Seven percent of primary anterior crucial ligament reconstruction patients have arthroscopic resection of cyclops lesions within 2 years: A cohort study of 2556 patients

Purpose After anterior cruciate ligament reconstruction (ACL‐R), a localised scar tissue called cyclops lesion may develop anterior to the graft causing knee extension deficits, pain, oedema, clicking and reduced knee function. This study determined the incidence of arthroscopic resection of a cyclops lesion within 2 years after ACL‐R and investigated the associations of patient characteristics and surgical techniques with the need for arthroscopic resection of a cyclops lesion. Methods This study included patients who underwent primary ACL‐R with adult surgical technique from 2005 to 2019 at Aarhus University Hospital, Denmark. The cohort was identified in a national registry. To identify patients who had resected a cyclops lesion within the first 2 years after ACL‐R, patients' surgical records were reviewed. Results In 2005–2019, 2556 patients underwent primary ACL‐R; 176 developed cyclops lesions that were resected within 2 years, equivalent to an incidence of 6.9% (95% confidence interval [CI]: 5.9–7.9). When stratified by the femoral drilling technique used, this incidence was 8.9% (95% CI: 7.7–10.3) with the anteromedial technique and 1.9% (95% CI: 1.0–3.1) with the transtibial technique. The incidence was 8.5% (95% CI: 6.8–10.3) in women and 5.7% (95% CI: 4.6–7.1) in men. Age, graft choice and the presence of cartilage or meniscal lesions did not affect the incidence. Conclusion The overall incidence of a cyclops lesion removal within 2 years post‐ACL‐R was 6.9%. This was five times higher with the anteromedial femoral drilling technique than with the transtibial technique. Women had a 47% higher incidence of cyclops lesion removal than men. This is relevant for the surgeon when planning an ACL‐R. Level of Evidence Level II