Assessment of Cruciate Ligament Injury of the Knee on Magnetic Resonance Imaging Taking Arthroscopy as the Gold Standard

Abstract

Background: Cruciate ligament injuries are among the most common causes of knee instability, pain, and functional impairment. Accurate diagnosis is essential for timely management and surgical planning. Arthroscopy remains the gold standard for diagnosis but is invasive and costly. Magnetic resonance imaging (MRI) provides a non-invasive alternative, offering detailed visualization of soft tissue structures. Objective: To determine the diagnostic accuracy of MRI in detecting cruciate ligament injuries of the knee, taking arthroscopy as the gold standard. Methods: This diagnostic validation study was conducted in the Orthopaedic Surgery, Ghurki Trust Teaching Hospital, Lahore, from December 18^th, 2024 to May 30^th 2025. Fifty-nine patients aged 18 years and above with clinically suspected cruciate ligament injury were included through consecutive sampling. MRI was performed using a 1.5 Tesla scanner with standard sagittal, coronal, and axial sequences, and findings were compared with arthroscopy performed within the same admission. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and overall diagnostic accuracy were calculated for both anterior cruciate ligament (ACL) and posterior cruciate ligament (PCL) tears. Results: MRI demonstrated a sensitivity of 92.9%, specificity of 88.2%, PPV of 95.1%, NPV of 83.3%, and diagnostic accuracy of 91.5% for ACL tears. For PCL tears, sensitivity, specificity, PPV, NPV, and accuracy were 81.8%, 97.9%, 90.0%, 95.9%, and 94.9%, respectively. Conclusion: MRI provides excellent diagnostic performance for cruciate ligament injuries, closely matching arthroscopy in accuracy. It offers a safe, non-invasive, and reliable alternative for diagnosis and preoperative assessment in patients with suspected ligamentous knee injuries.