Long vs short intramedullary nails for reverse pertrochanteric fractures: A biomechanical study

Med Eng Phys. 2024 Sep:131:104230. doi: 10.1016/j.medengphy.2024.104230. Epub 2024 Aug 13.

Abstract

There is currently no definitive evidence for the implant of choice for the treatment of reverse pertrochanteric fractures. Here, we aimed to compare the stability provided by two implant options: long and short intramedullary nails. We performed finite element simulations of different patterns of reverse pertrochanteric fractures with varying bone quality, and compared the short vs long nail stabilization under physiological loads. For each variable combination, the micromotions at the fracture site, bone strain, and implant stress were computed. Mean micromotions at the fracture surface and absolute and relative fracture surface with micromotions >150 µm were slightly lower with the short nail (8%, 3%, and 3%, respectively). The distal fracture extension negatively affected the stability, with increasing micromotions on the medial side. Bone strain above 1 % was not affected by the nail length. Fatigue stresses were similar for both implants, and no volume was found above the yield and ultimate stress in the tested conditions. This simulation study shows no benefit of long nails for the investigated patterns of reverse pertrochanteric fractures, with similar micromotions at the fracture site, bone strain, and implant stress.

Keywords: Fem simulation; Intra-medullary nails; Reverse pertrochanteric fractures.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Biomechanical Phenomena
  • Bone Nails*
  • Finite Element Analysis*
  • Fracture Fixation, Intramedullary* / instrumentation
  • Hip Fractures / physiopathology
  • Hip Fractures / surgery
  • Humans
  • Mechanical Phenomena
  • Stress, Mechanical