Assessing Quadriceps Strength Deficiency After Anterior Cruciate Ligament Reconstruction: The Role of Normalized Peak...

To evaluate the role of normalized peak torque relative to body weight in assessing quadriceps strength deficits after anterior cruciate ligament (ACL) reconstruction, based on the type of graft used. Our primary hypothesis was that the use of a quadriceps tendon (QT) graft results in greater quadriceps strength loss than a semitendinosus-gracilis (STG) graft.

Cohort study with prospective data collection and retrospective analysis.

University hospital ACL reconstruction between May 2019 and July 2021.

A total of 130 patients who underwent ACL reconstruction without exclusion criteria were included. Ninety patients received QT grafts and 40 received STG grafts, between May 2019 and July 2021.

ACL reconstruction using either a quadriceps tendon graft or a semitendinosus-gracilis graft.

Normalized peak torque to body weight measured at 60 degrees/s 1 year postoperatively.

Analysis using a linear mixed model revealed a significantly greater deficit in normalized peak extensor torque in the QT graft group compared with the STG group when comparing the operated limb with the healthy limb at 60 degrees/s ( P < 0.001).

Normalized peak torque at a velocity of 60 degrees/s is a critical variable in assessing quadriceps strength recovery during isokinetic testing and should be routinely correlated with limb symmetry indices. Patients who underwent ACL reconstruction with a QT graft demonstrated larger quadriceps strength deficits than those with an STG graft 1 year postsurgery, although no functional impairments were observed.