood bacterial culture was negative. We determined that two patients had acute brucellosis knee arthritis complicated by acute osteomyelitis. Antibiotic treatment was given during hospitalization consisting of doxycycline (0.1 g po bid) and rifampicin (0.6 g po qd) for six weeks, and the changes of inflammatory indexes were closely monitored. At discharge, the symptoms had completely resolved, imaging abnormalities disappeared, and inflammatory indexes returned to normal. There was no recurrence of the disease at 1-year follow-up. CONCLUSION: Acute brucellosis knee arthritis complicated by acute osteomyelitis is a rare but serious complication of brucellosis in adults. There is no obvious specificity of clinical manifestation and imaging examination. Early diagnosis and treatment can prevent the occurrence of knee joint deformity and even pathological fracture. Clinicians should fully consider the possibility of brucellosis where the travel or occupational history is suggestive.

Deciphering the low abundance microbiota of presumed aseptic hip and knee implants.

16S rRNA gene sequencing of DNA extracted from clinically uninfected hip and knee implant samples has revealed polymicrobial populations. However, previous studies assessed 16S rRNA gene sequencing as a technique for the diagnosis of periprosthetic joint infections, leaving the microbiota of presumed aseptic hip and knee implants largely unstudied. These communities of microorganisms might play important roles in aspects of host health, such as aseptic loosening. Therefore, this study sought to characterize the bacterial composition of presumed aseptic joint implant microbiota using next generation 16S rRNA gene sequencing, and it evaluated this method for future investigations. 248 samples were collected from implants of 41 patients undergoing total hip or knee arthroplasty revision for presumed aseptic failure. DNA was extracted using two methodologies-one optimized for high throughput and the other for human samples-and amplicons of the V4 region of the 16S rRNA gene were sequenced. Sequencing data were analyzed and compared with ancillary specific PCR and microbiological culture. Computational tools (SourceTracker and decontam) were used to detect and compensate for environmental and processing contaminants. Microbial diversity of patient samples was higher than that of open-air controls and differentially abundant taxa were detected between these conditions, possibly reflecting a true microbiota that is present in clinically uninfected joint implants. However, positive control-associated artifacts and DNA extraction methodology significantly affected sequencing results. As well, sequencing failed to identify Cutibacterium acnes in most culture- and PCR-positive samples. These challenges limited characterization of bacteria in presumed aseptic implants, but genera were identified for further investigation. In all, we provide further support for the hypothesis that there is likely a microbiota present in clinically uninfected joint implants, and we show that methods other than 16S rRNA gene sequencing may be ideal for its characterization. This work has illuminated the importance of further study of microbiota of clinically uninfected joint implants with novel molecular and computational tools to further eliminate contaminants and artifacts that arise in low bacterial abundance samples.

Active rheumatoid arthritis in a mouse model is not an independent risk factor for periprosthetic joint infection.

INTRODUCTION: Periprosthetic joint infection (PJI) represents a devastating complication of total joint arthroplasty associated with significant morbidity and mortality. Literature suggests a possible higher incidence of periprosthetic joint infection (PJI) in patients with rheumatoid arthritis (RA). There is, however, no consensus on this purported risk nor a well-defined mechanism. This study investigates how collagen-induced arthritis (CIA), a validated animal model of RA, impacts infectious burden in a well-established model of PJI. METHODS: Control mice were compared against CIA mice. Whole blood samples were collected to quantify systemic IgG levels via ELISA. Ex vivo respiratory burst function was measured via dihydrorhodamine assay. Ex vivo Staphylococcus aureus Xen36 burden was measured directly via colony forming unit (CFU) counts and crystal violet assay to assess biofilm formation. In vivo, surgical placement of a titanium implant through the knee joint and inoculation with S. aureus Xen36 was performed. Bacterial burden was then quantified by longitudinal bioluminescent imaging. RESULTS: Mice with CIA demonstrated significantly higher levels of systemic IgG compared with control mice (p = 0.003). Ex vivo, there was no significant difference in respiratory burst function (p = 0.89) or S. aureus bacterial burden as measured by CFU counts (p = 0.91) and crystal violet assay (p = 0.96). In vivo, no significant difference in bacterial bioluminescence between groups was found at all postoperative time points. CFU counts of both the implant and the peri-implant tissue were not significantly different between groups (p = 0.82 and 0.80, respectively). CONCLUSION: This study demonstrated no significant difference in S. aureus infectious burden between mice with CIA and control mice. These results suggest that untreated, active RA may not represent a significant intrinsic risk factor for PJI, however further mechanistic translational and clinical studies are warranted.

Native joint infections caused by Parvimonas micra.

