Pathogenic potential of Parabacteroides distasonis revealed in a splenic abscess case: a truth unfolded.

Splenic abscess is a rare entity, however if unrecognised or left untreated, it is invariably fatal. We herein report a case of splenic abscess in a 40-year-old man presenting with fever, left-sided abdominal pain, altered sensorium and vomiting. On clinical examination, hepatosplenomegaly was noted and the ultrasound of the abdomen showed multiple hypoechoic regions in the upper pole of spleen, and the diagnosis of splenic abscess was made. The patient received antimicrobial therapy and underwent an open splenectomy with full recovery. Pus aspirated from the splenic abscess grew an unusual organism named Parabacteroides distasonis In the literature, there are only a few recorded cases of P. distasonis causing splenic abscess. Through this case report, we would like to emphasise the pathogenic role of P. distasonis in causing clinical disease, as this organism is typically known to constitute a part of the normal flora.

Roseomonas gilardii in patient with leukemia and acute appendicitis: case report and review.

Appendicitis is one of the most common abdominal conditions requiring emergency surgery. However, acute appendicitis in patients with leukemia is a rare condition. We report herein the case of an 18-year-old female with acute lymphoblastic leukemia (ALL), who was hospitalized in hematology department because of abdominal pain and fever. Ultrasound (US) of the abdomen revealed appendicitis and the patients underwent open appendectomy. The patient recovered without complications and was discharged in a good condition. The day of the operation blood and peritoneal fluid cultures were taken and Roseomonas gilardii was detected and healed empirically. The correct diagnosis of appendicitis in patients with leukemia and their management is challenging for physicians. Very rare microorganisms can be detected in these patients.

Surgical site infection caused by Aeromonas hydrophila presenting as necrotizing soft tissue infection after esophagectomy.

Several virulence factors of Aeromonas such as hemolysin, proteases and lipases have been characterized. The relationship between these virulence factors and disease remains unclear. A 71-year-old man underwent thoracoscopic esophagectomy, lymph node dissection and Roux-en-Y reconstruction for esophageal cancer. On postoperative day 1, redness around the wound on the thoracic abdominal wall gradually enlarged and necrosis became apparent with septic shock. Necrotizing soft tissue infection was suspected and emergency surgical debridement was performed. Blood and wound cultures were positive for Aeromonas hydrophila. The strain was found to have hemolytic activity, proteolytic activity and extremely high elastolytic activity. In addition, the strain actively produced elastolytic metalloprotease, which may contribute to extensive tissue necrosis.

Replacement of the Native Mitral Valve Due to Endocarditis Caused by Stenotrophomonas Maltophilia.

We report a case of a 59-year-old female patient with vegetative native mitral valve endocarditis caused by Stenotrophomonas maltophilia (SM). She had hemodialysis-dependent chronic renal failure, but no immunosuppressive disease. Echocardiography showed mobile vegetation on her native mitral valve. Right femoral artery embolectomy and mitral valve replacement were performed simultaneously. She awakened from anesthesia, but she passed away due to septic shock complications. To the best of our knowledge, this was the first case in whom native mitral valve endocarditis caused by SM was observed (despite of absence of any immunosuppressive event) and needed to undergo valve replacement.

Replacement of the native mitral valve due to endocarditis caused by stenotrophomonas maltophilia

Abstract We report a case of a 59-year-old female patient with vegetative native mitral valve endocarditis caused by Stenotrophomonas maltophilia (SM). She had hemodialysis-dependent chronic renal failure, but no immunosuppressive disease. Echocardiography showed mobile vegetation on her native mitral valve. Right femoral artery embolectomy and mitral valve replacement were performed simultaneously. She awakened from anesthesia, but she passed away due to septic shock complications. To the best of our knowledge, this was the first case in whom native mitral valve endocarditis caused by SM was observed (despite of absence of any immunosuppressive event) and needed to undergo valve replacement.

Outcomes of repeat two-stage exchange hip arthroplasty for prosthetic joint infection.

