Surgical management of septic knee arthritis with open arthrotomy and debridement-a case report

<p>Septic arthritis is an inflammatory destruction of the native joint following inoculation of pathogen. Most common organisms causing septic arthritis are <em>Staphylococcus</em> and <em>Streptococcus</em>. Large joints are commonly involved with hip and knee joint accounting for approximately 60% of the total cases. Diagnosis is usually straightforward with the patient presenting with obvious local signs and symptoms along with toxic constitutional symptoms owing to the aggressive nature of the disease. Medical management in form of intra-venous antibiotics forms the mainstay of treatment but it is often required for a prompt surgical intervention in order to provide acute relief from symptom and also to decrease the disease load so as to save the joint from irreversible damage. We have a 63-year-old male patient came presented to us with a right knee swelling and tenderness of 3 weeks duration with restricted ROM with severe toxic constitutional symptoms of 1 week duration. Patient was planned for open arthrotomy and debridement and drainage of the pus and was started on an empirical therapy of injection piperacillin and tazobactam combination for 3 weeks. Immediate relief from symptoms following arthrotomy with good range of motion at 4 weeks post-surgery. As is clear from our case, an early diagnosis of septic arthritis and starting of appropriate antibiotics along with appropriately aggressive surgical interventions in the form of open debridement is the key for treatment of septic arthritis in order to save the joint from irreversible inflammatory damage. Surgical intervention not only gives immediate symptomatic relief but also decreases the load over antibiotics and increases local blood supply subsequently helping in better healing.</p><p><strong> </strong></p>

Diagnostic Criteria for the Painful Swollen Pediatric Knee: Distinguishing Septic Arthritis From Aseptic Effusion in a Non-Lyme Endemic Area

Purpose: The child with a painful swollen knee must be worked-up for possible septic arthritis; the classic clinical prediction algorithms for septic arthritis of the hip may not be the best models to apply to the knee.Materials and methods: This was a retrospective case-control study of 17 years of children presenting to one hospital with a chief complaint of a painful swollen knee, to evaluate the appropriateness of applying a previously described clinical practice algorithm for the hip in differentiating between the septic and aseptic causes of the painful knee effusions. The diagnoses of true septic arthritis, presumed septic arthritis, and aseptic effusion were established, based upon the cultures of synovial fluid, blood cultures, synovial cell counts, and clinical course. Using a logistic regression model, the disease status was regressed on both the demographic and clinical variables.Results: In the study, 122 patients were included: 51 with true septic arthritis, 37 with presumed septic arthritis, and 34 with aseptic knee effusion. After applying a backward elimination, age &lt;5 years and C-reactive protein (CRP) &gt;2.0 mg/dl remained in the model, and predicted probabilities of having septic knee arthritis ranged from 15% for the lowest risk to 95% for the highest risk. Adding a knee aspiration including percent polymorphonucleocytes (%PMN) substantially improved the overall model performance, lowering the lowest risk to 11% while raising the highest risk to 96%.Conclusions: This predictive model suggests that the likelihood of pediatric septic arthritis of the knee is &gt;90% when both “age &lt;5 years” and “CRP &gt; 2.0 mg/dl” are present in a child with a painful swollen knee, though, in the absence of these factors, the risk of septic arthritis remains over 15%. Aspiration of the knee for those patients would be the best next step.

Fungal Septic Knee Arthritis Caused by Aspergillus fumigatus following Anterior Cruciate Ligament Reconstruction

Postoperative infections after arthroscopic anterior cruciate ligament (ACL) reconstruction (ACLR) represent a rare but severe complication. An extremely rare case of Aspergillus septic arthritis in a 27-year-old patient following arthroscopic ACLR is reported. The patient presented with signs of knee infection 14 days after ACLR. Two consecutive arthroscopic debridements were performed, while eventually histopathology, cultures and multiplex PCR test revealed Aspergillus identified as A. fumigatus by mass spectrometry. The patient commenced long-term treatment with voriconazole. Fungal arthritis or osteomyelitis following ACLR has a mild local and general inflammatory reaction when compared to the bacterial ones. Nevertheless, such infections may lead to aggressive osseous destruction and necrosis. A high index of suspicion is of utmost importance for early detection, while microscopic, histological examination and multiplex PCR may be more helpful for the diagnosis than cultures since cultures are more time-consuming and may vary depending on different factors.

