To investigate the safety, early effectiveness and return-to-sport outcomes of all-inside peroneus longus tendon reconstruction and compare with anatomic single-bundle reconstruction of hamstring tendon in the treatment of anterior cruciate ligament (ACL).

From January 2021 to December 2022, 110 patients who were diagnosed with ACL injury and operated by the same surgeon in Changhai Hospital were prospectively analyzed. Inclusion criteria: ACL injury and no previous knee surgery history, willing to undergo all-inside peroneus longus tendon reconstruction or anatomical single-bundle hamstring tendon reconstruction, and able to be followed up regularly. According to the random number table method, they were divided into two groups. Fifty-five patients underwent total internal reconstruction of peroneus longus tendon (experimental group), aged from 24 to 40 years. Fifty-five patients underwent traditional hamstring tendon reconstruction (conventional group), with age from 27 to 40 years.The time of tendon harvesting, diameter of graft, and operation time were recorded. Lysholm score, International Knee Documentation Committee (IKDC) score, Tegner score, visual analogue scale (VAS) score, and American Foot and Ankle Society (AOFAS) score were evaluated before operation and at three, six, nine months, andone year after operation. Ligs knee relaxation test and return-to-sport evaluation were performed at one year after surgery. Independent sample t test was used for comparison of normal measurement data between groups, and repeated measurement variance was used for comparison within multiple time points. Mann-Whitney U rank sum test was used for comparison of non-normal measurement data between groups, Friedman test was used for comparison of multiple time points, and Wilcoxon rank sum test was used for comparison of two time points. Chi square test was used to compare count data between groups, and Mann-Whitney U rank sum test was used to compare rank data between groups.

The diameter of grafts in the experimental group was significantly larger than that in the conventional group(Z=-6.636, P<0.001), and the time of tendon harvesting was significantly shorter (Z=-9.304, P<0.001). At one year after operation, IKDC score(H=115.018, 105.664, both P<0.001), Lysholm score(H=120.783, 136.202, both P<0.001), Tegner score(H=98.690, 105.467, both P<0.001), and knee relaxation test(F=304.276, 373.941, both P<0.001) of the two groups were significantly improved when compared with those before operation, there was no statistically significant difference between the two groups (all P>0.05). At three and six months after operation, VAS in the experimental group was lower than that in the conventional group(Z=-2.358, -2.007, both P<0.05), but there was no statistically significant difference between the two groups at one year after operation(P>0.05). At one year after operation, the proportion of patients who passed the return-to-sport test in the experimental group was higher than that in the conventional group, and the difference was statistically significant (χ²=4.406, P=0.036).

Both all-inside peroneus longus tendon reconstruction and conventional hamstring tendon reconstruction can restore knee stability and significantly improve knee function at one year after operation. But the all-inside reconstruction graft of peroneus longus tendon has larger diameter, shorter time for harvesting tendon, milder early postoperative pain, it may be more beneficial for patients returning to sports after surgery.