The anterior cruciate ligament does play a role in controlling axial rotation in the knee

Abstract

This study deals with the influence of peroperative ligament tension on total tibial rotation at different knee flexion angles. Fourteen human cadaver knees with a mean age of 56 years (range 42-84 years) were examined. The cadaver knees were subjected to internal/external (i/e) rotational torque of 6 Nm, at 10, 30, 50, 70 and 90 deg of knee flexion. The mean total i/e rotation with the anterior cruciate ligament (ACL) intact at 10 deg of knee flexion was 30.4 deg and after removing the ACL, 33.1 deg. At 10 and 30 deg of knee flexion, the increase in i/e rotation was significant, while there was no significant difference in mean values at greater knee flexion. Ligament reconstruction with a tension of 5 N at 30 deg of knee flexion using either the over the top or through the femoral condyle reconstructive procedure restored normal tibial rotation. With increased graft tension the knee motion was increasingly restricted at low angles of knee flexion. Our results indicate that the ACL does play a role in limiting axial rotation, and even minor tensioning forces introduced in any of the two ACL reconstructions used produced restricted knee motion.

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]. Early in vivo studies demonstrated a similar increase of rotation in the injured knee by 10 % (3°) compared to the healthy knee [72].…”

Altered knee kinematics in ACL‐deficient non‐copers: A comparison using dynamic MRI

“…3 The ACL primarily functions to limit anterior translation of the tibia relative to the femur, [4][5][6] and also plays a role in governing the coupled tibiofemoral axial rotation with knee flexion. 7,8 In vitro cadaveric studies have provided some insight into the behavior of the ACLdeficient knee under controlled conditions, 9,10 including simulated muscle loads, but here the relationship to the in vivo situation is not straightforward. In order to investigate the potential for ACL injury to elicit changes in knee kinematics during activity, precise dynamic studies of smallscale differences in motions are therefore important.…”

The Effect of Tibial Rotation on the Presence of Instability in the Anterior Cruciate Ligament Deficient Knee

“…3 The effect on tibial rotation of cutting the ACL has been well reported. 4,5,6,7 In a cadaveric study, 4 total (internal and external) rotation at 10 and 30 degrees of knee " exion increased signi! cantly after the ACL was cut.…”

“…12 Functional tests, which are designed to simulate the stress the knee encounters during selected functional activities, are both useful and simple to perform and are commonly used to determine such functional limitations as running and hopping in patients with ACL injuries. 5,13,14 Although unable to detect speci! c knee abnormalities, functional tests can be used to assess knee function in various clinical settings.…”