title: Pseudocyclops: two cases of ACL graft partial tears mimicking cyclops lesions on MRI.
abstract: Arthroscopic reconstruction of the anterior cruciate ligament (ACL) using autografts or allografts is a common surgical procedure, particularly in young athletes. Although the procedure has excellent success rates, complications such as mechanical impingement, graft rupture, and arthrofibrosis can occur, often necessitating additional surgery. Magnetic resonance (MR) imaging has become a valuable tool in evaluating complications after ACL reconstruction. We report two cases of ACL reconstruction complicated by arthroscopically proven partial graft tears. In both cases the torn anterior graft fibers were flipped into the intercondylar notch, mimicking anterior arthrofibrosis, i.e., a "cyclops lesion," on MR imaging. Careful review of the direction of graft fibers on MR imaging in the "pseudocyclops" lesions can help differentiate these partial tears from the fibrosis of a true cyclops. The "pseudocyclops" lesion is a previously undescribed MR imaging sign of partial ACL graft tear. Larger studies are required to determine the sensitivity and specificity of the sign, as well as the clinical importance of these partial graft tears.
authors.affiliation: Department of Radiology, Cleveland Clinic, 9500 Euclid Avenue, Cleveland, OH, 44195, USA, simpfec2@ccf.org.
authors.forename: Claus
authors.initials: C
authors.lastname: Simpfendorfer
authors.forename: Anthony
authors.initials: A
authors.lastname: Miniaci
authors.forename: Naveen
authors.initials: N
authors.lastname: Subhas
authors.forename: Carl S
authors.initials: CS
authors.lastname: Winalski
authors.forename: Hakan
authors.initials: H
authors.lastname: Ilaslan
mesh_terms: D016118:Anterior Cruciate Ligament / Q000473:pathology* / Q000601:surgery; D000070598:Anterior Cruciate Ligament Injuries; D059549:Anterior Cruciate Ligament Reconstruction / Q000009:adverse effects*; D003937:Diagnosis, Differential; D005189:False Positive Reactions; D005260:Female; D006801:Humans; D007592:Joint Diseases / Q000209:etiology* / Q000473:pathology*; D007718:Knee Injuries / Q000473:pathology / Q000601:surgery; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D012421:Rupture / Q000473:pathology; D055815:Young Adult