Evaluation of knee stability before and after participation in a functional sports agility program during rehabilitation after anterior cruciate ligament reconstruction.

We sought to determine whether participation in a functional sports agility program as early as 4 weeks after anterior cruciate ligament reconstruction with autogenous patellar tendon graft would affect objective knee stability in 603 patients. The rehabilitation program prescribed a functional sports agility program at a mean of 5.1 +/- 1.0 weeks postoperatively when full knee hyperextension, knee flexion to 120 degrees, and quadriceps muscle strength of 60% of the normal leg had been achieved. The patients had KT-1000 arthrometer testing before beginning the program and at subsequent follow-up after they had performed the sport activity. The mean manual maximum KT-1000 arthrometer difference was 1.9 +/- 1.3 mm at initial testing and 1.9 +/- 1.2 mm at follow-up testing. The frequency distribution of the KT-1000 arthrometer scores revealed that 92.7% of patients at initial testing and 93.2% of patients at follow-up testing had displacement difference of 3 mm or less. The results of this study show that functional sports agility programs during the early rehabilitation period after anterior cruciate ligament reconstruction with a correctly placed autogenous patellar tendon graft do not cause a change in graft stability.