MENISCAL INJURY DUE TO FATIGUE

Objective: The purpose of the present study was to review a group of patients with meniscal injuries resulting from structural failure unrelated to trauma or degenerative problems to which was given the name ""meniscal injury due to fatigue"". Material and Method: Evaluations were made on 140 patients with meniscal injuries without any apparent cause, who were therefore considered to have meniscal injuries due to fatigue. Among these, 85 patients were male and 55 were female. The medial meniscus was the most affected site (92% of the cases). Results: All these injuries were diagnosed by means of clinical examination and magnetic resonance imaging. The patients underwent meniscectomy by means of arthroscopy and the results were divided into two types: good and poor. Poor results were found in 27% of the cases, among which nine patients progressed to idiopathic osteonecrosis. Conclusion: We conclude that injuries due to fatigue must be assessed as injuries caused by failure and, therefore, constituting a syndromic pathological condition that may progress to idiopathic osteonecrosis.

The relationship between prevalent medial meniscal intrasubstance signal changes and incident medial meniscal tears in women over a 1-year period assessed with 3.0 T MRI

Objective Intrasubstance meniscal signal changes not reaching the articular surface on fast spin echo (FSE) sequences are considered to represent mucoid degeneration on MRI. The aim of this study was to evaluate the association of prevalent intrasubstance signal changes with incident tears of the medial meniscus detected on 3.0 T MRI over a 1-year period. Materials and methods A total of 161 women aged a parts per thousand yen40 years participated in a longitudinal 1-year observational study of knee osteoarthritis. MRI (3.0 T) was performed at baseline and 12-month follow-up. The anterior horn, body, and posterior horn of the medial meniscus were scored by two experienced musculoskeletal radiologists using the Boston-Leeds Osteoarthritis Knee Score (BLOKS) system. Four grades were used to describe the meniscal morphology: grade 0 (normal), grade 1 (intrasubstance signal changes not reaching the articular surface), grade 2 (single tears), and grade 3 (complex tears and maceration). Fisher`s exact test and the Cochran-Armitage trend test were performed to evaluate whether baseline intrasubstance signal changes (grade 1) predict incident meniscal tears/maceration (grades 2 and/or 3) in the same subregion of the medial meniscus, when compared to subregions without pathology as the reference group (grade 0). Results Medial meniscal intrasubstance signal changes at baseline did not predict tears at follow-up when evaluating the anterior and posterior horns (left-sided p-values 0.06 and 0.59, respectively). No incident tears were detected in the body. Conclusion We could not demonstrate an association between prevalent medial meniscal intrasubstance signal changes with incident tears over a 1-year period.

The association of prevalent medial meniscal pathology with cartilage loss in the medial tibiofemoral compartment over a 2-year period

Objective: To investigate the association of different types of magnetic resonance imaging (MRI)-detected medial meniscal pathology with subregional cartilage loss in the medial tibiofemoral compartment. Methods: A total of 152 women aged >= 40 years, with and without knee osteoarthritis (OA) were included in a longitudinal 24-month observational study. Spoiled gradient recalled acquisitions at steady state (SPGR) and T2-weighted fat-suppressed MRI sequences were acquired. Medial meniscal status of the anterior horn (AH), body, and posterior horn (PH) was graded at baseline: 0 (normal), 1 (intrasubstance meniscal signal changes), 2 (single tears), and 3 (complex tears/maceration). Cartilage segmentation was performed at baseline and 24-month follow-up in various tibiofemoral subregions using computation software. Multiple linear regression models were applied for the analysis with cartilage loss as the outcome. In a first model, the results were adjusted for age and body mass index (BMI). In a second model, the results were adjusted for age, BMI and medial meniscal extrusion. Results: After adjusting for age, BMI, and medial meniscal extrusion, cartilage loss in the total medial tibia (MT) (0.04 mm, P=0.04) and the external medial tibia (eMT) (0.068 mm, P=0.04) increased significantly for compartments with grade 3 lesions. Cartilage loss in the total central medial femoral condyle (cMF) (0.071 mm, P=0.03) also increased significantly for compartments with grade 2 lesions. Cartilage loss at the eMT was significantly related to tears of the PH (0.074 mm; P=0.03). Cartilage loss was not significantly increased for compartments with grade 1 lesions. Conclusion: The protective function of the meniscus appears to be preserved in the presence of intrasubstance meniscal signal changes. Prevalent single tears and meniscal maceration were found to be associated with increased cartilage loss in the same compartment, especially at the PH. (C) 2009 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.

Nervo alógeno conservado em glicerol: estudo experimental em ratos

A utilização de aloenxerto de nervo conservado em glicerol é uma alternativa a auto-enxertia em casos de lesões de nervos periféricos com perda de substância que diminui a morbidade cirúrgica e provem material suficiente para a reparação neural. O objetivo deste trabalho foi comparar o grau de reparação nervosa, utilizando análises histológica e funcional, através da interposição de enxerto autógeno (grupo A), de tubo de veia conservada em glicerol (grupo B) e de interposição de nervo alógeno conservado em glicerol (grupo C) em defeitos de 5 mm no nervo fibular de ratos Wistar. A análise histológica foi feita após o sacrifício dos animais( 6 semanas) , usando o corante azul de toluidina a 1%. No grupo A (auto-enxerto) verificou-se reação tecidual perineural e escape de fibras axonais mielinizadas para fora dos limites do epineuro que foi maior se comparada ao verificado no Grupo B (Veia autógena + glicerol) e Grupo C (aloenxerto de nervo).A avaliação funcional foi feita através da análise dos padrões das pegadas das patas posteriores dos ratos ("Walking Track Analysis"), nos períodos: pré-operatório, pós-operatório imediato, na terceira e sexta semanas. Na recuperação funcional, não houve diferença estatisticamente significativa entre os três grupos em nenhum dos períodos avaliados.

Magnetic Resonance Imaging Assessment of Subchondral Bone and Soft Tissues in Knee Osteoarthritis

Knee osteoarthritis (OA) has to be considered a whole joint disease. Magnetic resonance imaging (MRI) allows superior assessment of all joint tissues that may be involved in OA, such as the subchondral bone, synovium, ligaments, and periarticular soft tissues. Reliable MRI-based scoring systems are available to assess and quantify these structures and associated pathology. Cross-sectional and longitudinal evaluation has enabled practitioners to understand their relevance in explaining pain and structural progression.

Magnetic Resonance Imaging in Knee Osteoarthritis Research: Semiquantitative and Compositional Assessment

Semiquantitative assessment of the knee by expert magnetic resonance imaging readers is a powerful research tool for understanding the natural history of osteoarthritis (OA). Several reliable semiquantitative scoring systems have been applied to large observational cross-sectional and longitudinal epidemiologic studies and interventional clinical trials. Such evaluations have enabled understanding of the relevance of disease in structures within the knee joint to explain pain and progression of OA. Compositional imaging of cartilage has added to our ability to detect early degeneration before morphologic changes are present, which may help to prevent the permanent morphologic changes commonly seen in knee OA.