INTRODUCTION

To preserve knee function and reduce degenerative, meniscal tears should be repaired where possible. Meniscal wrapping with collagen matrices has shown promising clinical outcome (AAOS meniscal algorithm), however there is limited basic science to support this.

AIM

to model the contact pressures on the human tibial plateau beneath a (1) a repaired radial meniscal tear and (2) a wrapped and repaired radial meniscal tear.

METHODOLOGY

Complete anterolateral radial tears were formed across 4 lateral human menisci, before repairing with ‘rip-stop’ H sutures using 2mm Arthrex Meniscal Suture tape. This was then repeated with the addition of a ChondroGide collagen matrix wrapping. From this experimental setup a finite element (FE) analysis model was construted.

FE models of the two techniques (i) suture alone and (ii) suture and collagen-matrix wrap, were then modelled; bone was linear elastic, articular cartilage was a hyperelastic Yeoh model, and a linear elastic and transversely isotropic material model for the meniscus.

The contact areas of the articulating surfaces, meniscus kinematics, and stress distribution around the repair were compared between the two systems.

RESULTS

Meniscal suture-tape repair had higher local stresses and strains (σ_max=51 MPa ε_max=25%) around the repair compared to with Collagen wrapping (σ_max=36.6MPa ε_max=15%). Radial displacement and pressure on the meniscal contact surfaces were higher in the suture only repair.

CONCLUSION

Collagen-matrix wrapping strengthens the repair, reducing local peak stresses and strains around the suture-tape. This could reduce the chance of suture-tape pull-out and subsequent repair failure.