title: A Systematic Review of Failed Anterior Cruciate Ligament Reconstruction With Autograft Compared With Allograft in Young Patients.
abstract: BACKGROUND
  The advantages of allograft anterior cruciate ligament reconstruction (ACLR), which include shorter surgical time, less postoperative pain, and no donor site morbidity, may be offset by a higher risk of failure. Previous systematic reviews have inconsistently shown a difference in failure prevalence by graft type; however, such reviews have never been stratified for younger or more active patients.
  
  
  OBJECTIVE
  To determine whether there is a different ACLR failure prevalence of autograft compared with allograft in young, active patients.
  
  
  METHODS
  EMBASE, MEDLINE, Cochrane trials registry.
  
  
  METHODS
  Comparative studies of allograft versus autograft primary ACL reconstruction in patients <25 years of age or of high-activity level (military, Marx activity score >12 points, collegiate or semiprofessional athletes).
  
  
  METHODS
  Systematic review with meta-analysis.
  
  
  METHODS
  Level 3.
  
  
  METHODS
  Manual extraction of available data from eligible studies. Quantitative synthesis of failure prevalence and Lysholm score (outcomes in ≥3 studies) and I (2) test for heterogeneity. Assessment of study quality using CLEAR NPT and Newcastle-Ottawa Scale (NOS).
  
  
  RESULTS
  Seven studies met inclusion criteria (1 level 1; 2 level 2, 4 level 3), including 788 patients treated with autograft tissue and 228 with various allografts. The mean age across studies was 21.7 years (64% male), and follow-up ranged between 24 and 51 months. The pooled failure prevalence was 9.6% (76/788) for autografts and 25.0% (57/228) for allografts (relative risk, 0.36; 95% CI, 0.24-0.53; P < 0.00001; I (2) = 16%). The number needed to benefit to prevent 1 failure by using autograft was 7 patients (95% CI, 5-10). No difference between hamstrings autograft and patella tendon autograft was noted. Lysholm score was reported in 3 studies and did not differ between autograft and allograft.
  
  
  CONCLUSIONS
  While systematic reviews comparing allograft and autograft ACLR have been equivocal, this is the first review to examine young and active patients in whom allograft performs poorly.
authors.affiliation: Division of Orthopaedic Surgery, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario, Canada ; Vanderbilt Sports Medicine, Vanderbilt University Medical Center, Nashville, Tennessee.
authors.forename: David
authors.initials: D
authors.lastname: Wasserstein
authors.affiliation: Division of Orthopaedic Surgery, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Ujash
authors.initials: U
authors.lastname: Sheth
authors.affiliation: Vanderbilt Sports Medicine, Vanderbilt University Medical Center, Nashville, Tennessee.
authors.forename: Alison
authors.initials: A
authors.lastname: Cabrera
authors.affiliation: Vanderbilt Sports Medicine, Vanderbilt University Medical Center, Nashville, Tennessee ; Cleveland Clinic Sports Medicine, Cleveland Clinic, Cleveland, Ohio.
authors.forename: Kurt P
authors.initials: KP
authors.lastname: Spindler
keywords: allograft; anterior cruciate ligament reconstruction; autograft; revision; young age