STORM

Tibial fractures, including pilon and plateau fractures, are challenging injuries to treat. At present the main options for the management of these fractures are:

1. Plaster cast
2. Intramedullary nailing (if the fracture is extra-articular)
3. Plating
4. External fixation

For all the methods, the final aim is to attain an aligned, united tibia, with no complications and free joint motion above and below the fracture.

For the surgical management, prior to definitive fixation, it is necessary to align the fracture. Certain methods of fixation, aid the reduction intra-operatively, for example passing the nail in a simple tibial fracture, or lagging the fracture to a plate. The joints on an external fixator may also be used as a reduction aid.

However, prior to any fixation, the ideal aim is to have a fully aligned fracture that will stay aligned with ease, until the definitive fixation has been applied.

Many methods are available to help align the fracture, including manual reduction (requires a skilled assistant), a traction table, or some form of distractor. None of these methods address all of the components required to reduce and hold a fracture prior to, and during fixation, namely:

1. Length
2. Rotation
3. Alignment

The Staffordshire Orthopaedic Reduction Machine (STORM) is a simple, but ingeniously developed device that helps reduce the fracture, and then holds it until the definitive method of fixation is applied. STORM is a re-usable device, with the only disposables (and hence cost after the initial purchase), being 2 K-wires, 2 unicortical screws and a drill bit.

STORM is used in the operating theatre within the sterile field. Both legs are prepped to allow an intra-operative assessment of rotation.

Two 2mm k-wires are inserted, one in the proximal tibia / distal femur (see below) and one in the calcaneum; these are then tensioned onto the STORM frame. Through these two wires, controllable axial traction can be applied and malrotation corrected.

Figure 2a: Pre-operative radiograph Figure 2b: Fracture with controlled axial traction applied by STORM (note that traction has not corrected the translation)

Finally, two or more uni-cortical screws are inserted into the tibia, one proximal, and one distal to the fracture. These are attached to translation arms which are then used to pull or push fracture fragments horizontally and vertically to fine-tune any remaining angulation or translation. An anatomically accurate reduction can then be achieved and held by STORM. The mechanics and configuration of the fracture can be assessed post-reduction and held in place while being fixed by a method considered to be most appropriate to the individual patient; intramedullary nail, percutaneous locking plate, external fixation, or a combination.

The device can be used to reduce fractures throughout the tibia, including pilon and plateau fractures, where it's ability to help achieve and hold a good reduction is also useful for percutaneous screw, plate or fine-wire fixation. For plateau fractures the proximal tensioned STORM wire can be placed through the femoral condyles.

STORM is a very simple device to use, and takes approximately 15 minutes to apply. Once applied the fracture can typically be reduced and held within 20 minutes1. The definitive procedure should then be relatively simple, and the time taken reproducible, as the fracture is already reduced and held.

When nailing a tibial fracture, the anatomical reduction which is held throughout the procedure does away with the need for 'pollar' or bollard screws.

Theoretically STORM obviates the need for a surgical assistant, as it's application is simple. The reduction is mechanical, and does not require any surgical force, and once reduced the fracture is held stable whilst the definitive procedure is performed.

Always insist on using a radiolucent table, to enable ease of imaging intra-operatively.

For percutaneous plating from the medial side, place the translation screws and arms on the anterolateral tibial crest, to ensure there is a clear passage for the plate. STORM is particularly valuable when using locking plates, as these plates rely on perfect reduction, prior to their application, as the locking screws are unable to lag the bone to the plate.

For nailing, the proximal tibial wire is placed more posteriorly (although remembering the location of the lateral peroneal nerve posterior to the neck of the fibula), so as not to interfere with the nail insertion point.

When nailing, the uni-cortical screws need to be inserted away from the isthmus, to allow the reamer and nail to pass easily.

When using STORM to reduce a fracture prior to nailing, some form of bolster to rest the distal end of STORM against to keep the knee flexed, makes the nailing part of the procedure easier for any assistant.

Figure 2c: The fracture is then reduced using the unicortical screws, attached to the translation arms. Following this reduction, the axial traction was reduced, to close the fracture gap (note this fracture was treated definitively with an external fixator, hence the screws could be placed near the isthmus)

Figure 3: STORM being using successfully to reduce a fracture prior to intramedullary nailing

When nailing, the STORM device prevents flexion of the knee past 80 degrees due to it impinging on the back of the thigh (although this is not usually a problem).

STORM has been successfully used with complex frames (for example Ilizarov), however careful pre-operative planning is required to prevent STORM impeding the correct placement of pins / wires. It is possible to apply the translation arms after placement of any rings or Schantz screws in the tibia. Reduction is then completed before connecting components.

STORM is a simple yet effective device for achieving and then holding anatomical tibial reduction relatively effortlessly, prior to definitive fixation. It is re-usable, and the only disposable kit for each procedure is a drill bit, 2 wires and 2 screws. Therefore, it is a cost effective device; both in terms of up front costs, and also by reducing theatre time1.

1. Moorcroft CI, Ogrodnik PJ, Thomas PBM,Verborg SA. A Device for Improved Reduction of Tibial Fractures Treated with External Fixation. Proceedings of the Institute of Mechanical Engineers 2000; 214: 449-457.

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