Importance of selection and duration of antibiotic regimen in prosthetic joint infections treated with debridement and implant retention.

OBJECTIVES: Early prosthetic joint infections (PJIs) are managed with debridement, implant retention and antibiotics (DAIR). Our aim was to evaluate risk factors for failure after stopping antibiotic treatment. METHODS: From 1999 to 2013, early PJIs managed with DAIR were prospectively collected and retrospectively reviewed. The main variables potentially associated with outcome were gathered, and the minimum follow-up was 2 years. For the present study, only patients who were in remission after one debridement and without long-term antibiotic suppression were included. The primary endpoint was implant removal or the need to reintroduce antibiotic treatment due to failure. RESULTS: One-hundred-and-forty-three patients met the inclusion criteria. The failure rate after a median duration of oral antibiotic treatment of 69 days (IQR 45-95 days) was 11.8%. In 92 cases, PJI was due to Gram-positive microorganisms, in 21 cases PJI was due to Gram-negative microorganisms and in 30 cases PJI was due to a polymicrobial infection with both Gram-positive and Gram-negative microorganisms. In Gram-positive infections, rifampicin administered in combination with linezolid, co-trimoxazole or clindamycin was associated with a higher failure rate (27.8%, P = 0.026) than that in patients receiving a combination of rifampicin with levofloxacin, ciprofloxacin or amoxicillin (8.3%) or monotherapy with linezolid or co-trimoxazole (0%). Among patients with a Gram-negative infection, the use of fluoroquinolones was associated with a lower failure rate (7.1% versus 37.5%, P = 0.044). CONCLUSIONS: The only factor associated with failure was the oral antibiotic selection, not the duration of treatment. Linezolid, co-trimoxazole and clindamycin, but not levofloxacin, serum concentrations are reduced by rifampicin; a fact that could explain our findings. Further studies monitoring serum concentration could help to improve the efficacy of these antibiotics when administered in combination with rifampicin.

Prophylaxis with teicoplanin and cefuroxime reduces the rate of prosthetic joint infection after primary arthroplasty.

The aim of this study was to compare the prosthetic joint infection (PJI) rate after total joint arthroplasty in two consecutive periods of treatment with different antibiotic prophylaxes: cefuroxime versus cefuroxime plus teicoplanin. We retrospectively reviewed 1,896 patients who underwent total hip arthroplasty or total knee arthroplasty between March 2010 and February 2013. From March 2010 to August 2011, patients received 1.5 g of cefuroxime during induction of anesthesia and another 1.5 g 2 h later (the C group). From September 2011, 800 mg of teicoplanin was added to cefuroxime (the CT group). Throughout the period studied, there were no variations in pre- or postoperative protocols. Univariate and multivariate analyses were performed to evaluate independent predictors of PJI. There were 995 (55.7%) patients in the C group and 791 (44.3%) in the CT group. Patients in the CT group had a significantly lower PJI rate than patients in the C group (1.26% versus 3.51%, P=0.002). There were no infections due to Staphylococcus aureus in the CT group (0% versus 1.6% in the C group, P<0.001). A stepwise forward Cox regression model identified male sex (hazard ratio [HR], 3.85; 95% confidence interval [CI], 2.09 to 7.18), a body mass index of ≥35 kg/m2 (HR, 2.93; 95% CI, 1.37 to 6.27), the presence of lung disease (HR, 2.46; 95% CI, 1.17 to 5.15), and red blood cell transfusion (HR, 3.70; 95% CI, 1.89 to 7.23) to be independent variables associated with a higher risk of PJI. The addition of teicoplanin was associated with a lower risk of infection (HR, 0.35; 95% CI, 0.17 to 0.74). In conclusion, the addition of teicoplanin to cefuroxime during primary arthroplasty was associated with a significant reduction in the global PJI rate due to a reduction of infections caused by Gram-positive bacteria.

Risk factors for failure in early prosthetic joint infection treated with debridement. Influence of etiology and antibiotic treatment.

