Biomechanics Research Today is a free monthly online journal that collates and summarizes the latest research about Biomechanics, including details on mechanics of living organisms, movement, locomotion, prosthetic limbs.

Syndesmosis fixation: analysis of shear stress via axial load on 3.5-mm and 4.5-mm quadricortical syndesmotic screws.

Hansen M, Le L, Wertheimer S, Meyer E, Haut R

St. John North Shores Hospital, 26755 Ballard Road, Harrison Township, MI 48045, USA. mphansen43@hotmail.com

The effect of shear stress on a fixated distal syndesmosis of the ankle was evaluated with a servohydraulic materials-testing machine. Eighteen syndesmoses were fixated in a quadricortical technique using 3.5-mm cortical and 4.5-mm cortical stainless steel screws. A shear stress was applied via an axial load in an attempt to simulate weightbearing. The 4.5-mm quadricortical screws produced a higher yield load and peak load (484.3 +/- 93.8 N and 597.7 +/- 81.4 N) when compared with the 3.5-mm quadricortical syndesmotic screws (412.8 +/- 55 N, P = .033 and 511.2 +/- 64.4 N). These findings suggest that a larger diameter screw provides greater resistance to an applied shear stress at the distal syndesmosis.

Published 3 March 2006 in J Foot Ankle Surg, 45(2): 65-9.
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