Histological and clinical analysis of knee cyclops lesions

Background and aim: Cyclops Syndrome, first described by Jackson and Schaefer in 1990, is known as a complication of anterior cruciate ligament reconstruction (ACLR). However further researches have demonstrated that cyclops can be present even without symptoms and/or in absence of ACLR, simply con-figuring itself as a lesion in patients with rupture of the native ligament. Methods: This is a retrospective cohort study in which we report our experience of 13 cyclops lesions found between 126 patients during a primary arthroscopic ACLR. Preoperative examination with tests of joint stability and range of movement measure-ment was performed and recorded. Accurate joint examination was performed during arthroscopy and the cyclops lesions found were removed and analyzed with haematoxylin-eosin coloration. Post-operative clinical examination was performed until 6 months of follow-up. Results: Histological analysis showed proliferation of dense fibroelastic polypoid nodules with a macroscopically histological aspects of a “blue eye”, hence the name Cyclops. At 6 months of follow-up after surgery, none of the patients reported pain at terminal extension or instability and they were all able to resume their previous activities. Conclusions: Our study confirmed that surgical reconstruction of the ACL is not the only condition in which the Cyclops Syndrome develops; in fact our histological analysis indicate that the Cyclops lesions develop like a reactive fibroproliferative process following the rupture of the native ACL fibers, as scar reaction to the trauma: for this reason an accurate ar-throscopic detection of these Cyclops lesions is crucial during primary ACL reconstruction in order to obtain the best surgical outcomes. (www.actabiomedica.it).