PURPOSES: The aim of the present study was to evaluate the importance of isolated microorganisms according to the Gram stain and the type of antibiotic received on the outcome of early prosthetic joint infection (PJI) treated with debridement, antibiotics and implant retention (DAIR). METHODS: From January 1999 to December 2009, all patients with an early PJI were prospectively registered in a database and they were retrospectively reviewed for this study. RESULTS: During the study period, 160 patients met the inclusion criteria of the study. After a mean (SD) post-debridement follow-up of 5.2 (2.5) years, 117 patients (73.1%) were considered to be in remission and 43 (26.9%) were classified as failure. Variables associated with failure were liver cirrhosis (66.7% vs. 22.8%, p=0.001), diagnosis within the first 30 days from arthroplasty (30.4% vs. 8.0%, p=0.020), C-reactive protein (CRP) >12 mg/dl (46.7% vs. 21.2%, p=0.005), microorganism isolated in all deep samples (31.1% vs. 16.0%, p=0.047) and Gram-negative (GN) infection not treated with a fluoroquinolone (57.1% vs. 20.0%, P=0.004). Gram-positive (GP) infection not treated with rifampin was close to be statistically significantly associated with failure (34.4% vs. 19.2%, p=0.067). A multivariate analysis identified liver cirrhosis (OR: 12.4 CI95%: 3.1-49.7, p<0.001), CRP-value (OR: 1.06 CI95%: 1.0-1.11, p=0.049), and when a GN-infection was not treated with a fluoroquinolone (OR: 6.5, CI95%: 1.8-23.8, p=0.005) as independent predictors of failure. CONCLUSION: The remission rate of PJI treated with DAIR after 3 years of follow-up was 73%. The main predictors of failure were liver cirrhosis, the selected antibiotic most specially fluoroquinolones for GN and rifampin for GP infections, the C-reactive protein and the number of samples culture positive as a potential surrogate markers of bacterial density.

Clinical experience with linezolid for the treatment of orthopaedic implant infections.

Gram-positive cocci are commonly isolated in orthopaedic implant infections and their resistance to ß-lactams and fluoroquinolones is increasing. The high oral bioavailability of linezolid makes it an attractive oral alternative to glycopeptides and its use has increased in the last decade. To evaluate experience with linezolid in orthopaedic implant infections a systematic review of the literature available in English was undertaken. Only those articles describing series of ≥10 patients with acute or chronic orthopaedic implant infections treated with linezolid and with a clear definition of diagnosis and outcome were selected. A total of 293 patients (79.9% had prosthetic joint infections) were analysed in the 10 articles included. The overall remission rate with at least 3 months of follow-up was 79.9%, depending on whether the implant was removed or not (94% versus 69.9%). The addition of rifampicin was described in only two articles and no significant difference was observed. Adverse events were frequent during prolonged administration of linezolid (34.3%), requiring treatment discontinuation in 12.8%. The most common event was anaemia (13.4%) followed by gastrointestinal symptoms (11.1%). In conclusion, linezolid seems a good oral treatment alternative for orthopaedic implant infections due to Gram-positive cocci resistant to ß-lactams and fluoroquinolones. However, close monitoring of adverse events is required.

[Psoas abscess associated with hip arthroplasty infection]. / Absceso de psoas asociado a infección de una artroplastia de cadera.

INTRODUCTION: Psoas abscess associated with hip arthroplasty infection is a rare entity. The aim of this report was to review our experience. MATERIAL AND METHODS: Patients with computerized tomography (CT) diagnosis of psoas abscess associated with a hip arthroplasty infection from 2004 to 2009 were retrospectively reviewed. Demographics, microbiological data, CT results and outcome of each patient were recorded. RESULTS: Seven patients out of 214 evaluated by CT due to hip infection suspected were identified. Three women and 4 men, with a mean age of 69 years (range 46-89). Mean abscess diameter was of 62 x 47 mm. In all cases, a direct communication between abscess and prosthesis was observed. The most commonly isolated microorganisms were grampositive cocci. All patients were treated with two-stage revision surgery. After a mean follow-up of 65 months (28-113), six patients were in remission. CONCLUSIONS: The use of CT in the study of suspected infection of a hip arthroplasty identified a psoas abscess in 7 cases out of 214 evaluated. Patients treated with two-stage revision surgery and large debridement was associated with a good clinical outcome.

