An experimental study of the buckling behavior of L-rod implants used in the surgical treatment of scoliosis.
A test facility was developed to study the buckling behavior of the scoliotic spine fitted with L-rod implants. The facility included a model, constructed from polymeric materials, that was similar in geometric detail and flexural stiffness to the ligamentous thoracolumbar spine with a severe scoliotic curvature. Nondestructive tests were performed in which the transverse deflection was recorded at various axial load levels. Southwell regression was used on the data to estimate the buckling loads. Attaching L-rods of 3.2-mm diameter did not increase the buckling load significantly, compared to the uninstrumented spine and thus were judged to be ineffective in halting the progression of a scoliotic curve. However, L-rods of 4.8-mm diameter increased the buckling load about four times and L-rods of 6.4 mm increased the buckling load about eight times.
D001696:Biomechanical Phenomena; D006801:Humans; D008422:Materials Testing; D008433:Mathematics; D008961:Models, Structural; D019736:Prostheses and Implants; D012044:Regression Analysis; D012600:Scoliosis / Q000601:surgery*