Valentin Lance MD, Presenter: Nothing to Disclose

Ursula Renate Heilmeier MD, Abstract Co-Author: Nothing to Disclose

Gabby B. Joseph, Abstract Co-Author: Nothing to Disclose

Benjamin Ma MD, Abstract Co-Author: Nothing to Disclose

Lynne S. Steinbach MD, Abstract Co-Author: Nothing to Disclose

Thomas M. Link MD, PhD, Abstract Co-Author: Research funded, General Electric Company Research funded, InSightec Ltd

(1)To describe MR characteristics of meniscal flap tears (2)To investigate associated imaging findings such as the presence of bone marrow edema pattern, degree of cartilage loss, synovitis and capsular ligamentous injury and (3)To correlate these MR findings to clinical presentation in groups stratified by surgical versus non-operative management. 

307 patients with MR diagnosis of flap tear were identified through a retrospective query of the hospital radiologic database and chart review from 2010 to 2013. Clinical history and flap tear related treatment were recorded for each subject. Subjects were excluded if MR imaging included signs of traumatic injury such as fracture, ACL or PCL tear, severe osteoarthritis or if the size of the flap tear was not measurable in the sagittal or coronal images. 58 subjects (35 men and 25 women, mean age 49.6±14.5 yrs) were included. MR studies of the knee were reviewed and graded for flap tear location, size and presence of additional knee abnormalities by two radiologists. Statistical analysis employed t-tests, Spearman correlations, linear regression and logistic regression models.

The medial meniscus was the most common site of flap tears (87%, 52/60), with inferior displacement in 78% (47/60). Average flap area was 18.3±18.1mm2. Bone marrow edema pattern was present in 36.2% and cartilage defects in 25.9%. Synovitis was present in 48.3%, and complete medial meniscofemoral and meniscotibial ligament tears in 8.6% and 3.4%, respectively. Comparing MR characteristics to clinical pain scores, we found that the degree of tibial cartilage loss was positively correlated with the visual analog pain scale (p=0.03). Comparing operative to non-operative groups, patients who underwent arthroscopic surgery were younger than those who did not (45.6±12.3 years vs 55.3±15.7 years, p=0.01), and more likely to present with a positive clinical McMurray test (79.4% vs 41.7% , p=0.01).

Medial meniscal and inferiorly displaced flap tears are the most common tear pattern. A greater degree of cartilage loss involving the tibia was associated with increasing pain scores. Those undergoing arthroscopy are younger and more likely to have positive meniscal signs on clinical exam.  

Knowledge of common flap tear locations, MRI appearance and related injury, and associated clinical findings is important for radiologists as it may affect surgical planning.

Lance, V, Heilmeier, U, Joseph, G, Ma, B, Steinbach, L, Link, T, MR Imaging Characteristics and Clinical Symptoms Related to Displaced Meniscal Flap Tears.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14000477.html