Absceso de psoas asociado a infección de una artroplastia de cadera / Psoas abscess associated with hip arthroplasty infection

Introducción. El absceso del músculo psoas asociado a la infección de una artroplastia de cadera es una entidad poco frecuente. El objetivo de este trabajo fue revisar los casos diagnosticados en nuestro centro. Material y métodos. Se realizó una revisión retrospectiva entre 2004 y 2009 de los pacientes con infección de una artroplastia de cadera asociada a un absceso de psoas diagnosticado por tomografía computerizada (TC). Se recogieron las principales variables demográficas y microbiológicas, así como los hallazgos de la TC y la evolución de cada paciente. Resultados. Se identificaron 7 casos entre 214 pacientes evaluados mediante TC por sospecha de infección sobre una prótesis de cadera. Tres eran mujeres y 4 hombres, la edad media fue de 69 años (rango 46-89). El tamaño medio del absceso fue de 62x47mm. En todos los casos se observó una comunicación directa entre el absceso y la prótesis. Los microorganismos mas frecuentemente aislados fueron los cocos grampositivos. El tratamiento quirúrgico consistió en un recambio en dos tiempos en todos los casos. Tras un seguimiento medio de 65 meses (28-113), seis pacientes se encontraban en remisión. Conclusión. El uso de la TC en el estudio de sospecha de infección sobre una prótesis de cadera permitió identificar un absceso de psoas en 7 casos de 214 evaluados. El recambio en dos tiempos asociado a un amplio desbridamiento se asoció a una buena respuesta clínica (AU)

Introduction. Psoas abscess associated with hip arthroplasty infection is a rare entity. The aim of this report was to review our experience. Material and methods. Patients with computerized tomography (CT) diagnosis of psoas abscess associated with a hip arthroplasty infection from 2004 to 2009 were retrospectively reviewed. Demographics, microbiological data, CT results and outcome of each patient were recorded. Results. Seven patients out of 214 evaluated by CT due to hip infection suspected were identified. Three women and 4 men, with a mean age of 69 years (range 46-89). Mean abscess diameter was of 62x47mm. In all cases, a direct communication between abscess and prosthesis was observed. The most commonly isolated microorganisms were grampositive cocci. All patients were treated with two-stage revision surgery. After a mean follow-up of 65 months (28-113), six patients were in remission. Conclusions. The use of CT in the study of suspected infection of a hip arthroplasty identified a psoas abscess in 7 cases out of 214 evaluated. Patients treated with two-stage revision surgery and large debridement was associated with a good clinical outcome (AU)

Special issues involving periprosthetic infection in immunodeficiency patients.

Chronic systemic illnesses such as diabetes mellitus, chronic kidney disease (CKD), liver cirrhosis, neoplasia, etc. have been clearly associated with high rates of SWI. However, the exact mechanisms underlying these observations are still under investigation. Chronic kidney disease (CKD) is a growing problem in our society. Many of these patients will require an arthroplasty and it appears that the prosthetic infection risk for these types of patients is much higher than in the normal population. The risk of complications due to infection seems to be lower in patients with kidney transplants than in patients undergoing haemodialysis. Both prophylaxis and treatment of infection in patients with CKD should be carried out with a strict monitoring of potentially nephrotoxic antibiotics. The literature on the prognosis and risk of infection in patients with haematopoietic stem cell transplant is scarce and occasionally contradictory. The optimal time for the surgery should be determined by taking into account the immunological state of the patient and should be avoided, as much as possible, during the first year after the HSCT. Child's classification system is the most widely used method of stratifying the surgical risk for patients with cirrhosis; the infection appeared to be associated in a statistically significant way with advanced age and a Child B pre-operative classification. The prevention of prosthetic joint infections in HIV-infected patients should not be significantly different from the prevention for any other patient. Those patients that receive adequate antiretroviral treatment and periodic laboratory control show infection rates and periprosthetic complications that are similar to those for patients not affected by HIV. Therefore, the patient's level of immunodeficiency is the most important prognostic factor for prosthetic infection. The particular immunological condition of these patients can lead to infections due to particular microorganisms that immunocompetent patients do not have to deal with. Of all possibilities, because of their frequency and difficulty to treat, infections caused by methicillin-resistant S. aureus and fungus are highlighted.

