The Anterior Cruciate Ligament in Controlling Axial Rotation

Abstract

Changes in axial tibial rotation after anterior cruciate ligament sectioning were evaluated in 14 fresh human knee joints. Simulation of vertical stance in a quadriceps-stabilized knee was performed. Internal and external rotational torques were applied before and after anterior cruciate ligament sectioning. Pivot shift tests were done in the intact and anterior cruciate ligament sectioned knee. Results of pivot shift tests were all negative before sectioning and positive after isolated sectioning. No significant change in axial rotation occurred between the intact and sectioned knee for external rotation (P = 0.24) or internal rotation (P = 0.12). Presence of a load at the femoral housing in both the intact and ligament-sectioned knees caused a significant change in external rotation (P < 0.0001). No significant change was noted in internal rotation between loaded and unloaded states (P = 0.70). Total tibial rotation in the intact knee was noted to vary between 31 degrees at 0 degree of flexion and 42 degrees at 60 degrees of flexion. These results suggest that the anterior cruciate ligament does not play a significant role in limiting axial rotation and that rotational instability is not a major factor after isolated anterior cruciate ligament rupture.

Objective measurements of static anterior and rotational knee laxity

“…Cadaveric studies revealed that the section of the ACL led to 2.4 to 4°increase in rotation in knee flexion angles below 30° [ 69,70]. Above this degree of flexion, the increase in rotation induced by the lesion was not detectable anymore [25,71].…”

Evaluation of an external device measuring knee joint rotation: an in vivo study with simultaneous Roentgen stereometric analysis

“…~l i i i i c a~~y useful information concerniiig rotatory laxity of the knee has mainly been obtained from cadaver studies [7,9,11,15,17]. A few in vivo measurements of tibial axial rotation have been reported [3,16,18].…”

The Biomechanics of the Anterior Cruciate Ligament and Its Reconstruction

“…These differences though were typically small though statistically significant; Wroble et al (1993) concluded their results were "clinically unimportant". However other transection studies in cadaver knees have not shown an increase in internal rotation range (Lane et al, 1994;Reuben et al, 1989;Wünschel et al, 2010), and Lo et al (2008) showed no increase in ACL force on internal rotation in vitro. In an in vivo study, Hemmerich and colleagues (2011) found that ACL-deficient patients showed an increase in internal rotation range, but at 0° flexion and not at 30°.…”

“…So the effect of the ACL on the range of internal rotation is unclear. Lane et al (1994) and Oh et al (2011) concluded that the ACL is unlikely to resist rotation as its central position in the knee is too close to the rotational axis. Interestingly then, Lipke et al (1981) transected the lateral collateral ligament and posterolateral structures in addition to the ACL.…”