Mikai ENProductsHand surgeryBSS

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 Percutaneous fixation

 Avascular Proximal Pole Nonunion. Screw fixation


The compression strength of the differential screw is generated along the fracture line or nonunion due to the spacing adjustments between two bone fragments which occurs while turning the screw.

With each turn of a screwdriver the BSS screw advances 0.15 mm.  The complete compression of the thread head requires advancing 0.6 mm over the fracture line or nonunion which ensures an excellent primary stability.  At the discretion of the surgeon, the screw can be sunken further resulting in a greater compression.  Warning:  a greater compression causes an increased risk of an angular deformity in the case of an off-centered screw position or could lead to a shortening of the scaphoid in the case of nonunion.

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Different Screw Pitch

Tip threading penetrates the bone faster than the head threading. This allows for a gradual compression of a nonunion/fracture during the screw progression of approximately 0.15 mm per each rotation of the screwdriver./h3>

Threading Design

The special design of the threaded section simplifies both screwing function and screw removal. The reduced threaded section increases the quantity of bone material to provide greater stability.

Threaded Head Form

The truncated cone shape of the threaded head preserves inter-fragmentary compression during the screwing process.

Two Lengths of Screw Thread Tip

Screw thread tip long (6 mm) or short (4 mm) to fit the variable dimensions of the proximal end in the volar approach.

Specifically Designed Tools

Dedicated instrumentation to find the optimal insertion point and direction (as central as possible!) of the guide wire, for easier curettage and filling of the center of nonunion to prevent rotation of the proximal end during screw insertion

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