Finding the Optimal Balance - Isolated Posterolateral Corner Reconstruction with Allograft Tendon in a Combined Posterolateral Corner-Posterior Cruciate Ligament Injury: A Case Report

Abstract

Introduction: Posterolateral corner (PLC) injuries are often associated with cruciate ligament tears. Historically known as the "dark side" of the knee, advancements have greatly improved our understanding of the PLC, offering various management options today.

Case report: We present the case of a 44-year-old male with a combined PLC and posterior cruciate ligament (PCL) Grade 2 injury. He was managed with an isolated PLC reconstruction using an open anatomical Arciero-based technique with a tibialis anterior allograft. At subsequent follow-ups, the patient was shown to have excellent knee functional outcomes, no instability, and ease of performing regular activities, including low to moderate-demand sporting activities.

Conclusion: Effective management of combined PLC and PCL injuries necessitates early identification of the PLC injury and a case-specific management approach, considering factors such as the patient's condition, surgeon expertise, and graft availability. Allografts are a viable alternative to autografts for PLC reconstruction, offering several advantages over the latter.

Keywords: Posterolateral corner; allografts; arciero technique; isolated posterolateral corner reconstruction; multiligament knee injuries; posterior cruciate ligament; three window technique.

Figure 1

Dial test positive - External rotation asymmetry seen at 30° (top left) and at 90° (top right). Bilateral varus stress radiographs showing side to side difference of more than 4 mm (orange arrow- bottom left) indicative of a posterolateral corner lesion.

Figure 2

Image on the left showing lateral collateral ligament tear (yellow arrow), popliteus tendon disruption at myotendinous junction (green arrow). Image on the right showing partial to full thickness posterior cruciate ligament injury.

Figure 3

Femoral footprint of the lateral collateral ligament (LCL) indicated by the guide wire. Femoral footprint of the popliteus seen 18.5 mm distal and anterior to the femoral footprint of the LCL, in the anterior 1/5th of the popliteal sulcus.

Figure 4

Graft shunted through the fibula tunnel from anterolateral to posteromedial direction. Anterior limb of the graft designated for lateral collateral ligament and the posterior limb was planned for the popliteus.

Figure 5

Comparison of the preoperative and postoperative knee radiographs showing reduction in varus opening and posterior translation. Preoperative varus stress X-ray (top left), postoperative varus stress X-ray (top right), preoperative posterior tibial stress X-ray (bottom left) and postoperative posterior tibial stress X-ray (bottom right).

Figure 6

Dial test negative – Equal external rotation range at 30° (top left) and at 90° (top right). Complete range of motion with good function outcome (bottom left and bottom right).