Prosthetic joint infections due to Staphylococcus aureus and coagulase-negative staphylococci.

PURPOSES: To evaluate the specific characteristics, outcome, and predictors of failure of prosthetic joint infections (PJI) due to S. aureus and coagulase-negative staphylococci (CNS) treated with open debridement and retention of the implant. METHODS: PJI due to S. aureus or CNS prospectively registered in a database from 1999 to 2009 were retrospectively reviewed. During the study period, 106 patients met the inclusion criteria. The mean follow-up period was 3.8 years and for at least 2 years in all patients. The failure rate was 23.6% (25 out of 106). The only variable significantly associated with failure in the global cohort was polymicrobial infection (38.7% vs. 17.3%, p = 0.024). Fifty-seven (53.8%) patients had an infection due to S. aureus and 49 (46.2%) due to CNS. Among S. aureus infections, 95% corresponded to primary arthroplasties while 98% of PJIs due to CNS were after revision arthroplasties (p<0.001). C-reactive protein was significantly higher in PJI due to S. aureus (9.5 mg/dl vs. 4.9 mg/dl, p = 0.007). The rate of methicillin-resistance (8.8% vs. 59.2%, p<0.001) and fluoroquinolone-resistance (15.8% vs. 34.7%, p = 0.005) was significantly higher in CNS infections. The global failure rate was higher in S. aureus infections (28% vs. 18.3. p = 0.26). In S. aureus infections, patients diagnosed within the first 15 days after joint arthroplasty (p = 0.031) and with bacteremia (p = 0.046) had poor pro-gnosis. In CNS infections only the location of the prosthesis (knee 27.6% vs. hip 5%, p = 0.045) was associated with failure. CONCLUSIONS: PJIs due to S. aureus were mainly in primary arthroplasties; they had a higher inflammatory response; and the strains were more susceptible to fluoroquinolones and methicillin than CNS infections. S. aureus infections had a higher failure rate than CNS infections, however, the difference was not statistically significant. There were few factors associated with failure and they were different in S. aureus and CNS infections.

Long-term outcome of acute prosthetic joint infections due to gram-negative bacilli treated with retention of prosthesis

Objetivo: Actualizar la información clínica de 47 pacientes con una infección de una prótesis articular por bacilos gramnegativos incluidos en un estudio previo y determinar los factores asociados a fracaso tras un seguimiento prolongado. Métodos: Utilizando la historia médica electrónica de nuestro hospital, se revisó toda la información sobre reingresos, nuevos procedimientos quirúrgicos, el motivo de la reintervención quirúrgica (infección o aflojamiento aséptico) y la fecha de la última visita en el hospital. La historia de los 35 pacientes que fueron considerados curados en la publicación previa, fueron revisados. Resultados: En 30 pacientes no hubo evidencia clínica de fracaso y no requirieron intervenciones adicionales sobre la prótesis infectada después de un periodo largo de seguimiento. En 5 casos se identificó una complicación tardía. En un caso el paciente tuvo una reinfección por un estafilococo coagulasa-negativa después de 22 meses del primer desbridamiento y requirió un recambio en 2 tiempos. Los otros 4 casos desarrollaron un aflojamiento aséptico y fue necesario realizar un recambio en 1 tiempo. Recibir una fluoroquinolona cuando todos los microorganismos causales de la infección eran sensibles fue el único factor asociado con remisión de la infección en el análisis univariado (p=0.002). Conclusión: Después de un seguimiento prolongado, nuestros resultados apoyan la importancia de utilizar fluoroquinolonas en infecciones agudas de prótesis articulares por bacilos gramnegativos(AU)

