Single-bundle modified patellar tendon versus double-bundle tibialis anterior allograft ACL reconstruction: a prospective randomized study

Abstract

Purpose: The purpose of this study was to prospectively compare the outcomes of single-bundle (SB) anterior cruciate ligament (ACL) reconstruction with modified bone-patellar tendon-bone (BPTB) allograft and double-bundle (DB) reconstruction with tibialis anterior allograft.

Methods: With 94 patients enroled in the study, 43 subjects who had SB ACL reconstruction with modified BPTB allograft (group S) and 41 subjects of DB ACL reconstruction with tibialis anterior allograft (group D) were followed up for a minimum of 2 years. Clinical outcomes including Lachman and pivot-shift tests, KT-1000 arthrometer measurements, and the International Knee Documentation Committee (IKDC) classification, Lysholm and Tegner activity scores were compared between the two groups at the last follow-up.

Results: The mean graft size of the group S, the anteromedial bundle and posterolateral bundle in group D were 9.9 ± 0.2, 7.5 ± 0.4 and 6.6 ± 0.4 mm, with statistically significant difference between the group S graft to either bundle of group D grafts (p < 0.001). At the last follow-up, there was no statistical difference between the two groups for the Lachman test, pivot-shift test and side-to-side difference. Substantial improvements in the subjective knee function scores were achieved in both groups, but without significant difference between the two groups.

Conclusions: After a 2-year minimum follow-up, SB ACL reconstruction based on modified BPTB allograft achieved similar clinical outcomes to DB reconstruction with tibialis anterior allograft in knee stability, both anterior-posterior and rotational, as well as knee function. The modified BPTB allograft was recommended as an ideal graft option for the SB ACL reconstruction.

Level of evidence: Therapeutic, randomized controlled study, Level II.