Intact PCL is a potential predictor of ACL graft size in the skeletally immature knee and other anatomic considerations for ACL reconstruction

Abstract

Purpose To develop a method for using an intact posterior cruciate ligament (PCL) as a predictor of anterior cruciate ligament (ACL) graft size and examine possible differences in tunnel length based on all-epiphyseal drilling method. Methods One hundred one patients 5–18 years of age with magnetic resonance imaging (MRI) of the knee at an outpatient pediatric orthopaedic clinic from 2008 to 2020 were included. ACL and PCL coronal, sagittal, and length measurements were made in all patients. Tunnel length measurements were made in patients with open physes. Statistical analyses were performed to evaluate potential associations in patient bony or ligamentous measurements. Results PCL sagittal width and PCL coronal width were statistically significant predictors of ACL sagittal width and ACL coronal width, respectively (p = 0.002, R = 0.304; p = 0.008, R = 0.264). The following equations were developed to calculate ACL coronal and sagittal width measurements from the corresponding measurement on an intact PCL; ACL Coronal Width (mm) = 6.23 + (0.16 x PCL Coronal Width); ACL Sagittal Width (mm) = 5.85 + (0.53 x PCL Sagittal Width). Mean tibial maximum oblique length (27.8 mm) was longer than mean tibial physeal sparing length (24.9 mm). Mean femoral maximum oblique length (36.9 mm) was comparable to mean femoral physeal sparing length (36.1 mm). Both were longer than mean femoral straight lateral length (32.7 mm). Conclusion An intact PCL is a predictor of native ACL size. Tunnel length differs based on chosen drilling method in all-epiphyseal technique. Level of evidence Diagnostic Level III.

Anatomical Examination of The Ligamentum Cruciatum Posterior in Human Fetus

“…In the imaging study performed on 758 children aged 5-18 years, Heath et al (2022) formulated that the thickness of the ACL in the coronal plane was 0.16 times and plus 6.23 (mm) of the thickness of the PCL in the coronal plane, and the thickness in the sagittal plane was 0.53 times and plus 5.85 (mm) of the thickness of the PCL in the same plane. They also calculated that the ACL/PCL height ratio increased with age [33]. In their study, Kim et al (2021) examined the relationship between PCL and ACL dimensions in 400 children aged 13-18 years.…”

A Novel Predictor of the Length and Size of ACL Grafts in Chinese Han Adults for ACL Reconstruction: An MRI Study

“…All measurements were performed on T2‐weighted MR images. All data were rounded to two decimal places, and the sagittal and coronal diameters of the ACL and PCL were measured in the middle part of the ligament by two doctors (at the level of the largest ligament diameter, the width of the hypodense shadow in the middle of the ligament insertion site perpendicular to the long axis of the ligament was measured, with ACL and PCL measured at different levels on MRI) 29 …”

“…All data were rounded to two decimal places, and the sagittal and coronal diameters of the ACL and PCL were measured in the middle part of the ligament by two doctors (at the level of the largest ligament diameter, the width of the hypodense shadow in the middle of the ligament insertion site perpendicular to the long axis of the ligament was measured, with ACL and PCL measured at different levels on MRI). 29 Measurements of the following variables were made: (1) length, sagittal, and coronal diameters of the ACL and (2) length, sagittal, and coronal diameters of the PCL. The ACL length was measured from the most postero superior point of the femoral origin to the mid substance of the tibial insertion; the length of the PCL was measured from the midpoint of the PCL hypointense shadow at the junction with the tibia to the midpoint of the PCL hypointense shadow at the junction with the femur.…”

“…A study showed that, in populations with open physes, the sagittal and coronal diameters of the intact PCL are potential predictors of the sagittal and coronal diameters of the ACL, respectively. 29 However, there has been no study on this matter in adults. Another study showed that preoperative magnetic resonance imaging (MRI) can be used to predict the size of ACL grafts intraoperatively, 30 but there is no method to predict the size and length of grafts in patients to facilitate the most successful outcomes with ACL-R.…”

“…Accordingly, the primary issue to address was whether the nearly natural, intact PCL may be used as a predictor of the native ACL. A study showed that, in populations with open physes, the sagittal and coronal diameters of the intact PCL are potential predictors of the sagittal and coronal diameters of the ACL, respectively 29 . However, there has been no study on this matter in adults.…”