Parvimonas micra is an anaerobic, fastidious, gram positive organism commonly found in the oral cavity and gastrointestinal tract. It has been increasingly reported as the cause of septic arthritis of native joints, often times with delayed diagnosis leading to increased morbidity. Risk factors include immunosuppression, inflammation of the joint, and recent dental procedures or infections. It has been a historically difficult organism to culture. However, the development of and increasing use of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) has led to increased identification of P. micra. Common antibiotic susceptibilities, as well as data regarding susceptibilities in specific situations, have been reported, but susceptibility testing is required in all cases. Common treatments include clindamycin, penicillin, and metronidazole for six to ten weeks.

Late onset prosthetic joint infection caused by Parvimonas micra.

Parvimonas micra (P.micra) is a difficult to culture gram positive anaerobic microorganism, typically found in the human microbiota, specially in the oral cavity. There are limited cases in literature reporting prosthetic joint infection due to this bacteria, although its isolation has been reported in different settings in later years. We present the case of a late onset knee prosthetic joint infection caused by Parvimonas micra in an 87 year old woman treated with antibiotics and two-step surgery with prosthetic material removal, antibiotic-loaded cement spacer placement and new prosthetic material replacement after 2 weeks of intravenous antimicrobial therapy followed by 6 weeks of oral therapy.

Primary meningococcal arthritis in a COVID-19 18-year-old man: a case report and review of the literature.

BACKGROUND: SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) infection is associated with various complications. PMA (primary meningococcal arthritis) is a rare meningococcus-associated disease causing arthritis of the knee usually, without any signs of invasive meningococcal disease. No case of PMA in a COVID-19 (coronavirus disease, 2019) patient has yet been described. PMA mainly strikes young adults. PMA is not associated with any immunocompromising condition. It has a better outcome than usual septic arthritis CASE PRESENTATION: Herein, we report an 18-year-old man diagnosed with COVID-19, later admitted with persistent fever, right knee arthralgia and maculopapular rash. Due to family history, psoriasis and Henoch-Schönlein purpura were hypothesized and ruled out. Finally, synovial fluid culture confirmed Neisseria meningitidis serogroup B arthritis without any other symptoms of invasive meningococcal disease. Healing was achieved quickly with surgery and antibiotics. We concluded in a PMA. CONCLUSION: We describe here the first primary meningococcal arthritis in a COVID-19 patient and we hope to shine a light on this rare but serious complication.

Arthroscopic treatment of Mycobacterium massiliense septic arthritis outbreak after intra-articular injection: A case-series report and literature review.

ABSTRACT: Non-tuberculous mycobacteria (NTM) comprise mycobacteria, with the exceptions of Mycobacterium (M.) leprae and the M. tuberculosis complex. Septic arthritis caused by NTM is so rare that there is no standardized treatment.Between April and September 2012, 27 patients were infected with M. massiliense in a single clinic following injection of steroid in the knee joint. Clinical data of 9 patients who received arthroscopic treatment in Seoul Hospital of Soonchunhyang University were analyzed retrospectively.Arthroscopic irrigation and debridement were performed average 2.6 times (1-3 times). As 6 out of 9 cases (67%) had joint contracture of the knee joint, arthroscopic adhesiolysis, and brisement were performed. After surgical procedures, Hospital for Special Surgery and Lysholm knee score showed improvement compared before the surgery, but a radiographic result evaluated by Kellgren-Lawrence revealed that 6 cases got deteriorated to stage 4 in the 4-year follow-up.NTM septic arthritis had a higher recurrence and a higher contracture incidence than septic arthritis caused by tuberculous mycobacteria or other bacteria. Treatment was possible with repeated arthroscopic debridement and intravenous antibiotics.

Successful Two-Stage Exchange Arthroplasty for Periprosthetic Infection Following Total Knee Arthroplasty: The Impact of Timing on Eradication of Infection.

Background: Periprosthetic joint infection (PJI) represents a serious complication following total knee arthroplasty. In the setting of chronic infections, the two-staged approach has traditionally been the preferred treatment method. The aim of this study was to determine the optimal period of rest between the first and second stage. Furthermore, we analyzed potentially outcome-relevant parameters, such as general and local conditions and the presence of difficult-to-treat or unidentified microorganisms, with regard to their impact on successful treatment of PJI. Patients and Methods: We performed a retrospective analysis of prospectively collected data for all patients treated for PJI at our institution. Seventy-seven patients who had undergone two-stage revision arthroplasty for PJI of the knee were included into the study. Antibiotic-loaded cement spacers were used for all patients. Results: After a median follow-up time of 24.5 months, infection had reoccurred in 14 (18.7%) patients. A prolonged spacer-retention period of more than 83 days was related to a significantly higher proportion of reinfections. Furthermore, significant compromising local conditions of the prosthetic tissue and surrounding skin, as well as repeated spacer-exchanges between first- and second-stage surgery, negatively influenced the outcome. Neither the patients' age nor gender exerted a significant influence on the outcome regarding reinfection rates for patients' age or gender. Conclusions: We observed the best outcome regarding infection control in patients who had undergone second-stage surgery within 12 weeks after first-stage surgery. Nearly 90% of these patients stayed free from infection until the final follow-up. An increased number of performed spacer-exchanges and a bad local extremity grade also had a negative impact on the outcome.

