Professor Peter Thomas FRCS
University Hospital of North Staffordshire
Q: How long did it take from idea to finished product?
A: It took over five years to develop and perfect the STORM™ (Staffordshire Orthopaedic Reduction Machine) and involved working very closely with both clinical and engineering teams. Although, the time from initial idea to first prototype was pretty quick the process of refining and testing out each evolution takes time and involved at least five more prototype devices.
Q: Can you provide an insight into some of elements of the product development evolution?
A: Firstly, I would like to say that although this can be a long process it is also very exciting to see your ideas come to life. Perhaps the best way to demonstrate this is to answer some of the frequently asked questions.
Q: Why put the wire in the calcaneum rather than the talus or distal tibia?
A: Traction through the heel has always been favoured because it brings the foot plantargrade. If the wire is put through the talus the foot will go into equinus as traction is applied. A wire through the distal tibia would get in the way of many forms of fixation and it would also allow the foot to fall into equinus. The force of heel traction is balanced by the pull of the tendo-Achilles, which is why it works best.
Q: Why not use a Steinmann or Denham pin in the heel instead of the wire?
A: In our earlier prototypes we used a Denham pin but found that the 2mm wire works very well and with minimal disturbance to the calcaneum.
Q: Why does the heel-wire yoke have no adjustment for valgus and varus?
A:
Q: Why do the translation arms use unicortical screws?
A: We tried several different approaches in prototypes. Flexible straps and pushers against the skin did not give enough fine control. Schanz screws were tried but produced a strong turning moment which would change the torsional position as translation was being corrected. “Pinless” grippers were tried but were found to have the same disadvantages as Schnanz screws with the added problem that they would tend to come adrift. For pure translation with minimum torsion, the force has to be applied as close a possible to the centre of the tibia. Unicortical screws in fixed-angle holders give the best control.
Q: Can STORM be used for percutaneous plating?
A: Yes. It works very well for proximal and distal tibial locking plates, where it is vital to have the fracture perfectly reduced before the screws are inserted into the plate. You should still use the translation arms as these will hold a perfect reduction firmly while the plate is applied. For proximal LISS plates it can be helpful to have the whole tibia internally rotated about 10 deg in the STORM. This gives better access for the LISS plate guide antero-laterally.
Q: Will a tibial nail hit the proximal STORM wire?
A: No. The entry point for the nail is anterior to the wire in the proximal tibia.
Q: Q: Why are the STORM support bars not radiolucent?
A: To overcome this issue the bars are placed posterior to the axis of a lateral x-ray view, so AP and Lateral views are not impeded by the bars. They would be in the way for certain oblique views but adequate x-ray views can always be obtained either side of these positions. Whilst it is possible to specify radiolucent bars, they would add significantly to the price of the STORM and we found it to be unnecessary.
Q: Is STORM complicated to set-up and use?
A: No, as part of the development process we took great care to make everything as simple and intuitive as possible. We have many instances where a surgeon has used STORM successfully simply by following the manual. However, we are always very happy to provide whatever training and support is required and of course to welcome any surgeon wishing to visit me in Stoke.