Intramedullary (IM) nailing of the fibula is an emerging technique for the treatment of bi- and trimalleolar ankle fractures in patients with compromised soft-tissues, especially in the elderly. Traditional treatment of unstable ankle fractures consists of open reduction and internal fixation (ORIF). For this an incision of 6–10 cm is made across the lateral side of the fibula before the fracture is manually reduced and fixated using a plate and crews. An intramedullary locking nail stabilizes length and rotation of distal fibular fractures through a small incision enabling minimally invasive treatment of an ankle fracture. Such implant is designed specifically for percutaneous fixation of the lateral malleolus. In addition to the IM nail, the implant construct contains a lateral to medial syndesmotic screw and anterior-posterior locking screws to the distal end of the implant to maximize stability [1].

The construct of this implant results in weight-sharing, rather than weight-bearing as is the case in plate fixation. This permits earlier mobilization of the patient, and the injured limb can be loaded earlier [2,3]. It also allows for a minimally invasive treatment resulting in lower risk of infection and impaired wound healing as this nail is inserted in the bone through a small skin incision distal to the fracture site [4]. The nail therefore is a beneficial treatment of unstable ankle fractures in elderly patients with increased risk to develop wound complications. Moreover, ORIF is successful in terms of bony healing, but hardware removal rates are relatively high at 27 % [[5], [6], [7]].

Although IM nailing of the fibula seems easy to perform, it does carry some difficulties and pitfalls and is not always straightforward when it comes to acceptable reduction and optimal functional outcomes. Therefore, the aim of this technical note is to highlight the optimal insertion site of an intramedullary locking fibula nail and to provide a three-step guide to obtain optimal reduction of the fracture. Finally, the advanced option of refraining from rigid tibio-fibular fixation with a syndesmotic positioning screw and using a more dynamic approach in selected cases is shown and discussed.

We propose a step-by-step flow diagram to guide the surgeon in achieving optimal reduction whilst keeping soft tissue as uncompromised as possible (Fig. 1). In the authors’ practice the Fibula Rod System (Acumedࣨ, Hillsboro, Orgeon) is used.

The first step would be closed manual reduction of the fracture. In Lauge-Hansen supination-external rotation type 3 and 4 ankle fractures this means keeping the ankle internally rotated and supinated. The surgeon should strive to obtain a near anatomic position (Fig. 2, Fig. 3).

In case of anatomic reduction, the nail can be centrally introduced at the apex of the fibula. However, if dislocation persists after this maneuver, the second step is choosing an introduction site for the nail that lets the fracture reduce itself completely when gently driving the nail in. The pressure and pliability of the implant is used to help correct the fracture to its anatomic position. In this respect, to optimally use the nail as a reduction tool, the entry point should be chosen slightly dorsal and lateral to the distal fibula tip as opposed to the insertion site suggested by the manufacturer, which is just caudal and central to the distal fibula tip. (Fig. 4, Fig. 5)

When the first two steps do not provide sufficient reduction and optimal anatomic reduction is required due to the patient’s characteristics, a third step can be undertaken: A small incision should be made at the fracture site and the fracture is reduced anatomically with a reduction clamp (Fig. 6, Fig. 7). After which the nail is inserted centrally. This way correct and complete anatomic reduction is ensured whilst keeping the surgery minimally invasive. In typical Lauge Hansen SE injuries, this is usually also the site where an incision would have to be made for placing the syndesmotic screw.

This sequence of steps has been a frequently used method in the author’s practice. Nearly forty patients have been treated, and outcomes overall have been good. Regarding functional outcome the Olerud and Molander ankle score (OMAS) was assessed at one year follow-up in a dozen patients. The mean OMAS score was 81, which suggests overall excellent functional outcomes after 12 months. The most recent 12 patients were treated according to the flow-diagram suggested. Results show a (near) anatomic reduction rate (<2 mm dislocation) of 83 %. The majority of fractures were radiologically consolidated after three months. Complication rates were low. Four of the patients remained slightly painful after three months recovery. Two of the inserted nails had to be removed. One of them because of an infection of the implant which was placed to offer stability after revision of an infected plate osteosynthesis. The other one was removed to enable arthrodesis of the upper ankle joint (severe post-traumatic osteoarthritis of the ankle joint following SE 4 trimalleolar fracture-dislocation). In addition, length of stay was short in most cases. The vast majority of patients were operated and released from the hospital on the same day (Table 1).

It is argued that the syndesmotic screw is an integral part of the nail’s construct and therefore must be placed in all instances. However, the authors found that when the nail is sufficiently long and is tightly wedged in the medullary canal, the nail provides sufficient stability to the syndesmosis upon testing during surgery. Consequently, putting in the syndesmotic screw would unnecessarily create a rigid fixation of the fibula to the tibia leading to reduced range of motion, potentially chondronecrosis and osteoarthritis. Therefore, it is suggested by the authors to refrain from placing a syndesmotic screw when the syndesmosis is stable after nail placement and assessment of the syndesmosis using the hook test or external rotation stress test. This theory has been tested on several patients thus far with good outcomes. An example is the patient shown in previous figures. The 6 weeks post-operative X-ray shows good consolidation and anatomic position of the fracture (Fig. 8). Functional outcomes were also good. If syndesmotic instability persists after nail placement, the surgeon can still opt for screw placement.