The Polypin is made of polylactide, an absorbable biomaterial which has proved its worth as a material for biological implants, as shown by extensive in vitro an in vivo testing an in clinical use over several years. The special copolymer (Poly L/D, L- Lactide 70/30) has good absorption properties:
its flexural strength remains constant for 34 weeks, which is a sufficient time for the fracture to heal, and then drops at a constant rate.
Biological degradation takes place mainly due to hydrolysis, into lactic acid, which is a natural product of metabolism, and is subsequently metabolised into CO2 and H2O. Within 15 months the Polypin is completely degraded from a mechanical point of view, although it can still be detected in the form of a cylindrical fragment of the original pin.
After 18 to 21 month only fibrous cords are recognisable and after another three months the place of implant is filled with bony substance. Studies have shown that the same results are achieved both by the Polypin and a metal implant, but in the case of the Polypin no implantdependent complications arise.
The Polypin special design is its distinguishing feature and improves its performance:
The head exerts a slight compression on the facture fragments.
The X-ray contrast medium (ZrO2) contained in the heads renders the Polypin visible in X-ray images (2.0 mm and 2.7 mm Polypin).
Circular ribs prevent the Polypin from slipping.
The Polypin is available in three different diameters:
1.5 mm Polypin, length: 8-25 mm
2.0 mm Polypin, length 10-35 mm
2.7 mm Polypin, length: 12-60 mm