ABSTRACT
Background:
The Proximal Femoral
Nail Antirotation (PFNA)
device is the most commonly used implant to fix unstable femoral
trochanteric fractures (UFTFs), but it has a relatively high
incidence of
complications. Due to this factor, the modified intramedullary
nail (MIN) was created to treat
patients with UFTFs. The aim was to exhibit the MIN and make a comparison with PFNA and InterTAN using biomechanical
methods.
Methods:
An
adult UFTF model was developed using Mimics
software. The PFNA, InterTAN
nail, and MIN models were drawn referring to the corresponding
parameters and installed in the fracture models. Vertical, anteroposterior (AP) bending, and torsion loads of the
femoral head were set in advance and loaded onto the fracture models. The value of maximal displacement and von Mises stress was evaluated via
finite element analysis (FEA).
Results:
The MIN model had smaller values for maximal displacement than that of the PFNA model, and the increase in displacement was less pronounced for the MIN compared to PFNA under increasing vertical loads. For the
indicator of von Mises stress, the MIN model showed lower stress compared with the PFNA model in vertical loads ranging from 300 N to 2100 N. Except for the maximal stress at implants under AP bending loads, the MIN demonstrated the most superior biomechanical properties under AP bending and torsional loads.
Conclusion:
The MIN offered obvious advantages in terms of mechanical stability and stress distribution among the three studied implants, providing a promising implant option for
patients with UFTFs.