Objective: To update the clinical information of the 47 patients with a prosthetic joint infection due to Gram-negative bacilli included in a previous study and to reassess the predictors of failure after a longer follow-up. Methods: Using the electronic files of our hospital, all the information regarding readmissions to the hospital, new surgical procedures and the reason for the new surgery (infection, aseptic loosening), and the last visit in the hospital were registered. The medical chart of the 35 patients that were considered in remission in the previous publication was reviewed. Results: In 30 patients no clinical evidence of failure was detected and no additional surgery on the previously infected prosthesis was necessary and they were considered in long-term remission. In 5 cases a late complication was identified. One case had a reinfection due to coagulase-negative staphylococci after 22 months from the open debridement and required a 2-stage revision surgery. The other 4 cases developed an aseptic loosening and it was necessary to perform a 1-stage exchange. Receiving a fluoroquinolone when all the Gram-negatives involved in the infection were susceptible to fluoroquinolones was the only factor associated with remission in the univariate analysis (p=0.002). Conclusion: After a long-term follow-up, our results support the importance of using fluoroquinolones in acute PJI due to Gram-negative bacilli(AU)

Decreased serum linezolid concentrations in two patients receiving linezolid and rifampicin due to bone infections.

Methicillin-resistant Staphylococcus is a common cause of orthopaedic implant infections. In such cases, rifampicin is the antibiotic of choice, but it should not be administered alone to avoid the selection of resistant mutants. Linezolid has activity against resistant staphylococci and a high oral bioavailability; therefore, it could be a good option for combining with rifampicin. We describe 2 patients admitted to our hospital due to orthopaedic implant infections, who received combination therapy with linezolid and rifampicin. In both cases, the trough serum concentration of linezolid during rifampicin treatment was below the minimum inhibitory concentration required to inhibit the growth of 90% of organisms (MIC(90)) for staphylococci, but increased after rifampicin withdrawal. This finding suggests an interaction between rifampicin and linezolid, and a possible explanation is discussed.

Efficacy of debridement in hematogenous and early post-surgical prosthetic joint infections.

PURPOSES: To review patients with a hematogenous and early post-surgical prosthetic joint infection (PJI) due to S. aureus treated with debridement and retention of the implant and to compare their clinical characteristics and outcome. METHODS: From January 2000 all patients with a prosthetic joint infection treated in a single-center were prospectively registered and followed-up. All potentially variables associated with outcome were recorded. For the present study, cases with a hematogenous or early post-surgical PJI due to S. aureus treated with debridement and at least 2 years of follow-up were reviewed. Cox regression model to identify factors associated with outcome were applied. RESULTS: 12 hematogenous and 53 early post-surgical PJI due to S. aureus were included. Number of patients presenting with fever, leucocyte count, C-reactive protein concentration, and the number of bacteremic patients were significantly higher in hematogenous infections while the number of polymicrobial infections was lower in hematogenous than in early post-surgical infections. The global failure rate in hematogenous and early post-surgical PJI was 58.7% and 24.5%, respectively (p=0.02). The Cox regression model identified hematogenous infections (OR: 2.57, CI95%: 1.02-6.51, p=0.04) and the need of a second debridement (OR: 4.61, CI95%: 1.86-11.4, p=0.001) as independent predictors of failure. CONCLUSION: Hematogenous infections were monomicrobial and had more severe symptoms and signs of infection than early post-surgical PJI. Hematogenous PJI due to S. aureus, using debridement with implant retention, had a worse outcome than early post-surgical infections.

