Summary

Hamstring Autografts are significantly associated with larger knee valgus moments at initial contact and hip adduction moments compared to Quadriceps Autografts whereas Quadriceps Autografts with and without bone block have significantly decreased knee extension moment averages compared to Hamstring Autografts during DVJ.

Abstract

Objective

There is limited evidence related to the effects of autograft type on functional performance after anterior cruciate ligament (ACL) reconstruction (ACLR). This study compared biomechanical outcomes during the drop vertical jump test (DVJ) between patients with a hamstring autograft (HS), quadriceps autograft with bone block (QB), quadriceps autograft without bone block (Q), and bone-patellar tendon-bone autograft (BTB) six-months postoperatively in an adolescent population. The authors hypothesized that there would be differences in biomechanical profiles between athletes depending on autograft type used..

Methods

Patients aged 8 to 18 years who underwent primary ACLR were included for analysis. Kinematic and kinetic data collected during a DVJ using a 3D computerized marker system (Motion Analysis Corp. CORTEX software) was assessed six-months after ACLR and compared to the uninjured contralateral limb. Outcomes evaluated included hip internal rotation, hip adduction, knee valgus, and knee extensor moments between the graft types.

Results

One hundred fifty-five subjects were included for review. There were no significant differences in terms of age, sex, or affected leg (p > 0.1973) between groups. The HS group was significantly associated with larger knee valgus moments at initial contact as compared to the Q group (28 x 10-2 N*m/kg vs -35 x 10-2 N*m/kg, p = 0.0254) and significantly larger hip adduction moments compared to the QB group (30 x 10-2 N*m/kg vs -4.0 x 10-2 N*m/kg, p = 0.0426). Both the QB (-12 x 10-2 N*m/kg vs. -3.0 x 10-2 N*m/kg, p = 0.0265) and Q group (-13 x 10-2 N*m/kg vs. -3.0 x 10-2 N*m/kg, p = 0.459) demonstrated significantly decreased knee extension moment averages as compared to a hamstring autograft.

Conclusions

The findings of this study suggest that the quadriceps autograft may confer improved knee coronal plane biomechanics with regard to ACL reinjury mechanics but decreased extensor mechanism function when compared to a hamstring autograft at six-months after ACLR in adolescent patients performing a drop vertical jump.