Tibial-sided PCL avulsion fractures in children: the importance of diagnosing concomitant injuries

Purpose: Tibial-sided posterior cruciate ligament (PCL) avulsion fractures are a variant of PCL injury. Current literature on tibial-sided PCL injuries consists of small case reports or series in adults. There are no studies in the pediatric population describing the associated injuries and if concomitant injuries impact clinical decision-making. This study aims to identify common concomitant injuries in pediatric patients with tibial-sided PCL avulsion fractures and determine the utility of MRI in identification of concomitant injuries. Methods: A retrospective review of the electronic medical record identified all patients presenting to a single tertiary pediatric hospital with tibial-sided PCL avulsion fractures 1/2012-6/2024. MRI exams were reviewed by a musculoskeletal pediatric radiologist. Operative reports and clinical encounter notes were reviewed by a pediatric orthopedic surgeon. Results: Twenty-seven patients met the inclusion criteria, and 26 concomitant injuries were identified in 16 (59%) patients. Twenty of 27 (74%) of patients had a preoperative MRI; 23/26 (88%) injuries were identified on MRI, and 2/26 (8%) injuries were identified clinically without MRI. One concomitant injury was identified at the time of surgery but not on preoperative MRI. The most common concomitant finding on MRI was posterolateral corner injury (7/26, 27%). Eight of 26 (31%) of the concomitant injuries required surgical intervention. Conclusion: Concomitant injuries occurred in the majority of patients with tibial-sided PCL avulsion fractures. Posterolateral corner injury was the most common injury and anterior cruciate ligament tear was the most common requiring surgical intervention. Radiologists and surgeons should be cognizant of the association of concomitant injury.