Reliability of Preoperative Magnetic Resonance Imaging in Determining the Anterior Cruciate Ligament Tear Location.

Background: The accurate identification of the anterior cruciate ligament (ACL) tear location is important for preoperative planning, as it influences the choice between reconstruction or repair procedures, particularly for proximal tears. Therefore, there is a need for a reliable preoperative tool that yields findings consistent with diagnostic arthroscopy. Purpose: To evaluate the reliability of preoperative magnetic resonance imaging (MRI) for determination of the ACL tear location. Study Design: Cohort study (diagnosis); Level of evidence, 2. Methods: Patients diagnosed with a full-thickness ACL tear between January 2022 and January 2024 were included in this study. The modified Sherman classification was used to categorize the ACL tear location into 5 types: I (proximal avulsion tear), II (proximal tear), III (midsubstance tear), IV (distal tear), and V (distal avulsion tear). There were 2 musculoskeletal radiologists who reviewed preoperative MRI scans, whereas diagnostic arthroscopic video recordings were retrospectively reviewed by 2 orthopaedic surgeons. The MRI findings were then compared with the arthroscopic findings, with diagnostic arthroscopy serving as the reference standard for the exact tear location. The Fleiss kappa (κ) was used to assess the reliability of the MRI findings. Results: A total of 41 patients were included in this study. The rate of agreement between radiologists regarding the tear location based on preoperative MRI scans was 61.0% (25/41), while the rate of agreement between surgeons based on diagnostic arthroscopic video recordings was 87.8% (36/41). The interrater agreement between radiologists was moderate (κ = 0.460), whereas the interrater agreement between surgeons was excellent (κ = 0.833). The rate of agreement between radiologist 1 and surgeon 1 was 70.7% (29/41), and that between radiologist 1 and surgeon 2 was 75.6% (31/41). For radiologist 2, the rate of agreement was 75.6% (31/41) with both surgeon 1 and surgeon 2. The overall reliability analysis indicated good agreement (κ = 0.648) between the MRI and arthroscopic findings. Conclusion: Preoperative MRI reliably identified the tear location, with a good strength of agreement between preoperative MRI and diagnostic arthroscopy. Nevertheless, despite its reliability, the interrater agreement between radiologists in interpreting preoperative MRI scans was only moderate, whereas surgeons achieved excellent agreement based on diagnostic arthroscopic video recordings.