title: Comparisons of femoral tunnel enlargement in 169 patients between single-bundle and anatomic double-bundle anterior cruciate ligament reconstructions with hamstring tendon grafts.
abstract: OBJECTIVE
  Authors have hypothesized that the incidence and the degree of femoral tunnel enlargement after the hamstring ACL reconstruction may be significantly less in the anatomic double-bundle procedure than in single-bundle procedure. The purpose of this study is to test this hypothesis.
  
  
  METHODS
  Seventy-two patients who underwent single-bundle reconstruction (Group S) and 97 patients who underwent anatomic double-bundle reconstruction (Group D) were followed up for 2 years after surgery. The hamstring tendon grafts were used in each procedure. All of the 169 patients were examined with computed radiography, and the standard clinical evaluation methods.
  
  
  RESULTS
  In Group S, the incidence of femoral tunnel enlargement was 48.6 and 54.2% in the anteroposterior and lateral views. In Group D, the incidence of femoral anteromedial and posterolateral tunnel enlargement was 36.1 and 23.7%, respectively, in the anteroposterior view, and that of femoral anteromedial and posterolateral tunnel enlargement was 33.0 and 21.6%, respectively, in the lateral view. The incidence of femoral tunnel enlargement was significantly less in Group D than in Group S (P < 0.0133). Concerning the degree of the tunnel enlargement, a similar tendency with statistical significance was observed (P < 0.0001). In each group, there were no significant relationships between the degree of tunnel enlargement and each clinical measure.
  
  
  CONCLUSIONS
  Both the incidence and the degree of femoral tunnel enlargement after anatomic double-bundle reconstruction with the hamstring tendon grafts are significantly less than those after single-bundle reconstruction with the same graft.
  
  
  METHODS
  Prospective comparative cohort study, Level II.
authors.affiliation: Department of Sports Medicine and Joint Surgery, Hokkaido University Graduate School of Medicine, Kita-ku, Sapporo, Hokkaido, 060-8638, Japan.
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Kawaguchi
authors.forename: Eiji
authors.initials: E
authors.lastname: Kondo
authors.forename: Nobuto
authors.initials: N
authors.lastname: Kitamura
authors.forename: Shuken
authors.initials: S
authors.lastname: Kai
authors.forename: Masayuki
authors.initials: M
authors.lastname: Inoue
authors.forename: Kazunori
authors.initials: K
authors.lastname: Yasuda
mesh_terms: D000293:Adolescent; D000328:Adult; D016118:Anterior Cruciate Ligament / Q000601:surgery*; D000070598:Anterior Cruciate Ligament Injuries; D059549:Anterior Cruciate Ligament Reconstruction / Q000009:adverse effects / Q000379:methods*; D000886:Anthropometry; D001182:Arthroscopy / Q000379:methods; D015331:Cohort Studies; D005260:Female; D005269:Femur / Q000503:physiopathology; D005500:Follow-Up Studies; D006801:Humans; D007593:Joint Instability / Q000000981:diagnostic imaging / Q000453:epidemiology; D007718:Knee Injuries / Q000000981:diagnostic imaging / Q000601:surgery*; D007719:Knee Joint / Q000000981:diagnostic imaging / Q000503:physiopathology; D008297:Male; D015588:Observer Variation; D010808:Physical Examination / Q000379:methods; D011183:Postoperative Complications / Q000000981:diagnostic imaging* / Q000503:physiopathology; D011446:Prospective Studies; D016059:Range of Motion, Articular / Q000502:physiology; D013710:Tendons / Q000601:surgery* / Q000637:transplantation; D014057:Tomography, X-Ray Computed / Q000379:methods; D016896:Treatment Outcome; D055815:Young Adult