Genomic Characterization of a New Biofilm-Forming and Adhesive ST398 Human-Adapted MSSA Lineage Causing Septic Knee Arthritis Following Surgical Reconstruction

Methicillin-susceptible (MSSA) and methicillin-resistant Staphylococcus aureus (MRSA) is a pathogen commonly found in bone and joint infections, including septic arthritis. S. aureus virulence and the frailty of affected patients can cause several complications; a prompt and specific antibiotic treatment can positively affect the outcome of patients. We carried out an in-depth genomic characterization by Illumina whole genome sequencing and bioinformatics of two biofilm-producing M1 and M2 ST398 MSSA causing septic knee arthritis not-responding to antimicrobial therapy. The strains were characterized for antibiotic resistance, biofilm and adhesive properties as well as genomics, single nucleotide polymorphism phylogeny, resistomics and virulomics. Our results showed that M1 and M2 MSSA were ST398-t1451-agrI-Cap5, susceptible to cefoxitin and resistant to erythromycin and clindamycin, traits consistent with the lack of the SCCmec-locus and the presence of the sole blaZ and ermT. Furthermore, M1 and M2 were biofilm-producing and largely potentially adhesive strains, as indicated by the adhesion gene profile. Our data characterized a new human-adapted ST398 MSSA lineage, representing a “fusion” between the human-animal independent ST398 and the Livestock Associated (LA) ST398 lineages, forming biofilm and genomically predicted high adhesive, characterized by different genomic adaptation conferring a great ability to adhere to the host’s extracellular matrix causing septic knee arthritis.

Arthrocentesis, arthroscopy or arthrotomy for septic knee arthritis in children: a systematic review

Purpose Septic knee arthritis in children can be treated by arthrocentesis (articular needle aspiration) with or without irrigation, arthroscopy or arthrotomy followed by antibiotics. The objective of this systematic review was to identify the most effective drainage technique for septic arthritis of the knee in children. Methods The electronic PubMed, Embase and Cochrane databases were systematically searched for original articles that reported outcomes of arthrocentesis, arthroscopy or arthrotomy for septic arthritis of the knee. The quality of all included studies was assessed with the Methodological Index for Non-Randomized Studies (MINORS) criteria. This systematic review was performed and reported according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines (PROSPERO). Results Out of 2428 articles, 11 studies with a total of 279 knees were included in the systematic review. The quality of evidence was low (MINORS median 4 (2 to 7)). A meta-analysis could not be performed because of the diversity and low quality of the studies. In septic knee arthritis, additional drainage procedures were needed in 54 of 156 (35%) knees after arthrocentesis, in four of 96 (4%) after arthroscopy and in two of 12 (17%) after arthrotomy. Conclusion Included studies on treatment strategies for septic arthritis of the knee in children are diverse and the scientific quality is generally low. Knee arthroscopy might have a lower risk of additional drainage procedures as compared with arthrocentesis and arthrotomy, with acceptable clinical outcomes and no radiological sequelae. Level of evidence IV

Development of an experimental model of septic knee arthritis in rats through intra-articular inoculation of Staphylococcus aureus

Haematogenous models of septic arthritis have some inherent disadvantages, such as the manifestation of arthritis relies on chance, the size of the inoculum is unknown and the number of animals to be studied cannot be reduced because the animals cannot serve as their own controls. This study aimed to develop a rat model of knee septic arthritis by injecting a known inoculum of Staphylococcus aureus into the joint. The left knees of 27 Sprague Dawley rats were injected with four different inoculum concentrations of a sensitive strain of S. aureus (30,000 colony-forming units (CFUs), n = 3; 18,550 CFUs, n = 6; 15,500 CFUs, n = 9; and 7700 CFUs, n = 9); the right knees served as controls. Clinical, microbiological and histological variables were assessed two and seven days later. The main criterion for diagnosing septic arthritis was a positive culture of synovial fluid. The rate of microbiologically confirmed septic arthritis was high for all inoculum concentrations (3/3, 6/6, 8/9 and 7/9, respectively), and the rate of bacteraemia was also high. Animal welfare was better for the two lowest inoculum concentrations. No animal reached the pre-established humane end points. Overall, the third inoculum was considered the most suitable. Thus, acute septic arthritis can be caused in rats by inoculating 15,000 CFUs of an ATCC strain of S. aureus directly into the knee joint. Overall, the model seems to be useful for studying the effectiveness of drugs for the treatment of acute septic arthritis.