Our knee is probably the most overused part of our body. We use it every single day without fail and this increases the risk of injury. It is also one of the most flexible parts of our body with the other being our shoulder. To increase the flexibility of a joint, certain functions and strength will have to decrease, making it more prone to injuries. However, there are 4 different knee ligaments that help to stabilise the knee, namely the anterior cruciate ligament, medial collateral ligament, lateral collateral ligament and posterior cruciate ligament. We will be focusing on the posterior cruciate ligament (PCL) in this article. Injuries to the PCL are not as common as injuries to the ACL. This is largely due to the higher tensile strength of the PCL as compared to the ACL. The main role of the PCL is to prevent posterior translation of the tibia on the femur. It also helps to provide rotation stability and axis control functions to the knee. Due to its less common nature, injuries to the PCL are usually not managed properly and thus, lead to poor clinical outcomes. Injuries to the PCL are often accompanied by injuries to the surrounding tissues. There are 3 different grades for PCL injuries and they range from grade 1 to grade 3 depending on the severity.
A grade 1 sprain is minor and the ligament is only slightly injured. There are not many complications involved and the ligament is still able to fully perform its stabilising function. A grade 2 injury is a partial tear of the PCL and this will cause the ligament to become loose. A grade 3 injury is a complete tear to the PCL which renders the knee joint unstable. Some PCL injuries can heal on their own and most patients are able to return to pre-injury lifestyles without much adjustments needed.
Injuries to the PCL commonly occur due to a sudden traumatic impact to the front of the knee, causing the PCL to rupture. A sudden twisting action can also cause the PCL to be stretched out of its means and rupture. A grade 3 PCL injury will require surgical treatment to regain full knee stability. Since the ligament is unable to be regenerated, a graft will be required and this is often taken from the hamstring. For grade 1 or 2 PCL injuries, surgical treatments may not be required and immobilisation for a certain period will often be sufficient. However, the patient will need to undergo physiotherapy to build up surrounding muscles and strengthen them to allow them to help shoulder some of the loads.
Recovery from PCL injuries are often lengthy and frustrating for patients, especially those actively involved in sports. However, the recovery period cannot be rushed through or more serious complications may occur.