title: Comparison of hamstring tendon and patellar tendon grafts in anterior cruciate ligament reconstruction in a nationwide population-based cohort study: results from the danish registry of knee ligament reconstruction.
abstract: BACKGROUND
  The choice of graft for anterior cruciate ligament reconstruction (ACLR) remains controversial, and despite numerous studies, there is still an ongoing debate on this topic. The 2 most widely used grafts are the hamstring tendon and patellar tendon.
  
  
  OBJECTIVE
  In this study, we hypothesized that the revision rate after primary ACLR is greater when using hamstring tendon grafts compared with patellar tendon grafts.
  
  
  METHODS
  Cohort study; Level of evidence, 2.
  
  
  METHODS
  From the nationwide population-based Danish Knee Ligament Reconstruction Registry, we identified all primary ACLR procedures (n = 13,647) performed in Denmark between July 2005 and December 2011. The end point was revision ACLR. As other end points, we used objective measurements and patient-reported outcome scores. Revision rates and relative risk estimates for revision ACLR were calculated using Cox multiple regression.
  
  
  RESULTS
  The use of hamstring tendon grafts increased from 68% in 2005 to 85% in 2011. The cumulative revision rates for hamstring tendon grafts at 1 and 5 years were 0.65% (95% confidence interval [CI], 0.51%-0.82%) and 4.45% (95% CI, 3.94%-5.01%), respectively. For patellar tendon grafts, the revision rate was 0.16% (95% CI, 0.05%-0.50%) at 1 year and 3.03% (95% CI, 2.27%-4.05%) at 5 years. The adjusted overall relative risk of revision surgery in the hamstring tendon group compared with the patellar tendon group was 1.41 (95% CI, 1.03-1.92), and the adjusted relative risk of undergoing revision surgery performed after 1 and 5 years was 3.82 (95% CI, 1.20-12.2) and 1.90 (95% CI, 0.43-8.40), respectively.
  
  
  CONCLUSIONS
  In this population-based study, the use of hamstring tendon grafts in ACLR was associated with an increased risk of revision compared with patellar tendon grafts, in particular during the first year after surgery. These results demonstrate that both hamstring and patellar tendon grafts reveal good results after ACLR and suggest that graft selection should be based on an individual evaluation of patient demands and graft morbidity.
authors.affiliation: Lene Rahr-Wagner, Department of Clinical Epidemiology, Aarhus University Hospital, Olof Palmes Alle 43-45, 8200 Aarhus N, Denmark. lrw@dce.au.dk.
authors.forename: Lene
authors.initials: L
authors.lastname: Rahr-Wagner
authors.forename: Theis Muncholm
authors.initials: TM
authors.lastname: Thillemann
authors.forename: Alma Becic
authors.initials: AB
authors.lastname: Pedersen
authors.forename: Martin
authors.initials: M
authors.lastname: Lind
mesh_terms: D000293:Adolescent; D000328:Adult; D059549:Anterior Cruciate Ligament Reconstruction / Q000379:methods*; D050376:Bone-Patellar Tendon-Bone Grafting; D015331:Cohort Studies; D003718:Denmark; D005260:Female; D006801:Humans; D008297:Male; D017847:Patellar Ligament / Q000637:transplantation*; D012042:Registries; D012086:Reoperation / Q000706:statistics & numerical data; D018570:Risk Assessment; D015996:Survival Rate; D013710:Tendons / Q000637:transplantation*; D016896:Treatment Outcome
keywords: ACL; bone–patellar tendon–bone; graft choice; hamstring; patellar tendon; revision; semitendinosus/gracilis