Influence of gap size, screw configuration, and nail materials in the stability of anterograde reamed intramedullary nail in femoral transverse fractures

Sergio Gabarre; Jorge Albareda; Luis Gracia; Sergio Puértolas; Elena Ibarz; Antonio Herrera

doi:10.1016/S0020-1383(17)30793-3

Influence of gap size, screw configuration, and nail materials in the stability of anterograde reamed intramedullary nail in femoral transverse fractures

Injury. 2017 Nov:48 Suppl 6:S40-S46. doi: 10.1016/S0020-1383(17)30793-3.

Authors

Sergio Gabarre¹, Jorge Albareda², Luis Gracia³, Sergio Puértolas³, Elena Ibarz³, Antonio Herrera⁴

Affiliations

¹ Department of Mechanical Engineering, University of Zaragoza, Zaragoza, Spain.
² Department of Orthopaedic Surgery and Traumatology, Lozano Blesa University Hospital, Zaragoza, Spain; Aragón Health Research Institute, Zaragoza, Spain; Department of Surgery, University of Zaragoza, Zaragoza, Spain. Electronic address: albaredajorge@gmail.com.
³ Department of Mechanical Engineering, University of Zaragoza, Zaragoza, Spain; Aragón Institute for Engineering Research, Zaragoza, Spain.
⁴ Aragón Health Research Institute, Zaragoza, Spain; Department of Surgery, University of Zaragoza, Zaragoza, Spain.

PMID: 29162240
DOI: 10.1016/S0020-1383(17)30793-3

Abstract

Femoral shaft fractures are among the most severe injuries of the skeleton. They are associated with high morbidity and mortality. The most appropriate treatment depending on the type of fracture and location level should be chosen. A finite element model of the femur has been developed, analyzing various types of fractures in the subtrochanteric and diaphyseal supracondylar area, with several gap sizes, being stabilized with a single combination of screws for the intramedullary nail. The mechanical strength of the nail against bending and compression efforts was studied comparing two materials for the nail: stainless steel and titanium alloy. Beside the finite elements (FE) simulations, a clinical follow-up was carried out, considering a sample of 55 patients, 24 males, and 31 females, with mean age of 52.5 years. Localizations of fractures were 22 in the right femur and 33 in the left one, respectively. A good agreement between clinical results and the simulated fractures in terms of gap size was found. Non-comminuted fractures have a mean consolidation time of 4.1 months, which coincides with the appropriate mobility at fracture site obtained in the FE simulations, whereas comminuted fractures have a higher mean consolidation period estimated in 7.1 months, corresponding to the excessive mobility at fracture site obtained by means of FE simulations. The obtained results between both nail materials (stainless steel and titanium alloy) show a higher mobility when using titanium nails, which produce a higher rate of strains at the fracture site, amplitude of micromotions and bigger global movements compared to stainless-steel nails. Steel nails provide stiffer osteosyntheses than the titanium nails. In conclusion, anterograde locked nail is particularly useful in the treatment of a wide range of supracondylar fractures with proximal extension into the femoral diaphysis.

Keywords: anterograde reamed nail; femoral fracture; finite element analysis; gap analysis; intramedullary nail; osteosynthesis.

MeSH terms

Biocompatible Materials
Biomechanical Phenomena
Bone Nails
Bone Screws
Female
Femoral Fractures / physiopathology
Femoral Fractures / surgery*
Finite Element Analysis*
Follow-Up Studies
Fracture Fixation, Intramedullary*
Fracture Healing / physiology*
Humans
Male
Materials Testing
Middle Aged
Reproducibility of Results
Treatment Outcome

Substances

Biocompatible Materials