2025 ISAKOS Congress in Munich, Germany

2025 ISAKOS Biennial Congress Paper


Recurrent Cyclops Syndrome: Characteristics and Risk Factors in a Retrospective Observational Study

Victor Meissburger, MD FRANCE
Mohamad K Moussa, MD, Msc, FEBOT FRANCE
Alexandre Hardy, MD, PhD, Paris, Europe FRANCE
Olivier Grimaud, MD, Paris FRANCE
Antoine Gerometta, MD, Paris FRANCE
Nicolas Lefèvre, MD, Paris FRANCE

Clinique du Sport , Paris , FRANCE

FDA Status Not Applicable

Summary

Re-cyclops syndrome occured in 6.9% of patients post-cyclops arthrolysis and significant risk factors include age, type of graft, absence of LEAP, and shorter time from ACL surgery to initial cyclops formation

Abstract

Background

Cyclops syndrome is a complication of Anterior Cruciate Ligament (ACL) reconstruction. Its recurrence (re-cyclops) after surgical treatment is poorly understood, with limited research on risk factors and characteristics.
Hypothesis/Purpose: determine the recurrence rate of cyclops syndrome after prior surgery and identify associated risk factors. The hypothesis was that re-cyclops rate is non negligeable and is associated with certain modifiable and non-modifiable risk factors.
Study design: Retrospective Cohort Study, level III

Methods

This study included all patients with cyclops syndrome operated at a sports surgery center between 2005 and 2022. The primary outcome was the rate of re-cyclops and its associated risk factors. Secondary outcomes included knee mobility pre-operatively and six weeks post-operatively, compared between primary and revision cyclops cases.

Results

The study included 359 patients with a mean age of 25.34 ± 6.12 years and a male predominance of 57.38%. The rate of re-cyclops was 6.9% (25 patients out of 359). Risk factors identified in multivariate analysis were: age (patients older than 27 years, OR 11.63, 95% CI [3.41 - 39.73], p < .001), type of graft (quadrupled semitendinosus graft, OR 5.09, 95% CI [1.05 - 24.74], p = .044; bone patellar tendon bone grafts, OR 26.01, 95% CI [6.52 - 103.82], p < .001), absence of Lateral ExatraArticular procedure (LEAP, OR 8.49, 95% CI [1.64 - 43.97], p = .011), and delay from ACL surgery to first cyclops surgery of less than 7 months (OR 13.62, 95% CI [4.07 - 45.66], p < .001). At six-weeks post-operatively, mean residual flessum, after first arthrolysis was significantly higher in the relapse group than in no relapse group (0,05 degrees ± 0,5 versus 5 ± 2,83, p<.001).

Conclusion

Re-cyclops syndrome occured in 6.9% of patients post-cyclops arthrolysis. Significant risk factors include age, type of graft, absence of LEAP, and shorter time from ACL surgery to initial cyclops formation. Among patients operated the first time for cyclops, those who had residual flessum at 6-weeks post-operatively, were more likely to experience re-cylops.

Keywords: recurrent cyclops syndrome, ACL, arthroscopic arthrolysis