Failure Rate and Predictors of Failure after Anatomic ACL Reconstruction with Allograft (SS-61)

Abstract

Introduction ACL rupture is a common sports injury and ACL reconstruction is one of the most frequently performed orthopaedic procedures. Given the high number of ACL reconstructions that are performed, failures are to be expected. In the literature, ACL graft failure rates from 1 to 27% have been reported and many causes for failure have been suggested. The purposes of this study were to determine the rate and factors associated with graft failure after anatomic ACL reconstruction performed with allograft. Methods A prospective cohort study was conducted in which all consecutive subjects who underwent anatomic single- or double-bundle ACL reconstruction with allograft between January 2007 and December 2009 were included. Subjects were excluded if they had undergone previous knee surgery or underwent an ACL augmentation procedure. All subjects were followed for at least 9 months. Failure was defined as a subjective episode of instability, abnormal laxity on clinical examination and/or an MRI or arthroscopic diagnosis of rupture or absence of the ACL graft. The overall failure rate, as well as the failure rate for the single- and double-bundle ACL reconstruction, was determined. Potential predictors of failure that were explored included subject age, sex, height, weight, BMI, meniscus injury, and time of return to pre-injury sports. Chi-square and independent t-tests were used to identify differences between subjects that failed and those who did not fail. Results 206 subjects were included in this study, 168 double-bundle and 38 single-bundle reconstructions, 80% were available for ≥ 9 month follow-up. Fifty percent of the subjects were female, the average (standard deviation) age was 24 (10) years, BMI was 24.5 (4.6) and time to return to sports was 263(68) days. Twenty-nine percent had a medial meniscus tear and 37% a lateral meniscus tear. Overall, 26 (13%) subjects had a failed graft. Of the subjects undergoing anatomic double-bundle ACL reconstruction, 22 (13%) failed. Double-bundle subjects who failed were younger (19 vs. 25 year, p Conclusion The overall failure rate after anatomic ACL reconstruction with allograft was 13%. Younger age, earlier return to sports, and a higher body weight were associated with failure. The increased failure following ACL reconstruction with allograft reported in the literature combined with the failure rate presented in this study suggests that the use of allograft should be reconsidered in young people involved in competitive sports. Additionally, modifications in postoperative rehabilitation and return to sports may be necessary when the ACL is anatomically reconstructed.