Posterior cruciate ligament is twisted and flat structure: new prospective on anatomical morphology
This cadaveric study aimed to elucidate PCL morphology by observing the anatomical relationship with other structures and the fibre layers of the PCL in cross section for remnant preserving PCL reconstruction.
Seventeen fresh-frozen cadaveric knees were studied, using the clock-face method to analyse the anatomical relationship between the PCL and Humphrey’s ligament. The width and thickness of the PCL, Humphrey’s and Wrisberg’s ligaments were measured. The PCL was cut sharply perpendicular to the tibia shaft, and the fibre layers were observed in cross section.
The PCL was located between 12 and 4 o’clock in the right knee (8 and 12 o’clock in the left), while Humphrey’s ligament was located between 2 and 4 o’clock in the right knee (8 and 10 o’clock in the left). Humphrey’s ligament at femoral insertion, midsubstance and lateral meniscus insertion averaged 8.7 ± 2.3, 5.9 ± 2.1 and 6.1 ± 2.0 mm, respectively, while the thickness at each level averaged 2.0 ± 1.2, 1.6 ± 0.6 and 1.9 ± 0.6 mm. The width of the PCL at midsubstance and at medial meniscus level averaged 13.3 ± 2.0 and 11.0 ± 1.6 mm, respectively, while the thickness of the PCL averaged 5.4 ± 0.8 and 5.5 ± 1.4 mm. In cross section, multiple, interconnected layers were observed which could not be divided. The main layers at each level were aligned from the posterolateral to the anteromedial aspect and formed a C-shape at the medial meniscus level.
The PCL at midsubstance is flat. PCL appears as a twisted ribbon composed of many small fibres without clearly separate bundles. When remnant preserving PCL reconstruction is performed, it is necessary to take account of not only PCL morphology but also the ligaments of Humphrey and Wrisberg. These findings may affect the PCL footprint and the graft shape in the future remnant preserving PCL reconstruction.
KeywordsPCL Humphrey’s ligament Wrisberg’s ligament Fresh-frozen cadaver Morphology Remnant preserving PCL reconstruction
The authors gratefully thank Maciej Śmiarowski (firstname.lastname@example.org) for taking all photographs.
TK performed the study design, dissections, measurements, interpretation of the data and drafted the manuscript. RS performed the study concept, dissections, interpretation of the data and critical comments on drafting of the manuscript. YG performed the dissections. UZ interpreted the data. BC instructed the dissections. MO was involved in interpretation of data and approved the final manuscript.
Compliance with ethical standards
Conflict of interest
The authors declare that they have no competing interests.
There was no outside funding or grants received that assisted in this study.
This study has been performed in accordance with the ethical standards concerning investigations on human cadavers in Poland.
For this type of article informed consent is not required.
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