Objective To localize the tibial attachment of the posterior cruciate ligament (PCL) on the magnetic resonance imaging (MRI) and provide parameters for clinical PCL reconstruction.Methods We retrospectively analyzed 524 patients with intact tibial PCL attachment who had undergone knee MRI from January 2010 to January 2016.They were 286 men and 238 women with an average age of 35 years (from 20 to 50 years).The size and positions of the tibial PCL attachment were measured on the sagittal and coronal MRI slices.The differences were analyzed between different genders.Results On the sagittal slices,the mean distance from the central tibial PCL attachment to the posterior edge of the tibial plateau was 17.9 ± 3.0 mm and the mean anteroposterior diameter of the tibial PCL attachment was 9.7 ± 2.4 mm,with those for males significantly larger than for females (P ＜ 0.05).The above mean values when expressed as a percentage of the posterior tibial slop were 79.9％ ±4.5％ and 43.7％ ± 9.6％,respectively,showing no significant differences between males and females (P ＞ 0.05).On the coronal slices,the distances from the central tibial PCL attachment to the medial and lateral edges of the tibial plateau were 33.5 ± 3.1 mm and 37.4 ±4.1 mm,respectively,and the mediolateral diameter of the tibial PCL attachment was 12.0 ± 1.6 mm,with those for males significantly larger than for females (P ＜ 0.05).The above mean values when expressed as a percentage of the mediolateral diameter of the tibial PCL attachment were 47.4％ ± 3.2％,52.7％ ±3.1％ and 16.9％ ± 1.7％,respectively,showing no significant differences between males and females (P ＞ 0.05).Conclusions On knee MRI images,the distance from the central tibial PCL attachment to the posterior edge of the tibial plateau is about 17.9 mm,the anteroposterior diameter of the tibial PCL attachment around 9.7 mm,and the mediolateral diameter of the tibial PCL attachment roughly 12.0 mm.These measurements for males are larger than for females.

Posterior cruciate ligament (PCL) injury is common in sports medicine. Arthroscopic reconstruction of PCL has become a routine procedure to stabilize the knee joint after PCL injury. The location of tibial tunnel during operation is crucial to a successful surgery. This article reviews the current studies on transtibial PCL reconstruction from the aspects of the anatomy related to the tibial tunnel, the anteromedial and anterolateral tibial tunnels, the maximum angle and optimal angle of tibial tunnel, and the anatomical and non-anatomical tibial tunnels, hoping to provide helpful references for the treatment of PCL injury.

Objective:To measure the anatomical parameters of the simulated low tibial tunnel of posterior cruciate ligament (PCL) based on knee CT images so as to provide clinical reference for accurate location of the tunnel.Methods:The CT images of 201 healthy knee joints collected at Department of Orthopedics, The Second Hospital of Lanzhou University from June 2016 to September 2021 were used for simulation of the PCL low tibial tunnel. The anatomical parameters of the tibial tunnel were measured using the RadiAnt DICOM Viewer. The primary measures included the angle between tibial plateau and tibial tunnel (ATPT) and the perpendicular distances from the tibial tunnel entrance and exit point to the tibial plateau (L1 and L2). The secondary measures included the angle between tibial plateau and posterior slope (PSA), the angle between tibial anatomical axis and central line of tibial tunnel (ATAA), the angle between posterior tibial slope line and the central line of tibial tunnel (APST), the anterior and posterior diameter of tibial plateau (APD), the length of posterior tibial slope (LPTS), and the length of tibial tunnel (LTT). The measurement results were analyzed according to the body height (divided into 3 groups: a 1.00 to 1.60 m group, a 1.61 to 1.70 m group, and a ≥1.71 m group) and gender using the software IBM SPSS 26.Results:The primary measures: ATPT was 37.0°±4.5°, and L1 and L2 were respectively (57.8±7.4) mm and (34.5±3.3) mm. The secondary measures: PSA 128.1°±5.4°, ATAA 52.7°±4.1°, APST 89.1°±5.9°, APD was (32.9±2.6) mm, LPTS (20.5±2.4) mm, and LTT (40.9±5.7) mm. After grouping by gender, there was no significant difference in PSA between men and women ( P>0.05) while there were significant differences in the other indexes between men and women ( P<0.05). After grouping by body height, there was no significant difference in ATPT, PSA, APST or ATAA between the 3 groups (1.00 to 1.60 m group, 1.61 to 1.70 m group and ≥1.71 m group) ( P>0.05) while there were significant differences in L1, L2, APD, LPTS and LTT between the 3 groups ( P<0.05). Conclusions:Based on the knee CT images, the primary measures of PCL low tibial tunnel are as follows: the angle between tibial plateau and tibial tunnel is 37.0°±4.5°, and the perpendicular distances from the tibial tunnel entrance and exit point to the tibial plateau are (57.8±7.4) mm and (34.5±3.3) mm, respectively. Gender and body height are the important factors influencing the above measurement outcomes.

Objective:To compare the efficacy of open surgery and arthroscopic assisted surgery in treatment of knee dislocations.Methods:A retrospective case-control study was conducted to analyze the clinical data of 80 patients with knee dislocations admitted to Second Hospital of Lanzhou University from May 2013 to September 2019, including 59 males and 21 females, aged 18-66 years [(42.5±11.6)years]. Open multiple ligament reconstruction was performed in 49 patients (open group) and arthroscopic assisted multiple ligament reconstruction was performed in 31 patients (arthroscopic group). The postoperative hospitalization days, incidence of complications, time needed for recovery of knee range of motion (>0°, >90°, >120°), and time to complete weight-bearing were compared between the two groups. The Lysholm score, international knee documentation committee (IKDC) subjective knee form, Tegner activity level, score of the MOS item short-form health survey (SF-36), patient satisfaction and knee range of motion were compared between the two groups at the last follow-up.Results:All the patients were followed up for 1.2-7.4 years [(3.8±1.5)years]. There was no significant difference in postoperative hospitalization days or incidence of complications between the two groups ( P>0.05). No significant difference was found in time needed for recovery of knee range of motion (>0°, >120°) or time to complete weight-bearing ( P>0.05). The time needed for recovery of knee range of motion (>90°) was 90(60, 90)days in open group and 60(30, 90)days in arthroscopic group ( P<0.05). At the last follow-up, there was no significant difference in Lysholm score, IKDC subjective score, Tegner activity level, SF-36 score, or patient satisfaction between the two groups ( P>0.05). At the last follow-up, the knee range of motion was 120°(90°, 130°) in open group and 135°(120°, 140°) in arthroscopic group ( P<0.05). Conclusion:For treatment of knee dislocations, open surgery and arthroscopic assisted surgery have similar results in the long-term effect, while arthroscopic assisted surgery has benefits in early rehabilitation and ultimately better knee range of motion.

The main function of anterior cruciate ligament (ACL) is to maintain stability of the knee joint and prevent anterior displacement of the tibial plateau. ACL injury accounts for more than 50% of the knee joint injuries. If not timely handled, it will increase the risk of secondary injuries to structures such as the meniscus and cartilage, causing chronic pain and degeneration of the knee joint. Although most ACL injuries can be determined by their direct signs on MRI, the identification of complex situations and partial tears of ACL are still not satisfactory, which subsequently affects treatment strategies. After ACL injury, changes in anatomical relationship of the knee joint can also lead to morphological changes in other structures such as the posterior cruciate ligament (PCL) on MRI, and these indirect signs can assist in the diagnosis of ACL injury. The authors reviewed the application of MRI-related indicators of PCL in diagnosing ACL injury, hoping to provide references and new ideas for clinical decision-making.