Objective:To compare the clinical efficacies between arthroscopic anatomic single bundle reconstruction of posterior cruciate ligament (PCL) assisted by internal tension relieving technique combined with rapid rehabilitation and anatomic single bundle reconstruction combined with conventional rehabilitation in the treatment of PCL rupture.Methods:A retrospective cohort study was used to analyze the clinical data of 88 patients with PCL rupture admitted to First Affiliated Hospital of Kunming Medical University from September 2016 to September 2020. The patients included 65 males and 23 females, aged 18-55 years [(39.3±10.8)years]. Forty-four patients underwent arthroscopic anatomic single bundle reconstruction of PCL assisted by internal tension relieving technique combined with rapid rehabilitation therapy (tension-relieving group), and 44 patients underwent arthroscopic routine anatomic single bundle reconstruction of PCL combined with conventional rehabilitation (traditional group). The two groups were compared before and at 3, 12, and 24 months after surgery regarding the following items: International Knee Literature Committee (IKDC) score, Hospital for Special Surgery (HSS) score, Lysholm score, knee motion cycle (maximum stride length, minimum stride length, and stride frequency) and 6 kinematic indicators (angle of forward and back extension, angle of internal and external rotation, angle of internal and external rotation, up and down displacement, internal and external displacement, and forward and back displacement). The Marburger arthroscopy score (MAS) and Professor Ao Yingfang′s improved score by secondary arthroscopy were compared between the two groups at 12 months after surgery. The perioperative complications were observed.Results:All patients were followed for 24-36 months [(25.5±6.3)months]. In tension-relieving group and the traditional group, the values of IKDC score were (71.8±9.8)points and (68.5±6.5)points at 3 months after surgery, (87.6±6.0)points and (87.6±5.5)points at 12 months after surgery, and (95.5±3.1)points and (92.8±11.6)points at 24 months after surgery, respectively. The values were gradually increased, significantly higher than those before surgery [(48.1±16.9)points and (47.1±15.0)points] (all P<0.05). There were no significant differences between the two groups at each time point (all P>0.05). In tension-relieving group and the traditional group, the values of HSS score were (74.2±6.2)points and (68.4±9.5)points at 3 months after surgery, (91.9±5.4)points and (88.4±4.7)points at 12 months after surgery, and (97.1±2.0)points and (96.2±2.8)points at 24 months after surgery, respectively. The values of HSS score gradually increased, significantly higher than those before surgery [(57.5±17.7)points and (56.8±14.3)points] (all P<0.05). At 3 and 12 months after surgery, the values of HSS score in the tension-relieving group were significantly higher than those in the traditional group (all P<0.05), but others were not significantly different between the two groups (all P>0.05). In tension-relieving group and the traditional group, the values of Lysholm score were (74.2±14.9)points and (70.3±7.5)points at 3 months after surgery, (90.9±6.1)points and (88.7±4.7)points at 12 months after surgery, and (96.9±3.0)points and (96.3±2.8)points at 24 months after surgery, respectively. The values of Lysholm score were gradually increased, significantly higher than those before operation [(48.7±20.7)points and (48.2±19.9)points] (all P<0.05). There were no significant differences between the two groups at any time points (all P>0.05). At 3, 12, and 24 months after surgery, the motion cycle (maximum stride length, minimum stride length and stride frequency) and 6 kinematic indicators (angle of forward bending and backward extension, angle of internal and external rotation, angle of internal and external rotation, internal and external displacement, up and down displacement, and forward and backward displacement) of knee joint were significantly improved in both groups compared with those before surgery (all P<0.05). At 3, 12, and 24 months after surgery, the forward and backward displacement in the tension-relieving group was significantly decreased than that in the traditional group (all P<0.05), but others were not significantly different between the two groups (all P>0.05). The MAS was rated as excellent to good in 14 patients and fair to poor in 2, with the excellent and good rate of 87.5% (14/16) in the tension-relieving group, while the score was rated as excellent to good in 11 patients and fair to poor in 3, with the excellent and good rate of 78.6% (11/14) in the traditional group ( P>0.05). The Professor Ao Yingfang′s improved score was (10.6±1.5)points in the tension-relieving group, markedly higher than that in the traditional group [(9.6±2.3)points] ( P<0.05). No perioperative complications were observed. Conclusion:Compared with anatomic single bundle reconstruction combined with conventional rehabilitation, arthroscopic anatomic single bundle reconstruction of PCL assisted by internal tension relieving technique combined with rapid rehabilitation have higher subjective function score, better anteroposteric stability during knee movement, and better results of secondary microscopy.