title: Increased risk of revision with hamstring tendon grafts compared with patellar tendon grafts after anterior cruciate ligament reconstruction: a study of 12,643 patients from the Norwegian Cruciate Ligament Registry, 2004-2012.
abstract: BACKGROUND
  The graft choice for anterior cruciate ligament reconstruction (ACLR) is controversial. Hamstring tendon (HT) autografts and patellar tendon (PT) autografts are the most common grafts used and have shown similar subjective and objective outcomes.
  
  
  OBJECTIVE
  To compare the revision rate between HT and PT autografts used in ACLR in Norway and to estimate the influence of patient age and sex.
  
  
  METHODS
  Cohort study; Level of evidence, 2.
  
  
  METHODS
  The study included all patients who underwent primary ACLR without concomitant ligament injuries registered in the Norwegian Knee Ligament Registry from 2004 through 2012. The cohort was stratified by age group (15-19, 20-29, and ≥30 years) and autograft type (HT or PT). Revision rates at 1, 2, and 5 years were calculated using the Kaplan-Meier analysis, and hazard ratios (HRs) for revision were calculated using multivariate Cox regression models.
  
  
  RESULTS
  With a mean follow-up of 4.0 years, 12,643 primary ACLRs were identified, with 3428 PT and 9215 HT grafts, among which 69 revisions with PT grafts and 362 revisions with HT grafts were performed. The overall 5-year revision rate was 4.2%. A higher revision rate was recorded for HT versus PT grafts at all follow-up times. When adjusted for sex, age, and type of graft, the HR for revision was 2.3 (95% CI, 1.8-3.0) for HT grafts compared with PT grafts. The HR for revision in the youngest age group was 4.0 (95% CI, 3.1-5.2) compared with the oldest age group. Sex had no effect on the revision rate.
  
  
  CONCLUSIONS
  Patients with HT grafts had twice the risk of revision compared with patients with PT grafts. Younger age was the most important risk factor for revision, and no effect was seen for sex. Further studies should be conducted to identify the cause of the increased revision rate found for HT grafts.
authors: Andreas Persson, Department of Orthopaedic Surgery, Haukeland University Hospital, Jonas Lies vei 65, Bergen, 5021 Norway. andreas.persson@helse-bergen.no.
authors: Andreas
authors: A
authors: Persson
authors: Knut
authors: K
authors: Fjeldsgaard
authors: Jan-Erik
authors: JE
authors: Gjertsen
authors: Asle B
authors: AB
authors: Kjellsen
authors: Lars
authors: L
authors: Engebretsen
authors: Randi M
authors: RM
authors: Hole
authors: Jonas M
authors: JM
authors: Fevang
mesh_terms: D000293:Adolescent; D000328:Adult; D059549:Anterior Cruciate Ligament Reconstruction / Q000379:methods*; D064594:Bone-Patellar Tendon-Bone Grafts; D015331:Cohort Studies; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D009664:Norway; D017847:Patellar Ligament / Q000637:transplantation*; D012042:Registries; D012086:Reoperation / Q000706:statistics & numerical data; D012306:Risk; D013710:Tendons / Q000637:transplantation*; D014182:Transplantation, Autologous; D016896:Treatment Outcome
keywords: ACL; graft; hamstring tendon; patellar tendon; reconstruction; revision