Composition and Structure of OSTEOTRANS System
OSTEOTRANS is bioactive and totally resorbable osteosynthetic bone fixation device, consisting of composite materials of bioactive, bioresorbable unsintered hydroxyapatite (u-HA; 30 wt% in screws and 40 wt% in plates) combined with poly L-lactide (PLLA), which has been reinforced using a unique compression forging process. The u-HA fine particles are uniformly distributed throughout the composite materials, partially exposing on the surface (the white dots visible in the photograph on the right).
Strengths of OSTEOTRANS System
OSTEOTRANS has mechanical properties as follows
Possesses high mechanical strengths and moduli superior to those of osteosynthesis devices consisting of PLLA-only or PD/LLLA.
Possesses an initial bending strength higher than that of human cortical bone.
Possesses toughness without easily breaking off.
Maintains a bending strength equal to that of human cortical bone for about 6 months in vivo.
Bioactivity of OSTEOTRANS System
OSTEOTRANS is bioactive and has the feature of osteoconductivity and osteobinding ability. Early after surgery, small trabecular bone formation occurs peripheral to an OSTEOTRANS and gradually surrounds the outside of the device.The surrounding bone directly binds to the u-HA particles that are exposed at the surface of the device. This condition is maintained for a long period, during which time the rod is resorbed as the PLLA matrix extremely degrades and the composite breaks down. After continued osteoconduction, the composite is also replaced with new bone as the PLLA is resorbed.