Frequency

Ligament injuries are the most common knee injury, accounting for approximately 40% of all knee injuries, in addition to meniscal lesions (small pieces of cartilage inside the knee joint) or a ruptured kneecap. In 50% of cases, the anterior cruciate ligament tears, the posterior one is much better protected against tears due to its anatomical position. 73% of cruciate ligament tears occur in sports accidents, only 27% have other causes, such as accidents at work or accidents in the household.

Among the sports, skiers (28%) or footballers (23%) are the most frequent victims. Children are generally not affected as frequently as adults, as their ligaments are still somewhat more elastic, but they suffer more frequently from torn ligaments with bone involvement. The even softer bones of the little ones are responsible for this.

Causes

The cause of a rupture of the anterior cruciate ligament in children is primarily, as in adults, an excess of the ligament’s stretching capacity. If a ligament is overstretched to such an extent, the causal rotation is usually from the knock-knees (valgus) position. Cruciate ligament ruptures therefore often occur as sports injuries.

Especially soccer players, tennis players or skiers and snowboarders are often affected. But squash, field hockey or basketball, all sports in which frequent, rapid changes of direction occur, can also be a cause of knee injuries. Children who play soccer or are learning to ski also suffer such injuries.

But also in everyday life, for example when romping around or on the playground, sudden turns or twists can cause the child to suffer such an injury. However, not only extreme inward or outward twisting movements can cause a torn cruciate ligament, but also excessive stretching or bending movements when the thigh muscles are tense. Rupture of the posterior cruciate ligament is caused by rare traumas, such as a car accident.If the anterior cruciate ligament tears, the inner meniscus (small, crescent-shaped cartilage disc in the knee joint) and the inner ligament are often also affected because of the movement pattern and the spatial proximity to each other. The meniscus can tear completely or partially, as can the inner ligament. This injury pattern, also known as “classic skier injury”, is called “unhappy triad”.