The results of arthroscopic resection of Cyclops lesion after anterior cruciate ligament reconstruction

Background
This study evaluates the results of arthroscopic resection of Cyclops lesions that develop after anterior cruciate ligament (ACL) reconstruction.
Patients and methods
Between October 2016 and June 2021, 12 patients presented with lack of full knee extension due to Cyclops lesion after ACL reconstruction. All patients were subjected to local examination. The knee’s MRI and arthroscopy revealed the classic signs of a Cyclops lesion. The patients were treated by arthroscopic resection of these lesions. 9 patients (75%) underwent a notchplasty. After arthroscopy the patients underwent a short course of physiotherapy to regain full ROM. All patients (11 men and one women) with a mean age of 30 (25 to 40) years, were followed-up for a minimum of 12 months. Range of motion of all patients was documented.
Result
12 patients were treated with arthroscopic resection of Cyclops lesions. The average angle of knee extension improved from 15° (range 10 to 25°) to 2° (range 0 to 5°). After a minimum duration of follow-up of 12 months, full knee extension was achieved for all patients.
Conclusions
It is important to recognize a Cyclops lesion as a possible cause of extension loss in any patient with ACL reconstruction. They are usually symptomatic, and their removal can restore range of motion to levels that are very close to normal.