What did the study look at?
Meniscal and anterior cruciate ligament (ACL) tears are common knee problems. In acute injuries, pain and swelling can make examination difficult, so magnetic resonance imaging (MRI) becomes important. The authors note that earlier studies reported meniscal tears accompanying ACL tears to be harder to detect on MRI.
The aim was to calculate the sensitivity, specificity and accuracy of MRI for meniscal and cruciate ligament tears by comparison with arthroscopy, and to see whether accuracy for meniscal tears differs between patients with and without an ACL tear.
How was it done?
- This was a retrospective study of patients who had arthroscopy for meniscal and/or cruciate ligament injury between January 2015 and January 2018; after exclusions, 96 of 152 patients were included.
- Patients with previous knee surgery, severe degenerative changes, MRI performed elsewhere or age under 18 were excluded.
- Scans were reviewed retrospectively by a musculoskeletal radiologist unaware of the arthroscopy findings. The interval between MRI and arthroscopy was under 8 weeks in all cases.
- Arthroscopy was taken as the gold standard. Patients were also divided into those with (36) and without (60) an ACL tear.
What did it find?
- Medial meniscus: sensitivity 93.5%, specificity 88.8%, accuracy 92.7%.
- Lateral meniscus: sensitivity 64.8%, specificity 94.9%, accuracy 83.3%.
- Anterior cruciate ligament: sensitivity 55.5%, specificity 81.6%, accuracy 71.8%.
- Posterior cruciate ligament: sensitivity 100%, specificity 98.9%, accuracy 98.9%, although few patients had a tear of this ligament.
- For lateral meniscal tears, MRI specificity was significantly lower in the ACL-tear group (91.6% versus 97.1%; p=0.021). No other value differed significantly between the groups.
The authors' conclusion
The authors conclude that MRI is a non-invasive method that can be used safely to diagnose medial and lateral meniscal tears, with better diagnostic accuracy for meniscal tears than for ACL tears. With an ACL tear, specificity for lateral meniscal tears was lower, but overall accuracy for meniscal tears did not differ significantly between the two groups.
Limitations
- The radiologist was unaware of clinical findings, which may have led to lower rates than reported elsewhere.
- The study was retrospective.
- Few patients had posterior cruciate ligament tears; the authors call for larger studies.
Reference
Gürsoy M, Bulut T, Dirim Mete B, Tosun Ö, Horoz EM, Gürsoy S. The efficacy of magnetic resonance imaging in the determination of meniscus tears in patients with anterior cruciate ligament tears. Eastern Journal of Medicine. 2019;24(2):215–221.
Free full text: Eastern Journal of Medicine
This article summarises a published scientific paper for general information; it does not replace an examination or a personal medical assessment. Please consult your doctor about your symptoms.
