title: Correlation between fixation systems elasticity and bone tunnel widening after ACL reconstruction.
abstract: BACKGROUND
  Femoral and tibial tunnel widening (TW) after ACL reconstruction is a phenomenon increasing talk in the literature. It is underlying biological and mechanical causes.
  
  
  OBJECTIVE
  The aim of this study was to evaluate the relationship between bone tunnel enlargement and two different ACL fixation systems.
  
  
  METHODS
  40 patient underwent ACL reconstruction with hamstring; randomly divided into group A with 20 patients treated with stiff systems (femoral Rigidfix and tibial interference screw), and into group B, with 20 patients treated with morel elastic system (femoral and tibial Tight-rope). Evaluated postoperatively with knee MRI at 40 days, 3 months, 6 months to measure bone tunnel diameters widening.
  
  
  RESULTS
  At 40 days tunnel widening between two groups shows no statistically difference. At 3 months postoperatively, femoral bone tunnel widening amounted on average to 1.84 mm in middle of tunnel and 1 mm at the mouth in joint in group A, and respectively 3.2 mm and 2.5 mm in group B (p<0.05). Tibial tunnel widening was 1.24 mm at the mouth in joint and 1.3 mm in middle in group A and respectively 2.26 mm and 2.43 mm in group B (p<0.05). At 6 months femoral tunnel widening amounted on average to 2.45 mm in middle and 1.35 mm at the mouth in joint in group A and respectively 3.5 mm and 2.7 mm in group B (p<0.01). Tibial tunnel widening amounted on average to 1.27 at mouth in joint and 1 mm in middle of tunnel in group A and respectively 2.6 mm and 2.3 mm in group B (p<0.01).
  
  
  CONCLUSIONS
  This study results suggest elastic fixation system increases bone tunnel enlargement after ACL reconstruction with hamstring without correlation with worse clinical performance.
  
  
  METHODS
  IV.
authors.affiliation: Department of Basic Medical Sciences, Neurosciences and Sensory Organs, UO Orthopaedics and Traumatology, Azienda Ospe - daliero Universitaria "Policlinico di Bari", Bari, Italy.
authors.forename: Nicola
authors.initials: N
authors.lastname: Giorgio
authors.affiliation: Department of Basic Medical Sciences, Neurosciences and Sensory Organs, UO Orthopaedics and Traumatology, Azienda Ospe - daliero Universitaria "Policlinico di Bari", Bari, Italy.
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Moretti
authors.affiliation: UO University Diagnostic Radiology, Azienda Ospedaliero Universitaria "Policlinico di Bari", Bari, Italy.
authors.forename: Paolo
authors.initials: P
authors.lastname: Pignataro
authors.affiliation: Department of Basic Medical Sciences, Neurosciences and Sensory Organs, UO Orthopaedics and Traumatology, Azienda Ospe - daliero Universitaria "Policlinico di Bari", Bari, Italy.
authors.forename: Massimiliano
authors.initials: M
authors.lastname: Carrozzo
authors.affiliation: Department of Basic Medical Sciences, Neurosciences and Sensory Organs, UO Orthopaedics and Traumatology, Azienda Ospe - daliero Universitaria "Policlinico di Bari", Bari, Italy.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Vicenti
authors.affiliation: Department of Basic Medical Sciences, Neurosciences and Sensory Organs, UO Orthopaedics and Traumatology, Azienda Ospe - daliero Universitaria "Policlinico di Bari", Bari, Italy.
authors.forename: Biagio
authors.initials: B
authors.lastname: Moretti
keywords: anterior cruciate ligament reconstruction; clinical outcome; graft fixation methods; tunnel widening