A biomechanical comparison of tibial inlay and tibial tunnel posterior cruciate ligament reconstruction techniques. Graft pretension and knee laxity

Abstract

Background: Most posterior cruciate ligament reconstruction techniques use a tibial bone tunnel, which results in an acute bend in the graft as it passes over the posterior portion of the tibial plateau. Hypothesis: The tibial inlay technique will result in lower graft pretensions, less laxity, and less stretch-out after cyclic loading. Study Design: Controlled laboratory study. Methods: Graft pretensions necessary to restore normal laxity at 90° of knee flexion (laxity match pretension) and anteroposterior laxities at five knee flexion angles were recorded in 12 fresh-frozen knee specimens with bone-patellar tendon-bone posterior cruciate ligament graft reconstructions using both techniques and two femoral tunnel positions. Results: When the graft was placed in a central femoral tunnel, the tibial tunnel reconstruction required an average 15.6 N greater laxity match pretension than the tibial inlay reconstruction. There were no significant differences in mean knee laxities between the tibial tunnel and tibial inlay techniques at any knee flexion angle; both reconstruction techniques restored mean knee laxity to within 1.6 mm of intact knee values over the entire flexion range. Conclusions: There was no important advantage of one technique over the other with respect to the biomechanical parameters measured.