Mechanical Evaluation of Aluminum Alloy Ring Fixator
Somboon Tosborvorn MD*, Sukrom Cheechareon MD*, Kittiput Ruttanuchun MD**, Suparerk Sirivedin PhD**, Chaitawat Rhienumporn MD**
Affiliation : * Orthopaedic Department, Rajavithi Hospital ** King Mongkut Institute of Technology
Objective : To test the homemade ring fixator as a tool for correction of bony deformity.
Materials and Methods : 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
Keywords : Ring fixator, Ilizarov, Aluminium alloy, Aluminium, External fixator
