Elastic Centromedullary Nailing: Titanium Or Stainless Steel

1
Elastic Centromedullary Nailing Titanium Or
Stainless Steel
J.M. Clavert, P. Gicquel, M.C. Giacomelli, C.
Karger Pediatric Orthopaedics Unit Hautepierre
Hospital Strasbourg FRANCE
Centromedullary nailing is the gold standard for
femoral fractures in childhood. For
heavyadolescents, the results are not regularly
good because of axis deviation and shortening.
Nails, even of the highest diameter possible, are
too elastic. In these circumstances, we have to
choose between Titanium and Stainless Steel.
1. E-Modulus Titanium 110 GPa (Iso
5832-11) Stainless Steel 200 GPa (Iso
5832-1D) Titanium is approximativly twice as
elastic as steel
Case 3
Biomechanical differences between Titanium and
Stainless Steel
We have to consider three characteristics 1.
E-modulus 2. Bending stiffness 3. Reduction
forces at the fracture site
2. Bending Stiffness

• Bending stffness depneds to
• The E-modulus which is 110 Gpa for Titanium and
• 200 GPa for Stainless Steel
• -The Fourth power of the diameter

To have the highest stiffness, first choose the
highest diameter of elastic nail. And if it is
not possible to increase the diameter, choose
Stainless Steel instead of Titanium. Changing
Titanium to Stainless Steel is equivalent of an
increase of 0,5 mm of diameter. For example, in
the table, you can see that a 3,5 mm nail of
Titanium has a stiffness of 810 Nmm², which is
quite equivalent of a nail of 3,0mm of Stainless
Steel (795 Nmm²)
3. Reduction forces
At the fracture site, for the same pre-bending,
the reaction force of the nail is doubled with
Stainless Steel
Conclusions

• For young children, results are excellent with
  titanium or stainless steel
• For heavy adolescents, it would be better to
  choose stainless steel because it is less elastic
  and the reduction forces are doubled
• Choosing stainless steel instead of titanium is
  mechanically equivalent of having a titanium nail
  with an increase of 0.5mm of diameter