title: Outcome of Patellar Tendon Versus 4-Strand Hamstring Tendon Autografts for Anterior Cruciate Ligament Reconstruction: A Systematic Review and Meta-analysis of Prospective Randomized Trials.
abstract: OBJECTIVE
  To compare clinical outcomes of anterior cruciate ligament (ACL) reconstruction and investigate whether the clinical results of 4-strand hamstring tendon (HT) reconstruction are still inferior to that of the patellar tendon (PT).
  
  
  METHODS
  We performed a comprehensive systematic review and meta-analysis of the English literature on PubMed, Scopus, Web of Science, and the Cochrane register for papers that compared clinical outcomes of PT versus HT for ACL reconstruction. Outcome measures analyzed included rate of rerupture, KT-1000, International Knee Documentation Committee grade, Lachman, pivot shift, Lysholm score, Tegner Activity Scale, anterior knee pain, and discomfort on kneeling.
  
  
  RESULTS
  We included 19 studies from an initial 1,168 abstracts for the systematic review, and, eventually, 19 studies were included in the meta-analysis. The study population consisted of a total of 1784 patients. The average follow-up duration was 58.8 months. We found significant differences in favor of the HT technique in the domains of anterior knee pain, kneeling pain, and restriction in the range of active extension ("extension deficit"). We found no differences between the PT and HT technique in terms of rerupture rate. There were no clinically significant differences for the outcomes of Lysholm score and Tegner Activity Scale as well as the KT-1000 side-to-side at maximum manual force.
  
  
  CONCLUSIONS
  Contemporary 4-strand HT ACL reconstruction is comparable with the PT technique in terms of clinical stability and postoperative functional status across most parameters studied. The HT technique carries lower risk of postoperative complications such as anterior knee pain, kneeling discomfort, and extension deficit. Primary ACL reconstruction using the 4-strand HT technique achieves clinical results that are comparable with the PT technique with significantly less postoperative complications.
  
  
  METHODS
  Level I, systemic review and meta-analysis of Level I studies.
authors.affiliation: National University Hospital Sports Centre, National University Health System, Singapore.
authors.forename: Michael Y K
authors.initials: MY
authors.lastname: Chee
authors.affiliation: National University Hospital Sports Centre, National University Health System, Singapore. Electronic address: yongsheng_chen@nuhs.edu.sg.
authors.forename: Yongsheng
authors.initials: Y
authors.lastname: Chen
authors.affiliation: Department of Orthopaedic Surgery, Ng Teng Fong General Hospital, Singapore.
authors.forename: Christopher Jon
authors.initials: CJ
authors.lastname: Pearce
authors.affiliation: University Orthopaedic Hand and Microsurgery Cluster, National University Health System, Singapore.
authors.forename: Diarmuid P
authors.initials: DP
authors.lastname: Murphy
authors.affiliation: National University Hospital Sports Centre, National University Health System, Singapore.
authors.forename: Lingaraj
authors.initials: L
authors.lastname: Krishna
authors.affiliation: University Orthopaedic Hand and Microsurgery Cluster, National University Health System, Singapore.
authors.forename: James H P
authors.initials: JH
authors.lastname: Hui
authors.affiliation: University Orthopaedic Hand and Microsurgery Cluster, National University Health System, Singapore.
authors.forename: Wilson E J
authors.initials: WE
authors.lastname: Wang
authors.affiliation: Saw Swee Hock School of Public Health, National University of Singapore, Singapore.
authors.forename: Bee Choo
authors.initials: BC
authors.lastname: Tai
authors.affiliation: University Orthopaedic Hand and Microsurgery Cluster, National University Health System, Singapore.
authors.forename: Abhijeet A
authors.initials: AA
authors.lastname: Salunke
authors.affiliation: Department of Orthopaedic Surgery, Ng Teng Fong General Hospital, Singapore.
authors.forename: Xi
authors.initials: X
authors.lastname: Chen
authors.affiliation: National University Hospital Sports Centre, National University Health System, Singapore.
authors.forename: Zackary K H
authors.initials: ZK
authors.lastname: Chua
authors.affiliation: University Orthopaedic Hand and Microsurgery Cluster, National University Health System, Singapore.
authors.forename: Kandiah
authors.initials: K
authors.lastname: Satkunanantham
mesh_terms: D059549:Anterior Cruciate Ligament Reconstruction / Q000379:methods*; D064592:Autografts; D000070632:Hamstring Tendons / Q000637:transplantation*; D006801:Humans; D017847:Patellar Ligament / Q000637:transplantation*; D000071066:Patient Reported Outcome Measures; D011183:Postoperative Complications; D016032:Randomized Controlled Trials as Topic