title: Age as a predictor of residual muscle weakness after anterior cruciate ligament reconstruction.
abstract: OBJECTIVE
  The objective of this study was to reveal the predicting factors for muscle recovery in the lower extremity after anterior cruciate ligament (ACL) reconstruction.
  
  
  METHODS
  One hundred and thirty-five (135) patients who underwent ACL reconstruction using hamstring autograft were evaluated. Exclusion criteria were bilateral ACL injury, chondral treatment and multiple ligament injury. Nonanatomical single-bundle reconstruction (SB) was performed in 79 patients, and anatomical double-bundle reconstruction (DB) was performed in 56 patients. Strength of quadriceps and knee flexion muscles were assessed at 60°/s using a Cybex II dynamometer (Lumex, Ronkonkoma, NY) at 3, 6 and 9 months after ACL reconstruction. Anterior tibial translation and pivot shift test were also evaluated. The medical records were reviewed to extract the following information: age, gender, the amount of pre and postoperative KT 1000, technique of reconstruction (SB or DB) and postoperative knee rotation.
  
  
  RESULTS
  No significant difference of muscle recovery in the lower extremity was observed at any time point after ACL reconstruction between the SB and DB groups. The DB group showed significantly better postoperative antero-posterior and rotational knee laxity than the SB group. Logistic regression analysis showed significant correlation with only age and muscle recovery.
  
  
  CONCLUSIONS
  For clinical relevance, there is a risk of muscle recovery delay when ACL reconstruction is performed in elderly patients. Anatomical DB reconstruction resulted in significantly better knee stability, but had no positive effect on muscle recovery.
  
  
  METHODS
  Retrospective study, Level II.
authors.affiliation: Division of Rehabilitation Medicine, Gunma University Hospital, Showa machi 3-39-15, Maebashi, Gunma, Japan. sekaiwoseisu@yahoo.co.jp
authors.forename: Takanori
authors.initials: T
authors.lastname: Iriuchishima
authors.forename: Kenji
authors.initials: K
authors.lastname: Shirakura
authors.forename: Takashi
authors.initials: T
authors.lastname: Horaguchi
authors.forename: Naoki
authors.initials: N
authors.lastname: Wada
authors.forename: Makoto
authors.initials: M
authors.lastname: Sohmiya
authors.forename: Masayuki
authors.initials: M
authors.lastname: Tazawa
authors.forename: Freddie H
authors.initials: FH
authors.lastname: Fu
mesh_terms: D000328:Adult; D000367:Age Factors; D016118:Anterior Cruciate Ligament / Q000601:surgery; D000070598:Anterior Cruciate Ligament Injuries; D059549:Anterior Cruciate Ligament Reconstruction / Q000379:methods / Q000534:rehabilitation; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007593:Joint Instability / Q000209:etiology; D007718:Knee Injuries / Q000150:complications / Q000534:rehabilitation / Q000601:surgery*; D007866:Leg / Q000503:physiopathology; D016015:Logistic Models; D008297:Male; D018908:Muscle Weakness / Q000209:etiology*; D011183:Postoperative Complications / Q000209:etiology*; D016059:Range of Motion, Articular; D020127:Recovery of Function; D012189:Retrospective Studies