Usefulness of monitoring linezolid trough serum concentration in prolonged treatments

Linezolid ha demostrado ser eficaz en el tratamiento de infecciones musculo-esqueléticas, sin embargo, se han descrito casos de fracaso, desarrollo de resistencia y toxicidad en tratamientos de más de 28 días. Describimos nuestra experiencia en 5 casos consecutivos en los que la concentración de linezolid se determinó semanalmente y su relación con la respuesta clínica y la toxicidad(AU)

Linezolid has proven valuable in musculoskeletal infections, however, failure and resistance have been described and toxicity is worrisome when more than 28 days are necessary. We describe the first 5 cases in whom linezolid trough serum concentrations were weekly measured and its relationship with clinical outcome and toxicity(AU)

Infección por Candida spp. sobre prótesis articulares / Prosthetic joint infection by Candida spp

Introducción: Las infecciones periprotésicas por Candida spp. constituyen una entidad poco frecuente. El objetivo de este trabajo fue revisar la experiencia en dos centros hospitalarios. Material y Métodos: Se realizó una revisión retrospectiva de los casos de infección protésica de etiología fúngica atendidos en dos hospitales de Barcelona entre febrero de 2002 y octubre de 2010. Se incluyeron todos aquellos pacientes con criterios clínicos de infección y aislamiento de Candida spp. Se recogieron las principales variables demográficas, microbiológicas, terapéuticas y evolutivas. Resultados: Se identificaron 10 casos, 8 mujeres y 2 varones, cuya edad media fue de 77,7 (rango 66-92) años. Nueve pacientes habían tenido una infección bacteriana previa, por la que recibieron tratamiento antibiótico durante más de 15 días y precisaron desbridamiento en más de una ocasión. La especie más frecuente fue Candida albicans con 6 casos. Todos los pacientes recibieron fluconazol y tratamiento quirúrgico consistente en desbridamiento sin retirada de la prótesis en 3 casos y recambio en 2 tiempos con un espaciador en los 7 restantes. El tratamiento fracasó en los 10 casos y fue necesario practicar un desbridamiento adicional en 1 caso, artroplastia de resección en 8 y tratamiento “supresivo” con fluconazol en uno. Tras un seguimiento medio de 31 meses (rango 2-67) dos pacientes estaban libres de enfermedad. Conclusión: La infección protésica por Candida spp. se observa en pacientes que han recibido tratamiento antibiótico previo prolongado y han sido intervenidos en más de una ocasión. El tratamiento con fluconazol y desbridamiento o recambio en 2 tiempos con un espaciador se asoció a una elevada tasa de fracaso(AU)

Introduction: Fungal periprosthetic infection is a rare entity. The aim of this report was to review our experience in two different educational hospitals. Material ans methods: patients with documented prosthetic joint infection due to Candida spp. from February 2002 to October 2010 were retrospectively reviewed. Demographics, microbiological data, treatment and outcome of each patient was recorded. Results: Ten patients, 8 women and 2 men, with a mean age of 77.7 (range 66-92) years were identified. Nine patients had previous bacterial infection, received antibiotic treatment for more than 15 days and required multiple surgeries. The most frequent species was C. albicans with 6 cases. All patients received fluconazole and surgical treatment consisted of debridement without removing the implant in 3 cases and 2-stage exchange with a spacer in 7. The first surgical and antifungal approach failed in all cases and a second debridement was necessary in one case, a resection arthroplasty in 8 and chronic suppressive treatment with fluconazol in one. After a mean follow- up of 31 (range 2-67) months, two patients were free of infection. Conclusion: Prosthetic joint infection was associated with long-term antibiotic treatment and multiples previous surgeries. Treatment with fluconazol and debridement or two-stage replacement with a spacer was associated with a high failure rate(AU)

Outcome of acute prosthetic joint infections due to gram-negative bacilli treated with open debridement and retention of the prosthesis.

