Comparison of MRI T2 Relaxation Changes of Knee Articular Cartilage before and after Running between Young and Old Amateur Athletes

OBJECTIVE: To compare changes in T2 relaxation on magnetic resonance (MR) images of knee articular cartilage in younger and older amateur athletes before and after running. MATERIALS AND METHODS: By using a 3.0-T MR imager, quantitative T2 maps of weight-bearing femoral and tibial articular cartilages in 10 younger and 10 older amateur athletes were acquired before, immediately after, and 2 hours after 30 minutes of running. Changes in global cartilage T2 signals of the medial and lateral condyles of the femur and tibia and regional cartilage T2 signals in the medial condyles of femoral and tibia in response to exercise were compared between the two age groups. RESULTS: Changes in global cartilage T2 values after running did not differ significantly between the age groups. In terms of the depth variation, relatively higher T2 values in the older group than in the younger group were observed mainly in the superficial layers of the femoral and tibial cartilage (p < 0.05). CONCLUSION: Age-related cartilage changes may occur mainly in the superficial layer of cartilage where collagen matrix degeneration is primarily initiated. However, no trend is observed regarding a global T2 changes between the younger and older age groups in response to exercise.

Effect of low-power helium-neon laser irradiation on 13-week immobilized articular cartilage of rabbits.

Influence of low-power (632.8 nm, Helium-Neon, 13 J/cm2, three times a week) laser on 13-week immobilized articular cartilage was examined with rabbits knee model. Number of chondrocytes and depth of articular cartilage of experimental group were significantly higher than those of sham irradiated group. Surface morphology of sham-irradiated group had rough prominences, fibrillation and lacunae but surface morphology of experimental group had more similarities to control group than to sham irradiated group. There were marked differences between ultrastructure features of control group and experimental group in comparison with sham irradiated group. Low-power Helium-Neon laser irradiation on 13-week immobilized knee joints of rabbits neutrilized adverse effects of immobilization on articular cartilage.

In vitro development of autologous tissue engineered human articular neocartilage for orthopaedic surgery

Treatment of articular cartilage lesions remains a clinical challenge. The uses of prosthetic joint replace allograft and/or autograft transplant carry a risk of complications due to infection, loosening of its component, immunological rejection and morbidity at the donor site. There has been an increasing interest in the management of cartilage damages, owing to the introduction of new therapeutic options. Tissue engineering as a method for tissue restoration begins to provide a potential alternative therapy for autologous grafts transplantations. We aimed to evaluate how well a tissue engineered neocartilage implant, consist of human articular chondrocytes cultured with the presence of autologous serum and mixed in a fresh fibrin derived from patient, would perform in subcutaneous implantation in athymic mice.

Recuperación morfofuncional de la ATM postcondilectomía, tratada con ortopedia funcional de los maxilares / Morpho-functional postcondilectomy recovery of the TMJ treated by means of maxillary functional orthopedics

Paciente de 9 años, se presenta a la consulta con laterodesviación mandibular, debido a la falta del cóndilo derecho que fue extirpado como actitud terapéutica por un accidente del cuello de éste. El tratamiento se realiza con aparatología ortopédica funcional y al cabo de 3 años se logra, funcionalmente, que la mandíbula recupere la céntrica en sus movientos de apertura y de cierre. Se observa un crecimiento de tejido que asemeja una formación condílea. Se realizan estudios para comprobar los mecanismos compensatorios que se lograron para un funcionamiento cercano a lo normal

Cartílago normal y patológico / Normal and pathological articular cartilage

El cartílago articular es el tejido responsable de la lubricación y rigidez compresiva de las articulaciones durante el movimiento, gracias a sus propiedades de viscoelasticidad a la carga mecánica. Sin embargo, una vez dañado tiene una capacidad limitada o mínima de curación y a menudo evoluciona a cambios patológicos degenerativos. Debido a lo anterior se hace necesario revisar las ciencias básicas para comprender mejor el rol que éste cartílago articular juega durante éste proceso reparativo. Este artículo fue escrito en un esfuerzo para mejorar nuestra comprensión del proceso curativo del cartílago articular

Cartilagem articular e osteoartrose / Articular cartilage and osteoarthrosis

O conhecimento da fisiologia da cartilagem e da fisiopatologia da osteoartrose deverá, sem dúvida alguma auxiliar o ortopedista atuar de forma mais consciente na prevençäo e na terapêutica precoce.

Biomechanical and histological evaluation of hydrogel implants in articular cartilage

We evaluated the mechanical behavior of the repaired surfaces of defective articular cartilage in the intercondylar region of the rat femur after a hydrogel graft implant. The results were compared to those for the adjacent normal articular cartilage and for control surfaces where the defects remained empty. Hydrogel synthesized by blending poly(2-hydroxyethyl methacrylate) and poly(methyl methacrylate-co-acrylic acid) was implanted in male Wistar rats. The animals were divided into five groups with postoperative follow-up periods of 3, 5, 8, 12 and 16 weeks. Indentation tests were performed on the neoformed surfaces in the knee joint (with or without a hydrogel implant) and on adjacent articular cartilage in order to assess the mechanical properties of the newly formed surface. Kruskal-Wallis analysis indicated that the mechanical behavior of the neoformed surfaces was significantly different from that of normal cartilage. Histological analysis of the repaired defects showed that the hydrogel implant filled the defect with no signs of inflammation as it was well anchored to the surrounding tissues, resulting in a newly formed articular surface. In the case of empty control defects, osseous tissue grew inside the defects and fibrous tissue formed on the articular surface of the defects. The repaired surface of the hydrogel implant was more compliant than normal articular cartilage throughout the 16 weeks following the operation, whereas the fibrous tissue that formed postoperatively over the empty defect was stiffer than normal articular cartilage after 5 weeks. This stiffness started to decrease 16 weeks after the operation, probably due to tissue degeneration. Thus, from the biomechanical and histological point of view, the hydrogel implant improved the articular surface repair.