This in vivo study used MR and dual fluoroscopic imaging to measure knee kinematics during a single-legged lunge. It compared 7 knees with isolated PCL injury before and 2 years after single-bundle reconstruction against the intact contralateral side. The question: can single-bundle PCL reconstruction restore normal tibiofemoral and patellofemoral motion?
A clinically successful PCL reconstruction is not a kinematically normal knee. Single-bundle surgery reliably restores sagittal-plane stability: posterior tibial translation and patellar flexion return to normal, KT-1000 matches the contralateral side, and IKDC nearly doubles. That is why your patient feels good and would do the surgery again.
But the residual 1 mm of increased lateral tibial translation is the part that matters long-term. A sagittal graft cannot control mediolateral position, and this uncorrected translation increases medial compartment cartilage deformation and drives abnormal patellar rotation and tilt.
This offers a mechanism for the 20% to 60% OA rate seen after PCL reconstruction: the joint moves, contacts, and loads abnormally even when it feels stable.
The teaching point is that restoring mediolateral tibial stability may matter as much as anteroposterior stability, which is the rationale behind double-bundle techniques and tibial slope osteotomy. Note this is a 7-patient case series with no nonoperative control, so weight it as mechanistic insight, not a treatment mandate.
This in vivo study used MR and dual fluoroscopic imaging to measure knee kinematics during a single-legged lunge. It compared 7 knees with isolated PCL injury before and 2 years after single-bundle reconstruction against the intact contralateral side. The question: can single-bundle PCL reconstruction restore normal tibiofemoral and patellofemoral motion?
A clinically successful PCL reconstruction is not a kinematically normal knee. Single-bundle surgery reliably restores sagittal-plane stability: posterior tibial translation and patellar flexion return to normal, KT-1000 matches the contralateral side, and IKDC nearly doubles. That is why your patient feels good and would do the surgery again.
But the residual 1 mm of increased lateral tibial translation is the part that matters long-term. A sagittal graft cannot control mediolateral position, and this uncorrected translation increases medial compartment cartilage deformation and drives abnormal patellar rotation and tilt.
This offers a mechanism for the 20% to 60% OA rate seen after PCL reconstruction: the joint moves, contacts, and loads abnormally even when it feels stable.
The teaching point is that restoring mediolateral tibial stability may matter as much as anteroposterior stability, which is the rationale behind double-bundle techniques and tibial slope osteotomy. Note this is a 7-patient case series with no nonoperative control, so weight it as mechanistic insight, not a treatment mandate.