The different proportion samples of PLGA-Mg were made in this study. Then, they would be placed in the femoral condyle of the New Zealand rabbits. The appropriate proportion of PLGA-Mg is obtained after the experiment, which will be used to make the plate or screw to fix the fragments. Then, the clinical role for bone will be assessed.

The deposition of calcium could be facilitated by the increase of magnesium, which played an important role in fracture union. However, its degradation may be completed before the fracture line was disappeared. In addition, the hydrogen may be released during degradation. Thus, its clinical popularization was limited.

As a new polymer material, poly lactic-co-glycolic acid (PLGA) has been widely used clinically. The hydrolytic production of PLGA was acidic, which could neutralize the alkalinity of production degraded from magnesium. In addition, it was a long time before the total accomplishment of degradation of PLGA, which may postpone the degradation of magnesium.

The different proportion samples of PLGA-Mg were made in this study. Their physical and chemical properties were analyzed to estimate its safety of implantation. Then, they would be placed in the femoral condyle of the New Zealand rabbits. The osteogenesis and complication of samples are examined to select an appropriate proportion of PLGA-Mg is obtained. Then, the PLGA-Mg material will be used to fix the fracture of human as a fixation. The review of the patients will be conducted to assess its clinical role.

Inclusion Criteria:

• 18-65 years old
• Closed fracture
• Sign the agreement of the experiment

Exclusion Criteria:

• Pathologic fracture
• Open fracture
• Refused to participate
• Follow-up insufficient 12 months