AIMS: The increasing infection burden after total hip arthroplasty (THA) has seen a rise in the use of two-stage exchange arthroplasty and the use of increasingly powerful antibiotics at the time of this procedure. As a result, there has been an increase in the number of failed two-stage revisions during the past decade. The aim of this study was to clarify the outcome of repeat two-stage revision THA following a failed two-stage exchange due to recurrent prosthetic joint infection (PJI). PATIENTS AND METHODS: We identified 42 patients who underwent a two-stage revision THA having already undergone at least one previous two stage procedure for infection, between 2000 and 2015. There were 23 women and 19 men. Their mean age was 69.3 years (48 to 81). The outcome was analyzed at a minimum follow-up of two years. RESULTS: A satisfactory control of infection and successful outcome was seen in 26 patients (57%). There therefore remained persistent symptoms that either required further surgery or chronic antibiotic suppression in 16 patients (38%). One-third of patients had died by the time of two years' follow-up. CONCLUSION: The rate of failure and complication rate of repeat two-stage exchange THA for PJI is high and new methods of treatment including host optimization, immunomodulation, longer periods between stages, and new and more powerful forms of antimicrobial treatment should be investigated. Cite this article: Bone Joint J 2019;101-B(6 Supple B):110-115.

Identification of infectious species after resection of soft-tissue sarcomas.

BACKGROUND: Pathogenic species in deep tissue infections after soft-tissue sarcoma (STS) resection is largely unstudied, particularly the role of anaerobic bacteria, risks factors for those pathogens, and the time course of infection presentation. METHODS: Retrospective analysis of 64 patients requiring operative debridement for deep tissue infection after STS resection was undertaken to identify infectious species and study risk factors for anaerobic infections. Kaplan-Meier methods examined the time course of infection presentation. RESULTS: STS subtypes were most commonly pleomorphic STS, myxofibrosarcoma, and undifferentiated STS. Staphylococcus aureus was the most common organism isolated (56%). Twenty (31%) infections were positive for ≥1 anaerobic organism. Twelve gram-positive and 10 gram-negative aerobic organisms were isolated. Most (90%) anaerobic-containing infections were polymicrobial, vs 52% of purely aerobic infections. No significant risk factors for anaerobic infections were identified. Median time from tumor resection until debridement was significantly greater for anaerobic infections (54.5 days) than for purely aerobic infections (29.5 days; P = 0.004), a difference so pronounced that using "presentation after 53 days" as a proxy for the presence of anaerobic pathogens had an accuracy of 81%. CONCLUSIONS: Because polymicrobial and anaerobic bacterial infections are common, we strongly support antibiotic use with anaerobic coverage at debridement, particularly for infections presenting later.

5-ALA Fluorescence in Case of Brain Abscess by Aggregatibacter Mimicking Glioblastoma.

BACKGROUND: At present, the differential diagnosis of magnetic resonance imaging enhancing lesions can still be challenging. Preoperative imaging is a valuable tool characterized by high informative value, even if false-positive and false-negative results are possible. In this context, 5-aminolevulenic acid (5-ALA) represents a significant adjunct in glioblastoma (GBM) surgery displaying an assumed specific accumulation only in tumor cells. However, it was anecdotally reported that in some cases it can also be detected in nonneoplastic lesions mimicking GBM, thus potentially leading to misdiagnosis. Moreover, precise identification of involved pathogens from intraoperative brain samples may remain difficult. We report the case of an abscess from Aggregatibacter mimicking a GBM both during preoperative imaging and intraoperatively, since showing 5-ALA fluorescence. CASE DESCRIPTION: A 54-year-old man presented with intense cephalalgia, vomiting, and scotomas in his left eye. Brain magnetic resonance imaging demonstrated a right temporo-occipital rim-enhancing mass, highly suggestive of a GBM, and for this reason the patient underwent 5-ALA-guided complete removal. Histopathologic analysis proved the lesion to be a bacterial abscess from Aggregatibacter as confirmed by polymerase chain reaction on bacterial deoxyribonucleic acid. CONCLUSIONS: 5-ALA fluorescence may not be specifically involved only in malignant tumor cells, thus raising the suspect for alternative diagnoses to GBM and inviting caution into fluorescence-guided surgery.

