Page 240 - Advances in Biomechanics and Tissue Regeneration

236 11. ANALYSIS OF THE BIOMECHANICAL BEHAVIOR OF INTRAMEDULLARY NAILING

FIG. 11.27 Global movement of the top of the nail (mm), for the “B” study, corresponding to different nail materials: (A) steel intramedullary nail;
(B) titanium intramedullary nail.

11.5 CONCLUSIONS

Different FE models have been developed, on the one hand, to analyze various types of fractures in the subtrochan-
teric and diaphyseal supracondylar area with several gap sizes, stabilized with a single combination of screws for the
intramedullary nail, and, on the other hand, to characterize the stability of different interlocking systems and identify
the optimal one for every type of fracture in the distal location. In addition, the mechanical strength of the nail against
bending and compression efforts was studied comparing two nail materials: stainless steel and titanium alloy.
The results of the FE simulations were compared with a set of clinical cases included in the clinical follow-up. In this
way, the following conclusions were obtained:

• A good agreement between clinical results and the simulated fractures in terms of gap size was found.
Noncomminuted fractures have a minimum mean consolidation time (4.1months), which coincides with
appropriate mobility at the fracture site obtained in the FE simulations, whereas comminuted fractures have a
higher mean consolidation period (7.1months), corresponding to excessive mobility at the fracture site obtained by
means of FE simulations. The healing time rises as the comminution grade increases.

I. BIOMECHANICS