What will happen to me if the anterior cruciate ligament is not reconstructed?

This is the natural history of an ACL rupture. Let us tell you what happens in 80% of cases. If it is indicated, the reconstruction of the ACL should take place before the 9th month, when the risk of secondary traumatic injuries is high.

1. At the time of the initial accident (the first trauma to the knee)

In 9 out of 10 cases, when playing sport, the patient feels a cracking sound as a result of twisting the knee or landing from a jump. Intense pain makes it impossible for the patient to hold on or move. The patient finds it difficult to stand and loses confidence in the knee. Sometimes the knee even gives way. The knee swells up in the following minutes or hours. Applying ice and taking painkillers and anti-inflammatories will help. Initial treatment with a splint and walking with a cane may be unnecessary in the following days, especially if gentle re-education and mobilisation of the knee has been carried out. The patient readapts fairly quickly, drives a car after 10 to 15 days and returns to work. This post-trauma period is not very favourable for surgery. The knee is often immobile, painful and swollen.

2. The following months or years.

A few months or years later, you may decide to continue sports that you had temporarily stopped. A new instability accident may occur after a minor trauma. This is a secondary traumatic injury. On this occasion, the inner meniscus, which has become the main obstacle to abnormal movements, can tear. This is a critical point in the natural history because the laxity will get worse. If you have symptoms when the ACL is torn and the medial meniscus is damaged, treatment is more difficult. Other lesions that occur during these instability events may also involve the lateral meniscus or articular cartilage. Therefore, if indicated, ACL reconstruction should be considered before 9 months, when the risk of secondary traumatic injury is high.

3. Twenty to thirty years later.

When walking, there is an anterior translational movement of the tibia with each step, followed by its contraction These repeated movements eventually damage the cartilage in the medial compartment of the knee. Osteoarthritis gradually spreads to the other joints.

Knowledge of this natural history leads the surgeon to propose ACL reconstruction neither too early nor too late, within a reasonable range of between 6 weeks to 9 months after the initial injury.