Mechanical Effects of Lag Screw Retightening in a Simulated Hindfoot Arthrodesis Model.

ABSTRACT:

Background

Nonunion following hindfoot arthrodesis may be caused by failure to maintain compression at the arthrodesis site. The ability of lag screws, commonly used in arthrodesis, to maintain compression in hindfoot bones has not been well characterized. The aim of this work was to quantify the stress relaxation response of hindfoot bone with initial and repeated compression with a lag screw.

Methods

Ten sets of 25-mm-diameter bone cylinders were cut from the talus and calcaneus in fresh-thawed cadaveric feet. A load cell was compressed between cylinders with an 8.0-mm partially threaded cannulated lag screw simulating arthrodesis. For 7 sets, screws were tightened by 3 quarter-turns, rested for 3 minutes, retightened 1 quarter-turn, and rested for 30 minutes. Three sets s

SUBMITTER: Rugg AL 

PROVIDER: S-EPMC8702740 | biostudies-literature | 2021 Apr

REPOSITORIES: biostudies-literature