Predicting cancellous bone failure during screw insertion

Karen Reynolds, Tammy Cleek, Aaron Mohtar, Trevor Hearn

    Research output: Contribution to journalArticle

    19 Citations (Scopus)

    Abstract

    Internal fixation of fractures often requires the tightening of bone screws to stabilise fragments. Inadequate application of torque can leave the fracture unstable, while over-tightening results in the stripping of the thread and loss of fixation. The optimal amount of screw torque is specific to each application and in practice is difficult to attain due to the wide variability in bone properties including bone density. The aim of the research presented in this paper is to investigate the relationships between motor torque and screw compression during powered screw insertion, and to evaluate whether the torque during insertion can be used to predict the ultimate failure torque of the bone.A custom test rig was designed and built for bone screw experiments. By inserting cancellous bone screws into synthetic, ovine and human bone specimens, it was established that variations related to bone density could be automatically detected through the effects of the bone on the rotational characteristics of the screw. The torque measured during screw insertion was found to be directly related to bone density and can be used, on its own, as a good predictor of ultimate failure torque of the bone.

    Original languageEnglish
    Pages (from-to)1207-1210
    Number of pages4
    JournalJournal of Biomechanics
    Volume46
    Issue number6
    DOIs
    Publication statusPublished - 2013

    Fingerprint Dive into the research topics of 'Predicting cancellous bone failure during screw insertion'. Together they form a unique fingerprint.

  • Cite this