Evaluation kinaesthetic proprioceptive deficit after knee anterior cruciate ligament (ACL) reconstruction in athletes

PURPOSE: The objective of this study was to evaluate kinaesthetic proprioceptive deficit after knee anterior cruciate ligament (ACL) reconstruction in two populations of athletes, those in the post-surgery period and those in re-training during the intensive program-training phase. METHODS: We performed a prospective study in ACL-operated athletes without previous knee injuries, with 32 athletes in each group. Time since surgery in the operated athletes in the post-surgery group was 21 to 35 days, and between three and 9 months in the re-training group. We also analysed a control group of 32 uninjured non-operated subjects with a similar sporting level. Proprioception was evaluated using the threshold to detection of passive motion (TDPM) test with Biodex-type isokinetic equipment comparing operated knees, non-operated knees and control uninjured non-operated group. The control group was tested twice, 1 day apart to control reproducibility, using the intraclass correlation coefficient (ICC). The p-value threshold for statistical significance between different groups in hypothesis testing was <.05. RESULTS: TDPM reproducibility was excellent (right knee: ICC = 0.80, left knee: ICC =0.72). We found a bilateral kinaesthetic deficit in post-surgery patients compared to the control group (p < 0.001 and p = 0.011), which was significantly higher on the operated side (p = 0.001). Re-training patients had no significant difference between operated and uninjured knees, but had a kinaesthetic deficit on operated limbs (p = 0.036) compared to the control group. CONCLUSION: There was a bilateral deficit in post-surgery athletes with a significant difference between injured and healthy knees, which could be explained by a change in the central nervous system. Compared to the control group, a proprioceptive deficit was only seen for re-training patients on the operated side and not in the healthy limb. Kinaesthetic recovery may be faster for the uninjured side as initial deficit is lower. Level of evidence II.