title: Factors affecting quadriceps strength recovery after anterior cruciate ligament reconstruction with hamstring autografts in athletes.
abstract: OBJECTIVE
  Patients typically return to sports activities 6-12 months after anterior cruciate ligament (ACL) reconstruction, and quadriceps strength has been used as one of the criteria to return to sports activities. The purpose of this study is to identify the factors that affect quadriceps strength recovery after ACL reconstruction with a hamstring tendon autograft 6 months after surgery.
  
  
  METHODS
  Isokinetic quadriceps strength at 60°/s was measured preoperatively and 6 months after surgery in 193 athletes who underwent ACL reconstruction with a hamstring tendon autograft. The quadriceps strength index was calculated by normalizing the peak torque of the involved leg with the uninvolved leg. The subjects were divided into two groups according to the quadriceps strength index 6 months after surgery: at least 85 % (n = 84) or less than 85 % (n = 109). Multivariate logistic regression analysis and a receiver operating curve analysis were performed.
  
  
  RESULTS
  The preoperative quadriceps strength index [odds ratio (OR) 1.02; 95 % confidence interval (CI) 1.01-1.03], age (OR 0.92; 95 % CI 0.86-0.98), sex (OR 2.45; 95 % CI 1.19-5.18), and knee pain (OR 0.17; 95 % CI 0.04-0.52) were independently associated with quadriceps strength recovery. The cut-off value of the preoperative quadriceps strength index was 70.2 % to obtain at least 85 % quadriceps strength index 6 months after surgery.
  
  
  CONCLUSIONS
  To achieve sufficient quadriceps strength recovery at the timing of return to sports activities following ACL reconstruction using a hamstring tendon autograft, preoperative quadriceps strength, age, sex, and knee pain should be considered.
  
  
  METHODS
  III.
authors.affiliation: Division of Rehabilitation Medicine, Kobe University Hospital, Kobe, Japan.|Department of Community Health Sciences, Kobe University Graduate School of Health Sciences, Kobe, Japan.
authors.forename: Yuya
authors.initials: Y
authors.lastname: Ueda
authors.affiliation: Department of Orthopaedic Surgery, Kobe University Graduate School of Medicine, 7-5-2, Kusunoki-cho, Chuo-ku, Kobe, Hyogo, 650-0017, Japan. matsushi@med.kobe-u.ac.jp.
authors.forename: Takehiko
authors.initials: T
authors.lastname: Matsushita
authors.affiliation: Department of Orthopaedic Surgery, Kobe University Graduate School of Medicine, 7-5-2, Kusunoki-cho, Chuo-ku, Kobe, Hyogo, 650-0017, Japan.
authors.forename: Daisuke
authors.initials: D
authors.lastname: Araki
authors.affiliation: Division of Rehabilitation Medicine, Kobe University Hospital, Kobe, Japan.
authors.forename: Akihiro
authors.initials: A
authors.lastname: Kida
authors.affiliation: Division of Rehabilitation Medicine, Kobe University Hospital, Kobe, Japan.
authors.forename: Kohei
authors.initials: K
authors.lastname: Takiguchi
authors.affiliation: Division of Rehabilitation Medicine, Kobe University Hospital, Kobe, Japan.
authors.forename: Yohei
authors.initials: Y
authors.lastname: Shibata
authors.affiliation: Department of Community Health Sciences, Kobe University Graduate School of Health Sciences, Kobe, Japan.
authors.forename: Kumiko
authors.initials: K
authors.lastname: Ono
authors.affiliation: Department of Community Health Sciences, Kobe University Graduate School of Health Sciences, Kobe, Japan.
authors.forename: Rei
authors.initials: R
authors.lastname: Ono
authors.affiliation: Department of Orthopaedic Surgery, Kobe University Graduate School of Medicine, 7-5-2, Kusunoki-cho, Chuo-ku, Kobe, Hyogo, 650-0017, Japan.
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Matsumoto
authors.affiliation: Department of Orthopaedic Surgery, Kobe University Graduate School of Medicine, 7-5-2, Kusunoki-cho, Chuo-ku, Kobe, Hyogo, 650-0017, Japan.
authors.forename: Koji
authors.initials: K
authors.lastname: Takayama
authors.affiliation: Division of Rehabilitation Medicine, Kobe University Graduate School of Medicine, Kobe, Japan.
authors.forename: Yoshitada
authors.initials: Y
authors.lastname: Sakai
authors.affiliation: Department of Orthopaedic Surgery, Kobe University Graduate School of Medicine, 7-5-2, Kusunoki-cho, Chuo-ku, Kobe, Hyogo, 650-0017, Japan.
authors.forename: Masahiro
authors.initials: M
authors.lastname: Kurosaka
authors.affiliation: Department of Orthopaedic Surgery, Kobe University Graduate School of Medicine, 7-5-2, Kusunoki-cho, Chuo-ku, Kobe, Hyogo, 650-0017, Japan.
authors.forename: Ryosuke
authors.initials: R
authors.lastname: Kuroda
mesh_terms: D000328:Adult; D000070598:Anterior Cruciate Ligament Injuries / Q000503:physiopathology / Q000534:rehabilitation / Q000601:surgery*; D059549:Anterior Cruciate Ligament Reconstruction / Q000379:methods / Q000534:rehabilitation*; D001265:Athletic Injuries / Q000503:physiopathology / Q000534:rehabilitation / Q000601:surgery*; D005260:Female; D005500:Follow-Up Studies; D000070632:Hamstring Tendons / Q000637:transplantation*; D006801:Humans; D016015:Logistic Models; D008297:Male; D053580:Muscle Strength / Q000502:physiology*; D052097:Quadriceps Muscle / Q000502:physiology*; D012372:ROC Curve; D020127:Recovery of Function; D000068958:Return to Sport; D014182:Transplantation, Autologous; D016896:Treatment Outcome; D055815:Young Adult
keywords: Anterior cruciate ligament reconstruction; Cut-off value; Hamstring tendon autograft; Quadriceps strength recovery