The anatomic characteristics of the tibial insertion of the posterior cruciate ligament.

PURPOSE The purpose of the study was to better define the tibial insertion of the posterior cruciate ligament (PCL) and to identify landmarks that could be used to aid in placement of independent tibial tunnels for a 2-bundle PCL reconstruction. TYPE OF STUDY Descriptive anatomic study. METHODS Ten knees from 8 cadavers were dissected and the PCL was identified. The ligament was peeled away from its insertion and the sides of the insertion site were measured and recorded. The 4 corners of the insertion site were identified and marked. Observations were made of the morphology of the insertion site and the presence of any reproducible anatomic landmarks. A note was made of landmarks that could be easily identified on all of the specimens by direct vision and by palpation with a probe. RESULTS The ligament consisted of 2 regions, 1 anterolateral, and 1 posteromedial, with a gradual change in the laxity of the ligament as the knee was passed through flexion and extension. The insertion site was situated in a depression between the plateaus of the tibia and extended below the articular surface. The average length +/- standard deviation of the 4 sides was 128 +/- 21.2 mm (medial side), 107 +/- 26.5 mm (superior side), 160 +/- 30.0 mm (lateral side), and 169 +/- 34.5 mm (inferior side). The shape and sides of the insertion site were visually similar among the 10 specimens. The superolateral and superomedial corners were both represented by depressions and a reproducible ridge represented the inferior border. These structures could be visualized as well as palpated on all specimens. CONCLUSIONS Based on the findings of this study, we describe the anatomic characteristics of the tibial footprint of the PCL. Anatomic reference points that represent the corners of the tibial insertion of the PCL were identified by direct vision or palpation consistently on all specimens included in the study. These reference points could potentially aid in the placement of an anterolateral and posteromedial tibial tunnel for a 2 tibial tunnel PCL reconstruction. CLINICAL RELEVANCE Reproducible anatomic reference points exist at the tibial insertion of the PCL that can be identified by direct vision and palpation. These reference points may potentially aid in the placement of separate tibial tunnels for a 2-bundle PCL reconstruction.