THE DISTANCE BETWEEN TIBIAL PHYSIS AND CORONARY LIGAMENT: A PEDIATRIC CADAVERIC STUDY
Authors: Dingel Aleksei , Karius Alexander , Boucher Laura C. , Yen Yi-Meng , Ganley Theodore J. , Wilson Philip L. , Ellis Henry B. , Fabricant Peter D. , Tompkins Marc , Shea Kevin 
Published: March 2019

Background: Meniscal injuries in the skeletally immature have been increasingly reported. Many meniscal repair surgeries involve the approximation of the meniscus tissue to the peripheral meniscus capsule. This peripheral fixation may not be ideal for some meniscus tear patterns, and may contribute to ‘peripheralization’ of the meniscus during the healing process, which may alter the weight bearing distribution function of the meniscus/articular cartilage complex. Surgical procedures that do not periperalize the meniscus are being developed, which may better replicate the normal meniscus anatomy. Purpose: The primary purpose of this study was to evaluate the coronary ligament attachments of the meniscus, and how this may influence further development of anatomic repair techniques and implants to address meniscus injury. The secondary purpose of this study was to determine the distance between the tibial insertion of the coronary ligament and the proximal tibial physis. Methods: 10 skeletally immature knee cadaver specimens between the ages of 3 months and 11 years (3 female, 7 male) were included in this study. Prior to CT, pins were placed in the tibias marking the coronary ligament insertion at designated points surrounding both the medial and lateral menisci (Figure 1). Using OsiriX, a medical imaging software, the distances between the proximal tibial physis and the coronary ligament insertion sites were measured at 10 points (5 lateral: anterior root, 12 o’clock, 3/9 o’clock, 6 o’clock, and posterior root, and 5 medial: anterior root, 12 o’clock, 3/9 o’clock, 6 o’clock, and posterior root). Axial view was used confirm proper pin measurement and the measurements were gathered in either the sagittal and coronal view depending on the pin’s placement. The specimen were divided into two groups for analysis- Group 1: ages 3 months- 2 years, Group 2: ages 10-11 years. Results: Medial Meniscus The average distance from the proximal tibial physis to the posterior medial root of the coronary ligament was 0.48 ± 0.08 cm and 1.02 ± 0.10 cm for Group 1 and Group 2, respectively. The average distance from the physis and the 6 o’clock pin was 0.37 ± 0.19 cm and 0.78 ± 0.23 cm. The average distance from the physis and the 3/9 o’clock pin was 0.32 ± 0.13 cm and 0.73 ± 0.22 cm. The average distance from the physis to the 12 o’clock pin was 0.14 ± 0.22 cm and 0.65 ± 0.45 cm. The average distance from the physis to the anterior pin was 0.21 ± 0.30 cm and 1.01 ± 0.62 cm. Lateral Meniscus The average distance from the proximal tibial physis to the posterior lateral root of the coronary ligament was 0.48 ± 0.11 cm and 1.62 ± 0.29 cm for Group 1 and Group 2, respectively. The average distance from the physis and the 6 o’clock pin was 0.38 ± 0.16 cm and 1.72 ± 0.25 cm. The average distance from the physis and the 3/9 o’clock pin was 0.17 ± 0.15 cm and 0.1.41 ± 0.19 cm. The average distance from the physis to the 12 o’clock pin was -0.04 ± 0.20 cm and 0.60 ± 0.14 cm. The average distance from the physis to the anterior pin was 0.16 ± 0.07 cm and 0.31 ± 0.16 cm. Conclusions: Our results show an increase in the distance between the proximal tibial physis and the insertion points of the coronary ligament as age increases. For all measurements, medial and lateral, Group 1 (the younger specimen’s) tibial insertion of the coronary ligament was less than 1 cm away from the physis. Group 2’s coronary ligament insertion points were further away from the physeal line, however still less than 2 cm away, and sometimes even as close as <0.5 cm (anterolateral root). As this data shows the close proximity of the physis and coronary ligament attachements on the meniscus, they confirm the need for the development of anatomic repair techniques and implants that are mindful of the growth plate and avoid physeal injury. Clinical Significance: This study of pediatric cadaveric specimens allowed for direct visualization of the coronary ligament anatomy on the tibia. This information is clinically significant as it detailed the developmental pattern of coronary ligament anatomy in pediatrics and can be used by surgeons performing meniscal injury reconstructions and repairs in patients with open physes. [Figure: see text]