Synovial fluid NMR-based metabolomics in septic and aseptic revision total knee arthroplasty: Implications on diagnosis and treatment.

Periprosthetic joint infection (PJI) is one of the most challenging complications following total knee arthroplasty. Despite its importance, there is a paucity of reports in the literature regarding its pathogenesis. Recently, cellular metabolic reprogramming has been shown to play an important role in the progression and outcome of infectious diseases. Therefore, the aim of this study was to evaluate the metabolites composition of the synovial fluid from patients with PJI or aseptic failure of total knee arthroplasties. The synovial fluids from 21 patients scheduled for revision total knee arthroplasty (11 with the diagnosis of PJI and 10 with aseptic failures) were analyzed using 1D 1H NMR spectroscopy. Univariate and multivariate statistical analyzes were used to identify metabolites that were differentially abundant between those groups. A total of 28 metabolites were identified and five of them found to be differentially abundant between infected and non-infected synovial fluids. Lactate, acetate and 3-hydroxybutyrate were found to be in a higher concentration, and glucose and creatine were found reduced in the synovial fluid from PJI patients. Synovial fluid from patients with PJI exhibit a distinct metabolic profile, possibly reflecting metabolic adaptation that occurs in the infected periprosthetic microenvironment. Further research and studies are warranted to gain a broader insight into the metabolic pathways engaged by both pathogen and immune cells in the context of a PJI.

Positioning Technique of the Fixed Knee in Hyperflexion for the Transportal Femoral Tunnel During Reconstruction of the Anterior Cruciate Ligament.

During reconstruction surgery of the anterior cruciate ligament, the evolution of the femoral tunnel from the transtibial to the transportal path provides greater accuracy in reaching the desired anatomic point. However, there are also some new challenges, such as correct execution, reproducibility, and minimizing the risk of iatrogenic injury from its use. In an effort to overcome these challenges, we have proposed the use of a positioner, which was developed by our group and allows the leg to stay in the desired position, without variations in the operation or aid from a medical assistant. This manuscript presents our femoral tunnel preparation technique and its application in clinical practice.

Evaluation of intraoperative radioscopy on the coronal alignment of the tibial component in primary knee arthroplasty.

OBJECTIVES: The present study had the objective of evaluating the effect of the use of intraoperative radioscopy in cases of primary knee arthroplasty, on the final alignment of the tibial component. METHODS: Patients who underwent total knee arthroplasty (TKA) between April 13, 2013, and April 20, 2013, were included in the study. These patients were evaluated retrospectively and two groups were identified: one in which intraoperative radioscopy was used to assess the positioning of the tibial component during the surgery and the other in which this resource was not used. RESULTS: The mean angle of alignment of the tibial component in relation to the tibial diaphysis was greater in the group without use of intraoperative radioscopy (90.82) than in the group with radioscopy (90.63), which was a statistically significant result (p < 0.05). CONCLUSION: Use of intraoperative radioscopy during TKA produced a better mean angle of alignment between the tibial component and the tibial diaphysis, in comparison with nonuse.

OBJETIVOS: Avaliar o efeito do uso da radioscopia intraoperatória em artroplastias primárias de joelho sobre o alinhamento final do componente tibial. MÉTODOS: Foram incluídos no estudo os pacientes submetidos à artroplastia total do joelho (ATJ) entre 13/04/2013 e 20/04/2013. Os pacientes foram avaliados retrospectivamente e dois grupos foram identificados, um com uso de radioscopia intraoperatória para avaliação do posicionamento do componente tibial durante a cirurgia e o segundo sem uso desse recurso. RESULTADOS: A média do ângulo de alinhamento do componente tibial em relação à diáfise da tíbia foi superior no grupo sem uso de radioscopia intraoperatória (90,82) em comparação com o grupo com radioscopia (90,63), com resultado estatisticamente significativo (p < 0,05). CONCLUSÃO: O uso de radioscopia no intraoperatório de ATJ produz melhor média de ângulo de alinhamento entre o componente tibial em relação à diáfise da tíbia quando comparado ao não uso.

Femoropatellar radiographic alterations in cases of anterior cruciate ligament failure.

