A cyclops lesion is a bunched up area of scar tissue in the notch of the femur, usually seen as a complication of anterior cruciate ligament reconstruction.
Page updated September 2023 by Dr Sheila Strover (Clinical Editor)
The original cyclops of mythology was a one-eyed monster.
Extension deficit as a result of a cyclops lesion
The bunched up tissue causes problems with achieving full extension. There may be a complete inability to achieve full extension, or it may be possible with an uncomfortable clunk.
What cause a cyclops lesion
The problem may be triggered by doing the ACL reconstruction too early, when there is still inflammation in the area. In these circumstances the presence of bone debris can trigger the arthrofibrotic process.
- clunking- 8 weeks post ACL reconstruction
Patients discuss their experiences with the knee 'clunking' after ACL reconstruction.
Recommended strategies to prevent cyclops lesions include...."
Delaying ACLR until after recovery of ROM
Minimally invasive surgery compared with open ACLR
Creating less debris by use of a sequential reamer and thorough removal of debris
Correct tunnel positioning
Debridement in and around the bone tunnel"
Citation: Kambhampati SBS, Gollamudi S, Shanmugasundaram S, Josyula VVS. Cyclops Lesions of the Knee: A Narrative Review of the Literature. Orthop J Sports Med. 2020 Aug 28;8(8):2325967120945671. doi: 10.1177/2325967120945671. PMID: 32923503; PMCID: PMC7457408.