title: Post-operative complications following primary ACL reconstruction using allogenic and autogenic soft tissue grafts: increased relative morbidity risk is associated with increased graft diameter.
abstract: BACKGROUND
  The purpose of this study is to compare the risk of peri-operative complication events associated with allogenic and autogenic grafts during routine follow-up for six months after primary arthroscopic anterior cruciate ligament (ACL) reconstruction surgery.
  
  
  METHODS
  A retrospective cohort study identified patients that underwent ACL reconstruction via an arthroscopically assisted single tunnel technique. Fixation was primarily cortical suspension (endobutton) from the femora and bicortical fixation (Washer-loc) in the tibia. Patients were monitored for six months following surgery. Morbidity was defined as complications during this period requiring medical or surgical intervention. Risk of complications was compared according to tissue type and patient characteristics. The Cochran-Mantel-Haenszel method was applied to estimate risk ratios (RR) and confidence intervals (CI) as the measure of association between graft type and morbidity risk.
  
  
  RESULTS
  The cohort included 413 eligible patients. Sixty six percent received allograft tissue, while the remainder received autograft tissue. Morbidity risk was 7.0% among patients receiving allograft tissue and 2.8% among patients receiving autograft tissue. Allograft demonstrated elevated risk of complication versus autograft (RR=2.3 (95% CI: 0.9-7.2)), though the data are of borderline significance (p=0.11). Complications were associated with larger graft diameter in comparison to patients who experienced no complication (9.0+/-1.2 mm v. 8.4+/-1.0mm, p=0.005).
  
  
  CONCLUSIONS
  The relative morbidity risk was about two-fold greater among patients receiving allograft tissue. Regardless of tissue type, graft size was larger among patients who experienced a complication.
  
  
  METHODS
  Level III.
authors.affiliation: Department of Orthopaedics and Rehabilitation, Oregon Health and Science University, United States. Electronic address: crawfden@ohsu.edu.
authors.forename: Dennis C
authors.initials: DC
authors.lastname: Crawford
authors.forename: Sara E
authors.initials: SE
authors.lastname: Hallvik
authors.forename: Ryan C
authors.initials: RC
authors.lastname: Petering
authors.forename: Samantha M
authors.initials: SM
authors.lastname: Quilici
authors.forename: Loren O
authors.initials: LO
authors.lastname: Black
authors.forename: Stephanie A
authors.initials: SA
authors.lastname: Lavigne
authors.forename: Jodi
authors.initials: J
authors.lastname: Lapidus
authors.forename: Lynn M
authors.initials: LM
authors.lastname: Marshall
mesh_terms: D000293:Adolescent; D000328:Adult; D059549:Anterior Cruciate Ligament Reconstruction / Q000009:adverse effects* / Q000379:methods*; D001182:Arthroscopy / Q000379:methods*; D050376:Bone-Patellar Tendon-Bone Grafting / Q000009:adverse effects* / Q000379:methods; D016009:Chi-Square Distribution; D015331:Cohort Studies; D016001:Confidence Intervals; D005260:Female; D005500:Follow-Up Studies; D006084:Graft Rejection; D006085:Graft Survival; D006801:Humans; D008297:Male; D008875:Middle Aged; D064827:Myocutaneous Flap / Q000637:transplantation*; D011183:Postoperative Complications / Q000209:etiology* / Q000601:surgery*; D012086:Reoperation; D012189:Retrospective Studies; D018570:Risk Assessment; D014182:Transplantation, Autologous; D014184:Transplantation, Homologous / Q000009:adverse effects / Q000379:methods; D016896:Treatment Outcome; D055815:Young Adult
keywords: ACL allograft reconstruction; ACL autograft reconstruction; ACL reconstruction complications; Anterior cruciate ligament reconstruction