The aim of our study was to evaluate the outcome of acute prosthetic joint infections (PJIs) due to gram-negative bacilli (GNB) treated without implant removal. Patients with an acute PJI due to GNB diagnosed from 2000 to 2007 were prospectively registered. Demographics, comorbidity, type of implant, microbiology data, surgical treatment, antimicrobial therapy, and outcome were recorded. Classification and regression tree analysis, the Kaplan-Meier survival method, and the Cox regression model were applied. Forty-seven patients were included. The mean age was 70.7 years, and there were 15 hip prostheses and 32 knee prostheses. The median number of days from the time of arthroplasty was 20. The most frequent pathogens were members of the Enterobacteriaceae family in 41 cases and Pseudomonas spp. in 20 cases. Among the Enterobacteriaceae, 14 were resistant to ciprofloxacin, while all Pseudomonas aeruginosa isolates were susceptible to ciprofloxacin. The median durations of intravenous and oral antibiotic treatment were 14 and 64 days, respectively. A total of 35 (74.5%) patients were in remission after a median follow-up of 463 days (interquartile range, 344 to 704) days. By use of the Kaplan-Meier survival curve, a C-reactive protein (CRP) concentration of < or = 15 mg/dl (P = 0.03) and receipt of a fluoroquinolone, when all GNB isolated were susceptible (P = 0.0009), were associated with a better outcome. By use of a Cox regression model, a CRP concentration of < or = 15 mg/dl (odds ratio [OR], 3.57; 95% confidence interval [CI], 1.05 to 12.5; P = 0.043) and receipt of a fluoroquinolone (OR, 9.09; 95% CI, 1.96 to 50; P = 0.005) were independently associated with better outcomes. Open debridement without removal of the implant had a success rate of 74.5%, and the factors associated with good prognosis were a CRP concentration at the time of diagnosis < or = 15 mg/dl and treatment with a fluoroquinolone.

Timing of antibiotic prophylaxis for primary total knee arthroplasty performed during ischemia.

BACKGROUND: There is no clinical trial analyzing the best moment to infuse an antibiotic during knee arthroplasty performed during ischemia. We designed a single-center, randomized, double-blind, placebo-controlled trial to evaluate whether antibiotic therapy should be administered before tourniquet inflation or just before tourniquet deflation. MATERIAL AND METHODS: Patients who underwent a primary knee arthroplasty were randomized to receive (1) 1.5 g of cefuroxime 10-30 min before inflation of the tourniquet and placebo 10 min before release of the tourniquet (standard arm) or (2) placebo 10-30 min before inflation of the tourniquet and 1.5 g of cefuroxime 10 min before release of the tourniquet (experimental arm). In both arms, a postoperative dose of 1.5 g of cefuroxime was given 6 h after the surgical procedure. The main variables associated with the rate of deep-tissue infection after 3 and 12 months of follow-up were gathered. Continuous variables were compared using Student's t test, and categorical variables were compared using the chi(2) test or Fisher's exact test. RESULTS: From September 2004 through December 2005, a total of 908 patients were randomized, 442 and 466 of whom were allocated to the standard and experimental arms, respectively. There were no differences between treatment arms in terms of age, sex, comorbidity, American Society of Anaesthesiologists score, duration of surgery, need of blood transfusion, or fourth-day hematocrit. The rates of deep-tissue infection among the standard and experimental groups were 3.4% and 1.9%, respectively, at 3 months of follow-up (P = .21) and 3.6% and 2.6%, respectively, at 12 months of follow-up (P = .44). CONCLUSION: The administration of prophylactic antibiotics just before tourniquet release was not inferior to standard antibiotic prophylaxis.

Tuberculous osteomyelitis of the knee: a case report.

INTRODUCTION: With the resurge of tuberculosis, due to the pandemic of the human immunodeficiency virus and the increase in the number of immunocompromised patients, osteoarticular tuberculosis has increased too. MATERIALS AND METHODS: We report of a 55-year-old patient, with chronic renal failure on haemodialysis, who presented with a painful knee and fever. Culture on Lowënstein-Jensen medium of joint liquid revealed a tuberculous affectation of the proximal tibia. Wide excision was performed, completed with 9 months of tuberculostatic drugs. At 1 year follow-up, the patient was free of symptoms. CONCLUSION: Tuberculous aetiology should be considered in the differential diagnosis of knee arthritis.