Delayed diagnosis of posterior cruciate ligament avulsion following lower limb fracture surgery: a case report

Introduction: Avulsion fractures of the posterior cruciate ligament (PCL) are rare occurrences following knee trauma and are frequently missed during the initial assessment. These injuries are often overlooked due to subtle radiographic signs and the difficulty of performing a thorough physical examination in the presence of acute pain. Prompt and accurate diagnosis is essential to prevent long-term functional impairment of the knee. Case presentation: We report the case of a 42-year-old woman who sustained trauma to her left lower limb after falling from a height of approximately 3 m. She underwent orthopedic surgery for fractures in the left foot and was discharged in stable condition. However, during the second follow-up visit, persistent discomfort around the knee prompted further imaging. Radiographs revealed a previously undiagnosed avulsion fracture of the PCL in the left knee, which had not been identified during the initial trauma evaluation. Clinical discussion: This case highlights the diagnostic challenges associated with PCL avulsion fractures, particularly when overshadowed by more apparent injuries. It underscores the importance of maintaining a high index of suspicion and conducting comprehensive evaluations, including repeat imaging when clinical symptoms persist. Conclusion: Clinicians should be aware of the potential for missed PCL avulsion fractures, especially in polytrauma patients. Early recognition and management are critical to ensuring optimal functional recovery.