2017 ISAKOS Biennial Congress ePoster #1158

 

Mechanic evaluation of the tibial fixation of the postero-lateral band In ACL double-bundle reconstruction with and without Interference screw.

Mario Carneiro, MD, PhD, São Paulo, SP BRAZIL
Anderson De Aquino Santos, MD, São Paulo, São Paulo BRAZIL
Tales Mollica Guimarães, MD, São Paulo, São Paulo BRAZIL
Roberto Freire da Mota e Albuquerque, MD, PhD, São Paulo, SP BRAZIL
Joao Paulo Freire Martins De Moura, São Paulo, SP BRAZIL
Carlos E. D. Franciozi, MD, PhD, Prof., São Paulo, SP BRAZIL
Marcus V. M. Luzo, MD, PhD, São Paulo, SP BRAZIL

DOT-EPM-UNIFESP e IOT-FMUSP, São Paulo, São Paulo, BRAZIL

FDA Status Not Applicable

Summary

The authors did a biomechanical study in knee cadavers to compare the resistence o the anatomic tibial fixation of the flexor tendons versus the fixation with interference screw in double-bundle ACL reconstruction.

Abstract

Introduction

The objective of this study was to compare two tibial fixation techniques of the Postero-Lateral Band (PLB) in the reconstruction of the anterior cruciate ligament with double band: without an interference screw, preserving the native tibial insertion of the tendons of the gracilis and semitendinous muscles versus with an interference screw without preserving the insertion of the tendons.

Materials And Methods

A comparative study was conducted in cadavers with an universal mechanical test machine. Twenty three knees from cadavers were randomized for the tibial fixation of the PLB through two tecnhiques: maintaining the tibial insertion of the tendons during reconstruction, without the use of an interference screw (group A) – 11 cases; and fixating the graft with an interference screw, without maintaining the insertion of the tendons (group B) – 12 cases. A continuouse traction was performed (20mm/min) in the same direction as the produced tunnel, and force (N), deformation (mm), rigidity (N/mm), and tension (N/mm2) were objectively determined in each group.

Results

Group A exhibited a maximum force (MF) of 315.4 ± 124.7 N; maximum tension of 13.57 ± 3.65 N/mm2; maximum deformation of 19.73 ± 4.76 mm; force at the limit of proportionality (FLP) of 240.6 ± 144.0 N; and deformation at the limit of proportionality of 14.37 ± 6.58 mm. Group B exhibited a MF of 195.7 ± 71.8 N; maximum tension of 8.8 ± 3.81 N/mm2; maximum deformation of 15.3 ± 10.73 mm; FLP of 150.1 ± 68.7 N; and deformation at the limit of proportionality of 6.86 ± 2.42 mm. When comparing the two groups, significant differences were observed in the variables of maximum force (p=0.016), maximum tension (p=0.019), maximum deformation (p=0.007), and deformation at the limit of proportionality (p=0.003).

Conclusion

The use of the native insertion of the semitendineous and gracilis tendons without an additional fixation device presented mechanical superiority over their fixation with interference screws.
Keywords: Anterior cruciate ligament reconstruction; knee lesions; surgical fixation devices; mechanics.