title: Intercondylar notch size influences cyclops formation after anterior cruciate ligament reconstruction.
abstract: OBJECTIVE
  The purpose of this study was to investigate the incidence of cyclops lesions and its relationship with the cross-sectional area of the intercondylar notch.
  
  
  METHODS
  For this study, 55 patients (24 male and 31 female) underwent follow-up arthroscopy after bi-socket anterior cruciate ligament reconstruction with hamstring tendon grafts were included. All patients underwent magnetic resonance imaging measurements of intercondylar notch dimensions. We compared the femoral intercondylar notch sizes and bone tunnel sizes between knees with cyclops lesions (cyclops group) and those without cyclops lesions (no-cyclops group). The mean percentage of the tunnel size to the cross-sectional area of the femoral intercondylar notch was also compared between the groups. The median follow-up duration was 3.8 years.
  
  
  RESULTS
  Cyclops lesions were found in 15 of the 55 knees (27.3 %) on second-look arthroscopy (cyclops group). Only 6 of the 55 knees (10.9 %) had extension loss (cyclops syndrome). The cyclops group included 3 men and 12 women. The two groups showed a statistical difference in sex variation (P = 0.04). No significant differences were found in the femoral and tibial tunnel sizes between the two groups. The cross-sectional area of the femoral intercondylar notch was significantly smaller in the cyclops group (251.7 ± 63.2 mm(2)) than in the no-cyclops group (335.6 ± 77.6 mm(2)) (P < 0.001). The percentage of the total femoral tunnel size to the cross-sectional area of the femoral intercondylar notch was significantly higher in the cyclops group (18.6 ± 5.3 %) than in the no-cyclops group (13.2 ± 3.6 %) (P = 0.02).
  
  
  CONCLUSIONS
  A smaller intercondylar notch size may be a potential risk factor for cyclops lesion formation.
  
  
  METHODS
  Case-control study, Level IV.
authors.affiliation: Department of Orthopaedic Surgery, Science of Functional Recovery and Reconstruction, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Kita-ku, Okayama, 700-8558, Japan.
authors.forename: Masataka
authors.initials: M
authors.lastname: Fujii
authors.forename: Takayuki
authors.initials: T
authors.lastname: Furumatsu
authors.forename: Shinichi
authors.initials: S
authors.lastname: Miyazawa
authors.forename: Yukimasa
authors.initials: Y
authors.lastname: Okada
authors.forename: Takaaki
authors.initials: T
authors.lastname: Tanaka
authors.forename: Toshifumi
authors.initials: T
authors.lastname: Ozaki
authors.forename: Nobuhiro
authors.initials: N
authors.lastname: Abe
mesh_terms: D000328:Adult; D016118:Anterior Cruciate Ligament / Q000601:surgery*; D000070598:Anterior Cruciate Ligament Injuries; D059549:Anterior Cruciate Ligament Reconstruction / Q000009:adverse effects*; D001182:Arthroscopy / Q000379:methods; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D007718:Knee Injuries / Q000175:diagnosis / Q000601:surgery*; D007719:Knee Joint / Q000473:pathology / Q000601:surgery*; D008297:Male; D011183:Postoperative Complications / Q000175:diagnosis / Q000209:etiology*; D011446:Prospective Studies