The Influence of Knee Flexion Angle for Graft Fixation on Rotational Knee Stability During Anterior Cruciate Ligament Reconstruction: A Biomechanical Study

摘要

To evaluate the effect of knee flexion angle for hamstring graft fixation, full extension (FE), or 30 degrees, on acceleration of the knee motion during pivot-shift testing after either anatomic or nonanatomic anterior cruciate ligament (ACL) reconstruction using triaxial accelerometry. Methods: Two types of ACL reconstructions (anatomic and nonanatomic) using 2 different angles of knee flexion during graft fixation (FE and 30 degrees) were performed on 12 fresh-frozen human knees making 4 groups: anatomic-FE, anatomic-30 degrees, nonanatomic-FE, and nonanatomic-30 degrees. Manual pivot-shift testing was performed at ACL-intact, ACL-deficient, and ACL-reconstructed conditions. Three-dimensional acceleration of knee motion was recorded using a triaxial accelerometer. Results: The anatomic-30 degrees group showed the smallest overall magnitude of acceleration among the ACL-reconstructed groups (P = .0039). There were no significant differences among the anatomic-FE group, the nonanatomic-FE group, and the nonantomic-30 degrees group (anatomic-FE vs nonanatomic-FE, P = .1093; anatomic-FE vs nonanatomic-30 degrees, P = .8728; and nonanatomic-FE vs nonanatomic-30 degrees, P = .1093). After ACL transection, acceleration was reduced by ACL reconstruction with the exception of the nonanatomic-FE group that did not show a significant difference when compared with the ACL-deficient (P = .4537). Conclusions: The anatomic ACL reconstruction with the graft fixed at 30 degrees of knee flexion better restored rotational knee stability compared with FE. An ACL graft fixed with the knee at FE in anatomic position did not show a significant difference compared with the nonanatomic ACL reconstructions.