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Posterolateral Corner (PLC) Injuries


What is the posterolateral corner of the knee?

The posterolateral corner (PLC) consists of numerous different structures that provide stability to the back (posterior) and outer (lateral) aspects of the knee. Of these structures, four are considered the most important stabilizers due to the significant support they provide to this relatively unstable part of the knee:

  • Lateral collateral ligament (LCL)
  • Popliteus tendon
  • Popliteofibular ligament
  • Posterolateral capsule


What is a posterolateral corner injury?

The posterolateral corner of the knee is most commonly injured following a combined hyperextension and varus force to the knee. PLC injuries are associated with athletic traumas, motor vehicle accidents, and falls, and also commonly occur in conjunction with other cruciate ligament tears (ACL or PCL).


What are the symptoms of a PLC injury?

Symptoms of a PLC injury commonly include:

  • Pain and swelling over the posterolateral aspect of the knee
  • Feeling of weakness or ‘giving way’ around the knee
  • Pain which is aggravated by weight-bearing activities
  • Instability symptoms when the knee is in full extension 
  • Difficulty with navigating stairs, pivoting, and cutting
  • If the peroneal nerve is affected, you may also experience numbness or weakness in the lower leg and foot


How are PLC injuries treated? 

Treatment depends mostly on the severity of the injury, amount of instability, and presence of associated injuries. Most patients with a mild posterolateral injury start to recover within a few weeks of the injury with the appropriate conservative management, bracing, and rehabilitation.

Surgical intervention is the treatment of choice for patients with severe isolated PLC injuries, combined PLC injuries, or those who have failed non-operative treatment. For patients requiring surgery, Dr. Potts may recommend PLC surgery to repair or reconstruct the posterolateral corner of the knee.