Changes in laxity of the reconstructed ACL in professional and recreational athletes

Abstract

Objectives: The aim of the study was to follow up changes of the reconstructed ACL with hamstring graft in male athletes at a time of 3, 6 and 12 months after the surgery. Methods: 218 men at the age of 31.43 ± 8.57 years were tested. All the patients were professional or recreational athletes and suffered the ACL injury during the sport activities. 81 athletes were tested 3 months, 78 - 6 months and 59 - 12 months after the ACL reconstruction with hamstring graft. The knee laxity was measured with motorized and computerized arthrometer during the anteroposterior tibial translation at 20° of knee flexion thus reproducing the Lachman test at forces 134 N, 150 N, 200 N and 250 N. The healthy knees should have not more than 1 mm anteroposterior tibial translation, the partial tear of ACL can be suspected when the side-to-side difference of anteroposterior tibial translation is 1-3 mm. More than 3 mm difference is indicating total ACL tear. Slope of curves of displacement was measured as a unique indicator of the functional instability of the knee. Difference of slopes of curves delta P2 (µm/N) was analysed: delta P2 > 10 - high of risk of functional instability; 5 < delta P2 < 10 - medium and delta P2 < 5 - low risk of functional instability. Data presented in mean ± standard deviation and degree of statistical significance was set at P<0.05. Results: 3 months after the surgery the average of side-to-side difference at 134 N force during the anteroposterior tibial translation was 0.95 ± 1.45 mm. 6 months after the surgery we had similar side-to-side difference - 0.70 ± 1.22 mm. The average of side-to-side difference after the 12 months was 0.43 ± 1.40 mm. Despite the fact that results in the follow-up can be named as "acceptable" - we can conclude that the stability of the knee and the tightness of the ACL graft statistically significant increased. Side-to-side difference of anteroposterior tibial transl. [...].