title: Transtibial ACL femoral tunnel preparation increases odds of repeat ipsilateral knee surgery.
abstract: BACKGROUND
  Recent efforts to improve the results of anterior cruciate ligament (ACL) reconstruction have focused on placing the femoral tunnel anatomically. Medial portal femoral tunnel techniques facilitate drilling of femoral tunnels that are more anatomic than those made with transtibial techniques. Few studies have compared the clinical outcomes of these two femoral tunnel techniques. We hypothesized that the transtibial technique is associated with decreased Knee injury and Osteoarthritis Outcome Scores (KOOS) and an increased risk of repeat surgery in the ipsilateral knee when compared with the anteromedial portal technique.
  
  
  METHODS
  Four hundred and thirty-six patients who had undergone primary isolated autograft ACL reconstruction with a transtibial (229 patients) or anteromedial portal (207 patients) technique in 2002 or 2003 were identified in a prospective multicenter cohort. A multiple linear regression model was used to determine whether surgical technique (transtibial or anteromedial portal) was a significant predictor of KOOS at six years postoperatively, after controlling for preoperative KOOS, patient age, sex, activity level, body mass index (BMI), smoking status, graft type, and the presence of meniscal and chondral pathology at the time of reconstruction. A multiple logistic regression model was used to determine whether surgical technique was a significant predictor of repeat ipsilateral knee surgery, after controlling for patient age and activity level, graft type, and meniscal pathology at the time of reconstruction.
  
  
  RESULTS
  Postoperative KOOS were available for 387 patients (88.8%). Femoral tunnel drilling technique was not a predictor of the KOOS Quality of Life subscore (p = 0.72) or KOOS Function, Sports and Recreational Activities subscore (p = 0.36) at the six-year follow-up evaluation. Data regarding the prevalence of repeat surgery were available for 380 patients. Femoral tunnel technique was a significant predictor of subsequent ipsilateral knee surgery (odds ratio [OR] = 2.49, 95% confidence interval [CI] = 1.30 to 4.78, p = 0.006).
  
  
  CONCLUSIONS
  Patients who underwent ACL reconstruction with a transtibial technique had significantly higher odds of undergoing repeat ipsilateral knee surgery relative to those who underwent reconstruction with an anteromedial portal technique.
authors.affiliation: Shelbyville Orthopaedics and Sports Medicine, 101 Stonecrest, #2, Shelbyville, KY 40065.
authors.forename: Andrew
authors.initials: A
authors.lastname: Duffee
authors.forename: Robert A
authors.initials: RA
authors.lastname: Magnussen
authors.forename: Angela D
authors.initials: AD
authors.lastname: Pedroza
authors.forename: David C
authors.initials: DC
authors.lastname: Flanigan
authors.forename: Christopher C
authors.initials: CC
authors.lastname: Kaeding
mesh_terms: D000293:Adolescent; D000328:Adult; D016118:Anterior Cruciate Ligament / Q000601:surgery; D000070598:Anterior Cruciate Ligament Injuries; D059549:Anterior Cruciate Ligament Reconstruction / Q000379:methods*; D064592:Autografts; D005260:Female; D005269:Femur / Q000601:surgery*; D006801:Humans; D007719:Knee Joint / Q000601:surgery; D008297:Male; D012086:Reoperation; D013977:Tibia / Q000601:surgery*; D055815:Young Adult