Reconsidering Strategies for Managing Chronic Periprosthetic Joint Infection in Total Knee Arthroplasty: Using Decision Analytics to Find the Optimal Strategy Between One-Stage and Two-Stage Total Knee Revision.

BACKGROUND: Periprosthetic joint infection (PJI) following total knee arthroplasty is a growing concern, as the demand for total knee arthroplasty (TKA) expands annually. Although 2-stage revision is considered the gold standard in management, there is substantial morbidity and mortality associated with this strategy. One-stage revision is associated with lower mortality rates and better quality of life, and there has been increased interest in utilizing the 1-stage strategy. However, surgeons are faced with a difficult decision regarding which strategy to use to treat these infections, considering uncertainty with respect to eradication of infection, quality of life, and societal costs with each strategy. The purpose of the current study was to use decision analysis to determine the optimal decision for the management of PJI following TKA. METHODS: An expected-value decision tree was constructed to estimate the quality-adjusted life-years (QALYs) and costs associated with 1-stage and 2-stage revision. Two decision trees were created: Decision Tree 1 was constructed for all pathogens, and Decision Tree 2 was constructed solely for difficult-to-treat infections, including methicillin-resistant infections. Values for parameters in the decision model, such as mortality rate, reinfection rate, and need for additional surgeries, were derived from the literature. Medical costs were derived from Medicare data. Sensitivity analysis determined which parameters in the decision model had the most influence on the optimal strategy. RESULTS: In both decision trees, the 1-stage strategy produced greater health utility while also being more cost-effective. In the Monte Carlo simulation for Decision Trees 1 and 2, 1-stage was the dominant strategy in about 85% and 69% of the trials, respectively. Sensitivity analysis showed that the reinfection and 1-year mortality rates were the most sensitive parameters influencing the optimal decision. CONCLUSIONS: Despite 2-stage revision being considered the current gold standard for infection eradication in patients with PJI following TKA, the optimal decision that produced the highest quality of life was 1-stage revision. These results should be considered in shared decision-making with patients who experience PJI following TKA. LEVEL OF EVIDENCE: Economic and Decision Analysis Level IV. See Instructions for Authors for a complete description of levels of evidence.

Necrotising fasciitis caused by aeromonas sobria: Not just a simple catfish sting.

Necrotising fasciitis is a life-threatening infection of the soft tissue which can be caused by different microorganisms, but infection caused by Aeromonas spp. or Vibrio spp. is frequently associated with higher mortality rate. Necrotising fasciitis progresses rapidly and often need aggressive surgical intervention. We present a rare case of necrotising fasciitis cause by Aeromonas sobria which mortality was successfully prevented by swift diagnosis and aggressive surgery.

Multidrug-resistant and extensively drug-resistant Gram-negative prosthetic joint infections: Role of surgery and impact of colistin administration.

Factors influencing treatment outcome of patients with Gram-negative bacterial (GNB) multidrug-resistant (MDR) and extensively drug-resistant (XDR) prosthetic joint infection (PJIs) were analysed. Data were collected (2000-2015) by 18 centres. Treatment success was analysed by surgery type for PJI, resistance (MDR/XDR) and antimicrobials (colistin/non-colistin) using logistic regression and survival analyses. A total of 131 patients (mean age 73.0 years, 35.9% male, 58.8% with co-morbidities) with MDR (n = 108) or XDR (n = 23) GNB PJI were assessed. The most common pathogens were Escherichia coli (33.6%), Pseudomonas aeruginosa (25.2%), Klebsiella pneumoniae (21.4%) and Enterobacter cloacae (17.6%). Pseudomonas aeruginosa predominated in XDR cases. Isolates were carbapenem-resistant (n = 12), fluoroquinolone-resistant (n = 63) and ESBL-producers (n = 94). Treatment outcome was worse in XDR versus MDR cases (P = 0.018). Success rates did not differ for colistin versus non-colistin in XDR cases (P = 0.657), but colistin was less successful in MDR cases (P = 0.018). Debridement, antibiotics and implant retention (DAIR) (n = 67) was associated with higher failure rates versus non-DAIR (n = 64) (OR = 3.57, 95% CI 1.68-7.58; P < 0.001). Superiority of non-DAIR was confirmed by Kaplan-Meir analysis (HR = 0.36, 95% CI 0.20-0.67) and remained unchangeable by time of infection (early/late), antimicrobial resistance (MDR/XDR) and antimicrobials (colistin/non-colistin) (Breslow-Day, P = 0.737). DAIR is associated with higher failure rates even in early MDR/XDR GNB PJIs versus implant removal. Colistin should be preserved for XDR cases as it is detrimental in MDR infections.

