Executive summary: Guidelines for the diagnosis and treatment of septic arthritis in adults and children, developed by the GEIO (SEIMC), SEIP and SECOT / Resumen ejecutivo: Guía de diagnóstico y tratamiento de la artritis séptica en adultos y niños de GEIO (SEIMC), SEIP y SECOT

Infection of a native joint, commonly referred to as septic arthritis, is a medical emergency because of the risk of joint destruction and subsequent sequelae. Its diagnosis requires a high level of suspicion. These guidelines for the diagnosis and treatment of septic arthritis in children and adults are intended for use by any physician caring for patients with suspected or confirmed septic arthritis. They have been developed by a multidisciplinary panel with representatives from the Bone and Joint Infections Study Group (GEIO) belonging to the Spanish Society of Infectious Diseases and Clinical Microbiology (SEIMC), the Spanish Society of Paediatric Infections (SEIP) and the Spanish Society of Orthopaedic Surgery and Traumatology (SECOT), and two rheumatologists. The recommendations are based on evidence derived from a systematic literature review and, failing that, on the opinion of the experts who prepared these guidelines. A detailed description of the background, methods, summary of evidence, the rationale supporting each recommendation, and gaps in knowledge can be found online in the complete document.(AU)

La infección de una articulación nativa, generalmente denominada artritis séptica, constituye una urgencia médica por el riesgo de destrucción articular y las consecuentes secuelas. Su diagnóstico requiere un alto nivel de sospecha. Esta guía de diagnóstico y tratamiento de la artritis séptica en niños y adultos está destinada a cualquier médico que atienda pacientes con sospecha de artritis séptica o artritis séptica confirmada. La guía ha sido elaborada por un panel multidisciplinar en el que están representados el Grupo de Estudio de Infecciones Osteoarticulares (GEIO) de la Sociedad Española de Enfermedades Infecciosas y Microbiología Clínica (SEIMC), la Sociedad Española de Infectología Pediátrica (SEIP) y la Sociedad Española de Cirugía Ortopédica y Traumatología (SECOT); además han participado dos reumatólogos. Las recomendaciones se basan en la evidencia proporcionada por una revisión sistemática de la literatura y, en su defecto, en la opinión de los expertos que han elaborado la presente guía. En el texto completo online se hace una descripción detallada de los antecedentes, métodos, resumen de la evidencia, fundamentos que apoyan cada recomendación y las lagunas de conocimiento existentes.(AU)

Executive summary: Guidelines for the diagnosis and treatment of septic arthritis in adults and children, developed by the GEIO (SEIMC), SEIP and SECOT.

Infection of a native joint, commonly referred to as septic arthritis, is a medical emergency because of the risk of joint destruction and subsequent sequelae. Its diagnosis requires a high level of suspicion. These guidelines for the diagnosis and treatment of septic arthritis in children and adults are intended for use by any physician caring for patients with suspected or confirmed septic arthritis. They have been developed by a multidisciplinary panel with representatives from the Bone and Joint Infections Study Group (GEIO) belonging to the Spanish Society of Infectious Diseases and Clinical Microbiology (SEIMC), the Spanish Society of Paediatric Infections (SEIP) and the Spanish Society of Orthopaedic Surgery and Traumatology (SECOT), and two rheumatologists. The recommendations are based on evidence derived from a systematic literature review and, failing that, on the opinion of the experts who prepared these guidelines. A detailed description of the background, methods, summary of evidence, the rationale supporting each recommendation, and gaps in knowledge can be found online in the complete document.

Enterobacter cloacae Infection After Surgical Treatment of Ankle Fractures, a Multicenter Observational Study.

