Thick graft vs. double-bundle technique on posterior cruciate ligament reconstruction: experimental biomechanical study with cadavers

Abstract

ObjectiveTo evaluate the biomechanical effect of graft thickness compared to the double-bundle technique on posterior cruciate ligament (PCL) reconstruction in human cadaveric knees. MethodsNine human cadaveric knees were tested in five conditions: intact knee (INT), single-bundle reconstruction with a 10mm-quadriceps tendon (SB); double-bundle reconstruction with a 10mm-quadriceps tendon for the anterolateral bundle and a 7-mm doubled semitendinous tendon for the posteromedial bundle (DB); single-bundle reconstruction with a 10-mm quadriceps tendon plus a 7-mm doubled semitendinous tendon (SBT); and PCL-deficient (NoPCL). Posterior tibial translation (PTT) was measured in response to a 134N posterior tibial load at 0°, 30°, 60°, and 90° of knee flexion. ResultsThe PTT of the DB and SBT techniques was always significantly lower (better stability) than the PTT of the SB technique. The PTT of SBT technique was significantly lower than the PTT of the DB technique at 60° (p=0.005) and 90° (p=0.001). ConclusionsGraft enlargement improves knee stability in isolated PCL reconstructions, whereas the graft division in the two-bundle technique worsens this stability at 60° and 90° of knee flexion. The findings of this study suggest that knee stability in PCL reconstructions may be improved with the use of thicker grafts in a single-bundle technique rather than performing a double-bundle reconstruction.