Researchers found patients had increased mechanical properties of tendon healing with early tensional loading after repair surgery for Achilles tendon rupture compared to patients completely immobilized in a cast postoperatively.
“Despite the fact that both groups were allowed full weightbearing on their injured leg, the group with early tensional loading showed a higher modulus of elasticity. We could also confirm earlier results, showing that an early elastic modulus correlates with the heel-raise index after 1 year,” Thorsten Schepull,MD, and colleagues wrote in the study. “However, we could not find any difference in functional outcomes after 1 year between the groups. Short episodes of early tensional loading did not influence tendon length, as measured by the heel-raise height.”
Between February 2009 and October 2011, 35 consecutive patients with acute sports-related Achilles tendon rupture underwent surgical repair with a single suture. Surgeons placed metal markers in the tendon distally and proximally. One group wore a cast for 7 weeks and the other group wore a cast for 2 weeks and used a walking boot for 5 weeks.
Researchers had the walking boot group remove the boot twice daily and push a training pedal to add tensional load to the healing tendon. At 7, 19 and 52 weeks after surgery, researchers tensionally loaded all the patients’ tendons and studied its effect with Roentgen stereophotogrammetric analysis and CT.
The walking boot group had a higher modulus of elasticity at 19 weeks and 52 weeks, Schepull and colleagues noted, but at 52 weeks the Achilles tendon Total Rupture Score and heel-raise index were not significantly different between the groups, according to the results.
One limitation to the study may be the fact that patients and investigators were aware of the treatment used in each group, and the test group could remove the foam boot at times other than during tensional loading, although they were instructed not to, the researchers noted.