title: Tunnel communication and increased graft signal intensity on magnetic resonance imaging of double-bundle anterior cruciate ligament reconstruction.
abstract: OBJECTIVE
  This study aimed to evaluate the association between magnetic resonance imaging (MRI) findings of tunnel communication and increased graft signal intensity (SI) and clinical evaluation of knee stability and outcome after double-bundle (DB) anterior cruciate ligament (ACL) reconstruction.
  
  
  METHODS
  Fifty-nine patients were evaluated with 1.5 T MRI and with clinical evaluation 2 years after DB ACL reconstruction. The MRI finding of tunnel communication was defined as the absence of a bony bridge between the anteromedial (AM) and posterolateral (PL) tunnels. The SI of the intra-articular portion of both grafts was analyzed on proton-density (PD)-weighted and T2-weighted images and graded on a scale, with I being a normal SI similar to that of the posterior cruciate ligament, II being > 50% of the graft having a normal SI, and III being < 50% of the graft having a normal SI. The clinical evaluation of knee stability and function included KT-1,000 arthrometric side-to-side difference, pivot shift test, and International Knee Documentation Committee (IKDC) and Lysholm knee evaluation scores. The association between the MRI findings and the clinical findings was calculated using the Fisher exact test and the 2-tailed t test.
  
  
  RESULTS
  Tunnel communication was seen in the femur in 10% of patients and in the tibia in 27% of patients. Increased graft SI was seen in 15% of the AM grafts and 59% of the PL grafts. No statistically significant association (P < .05) between the MRI findings of tunnel communication or increased graft SI and knee laxity was found.
  
  
  CONCLUSIONS
  The MRI findings of tunnel communication or increased graft SI were not associated with knee laxity 2 years after DB ACL reconstruction. Tibial tunnel communication was associated with increased range of movement with flexion, and increased AM graft SI was associated with reduced range of flexion in the knee.
  
  
  METHODS
  Level IV, therapeutic case series.
authors.affiliation: Medical Imaging Centre, Tampere University Hospital, Tampere, Finland. Electronic address: tommi.kiekara@pshp.fi.
authors.forename: Tommi
authors.initials: T
authors.lastname: Kiekara
authors.affiliation: Sports Clinic and Hospital Mehiläinen, Tampere, Finland.
authors.forename: Timo
authors.initials: T
authors.lastname: Järvelä
authors.affiliation: School of Health Sciences, University of Tampere, Tampere, Finland.
authors.forename: Heini
authors.initials: H
authors.lastname: Huhtala
authors.affiliation: Clinic Koskiklinikka, Tampere, Finland.
authors.forename: Anna-Stina
authors.initials: AS
authors.lastname: Moisala
authors.affiliation: Tampere University Hospital, Tampere, Finland.
authors.forename: Piia
authors.initials: P
authors.lastname: Suomalainen
authors.affiliation: Medical Imaging Centre, Tampere University Hospital, Tampere, Finland; Tampere University Hospital, Tampere, Finland.
authors.forename: Antti
authors.initials: A
authors.lastname: Paakkala
mesh_terms: D000328:Adult; D016118:Anterior Cruciate Ligament / Q000601:surgery; D059549:Anterior Cruciate Ligament Reconstruction / Q000379:methods*; D005260:Female; D005269:Femur / Q000601:surgery*; D006801:Humans; D007593:Joint Instability / Q000175:diagnosis / Q000601:surgery*; D007717:Knee / Q000601:surgery; D007719:Knee Joint / Q000601:surgery; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D010027:Osteotomy / Q000379:methods*; D016059:Range of Motion, Articular; D013977:Tibia / Q000601:surgery*; D013997:Time Factors; D019737:Transplants; D016896:Treatment Outcome; D055815:Young Adult