Mechanical evaluation of aluminum alloy ring fixator.

OBJECTIVE To test the homemade ring fixator as a tool for correction of bony deformity. MATERIAL AND METHOD The authors developed an aluminum alloy ring fixator and tested it to find out the accuracy of manufacturing and strength of the ring systems under axial load with the Roundness Testing Machine and Lloyd Universal Testing Machine. RESULTS The mean diameter of the twenty five-drill holes was 6.5843872 +/- 0.0521594 mm (mean +/- SD). Distance between particular drill holes, which reflected the precision of drilling, had a high accuracy with standard deviation from 0.1138 to 0.1870 mm. The roundness of the rings was 0.2421376 +/- 0.12437977 mm (mean +/- SD). The system structure had minimal permanent deformity at breaking point, mean yield strength of the system was 4786.9 +/- 14.353 N (mean +/- SD). This was caused by the failure of the wire. Mean stiffness of the system was 127 N./mm. CONCLUSION The aluminum alloy ring fixator was strong enough and well tolerated for clinical usage