BACKGROUND: Infection is one of the challenging complications after open reduction and internal fixation for ankle fractures. Previously published case series conclude that Staphylococcus aureus is the most frequent causative microorganism. An unexpected increase in Enterobacter cloacae infections after this surgery was observed in a preliminary analysis of data at the promoting center of the study. In traumatology, its incidence has been reported in chronic osteomyelitis, prosthetic infections, septic osteoarthritis, open fractures in children and adults, and fractures other than the ankle. Because of this unexpected finding, we decided to perform this study to analyze the demographic and microbiological variables of acute osteosynthesis infection after ankle fracture and determine the distinctive features of the patients with E cloacae infection. METHODS: We performed a retrospective multicenter study including 4 university hospitals. All patients diagnosed with acute osteosynthesis infection after ankle fracture fixation between January 2015 and December 2018 were included. We analyzed demographic data, type of fracture, surgical technique, and microorganisms responsible for the infection. We performed a descriptive statistical analysis of the variables. Univariate and multivariate regression analysis were performed to compare patients with E cloacae infection to patients with infection caused by other microorganisms. RESULTS: A total of 65 patients were included. A predominance of polymicrobial infections (24.62%), followed by infections caused by S aureus (23.07%) and E cloacae (23.07%) was observed. When E cloacae isolated in polymicrobial infections were added, the incidence of E cloacae as a causative microorganism increased to 32.3%. Patients with E cloacae infection were older (64/53, P = .008) and had a higher requirement of negative-pressure therapy after surgical debridement (71%/40%, P = .017). CONCLUSION: A high incidence of E cloacae infections was observed. Patients with E cloacae infection were generally older and required a higher use of negative-pressure therapy after debridement. LEVEL OF EVIDENCE: Level V, mechanism-based reasoning.

Do Cultures Obtained During Primary THA Predict the Likelihood of Revision?

BACKGROUND: There can be unexpectedly positive culture results during elective hip arthroplasty, but the degree to which these are associated with an increased risk of subsequent premature revision is not known. QUESTION/PURPOSE: Are unexpectedly positive culture results obtained during elective THA associated with an increased likelihood of revision within 5 years of the procedure? METHODS: Between March 2007 and March 2011, the hip unit at our institution performed elective primary THA in 829 patients. We systematically collected three samples in 52% (428 of 829) of the interventions. Of those, 26 patients were excluded because of sampling errors; 94% (402 of 428) had samples that were collected systematically and were eligible for the study. We only considered one hip randomly in bilateral procedures (4% [15 of 428]); patients presenting with acute (< 3 months) periprosthetic joint infection undergoing open debridement (4% [16 of 402]) and patients who died before 5 years of follow-up (2% [seven of 402]) were excluded from the study, leaving 91% (364 of 402) eligible for analysis in this retrospective study of a previous prospective trial. No patient included in the final analysis was lost to follow-up within 5 years from the index surgery. The patient group consisted of 52% (188 of 364) women, with a mean ± SD age of 64.8 ± 13.9 years. RESULTS: Positives culture results were associated with a higher risk of revision within 5 years of the index surgery. The proportion of revision surgery was higher in the group with positive culture results than in those with negative results (10% [eight of 77] versus 2% [seven of 290]; p = 0.01). The difference was mainly attributable to a higher proportion of aseptic loosening in those with positive culture results than in those with negative results (8% [six of 74] versus 1% [four of 290]; p = 0.01). After a multivariable analysis, the only independent variable associated with 5-year revision surgery was the presence of positive results during THA (odds ratio 4.9 [95% confidence interval 1.72 to 13.99]). CONCLUSION: Our findings suggest that bacterial contamination during THA is associated with an increased likelihood of early revision. This higher risk of revision is mainly because of presumed aseptic loosening; thus, efforts should focus on the need to rule out infection. These results not only open new questions that should be answered in new prospective and well-designed studies, but also may help to better select patients to obtain a more favorable outcome after THA. LEVEL OF EVIDENCE: Level III, therapeutic study.

Is hip resection arthroplasty a successful definitive treatment?

