Background:Septic arthritis is an infrequent disease although very important due to the possibility of disastrous outcomes if treatment is not adequately established. Adequate information concerning the epidemiology of septic arthritis is still lacking due to the uncommon nature of the disease as well as the struggle to establish a correct case-definition.Objective:To epidemiologically characterize the population seen at Hospital das Clínicas, University of São Paulo with a diagnosis of septic arthritis between 2006 and 2011.Methods:Sixty-one patients diagnosed with septic arthritis of the knee between 2006 and 2011 were retrospectively evaluated. The patients' clinical and epidemiological characteristics, the microorganisms that caused the infection and the patients' treatment and evolution were analyzed.Results:Septic arthritis of the knee was more common among men, with distribution across a variety of age ranges. Most diagnoses were made through positive synovial fluid cultures. The most prevalent clinical comorbidities were systemic arterial hypertension and diabetes mellitus, and the most commonly reported joint disease was osteoarthritis. Staphylococcus aureus was the prevailing pathogen. Fever was present in 36% of the cases. All patients presented elevation in inflammatory tests. Gram staining was positive in only 50.8% of the synovial fluid samples analyzed. Six patients presented complications and unfavorable evolution of their condition.Conclusion:S. aureus is still the most common pathogen in acute knee infections in our environment. Gram staining, absence of fever and normal leukocyte count cannot be used to rule out septic arthritis.

OBJETIVO: Mostrar nossa experiência com haste não-cimentadas press-fit e fixação metafisária com cimento em série selecionada de pacientes que realizaram revisão de artroplastia total do joelho. MÉTODOS: Trinta e quatro pacientes (35 joelhos) foram submetidos a revisão de artroplastia total do joelho usando técnica "press-fit". Seguimento mínimo foi de um ano (média de 2,2 anos) e máximo de três anos. RESULTADOS: Dos 34 pacientes, 20 foram mulheres e 14 foram homens. Houve um óbito por causa não relacionada a artroplastia e perda de seguimento de um paciente. Não houve nenhum caso em que fosse necessária nova revisão. Os pacientes que foram submetidos à revisão apresentaram melhora clínica e funcional demonstrado pelos resultados do KSS, resultados do questionário de qualidade de vida SF-36, através do ganho de amplitude de movimento e da melhora no alinhamento do membro. CONCLUSÃO: Houve melhora clínica e funcional no pós-operatório em relação ao pré-operatório na revisão de artroplastia total do Joelho com haste não cimentada "press-fit". Nível de Evidência IV, Série de casos.

OBJECTIVE: To show our experience with press-fit cementless stem and metaphyseal fixation with cement in a selected series of patients who underwent revision total knee arthroplasty. METHODS: Thirty-four patients (35 knees) underwent revision total knee arthroplasty using the press-fit technique. Minimum follow-up was one year (mean 2.2 years) with a maximum length of three years. RESULTS: Of 34 patients, 20 were women and 14 were men. There was one death due to causes not related to arthroplasty and one patient dropout. There were no cases in which further review was necessary. Patients who underwent revision had clinical and functional improvement demonstrated by the results of the KSS, results of the SF-36 quality of life questionnaire, through gains in range of motion and improved limb alignment. CONCLUSION: There was postoperative clinical and functional improvement in comparison to the preoperative status in revision total knee arthroplasty with press-fit cementless stem. Level of Evidence IV, Case series.

OBJETIVO: Considerando a dificuldade para classificar os defeitos ósseos foi feito estudo para avaliar se a classificação de falha óssea da AORI baseada na radiografia pré-operatória é fidedigna e reprodutível entre diferentes médicos. MÉTODOS: Seis ortopedistas com subespecialização em cirurgia do joelho foram treinados para o uso da classificação radiográfica. Esses cirurgiões avaliaram e classificaram isoladamente as falhas ósseas de 26 radiografias de próteses de joelho pré revisão. RESULTADOS: Constatou-se que houve coincidência de >50% (correlação moderada) da classificação em 24 dos 26 casos no fêmur e em 22 dos 26 casos na tíbia; e correlação de >80% (boa correlação) em 12 dos 26 casos no fêmur e em sete dos 26 casos na tíbia. CONCLUSÃO: Em relação à concordância da classificação, observamos que a classificação AORI apresenta moderada correlação inter-observadores. Nível de evidência III, Estudo de pacientes não consecutivos; sem padrão de referencia "ouro" aplicado uniformemente.

OBJECTIVE: Considering the difficulty for classifying bone losses the present study was designed to analyse if the AORI classification based on pre-operative radiographies is consistent and reproductible between different orthopaedic surgeons. METHODS: Six orthopedists specialized in knee surgery were trained for the use of the classification based on radiographic evaluation. All the surgeons individually classified 26 pre operative knee radiographs. RESULTS: There was a moderate (> 50%) matching of the classification in 24 of 26 cases in the femur and 22 of 26 in the tibia. A good matching (> 80%) was present in 12 of 26 cases in the femur and in 7 of 26 cases in the tibia. CONCLUSION: We observed that the AORI classification presented a moderate radiographic correlation between surgeons. Evidence of level III, Study of nonconsecutive patients; without consistently applied reference ''gold'' standard.