Polytetrafluoroethylene (PTFE) as a Suture Material in Tendon Surgery

Elias Polykandriotis; Marcus Himmler; Shirin Mansouri; Florian Ruppe; Jasmin Grüner; Lars Bräeuer; Dirk W. Schubert; Raymund E. Horch

doi:10.3791/64115

Method Article

Polytetrafluoroethylene (PTFE) as a Suture Material in Tendon Surgery

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DOI:

10.3791/64115

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October 6th, 2022

Elias Polykandriotis¹^,² , Marcus Himmler³ , Shirin Mansouri² , Florian Ruppe⁴ , Jasmin Grüner¹ , Lars Bräeuer⁵ , Dirk W. Schubert³ , Raymund E. Horch¹

¹Department of Plastic and Hand Surgery, University of Erlangen Medical Center, ²Department of Plastic, Hand, and Microsurgery, Sana Hospital Hof, ³Department of Materials Science and Engineering, Friedrich-Alexander-University, Erlangen-Nürnberg, ⁴Department of Plastic Surgery, Bayreuth Municipal Hospital, ⁵Institute of Anatomy, Chair II, Friedrich Alexander University Erlangen-Nuremberg

Summary

The present protocol illustrates a method for assessing the biophysical properties of tendon repairs ex vivo. A polytetrafluoroethylene (PTFE) suture material was evaluated by this method and compared to other materials under different conditions.

Abstract

With the evolution of suture materials, there has been a change in paradigms in primary and secondary tendon repair. Improved mechanical properties allow more aggressive rehabilitation and earlier recovery. However, for the repair to hold against higher mechanical demands, more advanced suturing and knotting techniques must be assessed in combination with those materials. In this protocol, the use of polytetrafluoroethylene (PTFE) as a suture material in combination with different repair techniques was investigated. In the first part of the protocol, both linear tension strength and elongation of knotted against not-knotted strands of three different materials used in flexor tendon repair were evaluated. The three different materials are polypropylene (PPL), ultra-high molecular weight polyethylene with a braided jacket of polyester (UHMWPE), and polytetrafluoroethylene (PTFE). In the next part (ex vivo experiments with cadaveric flexor tendons), the behavior of PTFE using different suture techniques was assessed and compared with PPL and UHMWPE.

This experiment is comprised of four steps: harvesting of the flexor tendons from fresh cadaveric hands, transection of the tendons in a standardized manner, tendon repair by four different techniques, mounting, and measurement of the tendon repairs on a standard linear dynamometer. The UHMWPE and PTFE showed comparable mechanical properties and were significantly superior to PPL in terms of linear traction strength. Repairs with four- and six-strand techniques proved stronger than two-strand techniques. Handling and knotting of PTFE are a challenge due to very low surface friction but fastening of the four- or six-strand repair is comparatively easy to achieve. Surgeons routinely use PTFE suture material in cardiovascular surgery and breast surgery. The PTFE strands are suitable for use in tendon surgery, providing a robust tendon repair so that early active motion regimens for rehabilitation can be applied.

Introduction

The treatment of flexor tendon injuries of the hand has been an issue of controversy for over half a century. Until the 1960s, the anatomical area between the middle phalanx and the proximal palm was named "no man's land", to express that attempts of primary tendon reconstruction in this area were futile, producing very poor results¹. However, in the 1960s, the issue of primary tendon repair was revisited by introducing new concepts for rehabilitation². In the 1970s, with advances in neurosciences, new concepts of early rehabilitation could be developed, including dynamic splints³, but thereafter ....