Posterolateral Corner of the Knee: Current Concepts

Abstract

Injuries to the posterolateral corner (PLC) comprise a significant portion of knee ligament injuries. A high index of suspicion is necessary when evaluating the injured knee to detect these sometimes occult injuries. Moreover, a thorough physical examination and a comprehensive review of radiographic studies are necessary to identify these injuries. In this sense, stress radiographs can help to objectively determine the extent of these lesions. Non-operative and operative treatment options have been reported depending on the extent of the injury. Complete PLC lesions rarely heal with non-operative treatment, and are therefore most often treated surgically. The purpose of this article was to review the anatomy and clinically relevant biomechanics, diagnosis algorithms, treatment and rehabilitation protocols for PLC injuries.

Keywords: Anatomical; Fibular collateral ligament; Knee; Popliteus reconstruction; Posterolateral; Reconstruction.

Figure 1

Anatomic dissection of a right knee demonstrating the posterolateral structures of the knee. FCL: Fibular Collateral Ligament; PFL: Popliteofibular Ligament; LM: Lateral Meniscus; F: Fibula.

Figure 2

Posterolateral view of an anatomic photograph showing both arms (anterior and posterior) of the popliteofibular ligament in a right knee. A: Anterior; P: Posterior: PFL: Popliteofibular Ligament; PCL: Posterior Cruciate Ligament.

Figure 3

Demonstration of the varus stress test a) performed at 0 degrees of knee flexion and b) showing the test performed at 30 degrees of flexion with an alternative method for patients with larger legs.

Figure 4

Image of the dial test being performed with the patient prone on the operating table and the knees flexed to a) 90 degrees and b) 30 degrees. Note the increased external rotation of the right leg compared to the left.

Figure 5

Demonstration of the starting position to perform the reverse pivot shift test on a right knee. The knee is then slowly extended while externally rotating the tibia and placing a valgus force on the knee.

Figure 6

Demonstration of the external rotation recurvatum test being performed on a right leg.

Figure 7

Anatomical reconstruction of the PLC using Achilles allograft. Bone plugs are fixed to the femur with titanium interference screw. After fixing the graft to the fibula (reconstructing the FCL), the graft goes into the tibia tunnel becoming the PFL, and fixed with a biointerference screw together with the popliteus graft, thus all the 3 major static stabilizers of the PLC of the knee are reconstructed.