 So, this is going to be a demonstration of the tendo-calcaneus. The tendo-calcaneus is the combined tendon of the gastropameus, the soleus and of course the plantaris but we will focus on the gastropameus and the soleus. The tendo-calcaneus is one of the most powerful and the most useful tendon in the human body. It is the only tendon, large tendon which does not have its cyber-wheel sheath. Instead, it is covered by a structure called the paratino, which is going to play a useful role in surgical practice. The tendo-calcaneus starts as an aponeurotic expansion of the lower end of the gastropameus which we can see here and it merges with the fibres of the soleus and as the fibres descend down they rapidly converge to form this wrong tendon here on the back of the ankle joint and simultaneously the fibres twist by 90 degrees laterally such that the fibres which are coming from the gastropameus they point laterally and the fibres which are coming from the soleus they point immediately. This twisting of the fibres allows springiness of the gait and the plantar reflection. So this is the functional importance of the tendo-calcaneus. The tendo-calcaneus gets inserted onto the posterior aspect of the calcaneus and at the point of insertion there can be a sub-tendinous bursa to prevent friction between the tendo-calcaneus and the calcaneal bone. There can also be a bursa between the skin and the calcaneus that is known as the subcutaneous bursa. The subcutaneous bursa or the sub-tendinous bursa can get in frame to produce calcaneal bursitis especially when wearing tight shoes or new shoes. Sometimes there can be an accessory soleus. In this particular patient there is no accessory soleus but if such is present then that can also merge with the tendon of the tendo-calcaneus and rarely it can either also produce a painful calf condition. This tendo-calcaneus is so important that if there is an injury or rupture of the tendo-calcaneus it is considered as bad as cutting off the foot. Patient will not be able to plant or flex. So therefore repair of the tendo-calcaneus becomes of paramount importance and the repair of the tendo-calcaneus is done in a very unique way and we have only cut it to show how the repair procedure is done. When the tendo-calcaneus cut tendon is presented in front of us we are supposed to convert the cut into a form of a Z like this. That means we make a small cut horizontally then we make a cut vertically and then above that again a horizontal cut. So this is a Z and then we are supposed to repair it using non-absorbable soleus preferably stainless T and then we are supposed to carefully close the paratinone on top of that. And then we are supposed to put a cast extending from above the knee to below the foot because we have to immobilize both the knee joint and the ankle joint and this has to be kept for at least 3 months. So this is the procedure for repairing the ruptured tendo-calcaneus. This procedure of repairing ruptured tendo-calcaneus is known as Z plus T. The purpose of making this Z incision is if we were to repair it in a horizontal line then there will be too much tension exerted again and the suture line may give way again because the tendo-calcaneus is constantly in motion and therefore to break up this tension we divide it in the form of a Z and it is called Z plus T. So this is all I wanted to mention about the tendo-calcaneus and its clinical significance and its functional importance. Thank you very much for watching. If you have any questions or comments please put them in the comment section below. Talk to Sanjay Sanyal. Sanyal. Have a nice day.