The tibial capsular reflection and septum in posterior compartment are safe and reliable soft‐tissue landmark for tibial tunnel drilling in posterior cruciate ligament reconstruction

Abstract Purpose To investigate the validity of using tibial capsular reflection and septum in the posterior compartment as landmark during posterior cruciate ligament (PCL) reconstruction (PCLR). Methods Anatomic measurements were obtained for 12 fresh human cadaveric knee specimens to observe the spatial position of the tibial insertion of the PCL in relation to the posterior septum and the capsular reflection in the posterior compartment. Sixty patients who underwent reconstruction of the PCL between 2020 and 2023 were also retrospectively investigated. The tibial tunnel was replaced in all patients using the same method (with reference to the tibial capsular reflection and the posterior septum). The placement of the tibial tunnel was assessed using X‐ray fluoroscopy intraoperatively and computed tomography and three‐dimensional reconstruction postoperatively. Results All fibres in the tibial insertion of the PCL in the 12 cadaveric specimens were located in the posteromedial compartment, adjacent to the posterior septum. The inferior border of the PCL insertion is adjacent to the tibial capsular reflection, which is attached at the champagne glass drop‐off of the posterior tibia. In our previous cases, none of the patients experienced postoperative or intraoperative complications such as neurovascular injury, and the angle between the pin and the PCL facet was 93.1 ± 3.9° as measured on intraoperative radiographs. The mean distance from the centre of the tibial tunnel outlet to the inferior border of the PCL insertion was 5.6 ± 1.1 mm, and the distance from the centre of the tibial tunnel outlet to the outer border of the PCL insertion as a percentage of the length of the inferior border of PCL insertion was 42.2 ± 6.3%. Conclusion The tibial capsular reflection and septum in the posterior compartment are safe and reliable soft‐tissue landmark for tibial tunnel drilling in PCLR. Level of Evidence Level Ⅳ.