Innovative bioactive and bioresorbable interference screws

Manufacturing procedure marks out BioactIF Osteotrans from Richard Wolf

Knittlingen in September 2009 – Bioresorbable interference screws for fixation of tendons must have a high level of mechanical stability on the one hand, while also being biologically degradable without any side effects. Screws made of the polymer Polyactide (PLA) were the most widespread implants used for this purpose in reconstruction of the anterior and posterior cruciate ligaments for many years. However, problems have been increasingly encountered in practice. Lactic acid is produced during the breakdown process of PLA screws which can lead to inflammatory reactions in the surrounding bone and result in encapsulation of the implant.
Mechanical stability and the capacity for physiological resorption can only be achieved through the use of composite materials made of different materials. Richard Wolf presents BioactIF Osteotrans as a new generation of bioactive and bioresorbable interference screws made from this combination of materials.
BioactIF Osteotrans is a mix of PLA and hydroxylapatite (HA) with an average particle size of 5 µm. The HA buffers the acid pH value of the lactic acid produced during the breakdown of PLA. This avoids inflammatory reactions of the surrounding tissue and encapsulation of the implant. Since 40 percent of the bone in the human body is made up of HA, the surface of the screws is integrated directly into osteometabolism and the surrounding bone grows bioactively into the surface of the screws. This is the only way of ensuring continuous bone growth.
The manufacturing procedure exerts a key influence on the mechanical properties of the material and the resorption behavior. BioactIF Osteotrans is manufactured in a special forging process which provides a uniform distribution of the HA particles and ensures hardening of the material. This gives the interference screws the mechanical properties of human bone. Transfer of force vectors through the material is guaranteed when subject to loading and active bone growth is guaranteed. Optimum prerequisites are therefore provided for secure fixation of cruciate ligament transplants.

Press contact:
Richard Wolf GmbH    
Elke Lauser (Marketing)
Pforzheimer Str. 32
75438 Knittlingen
Germany
Tel. +49 (0) 70 43 35-305
Email: elke.lauser@richard-wolf.com