Although wrist fusion is a relatively rare indication, it may be an effective treatment for chronic wrist joint pain. The VariAx 2 Wrist Fusion System is a range of titanium plates which are contoured to bridge the radius and metacarpal bones to allow for stable fixation during fusion osteosynthesis. The plating system uses the VariAx 2 screws and instrumentation platform which includes variable-angled locking and non-locking screws. Made of titanium and treated with a Type II anodization, these plates are designed to carry the loads that are required of them while remaining low profile.

The VariAx 2 Wrist Fusion System offers 3 types of plates from which to choose: Standard Bend Plate, Short Bend Plate, and Straight Plate.  The bended plates contain 4 proximal holes for distal radius fixation and 4 distal holes for metacarpal fixation. Within the bend of the plate, there is an additional hole for capitate fixation.  The straight plate is also designed with 4 proximal and distal holes; however, there are 2 additional holes located centrally for carpal fixation.  Plate Trials may be provided to determine the proper plate to be implanted. This may be particularly useful when using sterile-packed plates.

For all plates, the distal radius holes are to be filled with 3.5mm (Orange). For the carpal and metacarpal holes, 2.7mm (Purple) or 2.4mm (Blue) screws are to be used.  The circular holes in the plates provide an option for locking and non–locking. In order to distinguish a locking screw from a non-locking screw, the top of the locking screw heads are laser marked with a black circular ring and inner dot.

The polyaxial locking technology works by using two different grades of titanium. Locking screws are made of titanium alloy (Ti6Al4V) and when a screw is driven into a plate hole, the locking threads on the underside of the screw head engage the circular ‘lip’ in the hole.  This technology allows the surgeon to aim and lock the screw within a 30° cone.