ANATOMICAL DISSECTION AND CT IMAGING OF THE ANTERIOR CRUCIATE AND MEDIAL COLLATERAL LIGAMENT FOOTPRINT ANATOMY IN SKELETALLY IMMATURE CADAVER KNEES

Abstract

Background: Anterior cruciate ligament (ACL) and medial collateral ligament (MCL) injuries in skeletally immature patients are increasingly recognized and surgically treated. However, the relationship between the footprint anatomy and the physes are not clearly defined. The purpose of this study was to identify the origin and insertion of the ACL and MCL, and define the footprint anatomy in relation to the physes in skeletally immature knees. Methods: Twenty-nine skeletally immature knees from 16 human cadaver specimens were dissected and divided into two groups: Group A (ages 2-5 years), and Group B (ages 7-11 years). Metallic markers were placed to mark the femoral and tibial attachments of the ACL and MCL. CT scans were obtained for each specimen used to measure the distance from the center of the ligament footprints to the respective distal femoral and proximal tibial physes. Results: Median distance from the ACL femoral epiphyseal origin to the distal femoral physis was 0.30cm (interquartile range, 0.20cm to 0.50cm) and 0.70cm (interquartile range, 0.45cm to 0.90cm) for Groups A and B, respectively. The median distance from the ACL epiphyseal tibial insertion to the proximal tibial physis for Groups A and B were 1.50cm (interquartile range, 1.40cm to 1.60cm) and 1.80cm (interquartile range, 1.60cm to 1.85cm), respectively. Median distance from the MCL femoral origin on the epiphysis to the distal femoral physis was 1.20cm (interquartile range, 1.00cm to 1.20cm) and 0.85cm (interquartile range, 0.63cm to 1.00cm) for Groups A and B, respectively. Median distance from the MCL insertion on the tibial metaphysis to the tibial physis was 3.05cm (interquartile range, 2.63cm to 3.30cm) and 4.80cm (interquartile range, 3.90cm to 5.10cm) for Groups A and B, respectively. Conclusion: Surgical reconstruction is a common treatment for ACL injury, and occasionally MCL reconstruction or repair is also required. Cadaveric dissection and CT scanning of exceptionally rare pediatric tissue clearly defines the location of the ACL and MCL with respect to the femoral and tibial physes, and may guide surgeons for physeal respecting procedures for both ACL reconstruction, and ACL repair procedures. (Figure Presented).