Posterior cruciate ligament (PCL) tear Ilka Štuhec

 

POSTERIOR CRUCIATE LIG.

Together with the anterior cruciate ligament (ligamenta cruciata anterior, ACL) and the collateral ligaments (ligamentum collaterale medialis et lateralis; MCL i LCL) the posterior cruciate ligament (ligamenta cruciata posterior, PCL) forms the most important set of passive knee joint stabilizers. PCL is situated in the middle of the knee joint behind the ACL. It originates from the distal part of the femur and connects to the proximal part of the shin bone, ie. tibia. PCL has the primary role of preventing posterior translation of the shin bone, the lower leg in regards to the femur, ie. the upper leg and its other role is to prevent lateral shifting or slidding of the knee along with the ACL, MCL and LCL.

PCL injuries are less common that ACL injuries, due to the fact that the PCL is more thick and strong and therefore it is more difficult to get it injured. Injuries to the PCL make less than 20% of all knee joint injuries and the most common injury mechanism in this case is a direct blow or fall on the front part of the shin bone with the knee slightly bent where posterior translation of the lower leg occurs. The injury is common during tackles, slidding chalenges, collisions or falls in sports like football, soccer, baseball, handball, skiing, etc. Alos the injury can occur either acutely, as a result of a sudden force or chronically, due to accumulation of microdamages to the PCL caused by overuse, overload or other knee joint problems.

Grades of PCL injury:

GRADE 1 – partial rupture of the PCL

GRADE 2 – partila rupture of PCL with a bigger tear than in GRADE 1

GRADE 3 – complete rupture of PCL, other knee structures are intact

GRADE 4 – complete rupture of PCL combined with an injury to other ligaments or knee structures

A popping sound which can be heard during an ACL rupture is rarely heard when the PCL ruptures and oftne individuals don not even think that they are seriously injured and try to continue with their normal activities. The pain occurs in the posterior part of the knee and it can also spread to the upper part of the calf region, the knee can swell, feel instable or even buckle under loads, patients can not walk or put loads on the injured leg, etc.

PCL injury treatment depends upon the degree or grade of the injury, with partial ruptures a conservative approach is commonly used and with complete ruptures both approaches, conservative or surgical, can be used. Surgical approach is used more oftenly with younger or more active population. During surgery the PCL is reconstructed using a graft which can be either an autograft (from the patient, taken out of either the hamstring tendons or the quaadriceps tendon) or an alograft (taken from a cadaver). In acute phase of rehabilitation the RICE method is used (rest, ice, compression, elevation) to reduce pain, swelling and hematoma and later on in the functional phase progressive knee joint range of motion, upper leg muscle strenght (first quadriceps and later hamstrings) and knee joint stability should be regained. Rehabilitation lasts up to 6 months and in some cases, combined PCL and other ligament injuries of the knee, it can last even longer.

Prevention: strenghtening of all upper leg muscles to prevent muscle deficits and additionaly actively stabilize the knee, proper treatment of earlier knee injuries and damages, maintaining a balanced body weight, etc.