Inverted Cyclops Lesion without Extension Block: A Case Report and Literature Review

Cyclops lesion was previously described as a fibrous lesion with a granulation tissue core originating from the tibial insertion of the anterior cruciate ligament (ACL) graft. Recently, two case reports described inverted cyclops lesions, which originated from the femoral aspect of the ACL. Both cyclops and inverted cyclops lesions are usually associated with a block to knee extension. Here we present a case of an 18-year-old female who developed a painful inverted cyclops lesion originating from the femoral notch above hamstring autograft without restriction to knee range of motion 20 months after arthroscopically assisted ACL reconstruction. The case is followed by literature review on presentation, diagnosis, and treatment of cyclops and inverted cyclops lesions.