We recorded anterior-posterior force-versus-displacement curves at 20
and 90 degrees of flexion preoperatively and three years after major
ligament reconstruction in patients with documented absence of the anterior
cruciate ligament. Patients who had an extracapsular stabilization
procedure alone showed no significant changes in laxity or stiffness of the
injured knee in either position of flexion. Those who underwent
reconstruction of the absent anterior cruciate ligament utilizing the
middle or medial one-third of the patellar ligament in addition to the
extracapsular procedure showed a significant decrease in anterior laxity
and increase in anterior stiffness of the injured knee at 20 degrees of
flexion. These changes in stability were not observed at 90 degrees of
flexion. Six patients with a cruciate substitution had improved laxity and
stiffness values at one year postoperatively which were unchanged at three
years. At three-year follow-up the increases in activity scores, decreased
feelings of giving-way and pain, and elimination of the pivot shift were
comparable in both groups of patients.