ArcoFix and Synex II: the AOSpine Anterior Fracture Solution

AOSpine type A fractures of the thoracolumbar spine account for 66% of all spine injuries. They often cause an initial or, if left untreated, a subsequent kyphotic deformity. Especially the type A2 and A3 fractures commonly require a fusion. Furthermore, these fractures are a symptom of osteoporosis. A very accurate reconstruction and a strong mechanical support is crucial for a good outcome.

With the ArcoFix/Synex II combination, the AOSpine TK developed straight forward instrumentation for the minimal invasive anterior stabilisation of thoracolumbar tumors and fractures.

The development of this combined system was based on the following requirements:

  • Implant and instrument must allow a maximum intraoperative versatility with regard to the realignment of the spine (kyphosis correction).
  • Ease of use with a short learning curve.
  • A less invasive procedure.
  • Compatibility with previously developed technology.
  • Respecting the AO philosophy for fracture treatment.


ArcoFix basically consists of three parts. The telescopic part allows for distraction and compression and the two swivelheads that enable a kyphosis or lordosis correction. Thanks to these unique features, the system allows the surgeon to first insert, position and fix the implant (vertebral body screws) and then perform the kyphosis correction and height restoration before everything is finally tightened (golden screws) and secured.

Synex II

After the fracture is reduced and stabilized, the Synex II expandable cage is introduced with the angled Synex II spreader tip.

Once Synex II is in place it is expanded until the implant and the vertebral endplates are in full contact. Synex II is a modular system. Eight different central bodies can be combined with 15 different types of endplates. This helps to reach an ideal cross-sectional load distribution and thus to provide a very good mechanical support of the previously achieved correction.

The central body of Synex II was slimmed down compared to the Synex I. This leaves more space to be filled with more bone thus promoting fusion.

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