Torn patella tendon

A torn patella tendon is when the tendon between the front thigh muscles and the lower part of the kneecap (patella) tears partially or completely. The term patella tendon rupture is also used as a synonym for patella tendon rupture. Tearing of the patella tendon is a relatively rare disease that can occur in cases where the tendon is already damaged or due to lifting effects.

It occurs mainly in younger people and should be treated by a physician to avoid a subsequent limitation of movement as a late consequence. Anatomically, this tendon is indispensable for stretching in the knee joint, since it is the starting point for the overlying extensor muscles of the thigh. This is primarily the four-headed extensor muscle (Musculus quadriceps femoris), which is located on the front of the thigh and whose four parts together end in the patellar tendon at the lower pole of the patella. In addition, the patellar tendon fixes the patella in its slide bearing and serves as a deflection roller during flexion in the knee joint.

Causes

Tearing of the patellar tendon usually occurs spontaneously due to excessive tension of the leg against a resistance or when the knee is tensed in the flexed position. Such accident mechanisms often occur during sports such as skiing or tennis. However, a completely healthy tendon is hardly likely to tear.

In most cases there is another pre-damage, which increases the probability of a tear during such an event. These are, for example, degenerative changes of the tendon in the context of other concomitant diseases, irritation of the patella tendon, previous operations or, in rare cases, cortisone injections into the knee joint. In children and adolescents, the patella tendon tear usually occurs at the transition of the tendon to the shin bone.

In adults, the tear is usually located further up, at the lower transition of the tendon to the patella. Sometimes a bone fragment of the kneecap is torn off in addition, this is called a bony tear of the tendon. In the middle, the tendon usually only tears in the context of injuries with direct violent impact.