Intracranial complications of pediatric sinusitis: Identifying risk factors associated with prolonged clinical course.

OBJECTIVE: Intracranial extension is one of the most serious and morbid complications of pediatric sinusitis. Managing this complication continues to be challenging even after widespread pneumococcal vaccination adoption. We aim to identify risk factors associated with complicated clinical courses, and to assess for altering microbial communities and increased antibiotic resistance. METHODS: A retrospective review was conducted of sinus procedures performed at a single institution for acute sinusitis with intracranial extension, and 16 cases were identified. Variables collected included patient demographics, vaccination status, laboratory results, imaging data, antibiotic therapy, sinus and intracranial cultures, perioperative and surgical reports, and hospital course. RESULTS: The average patient age was 11.9 years, and 75% were male. The dominant microbial organisms were gram positive in 93.8% (15/16) of cases and 37.5% (6/16) were anaerobic. There were no cases of resistant bacterial growth, and only one case of Streptococcus pneumoniae. Increased antibiotic therapy duration was associated with anaerobic and polymicrobial sinus cultures. A significant increase in length of hospital stay was identified in polymicrobial sinus cultures and frontal sinus involvement. Intracranial abscess re-accumulation was associated with sinus cultures positive for fusobacterium (p = 0.036), polymicrobial infections (p = 0.034), and involvement of brain parenchyma (p = 0.036). Patients with frontal sinus involvement required a greater number of surgical procedures for abscess drainage (p = 0.046). An anaerobic intracranial culture was associated with an increased number of revision craniotomies (p < 0.001). Parenchymal involvement of the infection was associated with an increased number of surgical complications. CONCLUSIONS: Frontal sinus involvement, and anaerobic and polymicrobial sinus cultures were predictive of a more severe infection requiring more surgical interventions, prolonged intravenous antibiotic treatment and overall hospital length of stay. Streptococcus pneumoniae was not prevalent in our series, and there seems to be a shift in the microbial profile of this patient subset, compared to previous studies, which can likely be attributed to the adoption of pneumococcal vaccinations. Sinus cultures were more predictive of a complicated clinical course compared to intracranial cultures, suggesting the importance of a thorough sinus debridement and obtaining directed sinus cultures.

Bacteriology and Comorbidities in Patients Requiring Surgical Management of Empyema.

Concern over the changing bacteriology of empyema has led to numerous attempts to characterize the most common locoregional bacterial isolates. The purpose of this study is to better characterize the bacteriology and demographics in patients with community-acquired pneumonia (CAP) and hospital-acquired pneumonia requiring surgery for empyema. All patients diagnosed with empyema preoperatively and had either a video-assisted thoracoscopic or open decortication surgery from January 2010 to September 2015 were reviewed. Forty-seven patients were identified with a mean age of 54.7 ± 16.8 years (X ± SD). Sixty per cent of patients had CAP. Anaerobes were the most common isolate at 21 per cent, followed by Streptococcus species and Staphylococcus aureus (50% Methicillin Resistant). Coagulase-negative Staphylococcus species were the next most frequent at 13 per cent. Hospital-acquired pneumonia patients had a higher incidence of S. aureus infections (P = 0.047). Cancer history had higher rates of both fungal (P = 0.004) and gram-negative infections (P = 0.03). Older patients had increased incidence of gram-negative infections (P = 0.05). The median length of stay for CAP patient who were intravenous drug abusers (n = 3) were 31 days (95% confidence interval (CI) [15, NA]), which was significantly longer than the others (median 12 days, 95% CI: [9, 18], P = 0.014). Streptococcus pneumoniae was not found in any of the isolates. Our data reveal that anaerobes and Staphylococcus species have replaced S. pneumoniae as the major regional pathogens in surgically treated empyema. In addition, anaerobic isolates were found in higher incidence in CAP than previously reported.

