A loose knee that has been in place for two years is usually not self-healing. Knee loosening is usually caused by damage or rupture of the ligaments around the knee. Common knee ligament injuries or ruptures include the anterior cruciate ligament (ACL), posterior cruciate ligament (PCL), medial collateral ligament (MCL) and lateral collateral ligament (LCL) of the knee. An ACL injury and rupture causes anterior instability of the knee and a posterior cruciate ligament injury causes posterior instability of the knee. It causes a slowing of initiation during strenuous exercise and a feeling of misalignment of the knee joint during walking activities. Injuries to the medial collateral ligament or lateral collateral ligament tend to cause lateral instability of the knee. If you have a loose knee joint, it is important to go to a regular hospital in time. After the doctor’s examination to find the cause of the loosening, if it is a complete rupture of the ligament, it should be reconstructed and repaired through surgery in time.