InternalBrace behavior at different orientation placements during anterior cruciate ligament repair: A computational finite element simulation

Abstract

Objectives

InternalBrace™ technique (Arthrex, Naples, USA) has been applied in anterior cruciate ligament repairs in recent years as an alternative to the anterior cruciate ligament reconstruction, with several advantages. The present study aimed to investigate the optimal location to place the InternalBrace during surgery to reduce the stress on the repaired anterior cruciate ligament.

Methods

In silico study of a finite element model of the knee and the anterior cruciate ligament was developed to test the position of the InternalBrace at the repaired anterior cruciate ligament. Five different InternalBrace positions inside the anterior cruciate ligament were analysed under two conditions: with and without damage. Stress and strain in both the InternalBrace and the anterior cruciate ligament were evaluated and compared with a healthy condition (without InternalBrace). The computational simulations using the finite element method were performed under predefined boundary conditions observed during anterior cruciate ligament tears.

Results

The peak strain (8.1%) was obtained in the damaged anterior cruciate ligament compared with a 4.8% strain in the undamaged anterior cruciate ligament in the case without InternalBrace with the same boundary conditions applied. The use of InternalBrace showed a decrease in the deformations of the anterior cruciate ligament, mainly when the InternalBrace was applied in the anteromedial bundle or crossed from the anterior cruciate ligament anteromedial tibial footprint to posterolateral femoral footprint.

Conclusion

The InternalBrace placement through the anteromedial bundle or crossed from the anteromedial tibial footprint to posterolateral femoral footprint showed the lowest peak stress and peak strain in the anterior cruciate ligament, with forces and deformation in the anterior cruciate ligament being partially shifted to the InternalBrace.

Level of evidence

Level V.