The effect of exercise and rehabilitation on anterior-posterior knee displacements after anterior cruciate ligament autograft reconstruction

We studied the effect of rehabilitation strength training and return to act ivities on anterior-posterior knee displacements after patellar tendon auto genous anterior cruciate ligament reconstruction. A total of 938 measuremen ts were sequentially collected for 142 patients with the KT-2000 arthromete r. Rehabilitation included immediate knee motion and early weightbearing, l ight sports at 6 months, and competitive sports at 8 months or later. At a minimum of 2 years after surgery, 121 patients (85%) had normal displacemen ts (less than 3 mm of increase at 134 N), 14 (10%) had 3 to 5.5 mm of incre ase (partial function), and 7 (5%) had more than 5.5 mm of increase (failed ), There was no association found between the initial onset of the abnormal displacements in the 21 knees and either the amount of time after surgery or the rehabilitation program. Six of the seven grafts that failed did so i n the Ist postoperative year. Serial displacement measurements allow early detection of graft stretching and subsequent modification of rehabilitation or delay in return to strenuous activities. These measurements showed that the rehabilitation program used in this study was not itself injurious and resulted in an acceptable failure rate of 5%.