Purpose: Hip resection arthroplasty as a definitive treatment is an uncommon indication, although still in use selectively. This study evaluates a cohort of patients who have undergone hip resection arthroplasty surgery indicated as a definitive treatment, in order to assess the rate of re-operation, the rate of infection, and the mortality rates. Methods: We conducted a retrospective, observational, descriptive analysis of a cohort of patients who had undergone a hip resection arthroplasty intended as a definitive treatment, in two University Hospitals from 1994 to 2020. The exclusion criteria were the implantation of a hip cement spacer, or a temporary hip resection arthroplasty in patients undergoing a two-staged surgical approach. We found 26 cases of hip resection arthroplasty. We recorded the indications for a definitive hip resection arthroplasty, the outcomes and complications, and analyzed the success of the hip resection arthroplasty as a definitive surgery using a Kaplan-Meier curve. Results: Seven cases (26.9%) required a re-operation after the hip resection arthroplasty, four cases for persistent hip infection, and in the three remaining a conversion to a total hip arthroplasty was re-considered due to a good medical evolution and non-tolerance to the low functional outcome. The mortality rate was 61.5% (27 days-20 years), with a 19.2% mortality rate in the first 5 years. All the cases that required another surgery after the hip resection arthroplasty were re-operated within the first 18 months. Conclusion: Unfortunately, hip resection arthroplasty continues to show elevated re-operation rate and early mortality rate, as well as low functional outcomes. Two-staged hip revision arthroplasty is the surgical treatment of choice in patients suffering from a periprosthetic joint infection, however we believe that hip resection arthroplasty should be considered in fragile patients, who have endured multiple revision surgeries, or their comorbidities make them unfit from further surgeries.

"In vitro" evaluation of bacterial biofilm formation on different cerclage systems.

Cerclage wiring may be used for fracture fixation or osteotomy stabilization in revision arthroplasty. There is a lack of evidence regarding the potential risk of bacterial colonization for the different types of cerclages. The objective of our research is to study the adhesion and biofilm formation of S. epidermidis, S. aureus, and P. aeruginosa on two different cerclage cable models, comparing a polymer cable and a stainless steel metal cable. A two-cm cerclage piece of each material was submerged in 2 mL of tryptic soy broth (TSB) inoculated with 10 µL of a 0.5 McFarland bacterial culture, and incubated at 37°C during 2 h for adhesion and 48 h for biofilm formation. The cerclages were washed with 1xPBS and sonicated in a new culture medium. Aliquots of several dilutions of each sonicated culture were spread in TSB agar and incubated at 37°C for 24 h. The number of colonies was counted. The colony-forming units per ml (CFU/mL) and the percentage of reduction were calculated. Experiments were triplicated. For P. aeruginosa, a statistically significant reduction in biofilm formation was found on the polymer cerclage cable, compared to the metal cerclage cable. Reductions of 59% and 88%, after 2 h and 48 h, respectively, were observed. For S. epidermis and S. aureus, there was a trend towards lower bacterial adhesion and biofilm formation for the polymer cerclage cable. In summary, these results demonstrate that the braided polymer cerclage cable may be less prone to bacterial adherence and biofilm formation compared to the braided metal cerclage cable.

Reducing bacterial adhesion to titanium surfaces using low intensity alternating electrical pulses.

BACKGROUND: Orthopedic implant-related infection remains one of the most serious complications after orthopedic surgery. In recent years, there has been an increased scientific interest to improve prevention and treatment strategies. However, many of these strategies have focused on chemical measures. AIM: To analyze the effect of alternating current electrical fields on bacterial adherence to titanium surfaces. METHODS: Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) were exposed to 6.5 V electrical currents at different frequencies: 0.5 Hz, 0.1 Hz, and 0.05 Hz. After exposure, a bacterial count was then performed and compared to the control model. Other variables registered included the presence of electrocoagulation of the medium, electrode oxidation and/or corrosion, and changes in pH of the medium. RESULTS: The most effective electrical model for reducing S. aureus adhesion was 6.5 V alternating current at 0.05 Hz achieving a 90% adhesion reduction rate. For E. coli, the 0.05 Hz frequency model also showed the most effective results with a 53% adhesion reduction rate, although these were significantly lower than S. aureus. Notable adhesion reduction rates were observed for S. aureus and E.coli in the studied conditions. However, the presence of electrode oxidation makes us presume these conditions are not optimal for in vivo use. CONCLUSION: Although our findings suggest electrical currents may be useful in preventing bacterial adhesion to metal surfaces, further research using other electrical conditions must be examined to consider their use for in vivo trials.

