Modified suture-bridge technique for tibial avulsion fractures of the posterior cruciate ligament: a biomechanical comparison.

Abstract

PURPOSE:

Displaced tibial posterior cruciate ligament (PCL) avulsion fractures require surgical fixation in order to provide an adequate bone healing and to avoid a loss of posterior stability. The purpose of this study was to compare the biomechanical properties of a recently established modified suture bridge technique to a well-established transtibial pullout technique. It was hypothesized that the suture bridge technique shows lower elongation and higher load to failure force compared to a transtibial pullout fixation.

METHODS:

Twelve fresh-frozen human cadaveric knees were biomechanically tested using an uniaxial hydrodynamic material testing system. A standardized bony avulsion fracture of the tibial PCL insertion was generated. Two different techniques were used for fixation: (A) suture bridge configuration and (B) transtibial pullout fixation. In 90° of flexion elongation, initial stiffness and failure load were determined.

RESULTS:

The suture-bridge technique resulted in a significant lower elongation (4.5 ± 2.1 mm) than transtibial pullout technique (12.4 ± 3.0 mm, p < 0.001). The initial stiffness at the beginning of cyclic loading was 46.9 ± 3.9 N/mm in group A und 40.8 ± 9.0 N/mm in group B (p = 0.194). Load to failure testing exhibited 286.8 ± 88.3 N in group A and 234.3 ± 96.8 N in group B (p = 0.377).

CONCLUSION:

The suture bridge technique provides a significant lower construct elongation during cyclic loading. But postoperative rehabilitation must respect the low construct strength of both techniques because both fixation techniques did not show a sufficient fixation strength to allow for a more aggressive rehabilitation.

• Authors: Philipp Forkel, Lucca Lacheta, Constantin von Deimling, Jan Lang, Louis Buchmann, Andreas B Imhoff, Rainer Burgkart, Lukas Willinger
• Journal: Archives of orthopaedic and trauma surgery (Arch Orthop Trauma Surg) Vol. 140 Issue 1 Pg. 59-65 (Jan 2020) ISSN: 1434-3916 [Electronic] Germany
• PMID: 31559489 (Publication Type: Journal Article)

Topics

• Biomechanical Phenomena (physiology)
• Fractures, Avulsion (surgery)
• Humans
• Materials Testing
• Models, Biological
• Posterior Cruciate Ligament (surgery)
• Suture Techniques
• Tibial Fractures (surgery)