Influence of Cyclops Syndrome after Anterior Cruciate Ligament Reconstruction on the Functional Outcome

Background: A review of recent reports concerning the functional Outcome after treatment for Cyclops syndrome can produce contradictory results. Therefore, the purpose of this study was to evaluate the functional outcome of our patients treated for Cyclops syndrome after anterior cruciate ligament reconstruction. Methods: Between 1998 and 2006 ten patients were followed for the occurrence of a Cyclops syndrome. The Lysholm score, Marshall score and Tegner activity score was used for clinical evaluation at final follow up; in addition, a subjective assessment of knee function and knee pain on a Visual analogue scale was registered. Knee stability was measured using the KT-1000 arthrometer. Results were compared with a control group of 24 uneventful ACL reconstructions. Results: Revision arthroscopy for symptomatic extension block was performed after a mean of 6.8 months. After a mean follow-up of 23 months after second surgery all patients' regained full range of motion. The mean Lysholm score and Marshall score was 85 and 41 after Cyclops syndrome and 92 and 46 for the control group. After Cyclops syndrome patients experienced a significantly increased ACL transplant laxity but no significant difference was found concerning patient's subjective rating of knee function and knee pain. Conclusion: Although patients Subjective rating of knee function and knee pain was nearly identical in both groups objective knee scores disclosed impaired knee function in our patients treated for Cyclops syndrome.