Monday  |  Lakeshore B  |  11:20 AM–11:40 AM

#19778, Achilles Tendon Strain Behavior Before and After Rupture: A Cadaveric Study Using 3D DIC

Achilles tendon (AT) acute ruptures are one of the most common tendon injuries in the adult population, with incidences ranging between 7 and 40 per 100,000 person-years. Athletes especially fear this injury due to the long recovery time, with 4-6 months being typical, and up to 12 months for return of full capability.

In this study, 3D DIC was used to extensively study the strain behavior of Achilles tendons, with the goal of improving patient outcomes after repairs. Baseline measurements were made on each of 12 cadaver lower legs, with incremental insertion and removal of 12 stacking wedges as the loading. A novel weightbearing test fixture was then used to represent the normal standing and walking condition. The tendons were then ruptured at the commonly occurring location of actual injuries, and repaired using the locking suture method. The weightbearing study was then repeated. For 6 of the cadavers, this was supplemented by manual application of varying forces pulling down on the severed tendon.

Prior encouraging DIC data had been obtained on several foot tendons, but the initial patterning method was not robust enough to survive the specimen handling and surgical procedures. An improved technique using Gentian violet dye and tattoo ink was extremely successful. Full-field strain data was obtained along as much as 6 inches of the tendons, from the calcaneous (heel bone) insertion point up to the fanned out region below the gastrocnemius and soleus muscles. Strains on individual fibers were resolved, and important non-linear behaviors were observed.

Timothy Schmidt   Trilion Quality Systems
Sean Bowers   Trilion Quality Systems
Jiyong Ahn   Foot and Ankle Research and Innovation Laboratory
Soheil Ashkani-Esfahani   Foot and Ankle Research and Innovation Laboratory