OBJECTIVE: To make a comparative analysis on three femoropatellar radiographic parameters, between knees with chronic failure of the anterior cruciate ligament (ACL) and normal knees. METHODS: Thirty volunteer patients with a diagnosis of unilateral isolated chronic ACL injury for more than one year and a normal contralateral knee were selected. Digital radiographs were produced for all the patients, on both knees in absolute lateral view at 30° of flexion, with and without load-bearing on one leg, and in axial view of the patella at 30°. The Caton-Deschamps patellar height index, Merchant patellar congruence angle and Laurin lateral patellar tilt angle were measured on the radiographs obtained from the normal knees and knees with ACL injuries, and comparative analysis was performed between these two groups. RESULTS: The patellar height was statistically significantly lower (p < 0.001) in the knees with ACL failure than in the normal knees, both on radiographs without loading and on those with single-foot loading. The Merchant patellar congruence angle was significantly smaller (p < 0.001) in the normal knees and the lateral patellar tilt angle was smaller (p < 0.001) in the knees with ACL failure. CONCLUSION: Chronic ACL failure gave rise to a statistically significant change in the femoropatellar radiographic values studied (p < 0.001). Knees with injuries to this ligament presented lower patellar height values, greater tilt and lateral displacement of the patella, in relation to the femoral trochlea, in comparison with the normal contralateral knees.

OBJETIVO: Análise comparativa de três parâmetros radiográficos femoropatelares entre joelhos com insuficiência crônica do ligamento cruzado anterior (LCA) e joelhos normais. MÉTODOS: Foram selecionados 30 pacientes voluntários com diagnóstico de lesão crônica isolada unilateral do LCA havia mais de um ano e joelho contralateral normal. Todos os pacientes foram submetidos a radiografias digitais de ambos os joelhos nas incidências em perfil absoluto a 30° de flexão, com e sem carga monopodal, e axial de patela a 30°. Foram mensurados, nas radiografias obtidas, o índice de altura patelar de Caton-Deschamps, o ângulo de congruência patelar de Merchant e o ângulo de inclinação lateral da patela, descrito por Laurin, nos joelhos normais e nos joelhos com lesão do LCA e foi feita análise comparativa entre esses dois grupos. RESULTADOS: A altura patelar foi inferior, de forma estatisticamente significante (p < 0,001), nos joelhos com insuficiência do LCA em comparação com os joelhos normais, tanto nas radiografias sem carga quanto nas com carga monopodal. O ângulo de congruência patelar de Merchant foi significativamente menor (p < 0,001) nos joelhos normais e o ângulo de inclinação lateral da patela foi inferior (p < 0,001) nos joelhos com insuficiência do LCA. CONCLUSÃO: A insuficiência crônica do LCA alterou de forma estatisticamente significante (p < 0,001) os valores dos parâmetros radiográficos femoropatelares estudados. Joelhos com lesão desse ligamento apresentaram menores valores de altura patelar, maior inclinação e deslocamento laterais da patela em relação à tróclea femoral comparados com os joelhos contralaterais normais.

Avulsion fracture of the posterior cruciate ligament in an uncommon location associated with distal injury to the patellar ligament.

Avulsion fractures of the posterior cruciate ligament in unusual locations are rare injuries. We report the first case in the literature of an avulsion fracture of the posterior cruciate ligament associated with distal injury to the patellar ligament. The aim of this study was to present a novel case, the therapy used and the clinical follow-up.

A fratura avulsão do ligamento cruzado posterior em localização não usual é uma lesão rara. Relatamos o primeiro caso da literatura de uma fratura avulsão do ligamento cruzado posterior associada a lesão distal do ligamento patelar. O objetivo deste estudo foi apresentar um caso inédito, a terapêutica adotada e o seguimento clínico.

ASSESSMENT OF TIBIAL SLOPE ANGLE AND PATELLAR HEIGHT AFTER MEDIAL-OPENING TIBIAL OSTEOTOMY.

OBJECTIVE: To measure the variation in posterior tibial slope angle and patellar height in patients who underwent proximal tibial valgus-producing osteotomy using the medial-opening wedge technique. METHODS: Anteroposterior panoramic radiographs of the lower limbs and lateral radiographs of the knee obtained before and after tibial valgus-producing osteotomy on 46 patients with unicompartmental arthrosis of the knee were analyzed. RESULTS: In 23 patients, an external fixator was used to gradually apply a medial-opening wedge; and in the other 23, a blocked plate with a stop bar was applied as a fixation method. Patients with tricompartmental knee disease and those who underwent osteotomy to treat fracture sequelae were excluded from this study. After surgery, the mean increase in the tibial slope was 1.7 degrees (p < 0.01) in the group in which the blocked plate with a stop bar was used; and 2.7 degrees (p < 0.05) in the group in which the external fixator was used. There was no statistical difference between the groups regarding the increase in the posterior tibial slope. CONCLUSION: The patellar height did not present any change in the cases in which the plate was used, when measured using the Insall-Salvati method, but it presented a decrease in 11 cases (47.8%) when the Caton-Deschamps method was applied. The same tendency was observed regarding change in the patellar height in the cases in which the external fixator was used, such that a decrease was observed in eight cases (34.7%) only when measured using the Caton-Deschamps method.