Septic arthritis following arthroscopic reconstruction of cruciate ligaments of the knee: retrospective case review. / Artritis séptica tras ligamentoplastia artroscópica de la rodilla: análisis retrospectivo de casos.

INTRODUCTION: Rupture of cruciate ligaments of the knee is a common injury that is repaired by arthroscopic reconstruction, which can give rise to septic arthritis. The objective of this article is to describe the clinical and microbiological aspects of this entity. METHODS: Retrospective review of cases of septic arthritis following arthroscopic reconstruction of cruciate ligaments of the knee that occurred at a single institution from 2000-2015. According to time elapsed from surgery, infections were classified as acute (< 14 days), subacute (> 14 days and<30 days), and late (> 30 days). A descriptive and comparative analysis stratified by type of infection and causative microorganism was performed. RESULTS: 3,219 patients underwent arthroscopic reconstruction of cruciate ligaments of the knee and 30 (0.9%) developed septic arthritis. Seventeen (57%) were acute infections and 12 (40%) subacute; there was one late infection. The causative microorganisms were coagulase-negative Staphylococci (n=13; 43%), Staphylococcus aureus (n=12; 40%), other grampositive cocci (n=3; 10%), and gramnegative bacilli (n=2; 7%). All patients underwent arthroscopic debridement; no grafts were removed. All patients received antibiotic therapy for a median of 23.5 days (range: 14 - 78 days); all infections were cured. No significant differences were found in any of the variables analysed among the infection type or the causative microorganism. CONCLUSIONS: Septic arthritis after arthroscopic reconstruction of cruciate ligaments of the knee is uncommon. It generally presents within 4 weeks of surgery and is caused by Staphylococci. Its treatment consists of arthroscopic debridement (without necessarily removing the graft) and antibiotic therapy.

Long-Term Success With Driveline Exit Site Relocation for Deep Driveline Infection in Left Ventricular Assist Device Patients.

OBJECTIVE: Driveline infection is a common complication of durable left ventricular assist device support. The majority involve the driveline exit site and can be treated with antibiotics and local wound care. Less frequently, these infections extend into deeper tissues and surgical debridement is necessary. Few studies have described the surgical strategy for treatment of deep driveline infection or have reported long-term outcomes. With a growing population of patients being implanted as destination therapy, there is an obvious need to evaluate and optimize treatment for complex driveline infections. METHODS: Outcomes of patients undergoing durable left ventricular assist device implantation at a single center between 2011 and 2017 were reviewed retrospectively. Data including occurrence of driveline infection, pathogen, time to driveline infection, and treatment strategy were abstracted from the electronic medical record. RESULTS: Driveline infection occurred in 10 (16.4%) of 61 patients at a median of 362 days (Q1 = 99, Q3 = 694) after primary left ventricular assist device implantation. Three (30.0%) of 10 driveline infections were categorized as deep and did not resolve with intravenous antibiotic therapy. In these cases, a multistage approach that included initial debridement and exteriorization of the infected driveline, followed by delayed surgical relocation of the driveline in a clean vascularized soft tissue bed, was used. Long-term device salvage was achieved in all cases. CONCLUSIONS: An aggressive surgical strategy, including debridement and formal relocation of the driveline exit site, can result in long-term device salvage after deep driveline infection. This approach is a less invasive alternative to device exchange for refractory driveline infections.

