A novel method for internal fixation of basal fifth metatarsal fracture in athletes: a cadaveric study of the F.E.R.I. technique (Fifth metatarsal, Extra-portal, Rigid, Innovative)

Abstract

Purpose: One of the main problems of Kirschner wire fixation of fifth metatarsal base fractures (in combination with a tension band wiring technique) seems to be hardware intolerance and several studies in athletes also report failure after isolated fixation with a screw only. These reports prompted us to look at new materials and a novel technique through fixation with an intramedullary screw combined with a high-resistance suture via the presented F.E.R.I. (Fifth metatarsal, Extra-portal, Rigid, Innovative) technique.

Methods: This cadaveric study describes F.E.R.I.

Technique: On a cadaver, through two mini portals, a full reduction and solid internal fixation with an intramedullary screw and suture cerclage with Fiberwire of a fifth metatarsal base fracture is achieved. In this article, the cadaveric study and proposed surgical technique are explained and illustrated step by step.

Results: The presented internal fixation F.E.R.I. technique is indicated in acute proximal fractures, stress fractures or non-union of metatarsal 5 (Zone 2-3 by Lawrence and Botte) and it resulted feasible and stable during manual stress test. The authors intend to study this technique in the clinical setting in the near future.

Conclusions: Fifth metatarsal base fractures gain specific interest when occurring in athletes. In this group of patients, internal fixation is often required to obtain a satisfactory outcome and time to return to play. The aim of the presented cadaveric study is to illustrate an innovative concept of internal fixation, named F.E.R.I.

Keywords: Athlete; Fifth metatarsal; Fracture; Internal fixation.

Fig. 1

Proximal fractures or stress fractures of MT-5 (Zone 2–3 by Lawrence and Botte) can be treated with the F.E.R.I. technique

Fig. 2

Creation of two portals allows for a minimally invasive technique, minimising soft tissue damage, when compared to classic tension band techniques or fixation with plate and screws

Fig. 3

Preparation for screw fixation. A hole for the screw is drilled at the entry point. A 5.5 mm partially threaded screw is placed in the medullary cavity through the entry point and screwed to, or just beyond, the fracture line

Fig. 4

Preparation of cerclage. A through-hole is drilled vertically through the distal port, 10 mm distal to the fracture line. An Arthrex Fiberwire® (Arthrex, Naples, FL USA) no. 2 is passed through the hole using a figure-of-eight pattern

Fig. 5

The Fiberwire® is crossed subcutaneously, using small curved Klemmer forceps, from distal to proximal in a figure-of-eight pattern and looped around the neck of the screw. The dorsal wire is pulled plantarly and the plantar wire dorsally

Fig. 6

The screw is then tightened, the Fiberwire® cerclage is properly tensioned and securely knotted

Fig. 7

Diagram of screw position, of cerclage hole and final result. Note that the screw entry point in the figure has been deliberately drawn slightly lateral to aid visualisation