Comparison of Allograft Versus Autograft Anterior Cruciate Ligament Reconstruction Graft Survival in an Active Adolescent Cohort

Abstract

Background: Graft selection for anterior cruciate ligament (ACL) reconstructive surgery is a controversial topic. Few studies have compared graft outcomes in adolescents. Purpose: To identify factors related to ACL graft failure in an adolescent cohort. Study Design: Case-control study; Level of evidence, 3. Methods: After institutional review board approval was obtained, adolescent subjects (age range, 11-18 years) who underwent primary ACL reconstruction surgery at a large tertiary pediatric hospital between July 2005 and July 2009 were identified through a query of International Classification of Diseases, 9th Revision, diagnostic and Current Procedural Terminology codes. Subject data were obtained by means of a retrospective chart review, phone survey, and the administration of functional knee outcome instruments. A multivariate Cox proportional hazards regression analysis was used to analyze factors related to graft survival. Results: The average ages at surgery in the allograft (n = 38) and autograft (n = 35) groups were 15.29 ± 2.24 and 15.60 ± 1.57 years, respectively. There were 11 graft failures (28.95%) in the allograft group compared with 4 graft failures (11.43%) in the autograft group. In the multivariate model, graft type ( P = .0352) and postoperative knee laxity according to the Lachman test ( P = .0217) were the only variables significantly related to graft survival. The hazard of graft failure was 4.4 (95% CI, 1.23-18.89) times greater in the allograft group compared with the autograft group. The hazard of graft failure was 5.28 times (95% CI, 1.1-12.72; P = .0217) greater for a subject who demonstrated increased postoperative knee laxity relative to the contralateral knee. The risk for autograft failure tended to remain constant 24 to 48 months after initial surgery, whereas the risk for allograft failure continued to increase during postoperative months 24 to 48. There were no differences ( P > .05) between the allograft and autograft groups with respect to International Knee Documentation Committee score, Lysholm score, and the rate of return to previous activity level. Conclusion: Graft type and postoperative knee laxity were identified as significant predictors of graft survival. On the basis of this large retrospective cohort, we recommend the use of autogenous grafts in children and adolescents undergoing primary, transphyseal ACL reconstruction. Patients who demonstrate increased translation during a postoperative Lachman test should be carefully followed because of concerns for subsequent graft failure.