POSTEROLATERAL CORNER (PLC) INJURY

The Posterolateral Corner (PLC) is a group of structures on the outside of the knee that provides the knee with rotational stability. The main anatomic structures of the posterolateral aspect of the knee are the lateral collateral ligament (LCL), the popliteus tendon, and the popliteofibular ligament. The common peroneal nerve runs adjacent to the PLC and can also be injured when posterolateral corner injuries occur. Damage to this area of the knee often occurs due to a sports injury or high energy injury, such as a car accident. Other structures in the knee, such as the posterior cruciate ligament, may also be injured in the setting of a PLC injury. Such an injury is called a “multi-ligament” knee injury.

Symptoms

• Pain on the outside of the knee
• Instability with turning and pivoting
• Numbness along the outside of the knee extending toward the foot

Diagnosis And Treatment

Dr. Welch considers each patient’s symptoms, as well as a detailed physical examination, x-rays, and usually an MRI of the knee to make the diagnosis. There are multiple clinical examination maneuvers that can help detect a PLC injury. The most common exam maneuvers include the Varus Stress Test, Dial Test, and Posterolateral Drawer Test.

Grade I (small partial tear) and Grade II (more severe partial tear) injuries can be treated with non-operative management, including a dedicated physical therapy program and bracing. Grade III (complete tear) injuries usually require surgery. Surgery involves reconstructing the ligaments, usually with a hamstring allograft (donor graft). There are multiple techniques for PLC reconstruction and Dr. Welch typically employs a “fibular-based” technique, similar to the technique used for LCL reconstruction. Following surgery, patients start a dedicated rehabilitation program.