Microbiota periodontal y microorganismos aislados de válvulas cardiacas en pacientes sometidos a cirugía de reemplazo de válvulas en una clínica de Cali, Colombia / Periodontal microbiota and microorganisms isolated from heart valves in patients undergoing valve replacement surgery in a clinic in Cali, Colombia

Resumen Introducción. La periodontitis es una enfermedad infecciosa que afecta los tejidos de soporte del diente y se asocia con diferentes enfermedades sistémicas, incluida la enfermedad cardiovascular. Los estudios microbiológicos permiten detectar microorganismos a partir de muestras subgingivales y cardiovasculares. Objetivo. Describir la microbiota periodontal cultivable y la presencia de microorganismos en válvulas cardiacas de pacientes sometidos a cirugía de reemplazo valvular en una clínica de Cali. Materiales y métodos. Se analizaron 30 muestras subgingivales y de tejidos valvulares mediante cultivo en medio bifásico, agar de sangre con suplemento y agar tripticasa de soya con antibiótico. Las muestras de las válvulas se analizaron mediante reacción en cadena de la polimerasa (PCR) convencional. Resultados. Los patógenos periodontales aislados de bolsas periodontales fueron Fusobacterium ( 50 % ), Prevotella intermedia/nigrescens (40 %), Campilobacter rectus (40 %), Eikenella corrodens (36,7 %), bacilos entéricos Gram negativos (36,7 %), Porphyromonas gingivalis (33,3 %) y Eubacterium (33,3 %). Los agentes patógenos aislados de la válvula aórtica fueron Propionibacterium acnes (12 %), bacilos entéricos Gram negativos (8 %), Bacteroides merdae (4 %) y Clostridium bifermentans (4 %), y de la válvula mitral, P. acnes y Clostridium beijerinckii. La PCR convencional no arrojó resultados positivos para agentes patógenos orales y solo se detectó ADN bacteriano en dos muestras. Conclusiones. La microbiota periodontal de pacientes sometidos a cirugía de reemplazo valvular estaba conformada por especies Gram negativas que han sido relacionadas con infecciones en tejidos extraorales; sin embargo, no se encontraron agentes patógenos periodontales en los tejidos de las válvulas. Aunque hubo muestras de estos tejidos y subgingivales, positivas para bacilos entéricos Gram negativos, no es posible asegurar que tuvieran el mismo origen filogenético.

Abstract Introduction: Periodontitis is an infectious disease that affects the support tissue of the teeth and it is associated with different systemic diseases, including cardiovascular disease. Microbiological studies facilitate the detection of microorganisms from subgingival and cardiovascular samples. Objective: To describe the cultivable periodontal microbiota and the presence of microorganisms in heart valves from patients undergoing valve replacement surgery in a clinic in Cali. Materials and methods: We analyzed 30 subgingival and valvular tissue samples by means of twophase culture medium, supplemented blood agar and trypticase soy agar with antibiotics. Conventional PCR was performed on samples of valve tissue. Results: The periodontal pathogens isolated from periodontal pockets were: Fusobacterium nucleatum (50%), Prevotella intermedia/ nigrescens (40%), Campylobacter rectus (40%), Eikenella corrodens (36.7%), Gram negative enteric bacilli (36.7%), Porphyromonas gingivalis (33.3%), and Eubacterium spp. (33.3%). The pathogens isolated from the aortic valve were Propionibacterium acnes (12%), Gram negative enteric bacilli (8%), Bacteroides merdae (4%), and Clostridium bifermentans (4%), and from the mitral valve we isolated P. acnes and Clostridium beijerinckii. Conventional PCR did not return positive results for oral pathogens and bacterial DNA was detected only in two samples. Conclusions: Periodontal microbiota of patients undergoing surgery for heart valve replacement consisted of species of Gram-negative bacteria that have been associated with infections in extraoral tissues. However, there is no evidence of the presence of periodontal pathogens in valve tissue, because even though there were valve and subgingival samples positive for Gram-negative enteric bacilli, it is not possible to maintain they corresponded to the same phylogenetic origin.

A positive bacterial culture during re-implantation is associated with a poor outcome in two-stage exchange arthroplasty for deep infection.