Rothia mucilaginosa: a case of septic arthritis in a native knee and review of the literature.

Rothia mucilaginosa is a Gram-positive aerobic coccus usually found in the oral and respiratory tract. Septic arthritis is an uncommon condition, but is an orthopaedic emergency. A rare case of knee septic arthritis due to R. mucilaginosa is presented. Patient management and outcomes are discussed, and learning points from this case are outlined to help manage any further cases that may arise.

One-stage revision surgery provides infection eradication and satisfying outcomes for infected knee arthroplasty in selected patients.

OBJECTIVES: We conducted a retrospective study to evaluate the outcomes of one-stage revision total knee arthroplasty (TKA) in terms of eradication of the infection, improvement of pain, and knee function. METHODS: Between 2009 and 2016, 20 patients underwent one-stage revision TKA for the treatment of a prosthetic joint infection (PJI). Inclusion criteria were: patients nonimmunocompromised with minimal or moderate bone loss, known organisms with known sensitivity. Assessment included clinical signs of infection eradication, range of motion, Knee Society clinical rating score, visual analog scale pain score, and radiographic assessment. RESULTS: After a mean follow-up of 6.2 years (range, 2-10 years), none of the patients had signs suggesting recurrent infection. Follow-up examination showed significant improvement of all variables compared to preoperative values (p < 0.001). CONCLUSIONS: One-stage revision surgery provides infection eradication and satisfying subjective functional outcomes for infected knee arthroplasty in selected patients. EXPERT OPINION: One-stage revision knee arthroplasty is a valuable resource to approach PJIs in selected patients whose infecting micro-organism and sensitivity are determined before surgery. In order to succeed strict inclusion criteria should be applied, as only non-immunocompromised patients with healthy soft tissues with minimal or moderate bone loss are eligible for this procedure.

Difficult Diagnosis of Fungal Arthritis After Arthroscopic Anterior Cruciate Ligament Reconstruction: A Case Report.

CASE: An 18-year-old woman underwent arthroscopic anterior cruciate ligament reconstruction (ACLR) but developed recurrent knee effusion. At age 25 years, her right knee pain worsened, and radiographs revealed extensive bone loss. She was diagnosed with fungal (Candida parapsilosis) osteomyelitis by synovial fluid cultures. She underwent 2-stage surgery involving an amphotericin B-loaded cement spacer implantation and bone defect grafting. No recurrence of infection has been noted for 3 years postoperatively. CONCLUSIONS: Fungal osteomyelitis may have few signs of local infection and often remains undiagnosed until bone loss occurs. Differential diagnosis should include this disease when there is recurrent knee effusion after ACLR.

Management of an outbreak of invasive Kingella kingae skeletal infections in a day care center.

BACKGROUND: Kingella kingae (Kk) is frequently responsible for invasive skeletal infections in children aged 3-36months. However, few outbreaks of invasive Kk infections in day care centers have been reported. The objective of the present study was to describe (a) the clinical and laboratory data recorded during an outbreak of invasive Kk skeletal infections, and (b) the management of the outbreak. METHOD: Four children from the same day care center were included in the study May and June 2019. We retrospectively analyzed the children's clinical presentation and their radiological and laboratory data. We also identified all the disease control measures taken in the day care center. RESULTS: We observed cases of septic arthritis of the wrist (case #1), shoulder arthritis (case #2), knee arthritis (case #3) ans cervical spondylodiscitis (case #4). All cases presented with an oropharyngeal infection and concomitant fever prior to diagnosis of the skeletal infection. All cases were misdiagnosed at the initial presentation. The mean (range) age at diagnosis was 10.75months (9-12). The three patients with arthritis received surgical treatment. All patients received intravenous and then oral antibiotics. In cases 1 and 2, Kk was detected using real-time PCR and a ST25-rtxA1 clone was identified. The outcome was good in all four cases. Four other children in the day care center presented with scabies during this period and were treated with systemic ivermectin. The Regional Health Agency was informed, and all the parents of children attending the day care center received an information letter. The day care center was cleaned extensively. CONCLUSION: Our results highlight the variety of features of invasive skeletal Kk infections in children and (given the high risk of transmission in day care centers) the importance of diagnosing cases as soon as possible.

An uncommon case of native joint septic arthritis by Parvimonas micra.

Parvimonas micra is an anaerobic, Gram-positive coccus found in the oral cavity and gastrointestinal tract. We report a case of a 77-year-old male with right knee pain after a recent dental procedure and fall. Arthrocentesis was notable for Parvimonas micra which was successfully treated with metronidazole.