Role of joint aspiration before re-implantation in patients with a cement spacer in place.

BACKGROUND: The usefulness of a mandatory joint aspiration before re-implantation in patients with a cement spacer already in place is unclear. AIM: To evaluate the role of culturing synovial fluid obtained by joint aspiration before re-implantation in patients who underwent a two-stage septic revision. METHODS: A retrospective observational study was conducted, including patients that underwent a two-stage septic revision (hip or knee) from 2010 to 2017. After the first stage revision and according to intraoperative culture results, all patients were treated with an antibiotic protocol for 6-8 wk. Following 2 wk without antibiotics, a culture of synovial fluid was obtained. The results of these cultures were recorded and compared with cultures obtained during re-implantation surgery. RESULTS: Forty-one patients (20 hip and 21 knee spacers) were included in the final analysis. In 39 cases, the culture of synovial fluid was negative, while in the remaining 2 cases (knee spacers) no analysis was possible due to dry tap. In 5 of the patients, two or more intraoperative cultures taken during the re-implantation surgery were positive. CONCLUSION: We found no evidence to support mandatory joint aspiration before re-implantation in patients with a cement spacer in place.

Risk Factors of DAIR Failure and Validation of the KLIC Score: A Multicenter Study of Four Hundred Fifty-Five Patients.

Background: Debridement, antibiotic agents, and implant retention (DAIR) is a currently accepted approach for the treatment of early prosthetic joint infections (PJI). The success of a DAIR procedure has shown variable results throughout the published literature. Scoring systems such as the Kidney, Liver, Index surgery, Cemented prosthesis, and C-reactive protein value (KLIC) score for the selection of patients that are likely to benefit from DAIR have proved to be helpful in decision making. Our study aims to further validate the KLIC score using a large external multicentric cohort and to evaluate other risk factors for failure. Patients and Methods: A retrospective analysis of patients with an early acute PJI who were treated with DAIR and recorded in a database of eight Spanish university hospitals was performed. According to pre-operative variables of the KLIC study, patients were categorized into five groups: group A, ≤2 points; group B, 2.5-3.5 points; group C, 4-5 points; group D, 5.5-6.5 points; and group E, ≥7 points. Failure rates were compared between groups at 60 days and after 60 days of DAIR. Further variables for risk of failure were also analyzed. Results: A total of 455 patients with early acute PJI were included in the analyses. At 60 days, patients presenting with pre-operative elevated C-reactive protein serum levels, Staphylococcus aureus, and polymicrobial infections were associated with failure. Failure rates recorded were 12% for group A (n = 210), 18% for group B (n = 83), 26% for group C (n = 89), 24% for group D (n = 66), and 0% for group E (n = 7). Univariable analysis between consecutive groups of the KLIC score showed no differences for failure before 60 days of the DAIR procedure. Scheduled surgery and having the procedure performed by a specialized unit were also identified as important factors for DAIR success. Conclusions: Our results suggest the KLIC score was not useful for predicting failure in our cohort. Furthermore, our results indicate a specialized unit should conduct DAIR procedures.

A 3D-Printed Model of a Titanium Custom-Made Talus for the Treatment of a Chronic Infection of the Ankle.

Osteoarticular infections are challenging and difficult to treat. The use of innovative technologies like 3D printing already employed in other types of surgeries and pathologies can suppose a great asset to tackle the problem and improve functional results. We present a case of an osteoarticular infection of an ankle treated with a custom-made titanium talus made with 3D metal printing technology: A 63-year-old patient, with chronic infection of the ankle. A 2-staged surgery was performed, with a hand-made cement spacer used during the first stage and the implantation of a custom-made titanium talus with an arthrodesis nail in the second stage. After a 2-year follow-up, a good clinical evolution was achieved, with no signs of reactivation of the infection, no pain, good skin condition and optimal functionality: functional gait pattern without pain and any external aids.

Role of bacterial colonisation of vancomycin-gentamicin spacers in two-stage arthroplasty revision surgery: the usefulness of spacer sonication.

