Delayed detection of clinically significant posterior cruciate ligament injury after peri-articular fracture around the knee of 448 patients

Background The purpose of this study was to report the frequency with which posterior cruciate ligament (PCL) injuries occurred in combination with peri-articular fractures around the knee, and to determine the frequency with which the detection of these PCL injuries was delayed (i.e., detected in an outpatient clinic after fracture treatment). Methods This retrospective study included 448 subjects with peri-articular fractures around the knee, including femoral shaft fractures, distal femoral fractures, patellar fractures, tibial plateau fractures, and tibial shaft fractures. The PCL injuries were detected through clinical examination, magnetic resonance imaging, and stress X-rays. We determined both the frequency of PCL injuries that occurred in combination with peri-articular fractures around the knee, and the frequency with which the detection of these PCL injuries was delayed. We also compared the frequency with which PCL injuries were associated with either isolated or combined fractures for different fracture types. Results We identified concomitant PCL injury and periarticular fracture of the knee in 7.8 % of patients. In 22 of the 35 patients with concomitant PCL injury, the detection of the PCL injury was delayed. There were significant differences in the frequency with which PCL injuries were associated with isolated or combined fractures of the femoral shaft (P = 0.04), patella (P = 0.03), and distal femur (P = 0.03). Conclusion The delayed detection frequency was high for PCL injury after peri-articular fracture around the knee.