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[Tissue reaction and degradation of super-high molecular weight poly D, L-lactic acid mini-plates and screws: an animal experiment].

OBJECTIVE
To investigate the tissue reaction and degradation processes of the super-high molecular weight(Mv = 6.0 x 10(5) kD) poly D, L-lactic acid(PDLLA) mini-plates and screws through the internal fixation for zygomatic arch fracture.


METHODS
It was carried out by the self-contrast study method and comparing with the titanium mini-plates and screws.


RESULTS
There was no side-effects on bone healing. The reaction of soft and hard tissues to PDLLA mini-plates and screws was similar to that of the titanium mini-plates and screws. No complication had been seen with the use of PDLLA mini-plates and screws, including infection, foreign body reaction and underlying osteolysis. The PDLLA devices had no changes in shape after 3 months, and then became the grains in different sizes after 6 months, and were completely resorbed within 12 months in vivo.


CONCLUSION
The super-high molecular weight PDLLA mini-plates and screws has good biocompatibility and proper degradation time. It is safe and effective to use the mini-plates and screws made of the super-high molecular weight PDLLA for internal fixation of bone.