Segmental spinal instrumentation. A study of the mechanical properties of materials used for sublaminar fixation

Segmental spinal instrumentation with sublaminar fixation is widely used but a variety of materials and techniques are being employed for both scoliosis and other spinal surgery. This study addresses the question as to which is best. Both the materials and the methods of securing them were studied. The materials tested were stainless steel 316L, Ortron 90 high nitrogen steel, titanium alloys, nylon straps, and Mersilene tapes. Doubled cold-worked 00.84-mm diameter stainless steel formed in a knot with a twist proved to be the strongest and most secure means of fixation with a yield value of 1,610 N. Attention to the details of technique and material such as the incorporation of a secondary twist and avoidance of hot-worked stainless steel may reduce the incidence of implant failure.