Tendon the presence of denatured collagen are factors that are believed to cause weakening of the tendon ECM and an increase in the potential for another rupture to occur. In response to repeated mechanical loading or injury, cytokines may be released by tenocytes and can induce the release of MMPs, causing degradation of the ECM and leading to recurring injury and chronic tendinopathies. A variety of other molecules are involved in tendon repair and regeneration. There are five growth factors that have been shown to be significantly upregulated and active during tendon healing: insulin-like growth factor 1 (IGF-I), platelet-derived growth factor
Quadriceps tendon rupture Quadriceps tendon rupture A quadriceps tendon rupture is a tear of the tendon that runs from the quadriceps muscle to the top of the knee cap. Symptoms are pain and the inability to extend the knee against resistance. A gap can often be palpated at the tendon's normal location. The diagnosis is usually made clinically, but ultrasound or MRI can be used if there is any doubt. The tendon can be surgically repaired. Afterwards a brace is given that prevents flexion of the knee. Athletes who have suffered this injury generally return to action in about 9 months to a