PURPOSE: In two-stage replacements for septic loosening, some studies have suggested an association between bacterial colonisation of spacers and a higher number of complications after implantation of the definitive prosthesis. Our study aimed to determine the reoperation rate of patients undergoing two-stage revision surgery according to the culture results of spacer sonication. METHODS: A retrospective observational study was conducted in which hip or knee spacers implanted at our institution with a diagnosis of periprosthetic joint infection from 2010 to 2018 were analysed. Patients were grouped into three categories: A. Patients with positive spacer sonication fluid culture, with or without positive cultures of the rest of the samples. B. Patients with negative spacer sonication culture and negative cultures of the rest of intraoperative samples. C. Patients with negative spacer sonication culture but positive cultures of the rest of intraoperative samples. RESULTS: A total of 45 spacers were analysed: 10 were included in group A, 24 in group B and 11 in group C. The reoperation rate during the first year after the 2-stage revision surgery was 20%, 29.2% and 54.5% for each group, respectively, due to an infection in 10%, 20.8% and 45.5%. Spacers were colonised in all cases by low virulent micro-organisms. CONCLUSION: In our study, bacterial colonisation of the spacer is not associated with a higher rate of reoperation. The group of patients with positive intraoperative cultures during the second-stage had the highest reoperation rate.

Chronic Anterior Pelvic Instability.

INTRODUCTION: Chronic anterior pelvic instability means pathologic movement of the symphysis pubis with axial load. It is not a common pathology and its diagnosis is often delayed and difficult increasing the disability of affected patients. The pain is localized in the suprapubic area or groins, increasing with physical activity, direct palpation or compression. Main known causes are pregnancy, delivery, trauma, fractures, intense physical activity, infection, or previous surgeries. Treatment algorithms have not been standardized. Initially, it is managed with an orthosis, physical activity modification, medication, and rehabilitation. Surgical treatment with symphyseal arthrodesis is the last option. The literature on symphyseal plating for chronic instability found is sparse. CASE REPORT: We report the case of a 33-year-old female presenting lower abdominal pain after her third delivery. Several months after, magnetic resonance imaging and scintigraphy suggested chronic symphysitis. Single leg stance pelvic X-rays indicated chronic anterior pelvic instability. Pain-relievers, physical rehabilitation, and local corticosteroid injection were noneffective; surgery was indicated, performing a double plate symphyseal arthrodesis with iliac bone graft. CONCLUSION: Pelvic instability should be ruled out when persistent abdominal or lower back pain are present. Thorough physical examination and specific provocative maneuvers need to be assessed. In our presented case, symphyseal arthrodesis was performed without complications. After a two-year follow-up, the patient has recovered her previous functional status and bone scintigraphy is negative. Radiologic controls rule out loosening or material breaking as a complication. We hope this case report may give a clue in surgical options management.

Soft-tissue thickness radiographic measurement: a marker to evaluate acute periprosthetic joint infection risk in total hip replacement.

The objective of our study was to evaluate the association between acute periprosthetic joint infection (APJI) and radiographic measurement of soft-tissue thickness in elective total hip replacement surgery. A case-control study was conducted to compare the soft-tissue thickness radiographic measurement (SRM) at the hip in patients diagnosed with APJI based on Tsukayama et al. (2003) criteria after total hip replacement with patients that were not infected, at a single institution from 2013 to 2019. To minimize selection bias, each case was matched with two controls using the following methodology: patients of the same sex, with an age variation of ± 5 years, and nearest in surgery date to the cases were selected. All postoperative radiographs were performed in the first 24 h after total hip arthroplasty (THA) surgery as it is protocolized in our institution. Soft-tissue thickness radiographic measurement was defined as the distance from the tip of the greater trochanter to the skin following a perpendicular line to the femoral diaphysis in postoperative anteroposterior hip radiographs. In total, 78 patients were included (26 cases and 52 controls). The SRM median of the cases was 76.19 mm (SD: 26.518) and 53.5 mm (SD: 20.47) in controls. A multivariate logistic regression model showed an independent association between APJI and SRM (odds ratio (OR)  =  1.033, 95 % confidence interval (CI) 1.007-1.059, p = 0 .012). Patients with an SRM greater than 60 mm had a 7-fold increase in the odds of APJI (OR  =  7.295, 95 % CI  =  2.364-22.511, p < 0 .001). The results of our study suggest an association between large SRM at the hip and the risk of APJI in patients with primary total hip arthroplasty. SRM may be a helpful and easy tool for evaluating the risk of APJI before elective primary total hip replacement surgery.

