Tendon also have a role in the tensile properties of tendon. The structure of tendon is effectively a fibre composite material, built as a series of hierarchical levels. At each level of the hierarchy, the collagen units are bound together by either collagen crosslinks, or the proteoglycans, to create a structure highly resistant to tensile load. The elongation and the strain of the collagen fibrils alone have been shown to be much lower than the total elongation and strain of the entire tendon under the same amount of stress, demonstrating that the proteoglycan-rich matrix must also undergo deformation, and stiffening of
Patellar tendon rupture Patellar tendon rupture Patellar tendon rupture is a tear of the tendon that connects the knee cap (patella) to the tibia. Often there is sudden onset of pain and walking is difficult. In a complete rupture the ability to extend that knee is decreased. A pop may be felt when it occurs. Injury to the patellar tendon generally requires a significant force such as falling directly on the knee or jumping from a height. Risk factors include patellar tendinitis, kidney failure, diabetes, and steroid or fluoroquinolone use. There are two main types of ruptures partial and complete. In most cases,