Posterolateral tibial plateau impaction fractures in patients undergoing primary anterior cruciate ligament reconstruction—An MRI analysis of 556 cases

Abstract Purpose Posterolateral impaction fractures of the tibial plateau are known to be associated with anterior cruciate ligament (ACL) tears. These fractures are often related to high energy pivoting injuries, which is why the frequency of such injuries is of key concern for patients undergoing primary ACL reconstruction. The objective of this study is to evaluate the occurrence of posterolateral tibial fractures, as well as concomitant injuries in patients undergoing primary ACL reconstruction. Methods A retrospective case series was conducted to study the occurrence and type of posterolateral tibial impaction fractures in patients undergoing ACL reconstruction between October 2015 and October 2020. Patients records were reviewed to collect patient demographics, exact injury patterns and details about concomitant injuries. Descriptive statistics were performed to determine the incidence of each type of posterolateral tibial plateau impaction fracture, as well as concomitant injuries. Results Of the 556 knees with primary ACL reconstruction, a total of 171 posterolateral tibial plateau impaction fractures were identified. 385 patients showed no fracture. Intraoperative arthroscopic examination showed lateral meniscus (LM) tears in 144 cases and medial meniscus (MM) tears in 163 cases. LM posterior root tears were found in 21 patients, MM posterior root tears in eight patients. Medial meniscal ramp lesions were found in a total of 39 knees. Conclusion 30.8% of the patients showed posterolateral tibial plateau impression fractures, here LM tears were more frequent with the highest incidence in IIIB fractures. MM tears are more frequent in patients without posterolateral impaction fractures, while LM posterior root tears are more frequent than MM posterior root tears among the whole study population. The clinical relevance of this study lies in the exact analysis of posterolateral tibial plateau fractures in patients with ACL lesions, with the resulting therapeutic consequences dependent on the fracture type and concomitant injuries. Level of Evidence: Level III.