The posterolateral corner (PLC) of the knee is made up of a group of muscles and ligaments that stabilize the joint. Injuries to the PLC often occur when some other area of the knee has been damaged.
In this article, surgeons from the University of Pennsylvania bring us up-to-date on PLC injuries. They provide information on the anatomy and biomechanics of the injury. How the injury occurs and most common symptoms are discussed. The authors walk the reader through the diagnosis and treatment step-by-step.
PLC is linked most often with anterior cruciate ligament (ACL) or posterior cruciate ligament (PCL) tears. The most common mechanisms of injury are sports-related trauma, car accidents, and falls. It’s easy to miss the diagnosis of PLC injury when symptoms of other injuries are more pronounced.
An accurate diagnosis requires a careful history and examination. Tests specifically for this injury are presented. Imaging studies include X-rays, CT scans, and MRIs. MRIs offer the best view of the PLC. MRIs also show other injuries such as fractures, bone contusions, and other ligamentous damage.
PLC injuries are treated based on the grade of injury and when the diagnosis is made (acute versus chronic injury). Injuries are graded as I (no abnormal joint motion or instability), II (abnormal joint motion), and III (complete tear with joint instability). Arthroscopy may be done to see how severe the damage is and the location of any problems. Surgery to repair or reconstruct the PLC structures is often needed.
Surgical techniques used (approach, incision, methods) are presented for both acute and chronic injuries. Scar tissue, joint malalignment, and joint instability make the chronic injury a challenge. The surgeon must decide whether to restore the normal PLC anatomy or stabilize the joint by tightening up the soft tissue structures.
Complications are always possible with any surgical procedure. With surgery to manage PLC injuries, damage can occur to the peroneal nerve. Wound infection, knee stiffness, and hamstring weakness are also possible. Many of these problems can be avoided with careful surgical technique and the right rehab program.