Randomized Controlled Trial of All-inside and Standard Anterior Cruciate Ligament Reconstruction about Knee Laxity, Tunnel Widening and MRI-based Fluid Signal within Tunnel

Abstract Purpose: This study focused on the characteristics of the functional, knee laxity, tunnel widening and tunnel fluid signal of all-inside and standard single-bundle anterior cruciate ligament reconstruction (ACLR). Methods: This is a randomized controlled trial. From September 2018 to July 2019, 54 patients were enrolled and randomly assigned to all-inside group (n=27) and standard group (n=27). Followed up at postoperative 3 rd , 6 th , and 12 th month, the International Knee Documentation Committee (IKDC), Visual Analogue Scale (VAS), Lysholm，and Tegner score were recorded. The tunnel widening and tunnel liquid signal were measured by CT and MRI. The knee laxity was assessed by GNRB arthrometer at postoperative 12 th month. Results: The tibial tunnel widening at postoperative 3 rd , 6 th , and 12 th month in all-inside group was significantly less than that in standard group (P < 0.05). There was no statistical difference in femoral tunnel widening between the 2 groups (P > 0.05). At postoperative 3 rd and 6 th month the liquid signal in tibial tunnel between the 2 groups had no statistical difference. The VAS score in all-inside group was lower than the standard group (P < 0.05). There was no significant difference in Tegner, IKDC, and Lysholm score between the 2 groups. At postoperative 12 th month the knee laxity in all-inside group was higher than the standard group (P < 0.05). Conclusions: All-inside single-bundle ACLR can slow down tunnel widening, relieve postoperative pain, and achieve same functional recovery compared with the standard single-bundle ACLR but the knee laxity was relatively higher. Both techniques have the same fluid signal in tibial tunnel in the early postoperative period.