Subcutaneous Radiographic Measurement: A Marker to Evaluate Surgical Site Infection Risk in Elderly Hip Fracture Patients.

Objectives: Obesity is a documented comorbidity that is prevalent in the elderly population and a known predictor for surgical site infection (SSI). Body mass index is a convenient method to classify obesity, but it fails to account for fat distribution. The objective of our study was to evaluate the association between surgical site infection and a subcutaneous radiographic measurement (SRM) in elderly hip fracture patients. Materials and Methods: A retrospective case-control study was conducted to compare SRMs at the hip in patients diagnosed with surgical site infection after hip fracture surgery with patients that were not diagnosed with surgical site infection. Each case was matched to two controls. An SRM was defined as the distance from the tip of the greater trochanter to the skin following a perpendicular line to the femoral diaphysis in anteroposterior hip radiographs. Clinical diagnosis of acute surgical site infection was based on Tsukayama criteria. Results: Patients with an SRM greater than 6.27cm had a 7-fold increase in the odds of surgical site infection (OR=7.42, 95% Confidence Interval (CI)=3.01-18.28, p<0.001) compared to those with smaller measurements. The odds ratio (OR) for infection of patients with an ASA score of 3 was 15.82(95% CI=5.11-48.9, p-value<0.001) A statistically significant difference between cases and controls was also found when SRM at the hip was analyzed as a continuous variable. Patients with an infection had a 2.24cm (95% CI=1.59 - 2.90; p<0.001) greater mean SRM. Conclusion: Results of our study suggest an association between the SRM at the hip and the risk of SSI in elderly patients with surgically treated hip fractures. SRM may be a helpful tool for evaluating the risk of SSI in elderly hip fracture patients.

Pulsed electric fields reduce bacterial attachment to stainless steel plates.

The purpose of this study was to evaluate the capacity of pulsed bilateral electric fields to control bacterial attachment on stainless steel plates. Previously sterilized circular metal plates of stainless steel were submerged in a liquid medium with a known concentration of Staphylococcus epidermidis and incubated for 1 hour at 36oC while a 200 Hz pulsed electric field of 18 V/cm was applied for 2.5 µseg and then sonicated for 5 minutes in 10 ml of saline. Three different models were cultured and compared: 1) negatively-charged plate, 2) positively-charged plate, and 3) control plate without electric current. A total of 39 metal plates were processed. The median adherence in the control group and the electric field group was 312 CFU/mm2 and 16,2 CFU/mm2 respectively (p < 0.001, reduction of 95% of bacterial attachment). Bilateral pulsed electric field is able to reduce bacterial attachment on stainless steel plates in in vitro conditions.

Acute medullar compression secondary to a septic arthritis of a thoracic facet joint: a case report and review of literature.

INTRODUCTION: Septic arthritis of a facet joint (SAFJ) is a rare entity and frequently underdiagnosed. It is most frequently localised in the lumbar segment. CASE PRESENTATION: A 48-year-old woman presented at our emergency room with a chief complaint of lumbar pain and perineal hypoesthesia. An urgent lumbar Magnetic Resonance Imaging (MRI) was performed showing no signs of compressive pathology. Intravenous painkillers were administered improving her clinical symptoms, so she was discharged from the emergency department to be followed at our out-patient clinic. After 12 h, the patient presented again referring an acute loss of strength in her lower limbs and paresthesias at a T10 sensitive level. Due to the severity of the symptoms, we performed an urgent dorsal MRI that showed a septic arthritis of the left T8-T9 facet joint and an epidural abscess causing a medullar compression. Blood cultures were performed before surgical treatment. An urgent laminectomy of T8 and debridement of the abscess were performed. Intraoperative microbiology and blood cultures were positive for Streptococcus constellatus. After surgery, the patient presented a progressive improvement of her symptomatology. DISCUSSION: Physicians should have in mind and rule out this clinical entity to avoid severe consequences that a misdiagnosed SAFJ could develop.

