title: Clinical Outcomes After Anatomic Double-Bundle Anterior Cruciate Ligament Reconstruction: Comparison of Extreme Knee Hyperextension and Normal to Mild Knee Hyperextension.
abstract: OBJECTIVE
  The aim of this study was to compare postoperative outcomes after anatomic double-bundle anterior cruciate ligament reconstruction (ACLR) in extreme knee hyperextension versus normal to mild knee hyperextension.
  
  
  METHODS
  For 100 patients who underwent anatomic double-bundle ACLR using semitendinosus tendon, we evaluated the side-to-side difference (SSD) in anterior tibial translation (measured on stress radiographs) and rotational stability (assessed by the pivot-shift test) 2 years after surgery. Loss of extension (LOE) was evaluated on lateral radiographs of both knees in full extension, and graft integrity was assessed during second-look arthroscopy 1 to 2 years after surgery. In accordance with the Beighton and Honan criteria, patients with an extension angle less than or equal to 10° in the contralateral uninjured knee composed the group with 10° or less hyperextension (N group), and those with an extension angle of greater than 10° composed the group with more than 10° hyperextension (H group). Postoperative results were compared between these groups.
  
  
  RESULTS
  Mean extension angles in the N and H groups were 5.8° ± 2.9° and 14.7° ± 3.0°, respectively. The mean SSD in anterior translation was 2.2 ± 2.9 mm for the N group and 2.8 ± 2.9 mm for the H group, with no significant difference. The positive ratios on the pivot-shift test were not significantly different between the groups. Mean LOE in the N and H groups was -0.7° ± 3.7° and 1.3° ± 3.3°, respectively, with a significant difference (P = .007). During second-look arthroscopy, 6 of 58 knees in the N group and 13 of 42 knees in the H group had superficial graft laceration of the anteromedial bundle graft, with a significant difference (P = .01) seen between groups.
  
  
  CONCLUSIONS
  Anatomic double-bundle ACLR for extreme knee hyperextension may attain the same postoperative anterior and rotational stability as seen in knees with normal to mild hyperextension. However, it increased superficial graft laceration.
  
  
  METHODS
  Level III, retrospective comparative study.
authors: Department of Orthopaedic Surgery, Gunma University Graduate School of Medicine, Maebashi, Gunma, Japan; Department of Orthopaedic Surgery, Japan Community Health Care Organization, Gunma Central Hospital, Maebashi, Gunma, Japan.
authors: Kenichi
authors: K
authors: Saito
authors: Department of Orthopaedic Surgery, Japan Community Health Care Organization, Gunma Central Hospital, Maebashi, Gunma, Japan. Electronic address: kazuhisa@zg7.so-net.ne.jp.
authors: Kazuhisa
authors: K
authors: Hatayama
authors: Department of Orthopaedic Surgery, Japan Community Health Care Organization, Gunma Central Hospital, Maebashi, Gunma, Japan.
authors: Masanori
authors: M
authors: Terauchi
authors: Department of Orthopaedic Surgery, Japan Community Health Care Organization, Gunma Central Hospital, Maebashi, Gunma, Japan.
authors: Keiichi
authors: K
authors: Hagiwara
authors: Department of Orthopaedic Sports Surgery, Asakura Sports Rehabilitation Clinic, Maebashi, Gunma, Japan.
authors: Hiroshi
authors: H
authors: Higuchi
authors: Department of Orthopaedic Surgery, Gunma University Graduate School of Medicine, Maebashi, Gunma, Japan.
authors: Kenji
authors: K
authors: Takagishi
mesh_terms: D000293:Adolescent; D000328:Adult; D016118:Anterior Cruciate Ligament / Q000601:surgery*; D000070598:Anterior Cruciate Ligament Injuries; D059549:Anterior Cruciate Ligament Reconstruction / Q000379:methods*; D001182:Arthroscopy / Q000379:methods; D005260:Female; D006801:Humans; D007717:Knee / Q000502:physiology* / Q000503:physiopathology / Q000601:surgery; D008297:Male; D008875:Middle Aged; D011184:Postoperative Period; D012189:Retrospective Studies; D024162:Second-Look Surgery; D013710:Tendons / Q000637:transplantation; D013848:Thigh / Q000601:surgery; D013977:Tibia / Q000502:physiology; D016896:Treatment Outcome; D055815:Young Adult