We tested four types of surgical
repair for load to failure and distraction in a bovine model of
Achilles tendon repair. A total of 20 fresh bovine Achilles tendons
were divided transversely 4 cm proximal to the calcaneal insertion
and randomly repaired using the Dresden technique, a Krackow suture,
a triple-strand Dresden technique or a modified oblique Dresden
technique, all using a Fiberwire suture. Each tendon was loaded
to failure. The force applied when a 5 mm gap was formed, peak load
to failure, and mechanism of failure were recorded. The resistance
to distraction was significantly greater for the triple technique
(mean 246.1 N (205 to 309) to initial gapping) than for the Dresden (mean
180 N (152 to 208); p = 0.012) and the Krackow repairs (mean 101
N (78 to 112; p <
0.001). Peak load to failure was significantly
greater for the triple-strand repair (mean 675 N (453 to 749)) than
for the Dresden (mean 327.8 N (238 to 406); p <
0.001), Krackow
(mean 223.6 N (210 to 252); p <
0.001) and oblique repairs (mean
437.2 N (372 to 526); p <
0.001). Failure of the tendon was the
mechanism of failure for all specimens except for the tendons sutured using
the Krackow technique, where the failure occurred at the knot. The triple-strand technique significantly increased the tensile
strength (p = 0.0001) and gap resistance (p = 0.01) of bovine tendon
repairs, and might have advantages in human application for accelerated
post-operative rehabilitation