AIMS: The aim of this study was to identify the incidence of positive cultures during the second stage of a two-stage revision arthroplasty and to analyse the association between positive cultures and an infection-free outcome. PATIENTS AND METHODS: This single-centre retrospective review of prospectively collected data included patients with a periprosthetic joint infection (PJI) of either the hip or the knee between 2013 and 2015, who were treated using a standardised diagnostic and therapeutic algorithm with two-stage exchange. Failure of treatment was assessed according to a definition determined by a Delphi-based consensus. Logistic regression analysis was performed to assess the predictors of positive culture and risk factors for failure. The mean follow-up was 33 months (24 to 48). RESULTS: A total of 163 two-stage revision arthroplasties involving 84 total hip arthroplasties (THAs) and 79 total knee arthroplasties (TKAs) were reviewed. In 27 patients (16.6%), ≥ 1 positive culture was identified at re-implantation and eight (29.6%) of these subsequently failed compared with 20 (14.7%) patients who were culture-negative. The same initially infecting organism was isolated at re-implantation in nine of 27 patients (33.3%). The organism causing re-infection in none of the patients was the same as that isolated at re-implantation. The risk of the failure of treatment was significantly higher in patients with a positive culture (odds ratio (OR) 1.7; 95% confidence interval (CI) 1.0 to 3.0; p = 0.049) and in patients with a higher Charlson Comorbidity Index (OR 1.5; 95% CI 1.6 to 1.8; p = 0.001). CONCLUSION: Positive culture at re-implantation was independently associated with subsequent failure. Surgeons need to be aware of this association and should consider the medical optimisation of patients with severe comorbidities both before and during treatment. Cite this article: Bone Joint J 2017;99-B:1490-5.

Dog bites and diabetic peripheral neuropathy: a dangerous combination.

All animal bites have the potential to cause significant infection. In the UK, dogs are the most common source of bites. Incidence of hospital attendances attributable to dog bites has risen over the last decade. Patient groups at particular risk of bites and/or complications of infection include those at extremes of age, immunosuppressed and patients with diabetes. We report the case of a patient with diabetic peripheral neuropathy, who was admitted on two separate occasions with unprovoked bites to his toes whilst asleep, by his pet dog. He ultimately required terminalisation of the affected digits. Although unusual, this mechanism of injury has been previously described in literature. However, we are unaware of cases reporting multiple separate incidences involving the same patient and animal. We present this case to highlight the perils of untrained pet ownership in diabetic patients with peripheral neuropathy and the importance of prompt medical and surgical treatment of injuries.

The risk factors of failed reimplantation arthroplasty for periprosthetic hip infection.

BACKGROUND: Two-stage reimplantation arthroplasty is one of the standard treatments for chronic periprosthetic joint infection (PJI). Scanty data exist regarding the risk factors for failure after two-stage reimplantation for periprosthetic hip infection. The purpose of this study was to investigate and identify the risk factors associated with failure after two-stage reimplantation hip arthroplasty. METHODS: Sixty-two patients with hip PJI treated with a two-stage reimplantation protocol at our institution from 2005 to 2012 were reviewed. Patients requiring medical treatment or reoperation for recurrent infection were defined as treatment failure. A multivariate Cox proportional hazards model was used to analyze the risk factors associated with treatment failure. RESULTS: Of the 62 patients, 11 (17.7%) patients had developed reinfection after the two-stage reimplantation with a mean follow-up of 5.7 years. The implant survival was 82.2% (95% confidence interval [CI] 75.19-92.55) at 10 years. Multivariate analysis revealed BMI ≥30 kg/m2 (hazard ratio [HR] 9.16; 95% CI 1.51-55.3; p = 0.0158), liver cirrhosis (HR 6.39; 95% CI 1.09-37.4; p = 0.0398), gram-negative organism (HR 5.68; 95% CI 1.18-27.4; p = 0.0303), and presence of sinus tract (HR 18.2; 95% CI 2.15-153; p = 0.0077) as the independent risk factors for treatment failure. CONCLUSIONS: We found obesity, liver cirrhosis, gram-negative organism, and the presence of sinus tract were significantly related to the risks of failure after reimplantation arthroplasties.