Accuracy of Magnetic Resonance Imaging in the Diagnosis of Multiple Ligament Knee Injuries: A Multicenter Study of 178 Patients

Abstract

Background: Magnetic resonance imaging (MRI) has shown limited diagnostic accuracy for multiple ligament knee injuries (MLKIs), especially posterolateral corner (PLC) injuries. Hypothesis: The diagnostic accuracy of MRI for MLKIs will only be moderate for some knee structures. Patient-related factors and injury patterns could modify the diagnostic accuracy of MRI. Study Design: Cohort study; Level of evidence, 3. Methods: All patients with MLKIs surgically treated between January 2014 and December 2020 in the centers participating in the study were reviewed. We recorded sex, age, mechanism of injury, time from injury to MRI, and vascular and neurological associated lesions. Lesions to the anterior cruciate ligament (ACL), posterior cruciate ligament, medial collateral ligament, lateral collateral ligament (LCL), popliteus tendon, popliteofibular ligament, iliotibial band, biceps tendon, medial and lateral meniscus, and articular cartilage from MRI reports and surgical records were also collected. The sensitivity, specificity, positive predictive value, negative predictive value, diagnostic accuracy, diagnostic odds ratio, positive and negative likelihood ratio, and intraclass correlation coefficient of MRI were calculated for each knee structure. With logistic regression, associations between patient and injury characteristics and MRI accuracy were assessed. Results: A total of 178 patients (127 male; mean age, 33.1 years) were included. High-energy trauma was the most common mechanism of injury (50.6%), followed by sports trauma (38.8%) and low-energy trauma (8.4%). The ACL was the structure with the best diagnostic accuracy, diagnostic odds ratio, and positive predictive value (94.4%, 113.2, and 96.8%, respectively). PLC structures displayed the worst diagnostic accuracy among knee ligaments (popliteus tendon: 76.2%; LCL: 80.3%) and diagnostic odds ratio (popliteus tendon: 9.9; LCL: 17.0; popliteofibular ligament: 17.5). MRI was more reliable in detecting the absence of meniscal and chondral lesions than in identifying them. Logistic regression found that the diagnostic accuracy was affected by the Schenck classification, with higher Schenck grades having worse diagnostic accuracy for peripheral structures (iliotibial band, popliteus tendon, and biceps tendon) and improved diagnostic accuracy for the ACL and posterior cruciate ligament. Conclusion: The diagnostic accuracy of MRI for MLKIs largely varied among knee structures, with many of them at risk of a misdiagnosis, especially PLC, meniscal, and chondral lesions. The severity of MLKIs lowered the diagnostic accuracy of MRI for peripheral structures.

Diagnosing popliteofibular ligament injuries in anterior cruciate ligament‐injured knees: A prospective magnetic resonance imaging study investigating the inter‐ and intraobserver reliability of identification of the popliteofibular ligament

“…Rakhra et al found a high accuracy of MRI for detecting tears of the PLC components (lateral collateral ligament, biceps femoris tendon, PT and posterolateral ligamentocapsular complex), ranging from 82% to 95% in multiligament‐injured knees but did not evaluate the PFL as a separate structure [ 29 ]. In a large study evaluating 178 MRIs in patients with multiligamentous knee injuries, the reporting percentage of the PFL was only 47.8% [ 32 ]. The diagnostic accuracy, however, was 80.7%, equal to that of the LCL, but the LCL had a reporting percentage of 94.9%.…”

“…The diagnostic accuracy, however, was 80.7%, equal to that of the LCL, but the LCL had a reporting percentage of 94.9%. The positive predictive value of the PFL in the study by Sanchez‐Munoz et al was 80.8%, almost equal to that of the medial collateral ligament (MCL), but the MCL had a reporting percentage of 99.4% [ 32 ]. McKean et al found a sensitivity for visualization of the PFL of 90% and they mention that routine review of the PLC and PFL should be an essential part of acute knee imaging [ 23 ].…”

“…Many authors have therefore suggested a thorough magnetic resonance imaging (MRI) investigation of all PLC structures in injured knees [ 8 , 26 , 33 , 34 , 35 ]. Routine evaluation of the PFL on MRI scans, however, is not common with papers mentioning a reporting frequency of less than 50% [ 8 , 11 , 32 ]. We found that only one study had published reporting on the interobserver reliability of the PFL on MRI scans in ACL‐injured knees [ 11 ].…”

ESR essentials: MRI of the knee—practice recommendations by ESSR

“…We recommend reporting ligament pathology as full-or partial-thickness tears, bearing in mind the limitations of MRI in diagnosing partial tears [6,26,27]. Searching for indirect signs of ligament insufficiency or deficiency as well as evaluation of joint malalignment may increase confidence in diagnosis [23,25].…”

Higher success rate observed in reconstruction techniques of acute posterolateral corner knee injuries as compared to repair: an updated systematic review

“…Once considered the "dark side" of the knee, understanding of the anatomy and biomechanics of the posterolateral corner (PLC) was originally limited, resulting in poor diagnostic capabilities and limited treatment options in patients sustaining PLC injuries [5,6]. However, an advanced understanding of the biomechanical role of each anatomic structure comprising the PLC, along with recent investigations correlating physical examination findings with specific anatomic deficiencies, coupled with improvements in diagnostic imaging [22,44], have resulted in increased awareness and diagnosis of PLC injuries [23,36,40,41,48]. PLC injuries are commonly associated with injuries to the anterior cruciate ligament (ACL) and/or posterior cruciate ligament (PCL), with only 28% of PLC injuries reported to occur in isolation [5,11].…”