Tibial and Femoral Tunnel Volume Enlargement is Equal with Mixed Graft, Achilles Allograft

A recent study found no significant difference in femoral or tibial tunnel volume enlargement between patients who underwent posterior cruciate ligament (PCL) reconstruction with Achilles allograft or mixed graft.

“The femoral and tibial tunnel volume enlargement caused by single-bundle PCL reconstruction using the remnant bundle preservation technique showed no significant difference between the Achilles allograft and the mixed graft over a short-term follow-up,” the authors wrote in the study. “Furthermore, the overall incidence of tunnel volume enlargement (TVE) in PCL reconstruction in the study was low.”

In the prospective computed tomography study, researchers compared patients who underwent PCL reconstruction with either Achilles allograft or mixed tibialis anterior allograft and hamstring tendon autograft at a single center between 2007 and 2011. The Achilles allograft group had 22 male and five female patients with an average age of 30.6 years old and follow-up of 22.1 months. In the mixed graft group, there were 22 male and seven female patients with an average age of 29 years old and follow-up of 21.2 months.

Overall, the incidence rate of TVE was 3.6 percent for the femoral tunnel and 5.4 percent in the tibial tunnel. The average tunnel volume difference was 12 percent for the femoral tunnel and 10.6 percent for the tibial tunnel. The average femoral TVE for the Achilles allograft group was 10.1 percent and 13.8 percent in the mixed graft group while the average tibial TVE was 9.9 percent in the Achilles allograft group and 11.2 percent in the mixed graft group. Researchers found no significant difference in functional outcomes or posterior laxity.

“We hypothesize that a higher tendon healing potential and delayed postoperative rehabilitation can reduce the incidence and degree of tunnel volume enlargement after PCL reconstruction,” the researchers wrote.