Ross Hauser, MD, Danielle Matias, PA-C, Demi Foster, APRN
An MRI reading can misdiagnose an ACL (Anterior Cruciate Ligament) rupture, especially in instances of non-obvious, complete tears or chronic injuries. Although MRI readings are valuable tools for diagnosing ACL injuries, accuracy can be called into question based on the nature and severity of the tear, the radiologist’s expertise, and the existence of other knee injuries.
Is an MRI actually showing a complete or partial rupture
Let’s look back at two decades of research into the accuracy of MRI for detecting a true MRI tear. The question of is an MRI actually showing a complete or partial rupture in some cases remains controversial and debated. Let’s jump into this debate starting in 2007 and take it to 2025.
MRI is very good, but not quite perfect.
In 2007, doctors writing in the British Medical Bulletin (1) wrote: “MRI is highly accurate in diagnosing meniscal and anterior cruciate ligament (ACL) tears. It is the most appropriate screening tool before therapeutic arthroscopy (exploratory and fix-it surgery). It is preferable to diagnostic arthroscopy in most patients because it avoids the surgical risks of arthroscopy. The results of MRI differ for medial and lateral meniscus and ACL, with only 85% accuracy.” So the suggestion is MRI is very good, but not quite perfect. Now of course that research is from 2007. There has been fantastic progress since then. In fact, there has been so much progress that the question now has to be asked: Does the MRI correctly see the ligament damage? Does it see “too much?”
Does the MRI correctly see the ligament damage? Does it see “too much and mistake the severity of the tear?”
What does it mean when we suggest the MRI is seeing too much? It means that the MRI took a picture and the radiologist’s interpretation suggests a full-blown tear when a full-blown tear may not be there. In January 2022, doctors writing in the journal BioMed Central Musculoskeletal Disorders (2) assessed the accuracy of MRI in diagnosing and classifying acute traumatic multiple ligament knee injuries. Here is what they wrote:
“Magnetic resonance imaging (MRI) is widely used for the evaluation of knee injuries, however, the accuracy of MRI in classifying multiple ligament knee injuries remains unknown.” (In other words the study’s authors are saying, we do not know how accurate this is).
Therefore, their study’s goals aimed to investigate the accuracy of MRI in diagnosing and classifying acute traumatic multiple ligament knee injuries. The study authors noted that they went into this study believing that the MRI had high accuracy in detecting and classifying multiple ligament knee injuries. Let’s see if those beliefs are founded.
The doctors looked at 97 patients who were diagnosed with acute traumatic multiple ligament knee injuries and managed by multi-ligament reconstruction. The MR images were read by two experienced radiologists and results were compared with intraoperative findings, which were considered as the reference for the identification of injured structures.
Results: For detecting the specific injured structures in multiple ligament knee injuries, MRI had high sensitivity (90.7% for ACL, 90.4% for Posterior Cruciate Ligament, and moderate specificity (63.6% for ACL, 50% for PCL).
What does this mean?
Sensitivity for MR imaging to identify something that MAY be a tear was at 90%. Meaning that the MRI interpretation was correct in seeing a tear 90% of the time. The significance of the tear, full or partial, then because less odds-worthy. Moderate specificity for the ACL tear means that when these 90% of people were separated into probable and non-probable (specific to the type of tear, hence the word specificity) 63.6% of the time the tear was correctly identified. About two out of three times.
Limited diagnostic accuracy for multiple ligament knee injuries
A February 2023 paper in the American Journal of Sports Medicine (3) did suggest however that while MRIs have “shown limited diagnostic accuracy for multiple ligament knee injuries” . . . ACL tears ACL), showed the best diagnostic accuracy (94.4%) versus diagnosing other multiple ligament knee injuries in trauma injury. While the ACL tear was seen with high accuracy, the researchers noted that “diagnostic accuracy of MRI for multiple ligament knee injuries largely varied among knee structures, with many of them at risk of a misdiagnosis, especially posterolateral corner, meniscal, and chondral lesions (injuries).”
A June 2025 study in the Orthopaedic journal of sports medicine (4) looked at 203 patients who underwent ACL reconstruction or repair. What the study was looking for was if the pre-surgical MRI accurately predicted the location of the tear. What they found was MRI accurately predicted the ACL tear type seen arthroscopically in only 35.5% (72/203) of the patients.
When MRI did not match the arthroscopic diagnosis, the MRI was:
- within 1 classification grade 74.8% (98/131) of the time.
- Of the incorrect gradings, 71.0% (93/131) were overclassifications (MRI tear classification more distal than found during arthroscopy).
Conclusion: MRI was unreliable for determining the precise location of an ACL tear. MRI tended to overestimate how distal (far from the knee center) a tear was compared with arthroscopic findings, which may influence patient counseling, preoperative planning, and surgical decision making.
MRI’s, artificial intelligence, and lesser experienced technicians.
The point of this section was to demonstrate that the MRI, in some cases, may not reveal what is actually going on in the knee and care should be taken in perusing treatment options. Of note is an August 2023 paper (5) which introduced artificial intelligence (AI) into the equation. Here researchers recruited clinicians of varying expertise levels in sports medicine and radiology to test their capacities in diagnosing ACL injuries in terms of accuracy and diagnosing time. The researchers found that AI assistance significantly improved the accuracy of all clinicians, exceeding 96%. “The most significant improvements in accuracy and time efficiency were observed in the trainee groups, suggesting that AI support is particularly beneficial for clinicians with moderately limited diagnostic expertise.” Even still, about 1 in 25 MRI readings were not accurate.
Post-ACL surgery complications and the need for revision surgery
References
1 Crawford R, Walley G, Bridgman S, Maffulli N. Magnetic resonance imaging versus arthroscopy in the diagnosis of knee pathology, concentrating on meniscal lesions and ACL tears: a systematic review. British medical bulletin. 2007 Dec 1;84(1):5-23. [Google Scholar]
2 Li X, Hou Q, Zhan X, Chang L, Ma X, Yuan H. The accuracy of MRI in diagnosing and classifying acute traumatic multiple ligament knee injuries. BMC Musculoskeletal Disorders. 2022 Dec;23(1):1-7. [Google Scholar]
3 Sanchez-Munoz E, Lozano Hernanz B, Zijl JA, Passarelli Tirico LE, Angelini FJ, Verdonk PC, Vuylsteke K, Andrade R, Espregueira-Mendes J, Valente C, Figueroa F. Accuracy of Magnetic Resonance Imaging in the Diagnosis of Multiple Ligament Knee Injuries: A Multicenter Study of 178 Patients. The American Journal of Sports Medicine. 2023 Feb;51(2):429-36. [Google Scholar]
4 Kantrowitz DE, Darden CN, Bienstock DM, Jalloh H, Rosenberg AM, McMillan S, Gladstone JN, Anthony SG. Reliability of Preoperative MRI in the Prediction of ACL Tear Type. Orthopaedic Journal of Sports Medicine. 2025 Jun;13(6):23259671251339491. [Google Scholar]
5 Wang DY, Liu SG, Ding J, Sun AL, Jiang D, Jiang J, Zhao JZ, Chen DS, Ji G, Li N, Yuan HS. A Deep Learning Model Enhances Clinicians’ Diagnostic Accuracy to More Than 96% for Anterior Cruciate Ligament Ruptures on Magnetic Resonance Imaging. Arthroscopy: The Journal of Arthroscopic & Related Surgery. 2023 Aug 18. [Google Scholar]