Pediatric PCL Insufficiency from Tibial Insertion Osteochondral Avulsions

Abstract

Posterior cruciate ligament (PCL) insertion-site osteochondral avulsions in children, particularly from the tibia, are not commonly seen by orthopaedic surgeons. Because of the rarity of these injuries, careful attention to the specific physical examination and imaging findings seen with these injuries is necessary so that the proper diagnosis can be made. Osteochondral avulsions of the PCL can be missed on plain radiographs in skeletally immature patients, and therefore magnetic resonance imaging is necessary for proper diagnosis. With this knowledge, clinicians can formulate treatment plans which can return their patients to activities while avoiding potential morbidity resulting from missed diagnoses or improper treatment. We report two rare cases of PCL insufficiency stemming from tibial insertion osteochondral avulsions. Both patients underwent subsequent open reduction and internal fixation of the avulsion using two different fixation methods (bioabsorbable anchors versus cannulated screw and washer) and have returned to full sporting activities.

Peel-Off Injury at the Tibial Attachment of the Posterior Cruciate Ligament in Children

“…Although this finding concurred with previous reports of bony avulsions at the tibial attachment of the PCL, 20,24,25,34 our study might reveal agedependent failure patterns in the tibia attachment of the PCL. Some authors have suggested the mechanism of PCL injuries in children as follows: hyperflexion injury often caused by a fall with the ankle in plantar flexion and a direct blow to the anterior tibia, which results in a PCL avulsion, usually with bone or perichondral femoral fragment.…”

“…32 Tibial avulsion of the PCL, which is seldom seen in the literature, results from a direct blow to the proximal tibia with the knee flexed. 20,25,26,34 In our study, falls resulted in force to the proximal tibia in 5 of the 6 patients, corresponding with earlier studies. 20,25,26,34 Plain radiographs often underestimate the size of the largely cartilaginous fragment or are negative.…”

“…20,25,26,34 In our study, falls resulted in force to the proximal tibia in 5 of the 6 patients, corresponding with earlier studies. 20,25,26,34 Plain radiographs often underestimate the size of the largely cartilaginous fragment or are negative. 20 Cruciate ligament injuries should be strongly considered in this age group when patients are seen with vague knee symptoms after trauma and a negative finding on plain radiographs.…”

“…12,32 To date, there has been only 1 report on mostly cartilaginous injuries at the tibial attachment of the PCL. 20 We obtained a biopsy specimen in which histologic sections showed the ligament avulsion at the fibrocartilage-osseous junction. Our report indicates that this type of injury may occur at the tibial attachment of the PCL as well as the femoral side.…”

Paediatric Sports Injuries - Principles of Management

“…Radiographs may also show an avulsion fracture. Management is generally conservative, with consideration of acute repair being reserved for the elite athlete with severe laxity [55].…”