title: Does adjustable-loop femoral cortical suspension loosen after anterior cruciate ligament reconstruction? A retrospective comparative study.
abstract: BACKGROUND
  Recent biomechanical research has suggested that adjustable-loop graft suspension constructs in anterior cruciate ligament (ACL) reconstruction may loosen after deployment. Our objective was to compare short-term knee stability and graft failure rate between adjustable-loop and fixed-loop femoral cortical suspension in patients undergoing primary ACL reconstruction.
  
  
  METHODS
  A consecutive series of 188 patients who underwent primary ACL reconstruction using hamstrings autograft by a single surgeon were divided into two groups; 73 received adjustable-loop (TightRope RT (Arthrex Inc., Naples, FL)) and 115 received fixed-loop (RetroButton (Arthrex Inc., Naples, FL)) femoral cortical suspension. The two groups were compared at six months, one year, and two years postoperatively using KT-1000 arthrometer testing and graft failure rate (revision surgery, grade 2+ Lachman test, any pivot shift, >5mm side-to-side KT-1000 difference).
  
  
  RESULTS
  There was no significant difference between the two groups in maximum side-to-side difference in KT-1000 testing at six months (mean 1.51mm (adjustable-loop group) vs. 1.79mm (fixed-loop group), p=0.23), one year (mean 1.44mm vs. 1.64mm, p=0.48), or two years (mean 1.14mm vs. 1.07mm, p=0.90) postoperatively. There was no significant difference between the two groups in rate of graft failure (10% vs. 11%, p=0.71) or timing of graft failure in affected patients (mean 11.4months vs. 13.8months, p=0.51).
  
  
  CONCLUSIONS
  We found no significant difference in postoperative knee stability or graft failure rate between adjustable-loop and fixed-loop femoral cortical suspension in patients undergoing primary ACL reconstruction. Our results suggest that adjustable-loop suspension does not clinically loosen after ACL reconstruction.
  
  
  METHODS
  III (retrospective cohort study).
authors.affiliation: Duke Sports Medicine, Department of Orthopaedic Surgery, Duke University Medical Center, 280 Frank Bassett Drive, Durham, NC 27710, USA. Electronic address: drmattboyle@hotmail.com.
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Boyle
authors.affiliation: Duke Sports Medicine, Department of Orthopaedic Surgery, Duke University Medical Center, 280 Frank Bassett Drive, Durham, NC 27710, USA.
authors.forename: Tyler J
authors.initials: TJ
authors.lastname: Vovos
authors.affiliation: Department of Engineering Science, The University of Auckland, 70 Symonds Street, Auckland, New Zealand.
authors.forename: Cameron G
authors.initials: CG
authors.lastname: Walker
authors.affiliation: Duke Sports Medicine, Department of Orthopaedic Surgery, Duke University Medical Center, 280 Frank Bassett Drive, Durham, NC 27710, USA.
authors.forename: Kathryne J
authors.initials: KJ
authors.lastname: Stabile
authors.affiliation: Duke Sports Medicine, Department of Orthopaedic Surgery, Duke University Medical Center, 280 Frank Bassett Drive, Durham, NC 27710, USA.
authors.forename: Jonathan M
authors.initials: JM
authors.lastname: Roth
authors.affiliation: Duke Sports Medicine, Department of Orthopaedic Surgery, Duke University Medical Center, 280 Frank Bassett Drive, Durham, NC 27710, USA.
authors.forename: William E
authors.initials: WE
authors.lastname: Garrett
mesh_terms: D000293:Adolescent; D000328:Adult; D016118:Anterior Cruciate Ligament / Q000601:surgery; D000070598:Anterior Cruciate Ligament Injuries; D059549:Anterior Cruciate Ligament Reconstruction / Q000295:instrumentation*; D001182:Arthroscopy / Q000379:methods; D001696:Biomechanical Phenomena; D002648:Child; D005260:Female; D005269:Femur / Q000601:surgery*; D005500:Follow-Up Studies; D006801:Humans; D016268:Internal Fixators; D007718:Knee Injuries / Q000503:physiopathology / Q000601:surgery*; D007719:Knee Joint / Q000503:physiopathology / Q000601:surgery*; D008297:Male; D008422:Materials Testing; D008875:Middle Aged; D011474:Prosthesis Design; D012189:Retrospective Studies; D013536:Suture Techniques / Q000295:instrumentation*; D055815:Young Adult
keywords: ACL reconstruction; Anterior cruciate ligament; Graft failure; Knee stability