Partial tear of the anterior cruciate ligament of the knee : injury patterns on MR imaging
Faculty of Medicine and Health Sciences
Knee surgery, sports traumatology, arthroscopy. - Heidelberg
, p. 256-261
University of Antwerp
Purpose To describe rupture patterns of partial anterior cruciate ligament (ACL) tears on magnetic resonance (MR) imaging. Methods MR images of 51 patients with a surgically confirmed partial ACL tear were retrospectively and independently interpreted by 2 experienced, blinded radiologists. Using previously described MR criteria, ACLs were categorized as follows: complete tear, partial tear, isolated anteromedial or posterolateral bundle tear, mucoid degeneration or normal ACL. MR interpretations were compared with the arthroscopic results as the standard of reference. Inter- and intraobserver agreements were determined using kappa (к) coefficients. Results On MR imaging, ACL injuries were categorized as complete tears (1623%), partial tears (2047%), mucoid degeneration (1227%) or normal ACLs (1823%). Isolated ACL bundle tears were diagnosed on MR in 6% of our patients. Accuracy of MR for the diagnosis of partial ACL tears was 2553%. Interobserver agreement was moderate (к = 0.480.56). Intraobserver agreement was good (к = 0.720.76). Conclusion MR diagnosis of a partial ACL tear is difficult because various tear patterns may be seen. Many partial tears demonstrate MR features that are indistinguishable from complete ACL tear, mucoid ACL degeneration or normal ACL. An isolated ACL bundle tear is infrequently detected on MR images.