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Outcome and Tunnel Widening After ACL Reconstruction: Comparison of Aperture and Cortical Fixation

The recruitment status of this study is unknown. The completion date has passed and the status has not been verified in more than two years.
Verified January 2013 by Medical University Innsbruck.
Recruitment status was:  Recruiting
Information provided by (Responsible Party):
Dr. René El Attal, Medical University Innsbruck Identifier:
First received: December 4, 2012
Last updated: January 15, 2013
Last verified: January 2013


Failure of graft incorporation and tunnel widening (TW) after anterior cruciate ligament (ACL) reconstruction has been frequently reported in the literature. The etiology of TW is still not fully understood.

Patients and Methods:

This is a prospective randomized study including 60 patients, conducted in a Level I trauma center in Innsbruck, Austria. The study protocol was approved by the hospital ethics committee. This study is planned and conducted following the Consolidated Standards on Reporting Trials (CONSORT) guidelines. Aperture fixation is performed using BioComposite interference screws (Arthrex, Naples, FL). Extracortical fixation is performed using the ACL Tightrope (Arthrex, Naples, FL). TW is measured on CT scan postoperative, after 6 and 24 months. Clinical outcome is determined at 1, 2 after reconstruction, IKDC with KOOS Knee-related QoL subscale, Lysholm, Tegner Activity scores, hop tests and KT-1000 measurements are performed.


The purpose of this randomized controlled trail is to determine the influence of two different fixation methods on TW and clinical outcome after anatomic ACL reconstruction using hamstring graft in young and active patients.

Condition Intervention
ACL Anterior Cruciate Ligament Injury
Device: Biocomposite interference screw
Device: Extracortical ACL Tightrope fixation

Study Type: Interventional
Study Design: Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Open Label
Primary Purpose: Treatment
Official Title: Clinical Outcome and Tunnel Widening After Hamstring Anterior Cruciate Ligament Reconstruction: A Prospective Randomized Computed Tomography - Based Trial Comparing Aperture With Cortical Fixation

Resource links provided by NLM:

Further study details as provided by Medical University Innsbruck:

Primary Outcome Measures:
  • Change of tunnel volume and diameter from baseline up to 2 year follow up [ Time Frame: 1-2 days before (knee) operation, 6 months FU, 2 year FU ]
    CT tunnel measurements are conducted. Tunnel volume are calculated by CT volumetry measured in mm³ and tunnel diameter is measured in mm.

Secondary Outcome Measures:
  • Clinical outcome: international knee score evaluating objective and subjective knee outcome variables [ Time Frame: 1-2 days before (knee)operation, 6 months FU, 1 year FU, 2 year FU ]

    Clinical outcome measured by IKDC (INTERNATIONAL KNEE DOCUMENTATION COMMITTEE) Subjective questionnaire (symptoms, sports activity, knee function): scaled from 0-100.

    Objective evaluation form (radiological assessment of cartilage and menisci, functional knee examination, range of motion): scaled A-D

  • Clinical outcome: influence on quality of life after knee ACL reconstruction [ Time Frame: 1-2 days before (knee)operation, 6 month FU, 1 year FU, 2year FU ]
    Clinical outcome measured by KOOS Knee related QoL subscale

  • Clinical outcome: subjective evaluation of knee function [ Time Frame: 1-2 days before (knee)operation, 6 months FU, 1 year FU, 2 year FU ]
    Clinical outcome measured by Lysholm Score: subjective questionnaire

  • Clinical outcome: return to sports activity [ Time Frame: 1-2 days before (knee)operation, 6 months FU, 1 year FU, 2 year FU ]
    Clinical outcome measured by Tegner Activity scores: sports activity level

  • Clinical outcome: strength in single leg jumping after ACL reconstruction [ Time Frame: 1-2 days before (knee)operation, 6 months FU, 1 year FU, 2 year FU ]
    Single leg hop test measured in cm. Comparing the injured and healthy knee.

  • Clinical outcome: objective knee anterior stability [ Time Frame: 1-2 days before (knee)operation, 6 months FU, 1 year FU, 2 year FU ]
    Clinical outcome measured by KT1000 arthrometer measurements in mm.

Estimated Enrollment: 60
Study Start Date: January 2013
Estimated Study Completion Date: January 2016
Estimated Primary Completion Date: January 2016 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Biocomposite interference screw
Thirty patients treated with ACL reconstruction and graft fixation is performed using Biocomposite interference screw on tibial and femoral side. Patients are randomized to one of the two study arms.
Device: Biocomposite interference screw
Extracortical ACL Tightrope fixation
Thirty patients treated with ACL reconstruction and graft fixation is performed using extracortical ACL Tightrope fixation on tibial and femoral side. Patients are randomized to one of the two study arms.
Device: Extracortical ACL Tightrope fixation

  Show Detailed Description


Ages Eligible for Study:   18 Years to 40 Years   (Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  1. The ACL injury can be either "isolated" or combined with one or several of the following injuries visualized on MRI and/or arthroscopy:

    • A meniscus tear that is either left untreated or treated with a partial resection
    • A small, stable meniscus tear treated with fixation, but fixation not interfering with the rehabilitation protocol
    • Cartilage changes verified on MRI with arthroscopically determine intact surface
  2. A radiographic examination with normal joint status or combined with either one of the following finding:

    • A small avulsed fragment located laterally, usually described as a Second fracture
    • JSN grade 1 or osteophytes grade 1 as determined by the OARSI atlas (Altman et al. 1995)
  3. Agreement to participate in the study and signed informed consent prior to inclusion.

Exclusion Criteria:

1.Presence of one of the following associated injuries to the index knee as visualized on MRI and/or arthroscopy:

  • An unstable longitudinal meniscus tear that requires repair and where the following postoperative treatment (i.e. bracing and limited ROM) interferes with the rehabilitation protocol
  • Bi-compartmental extensive meniscus resection
  • A cartilage injury representing a full thickness loss down to bone
  • A total rupture of MCL/LCL as visualized on MRI
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its identifier: NCT01755819

Contact: Rene EL Attal, Dr. 0043-50-504-80875

Medical University Innsbruck (Traumasurgery) Recruiting
Innsbruck, Tyrol, Austria, 6020
Contact: René El Attal, Dr.   
Contact: Mariette Fasser, MSc   
Sub-Investigator: Raul Mayr, Dr.         
Sponsors and Collaborators
Medical University Innsbruck
Principal Investigator: Rene El Attal, Dr. Medical University Innsbruck (Traumasurgery)
  More Information

Responsible Party: Dr. René El Attal, Principal Investigator, Medical University Innsbruck Identifier: NCT01755819     History of Changes
Other Study ID Numbers: ACL Tightrope vs. Biocomposite
Study First Received: December 4, 2012
Last Updated: January 15, 2013 processed this record on April 26, 2017