Pull-out strength of four tibial fixation devices used in anterior cruciate ligament reconstruction

M Chivot; S Harrosch; F Kelberine; M Pithioux; J-N Argenson; M Ollivier

doi:10.1016/j.otsr.2017.12.011

Pull-out strength of four tibial fixation devices used in anterior cruciate ligament reconstruction

Orthop Traumatol Surg Res. 2018 Apr;104(2):203-207. doi: 10.1016/j.otsr.2017.12.011. Epub 2018 Jan 31.

Authors

M Chivot¹, S Harrosch¹, F Kelberine², M Pithioux¹, J-N Argenson¹, M Ollivier³

Affiliations

¹ Aix-Marseille université, CNRS, ISM UMR 7287, 13288 Marseille cedex 09, France; Service de chirurgie orthopédique et traumatologique, institut du mouvement et de la locomotion, hôpital Sainte-Marguerite, 270, boulevard Sainte-Marguerite, BP 29, 13274 Marseille, France.
² Clinique La-Provençale, 67, Cours-Gambetta, 13100 Aix-en-Provence, France.
³ Aix-Marseille université, CNRS, ISM UMR 7287, 13288 Marseille cedex 09, France; Service de chirurgie orthopédique et traumatologique, institut du mouvement et de la locomotion, hôpital Sainte-Marguerite, 270, boulevard Sainte-Marguerite, BP 29, 13274 Marseille, France. Electronic address: ollivier.mt@gmail.com.

PMID: 29408566
DOI: 10.1016/j.otsr.2017.12.011

Abstract

Introduction: In reconstructions of the anterior cruciate ligament (ACL), tibial fixation can be the weak point in the assembly during the early postoperative period. The present study sought to compare pull-out strength between four tibial fixation systems used in ACL reconstruction.

Hypothesis: The study hypothesis was that all four devices show ≥450N pull-out strength with comparable biomechanical breakage characteristics.

Material and methods: An experimental study used a mechanical model to perform axial traction on a synthetic ligament (polypropylene cord folded in four) implanted in an artificial tibia (Sawbones Proximal Tibia # 1116-2: model: normal anatomy; solid foam; size: medium) using four tibial fixation systems: Ligafix^® interference screw (SBM™); Bio-Intrafix^® (Mitek™); Translig^® (SBM™); RIGIDfix^® (SBM™). For each system, four models were tested using an Instron 5566^® traction machine, allowing 100mm/min stretching up to breakage. Study parameters comprised: pull-out strength, maximal whole assembly slippage, stiffness at breaking point, and type of break.

Results: Mean pull-out strength was 450±24N (range, 421-488N) for Ligafix^®, 415±60N (327-454N) for Bio-Intrafix^®, 539±66N (449-636N) for RigidFix and 1067±211N (736-1301N) for Translig^®, and was significantly greater for Translig^® than for the other devices (p=0.02), which did not significantly differ from one another. The expected maximal load of 450N was reached in 100% of cases with Translig^® and RIGIDfix^® and in 50% of cases with Bio-Intrafix^® and Ligafix^®. There were no significant differences regarding stiffness. Ligafix^® showed significantly less slippage than the others (p=0.006), with breakage caused by the ligament sliding between bone and implant.

Discussion: In this in-vitro study, the Translig^® fixation device showed better pull-out strength than the other three devices tested.

Type of study and level of evidence: Comparative laboratory study. Level II.

Keywords: Anterior cruciate ligament reconstruction; Biomechanics; Fixation; Pull-out strength; Tibia.

Publication types

Comparative Study

MeSH terms

Anterior Cruciate Ligament Reconstruction / instrumentation*
Biomechanical Phenomena
Bone Screws*
Equipment Failure*
Humans
Materials Testing
Stress, Mechanical
Tibia / surgery