title: Isokinetic muscle strength and knee function associated with double femoral pin fixation and fixation with interference screw in anterior cruciate ligament reconstruction.
abstract: OBJECTIVE
  Intensive scheduling in sports requires athletes to resume physical activity shortly after injury. The purpose of this study was to investigate early isokinetic muscle strength and knee function on bone-patellar tendon-bone (BPTB) ACL reconstruction with double femoral pin fixation or interference screw technique.
  
  
  METHODS
  A prospective study was conducted from 2008 to 2009, with 48 athletes who received femoral BPTB fixation with interference screw (n = 26) or double pin (n = 22). Clinical (IKDC objective score and hop test) and isokinetic muscle strength (peak torque (PT), PT/body weight and flexion/extension rate (F/E) in 60 and 240°/s) were analyzed at 6 months of follow-up.
  
  
  RESULTS
  Analysis at baseline showed no differences between groups before surgery related to age, gender, associated injury, Tegner or Lysholm score; thus showing that groups were similar. During follow-up, however, there were significant differences between the two groups in some of the isokinetic muscle strength: PT/BW 60°/s (Double Pin = 200% ± 13% vs. Interference Screw = 253% ± 16%*, *P = 0.01); F/E 60°/s (Double Pin = 89% ± 29%* vs. Interference Screw = 74% ± 12%, *P = 0.04). No statistical differences between groups were observed on IKDC objective score, hop test and complications.
  
  
  CONCLUSIONS
  The significant muscle strength outcome of the interference screw group found in this study gives initial evidence that this fixation technique is useful for athletes that may need accelerated rehabilitation. Early return to sports ability signaled by isokinetic muscle strength is of clinical relevance as it is one of the main goals for athletes' rehabilitation.
authors.affiliation: Institute of Orthopedics and Traumatology, Hospital das Clínicas, School of Medicine, FIFA Medical Centre of Excellence, University of São Paulo, 333 Dr. Ovídio Pires de Campos, São Paulo, Brazil. tiago.lazzaretti@usp.br
authors.forename: Tiago Lazzaretti
authors.initials: TL
authors.lastname: Fernandes
authors.forename: Thiago Rocha
authors.initials: TR
authors.lastname: Protta
authors.forename: Felipe
authors.initials: F
authors.lastname: Fregni
authors.forename: Raul Bolliger
authors.initials: RB
authors.lastname: Neto
authors.forename: André
authors.initials: A
authors.lastname: Pedrinelli
authors.forename: Gilberto Luis
authors.initials: GL
authors.lastname: Camanho
authors.forename: Arnaldo José
authors.initials: AJ
authors.lastname: Hernandez
mesh_terms: D000293:Adolescent; D000328:Adult; D016118:Anterior Cruciate Ligament / Q000601:surgery; D000070598:Anterior Cruciate Ligament Injuries; D059549:Anterior Cruciate Ligament Reconstruction / Q000295:instrumentation / Q000379:methods* / Q000534:rehabilitation; D001265:Athletic Injuries / Q000503:physiopathology / Q000534:rehabilitation / Q000601:surgery; D001858:Bone Nails; D001863:Bone Screws; D050376:Bone-Patellar Tendon-Bone Grafting / Q000295:instrumentation / Q000379:methods* / Q000534:rehabilitation; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007718:Knee Injuries / Q000503:physiopathology / Q000534:rehabilitation / Q000601:surgery*; D007719:Knee Joint / Q000502:physiology* / Q000601:surgery; D008297:Male; D053580:Muscle Strength; D011446:Prospective Studies; D016059:Range of Motion, Articular; D020127:Recovery of Function; D053656:Tenodesis / Q000295:instrumentation / Q000379:methods* / Q000534:rehabilitation; D016896:Treatment Outcome; D055815:Young Adult