Cartilage fibrocartilage

The deposition of crystals of monosodium urate (gout), calcium pyrophosphate dehydrate (CPPD chondrocalcinosis, pseudogout) and calcium hydroxyapatite (HADD calcifying tendinitis) within synovium, articular cartilage, fibrocartilages and para-articular soft tissues may produce a spectrum of clinical conditions ranging from asymptomatic entities to severe rapidly destructive arthropathy (Steinbach 2004 Clement et al. 2005). The accumulation of crystals takes months to years to develop and leads to the establishment of a chronic synovitis with intermittent acute flares. 

In the knee, the menisci form an interarticular fibrocartilage base for femural and tibial articulation. The menisci form a crescent shape in the knee. The lateral meniscus is located on the outer side of the knee, and the medial meniscus is located on the inside of the knee. If the knee bends and twists the menisci can overstretch and tear. Menisci tears occur frequentiy and the knee can sustain more than one tear at a time. If not treated appropriately, however, a menisci tear can roughen the cartilage and lead to arthritis. A meniscus tear acts like grit in the ball bearings of a machine. The longer the torn tissue remains affected, the more irritation it causes. 

Wang, L., Lazebnik, M., Detamore, M. S. 2009. Hyaline cartilage cells outperform mandibular condylar cartilage cells in a TMJ fibrocartilage tissue engineering application. Osteoarthritis Cartilage 17(3) 346-53. 

Mechanical properties of the knee components are derived from selected referred articles (See Table 1). Bone s density and its mechanical properties varied along its length, but in this study tibia and femur simplified as a non-linear isotropic material. Meniscus is composed of fibrocartilage, an anisotropic nonlinear viscoelastic material and its viscoelastic behavior make constant after 1500s [2]. Because an instance load applied in the dynamic analysis, so the properties variation is neglected. Articular cartilage and tibia plateau cartilage are assumed as isotropic elastic material. 

Foldes 2002 Sofka et al. 2002 Frediani et al. 2005). Three main patterns of calcified deposits have been described (Frediani et al. 2005) thin hyperechoic bands parallel to the surface of the hyaline cartilage (more frequent in the knee) a punctate pattern, composed of several thin bright echogenic spots (commonly seen in fibrocartilage and tendons) and homogeneous hyperechoic nodular or oval deposits (found in bursae and articular recesses). 

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