From the Guidelines
To diagnose ACL injury and meniscal damage, MRI imaging is the most reliable method, with high sensitivity and specificity for both injuries, and can detect associated injuries that may be present. The clinical examinations, such as the Lachman test, anterior drawer test, and pivot shift test for ACL injuries, and the McMurray test, Apley test, and joint line tenderness assessment for meniscal injuries, should be used in conjunction with a thorough history and symptoms like instability, locking, or giving way 1.
Key Points to Consider
- A study by Magee and Williams found that 3T MRI has a sensitivity of 96% and specificity of 97% in detecting meniscal tears, which is comparable to the results of 1.5T MRI examinations 1.
- MRI can also diagnose the patterns and severity of bone marrow contusions, which are frequently associated with specific mechanisms of injury and can predict associated soft-tissue injuries 1.
- The presence of a bone contusion on MRI after acute knee trauma is highly predictive of the development of focal osteoarthritis 1 year after trauma 1.
- Ultrasound (US) is not the preferred imaging modality for evaluating radiographically occult fractures and/or internal derangement, but it can be useful in detecting knee joint effusions and certain types of injuries, such as quadriceps tendon tears 1.
Imaging Recommendations
- MRI is the preferred imaging modality for diagnosing ACL injury and meniscal damage, due to its high sensitivity and specificity for both injuries 1.
- US may be used as a supplementary imaging modality in certain cases, but its utility is limited by its technical limitations and variability in patient factors 1.
Clinical Examination Techniques
- The Lachman test, anterior drawer test, and pivot shift test are recommended for assessing ACL injuries, while the McMurray test, Apley test, and joint line tenderness assessment are recommended for assessing meniscal injuries.
- These physical examination techniques should be combined with a thorough history and symptoms like instability, locking, or giving way to increase diagnostic accuracy.
Important Considerations
- A thorough history and physical examination are essential in diagnosing ACL injury and meniscal damage, and should be used in conjunction with imaging studies to increase diagnostic accuracy.
- MRI imaging is the most reliable method for diagnosing ACL injury and meniscal damage, and should be used as the primary imaging modality in most cases.
From the Research
Diagnosis of ACL Injury
- The diagnosis of an ACL injury is made with a combination of patient's history, clinical examination, and, if appropriate, magnetic resonance imaging 2.
- The Lachman test is the most accurate test for detecting an ACL tear 3.
- Magnetic resonance imaging is the primary study used to diagnose ACL injury in the United States and can also identify concomitant meniscal injury, collateral ligament tear, and bone contusions 3.
Physical Examination Tests
- The lever sign test had the lowest LR- (0.21) and the pivot shift test had the highest LR+ (11.60) for diagnosing ACL injuries in an acute setting 4.
- The pooled sensitivities were 0.79,0.78,0.55, and 0.82 in the Lachman, anterior drawer, pivot shift, and lever sign tests, respectively, and the pooled specificities were 0.91,0.91,0.96, and 0.88, respectively 4.
- The anterior drawer test, Lachman test, and pivot shift test are commonly used to evaluate cruciate ligament injury, with the Lachman test being the most accurate 3, 5.
Meniscal Injury
- Magnetic resonance imaging can identify concomitant meniscal injury, collateral ligament tear, and bone contusions 3.
- The diagnosis of meniscal injury is often made in conjunction with the diagnosis of an ACL injury, as the two are commonly related 6.
Treatment and Management
- Treatment consists of conservative management or surgical intervention, with the latter being the better option for patients who want to return to a high level of activity 3.
- The objectives of management are to restore knee function, address psychological barriers to activity participation, prevent further injury and osteoarthritis, and optimize long-term quality of life 2.