Introduction

An alternative single bundle anatomic ACL reconstruction (ACL-R) devised by the senior author comprises an anterolateral reinforcement using an iliotibial band autograft (ITB). The knee biomechanics of this technique has not been compared with standard ACL-R methods.

Purpose

The aim of this study is to compare the knee kinematics of ACL-R using bone-patellar tendon bone (BTB) graft with lateral extra-articular tenodesis (BTB+LET) to ITB anterolateral reinforcement ACL-R (ITB).

Methods

Twenty unpaired fresh-frozen human cadaveric knees (mean age: 41.4 years) were tested using a robotic system under three loads: (a) 89 N anterior tibial (AT) load, (b) 5 N-m internal rotation (IR) tibial torque, and (c) a simulated pivot shift (PS) load, as a combined 7 N-m valgus moment, and 5 N-m internal rotation torque at different angles of knee flexion. One ACL-R group (n=10) was tested with iliotibial band reconstruction (ITB) and the other ACL-R group (n=10) was tested with BTB graft reconstruction (BTB) and additionally with a LET procedure (BTB+LET).

Results

There was no statistically significant difference during AT loading, IR torque, and simulated PS between BTB and ITB states at all knee flexion angles (p =.05). In response to AT loading, significantly less translation was detected in the BTB+LET state compared to the ITB state at 15° (mean difference (MD): 1.6 ± 0.7 mm (p = .047)), 30° (MD: 1.8 ± 0.7 mm (p = .028)), and 60° (MD: 1.5 ±0.6 mm (p = .032)) of knee flexion. In response to IR torque, the only statistically significant difference between ITB and intact state was at 0º of knee flexion. In response to simulated PS, significantly less tibial displacement was detected in the BTB+LET state compared to the intact state at 15° (MD: (1.7 ± 0.5 mm (p = .041)) of knee flexion.

Conclusion

BTB and ITB ACL-R both improved knee stability compared to the ACL deficient state in response to AT, IR and simulated PS loading, however, no method restored the intact ACL behavior. BTB+LET caused over-constraint at 15° of knee flexion during simulated PS loading. ITB ACL-R provides an alternative technique to improve stability of the ACL deficient knee.