Usefulness of Urinoculture to Patients With Dementia and Femoral Neck Fracture at Admission to Hospital: Preliminary Results.

INTRODUCTION: While preoperative urinary tract infection (UTI) has the potential to cause bacteremia and postsurgical acute prosthetic joint infections (APJIs), the influence of asymptomatic bacteriuria (AB) in these infections remains unclear. So the majority of guidelines not recommend the treatment of AB prior to the surgery. However, as patients with dementia usually cannot explain the symptoms of dysuria, the differential diagnosis between AB and UTI may be very difficult in this group of patients. The principal aim of the study was to compare the rate of positive urine culture at admission in patients with femoral neck fracture with and without dementia and secondarily try to assess the connection of positive urinoculture and postoperative acute gram-negative PJI. METHODS: All patients with a femoral neck fracture underwent a urine culture on hospital admission and were prospectively recorded. Variables such as sex, age, institutionalization, dementia and other comorbidities, PJI rate, and in-hospital death were collected. The results of cultures were retrospectively revised. Patients who received postoperative antibiotics or had been diagnosed with UTI during hospital stay were excluded. Statistical comparisons between patients with and without dementia were performed using SPSS software version 17. RESULTS: A total of 148 patients were included (52 with dementia). The rate of positive urine culture was 32% (n = 16) in patients with dementia and 11.5% in patients without dementia (P = .003). Of these 16 patients with dementia and positive urine culture, 2 (12.5%) developed an acute gram-negative PJI, whereas there were no cases in the group without dementia (P = .011). DISCUSSION: The only difference between UTI and AB is the expression of symptoms by the patient. However, as patients with dementia have difficulties to explain UTI symptoms, some UTI may be underdiagnosed. CONCLUSION: Patients with dementia have a statistically higher rate of presurgical positive urine culture compared with patients without dementia.

Adherence of S. epidermidis on different metals. A comparative in vitro study.

AIM: Staphylococcus epidermidis is the most common cause of orthopedic infections. Adhesion and biofilm formation on orthopedic implant surfaces play an important role in the physiopathology of these infections. The aim of our study was to evaluate the adhesion of S. epidermidis on the surface of metals usually used in orthopedics. METHODS: Previously sterilized circular metal plates of titanium (Ti), porous titanium (p-Ti), cobalt chromium (CoCr) and stainless steel (SS) were hung completely submerged in a liquid medium with a known concentration of S. epidermidis (RP62A). They were incubated for 1 h or 24 h at 36°C. After incubation, each plate was washed with PBS and sonicated during 5 minutes in 10 mL of saline. Different dilutions were performed and 100 µL from each sample was cultured on agar plates. RESULTS: 26 metal plates were incubated for 1 h and other 55 metal plates for 24 h. The lowest bacterial count (cfu/mm2) at 1 h was observed in CoCr plates while in p-Ti it was 6 times higher. At 24 h the highest bacterial count was observed in SS plates while the lowest in Ti. However, these differences were not statistically significant. CONCLUSIONS: After 1 h and 24 h of exposure, the lowest adherence was observed in CoCr and Ti plates, respectively. However, bacterial attachment occurred with all materials. It is necessary to further investigate new materials able to avoid bacterial attachment.

Use of cemented spacer with a handmade stem to treat acute periprosthetic tibial fracture infection: a case report.

We report an 85-year-old woman with dementia and dependent for normal life activities who was admitted due to a left periprosthetic tibial fracture. The tibial component was replaced by one with a long stem and she was discharged. Four weeks after the intervention the patient was re-admitted due to an acute prosthetic joint infection. All the components were removed and a bone-cement spacer with a handmade stem with a metal core was implanted. Radiological signs of fracture consolidation were observed after 3 months of follow-up. Due to the previous health status of the patient, it was decided to keep the spacer as a definitive treatment. After 24 months, the patient was able to sit without pain and to stand up with help using a knee brace. There were no radiological or clinical signs of infection.