title: Clinical and operative characteristics of cyclops syndrome after double-bundle anterior cruciate ligament reconstruction.
abstract: OBJECTIVE
  The purpose of this study was to investigate the clinical and operative characteristics of cyclops lesion in a consecutive series of patients with anterior cruciate ligament (ACL) double-bundle reconstruction.
  
  
  METHODS
  Included were 387 patients who underwent an ACL double-bundle reconstruction with quadriceps or hamstring tendons and were followed up at 6 weeks and 3, 6, and 12 months for clinical examination. When a persistent extension deficit was observed 3 months postoperatively, magnetic resonance imaging was performed to eventually diagnose a cyclops syndrome, and arthroscopic removal of the nodule was performed in these cases. The aspect of the nodule was explored before debridement. These patients were reviewed at a mean follow-up of 12 months (minimum, 6 months; maximum, 20 months) after nodule debridement for evaluation.
  
  
  RESULTS
  There were 14 patients who had cyclops syndrome (3.61%); 10 cases (5.37%) occurred in the quadriceps tendon group and 4 cases (1.99%) in the hamstring tendon group. In the postoperative period these patients had a mean loss of extension of 6° (range, 5° to 15°), and 78.6% had pain and/or swelling. At the 6-week follow-up, 78.6% of the 14 patients had a significant quadriceps dysfunction associated with an active extension deficit. During arthroscopic debridement, the cyclops lesion was always located on the roof of the intercondylar notch. At the last follow-up, 12 patients had full range of motion, but an extension loss was still present in 2 patients. On the International Knee Documentation Committee objective evaluation, 78.5% of patients were graded A, 14.3% were graded B, and 7.2% were graded C.
  
  
  CONCLUSIONS
  Cyclops syndrome after double-bundle ACL reconstruction was more frequently observed with quadriceps tendon graft than with hamstring graft. Its unique characteristic is that the nodule localization is from the roof of the intercondylar notch. The majority of the patients with cyclops syndrome presented with a significant quadriceps dysfunction and an active extension deficit in the immediate postoperative period.
  
  
  METHODS
  Level IV, therapeutic case series.
authors.affiliation: Centre Orthopédique Paul Santy, 24 Av. Paul Santy, Lyon, France. sonnerycottet@aol.com
authors.forename: Bertrand
authors.initials: B
authors.lastname: Sonnery-Cottet
authors.forename: Frédéric
authors.initials: F
authors.lastname: Lavoie
authors.forename: Roger
authors.initials: R
authors.lastname: Ogassawara
authors.forename: Houssine
authors.initials: H
authors.lastname: Kasmaoui
authors.forename: Rodrigo G
authors.initials: RG
authors.lastname: Scussiato
authors.forename: Jake F
authors.initials: JF
authors.lastname: Kidder
authors.forename: Pierre
authors.initials: P
authors.lastname: Chambat
mesh_terms: D000293:Adolescent; D000328:Adult; D016118:Anterior Cruciate Ligament / Q000601:surgery*; D000070598:Anterior Cruciate Ligament Injuries; D001182:Arthroscopy / Q000009:adverse effects / Q000379:methods; D015331:Cohort Studies; D005260:Female; D005500:Follow-Up Studies; D006084:Graft Rejection / Q000453:epidemiology / Q000209:etiology; D006801:Humans; D015994:Incidence; D016916:Joint Deformities, Acquired / Q000175:diagnosis* / Q000209:etiology / Q000601:surgery*; D007718:Knee Injuries / Q000601:surgery; D007719:Knee Joint; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D010147:Pain Measurement; D011182:Postoperative Care / Q000379:methods; D011183:Postoperative Complications / Q000175:diagnosis / Q000453:epidemiology / Q000209:etiology; D016059:Range of Motion, Articular / Q000502:physiology*; D019651:Plastic Surgery Procedures / Q000009:adverse effects* / Q000379:methods*; D018570:Risk Assessment; D013577:Syndrome; D013710:Tendons / Q000637:transplantation*; D000267:Tissue Adhesions / Q000175:diagnosis / Q000209:etiology / Q000473:pathology; D016896:Treatment Outcome; D055815:Young Adult