Laxity after cruciate ligament injury in 94 knees. The KT-1000 arthrometer versus roentgen stereophotogrammetry

We examined 94 knees with chronic anterior cruciate ligament injuries, 55 of which had been operated with ligament reconstruction, using the KT-1000 arthrometer (89 N anterior force) and roentgen stereophotogrammetry (RSA, 150 N anterior, 80 N posterior force). In intact knees the tibial displacement did not differ between the methods. In injured knees, operated or not, the KT-1000 recorded smaller AP translations and side-differences than RSA. Thus, the stabilizing effect of reconstructive surgery may be overrated, if evaluated with the standard KT-1000 technique.