Radioulnar joint reconstruction: a novel surgical technique and biomechanical assessment for chronic instability

Gustavo Pacheco Martins Ferreira,Robinson Esteves Pires,Marcella Rodrigues Costa Simões,Haroldo Oliveira De Freitas Junior,Marco Antonio Percope De Andrade,Ubiratan Brum De Castro

doi:10.1186/s40634-020-00291-1

Abstract

PurposeThis study aims to describe and biomechanically evaluate a novel technique using a strip of the flexor carpi ulnaris tendon for distal radioulnar joint reconstruction.MethodsSurgical technique was thoroughly detailed, and a cadaveric biomechanical test was conducted to evaluate sagittal plane stability. Pronosupination range of motion was measured before and after the procedure. Dorsal and volar translation resistances were checked in three situations: with the uninjured triangular fibrocartilage complex, after its complete resection and after the surgical procedure.ResultsFor distal radioulnar joint translation, higher values were found both in dorsal and volar translation in situations with an injured triangular fibrocartilage complex, with means equal to 25.4 mm (SD: 9.4 mm) and 26.1 mm (SD: 8.0 mm), respectively. For intact triangular fibrocartilage complex, both dorsal and volar translations averages were 3.4 mm (SD: 0.9 mm) and 4.5 mm (SD: 1.8 mm), respectively. Finally, when evaluating dorsal and volar translations after surgical reconstruction, means were 6.3 mm (SD: 1.3 mm) and 6.8 mm (SD: 0.9 mm), respectively. Regarding supination and pronation range of motion, which ranged from 57.9 to 63.4o, there were no differences in mean and median measures, when the cadavers with intact and reconstructed triangular fibrocartilage complex were compared (p > 0.05).ConclusionPromising mechanical evaluations encourage us to hypothesize that the technique effectively reconstructs the dorsal and volar radioulnar ligaments, preserving pronosupination and maintaining the physiological characteristics of the wrist joint. Clinical comparative studies are still necessary to fully validate this procedure.Level of evidenceTherapeutic - Level V.

Highlights

The distal radioulnar joint is mainly stabilized by the triangular fibrocartilage complex (TFCC), which is composed by the homologous meniscus, the extensor carpi ulnaris tendon sheath, and by the volar and dorsal ulnocarpal and radioulnar ligaments [1, 2]
This study aims to describe and biomechanically test a novel surgical technique for chronic non-arthritic distal radioulnar joint instability, with the least number of bone tunnels as possible and using a vascularized flap of tendon
After dissection and identification of anatomical structures, the flexor carpi ulnaris was isolated (Fig. 2 - b) For graft harvesting, two transverse approaches were performed on the volar aspect of the middle and proximal thirds of the forearm, over the path of the flexor carpi ulnaris tendon (Fig. 2 - c), splitting it longitudinally all over its length with a width of approximately 4 mm to resemble radioulnar ligament width [13] (Fig. 2 - e)

Summary

Introduction

The distal radioulnar joint is mainly stabilized by the triangular fibrocartilage complex (TFCC), which is composed by the homologous meniscus, the extensor carpi ulnaris tendon sheath, and by the volar and dorsal ulnocarpal and radioulnar ligaments [1, 2].The distal radioulnar functions are tensioning the interosseous membrane to control the pronosupination movement, transferring load from carpus to forearm, and maintaining the anatomical relationship and stability between the radius and ulna [1, 3,4,5]. The distal radioulnar joint is mainly stabilized by the triangular fibrocartilage complex (TFCC), which is composed by the homologous meniscus, the extensor carpi ulnaris tendon sheath, and by the volar and dorsal ulnocarpal and radioulnar ligaments [1, 2]. The most important associated factor to generate distal radioulnar joint injury is the distal radius fracture, especially when it occurs with the forearm in pronation [6]. A gold standard surgical procedure still lacks in the literature In such cases, treatment aims to restore joint stability by using surrounding soft tissues as grafts. For distal radioulnar ligament reconstruction, most techniques generally use tendons passed through bone holes in the distal end of the radius and ulna [7, 11]. A free graft has the disadvantage of losing its vascularity while a tendon flap preserves circulatory viability and elastic properties [7]

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Conclusion