# The Measure of Internal Rotation of the Knee in the Clinical Diagnosis of Association of Anterolateral Ligament and Anterior Cruciate Ligament Injury

## TL;DR

This study shows that increased internal knee rotation during physical exams can indicate combined injuries to the ACL and ALL ligaments.

## Contribution

The study demonstrates that internal knee rotation measurements can clinically identify combined ACL and ALL injuries.

## Key findings

- Isolated ACL release increases internal rotation by 55.6% at 90 degrees of flexion.
- Combined ACL and ALL release increases internal rotation by 162% compared to an intact ACL.
- ALL release after ACL and ITT release increases internal rotation by 27.8%.

## Abstract

To investigate the clinical correlation between internal knee rotation and the association of injuries between anterolateral (ALL) and anterior cruciate (ACL) ligaments.

Thirty-eight knees of 19 fresh corpses (all males, mean age: 28-years-old) were evaluated by simulating physical examination through manual rotational tests at 90 degrees of flexion. Kirschner wires were placed in parallel in the femur and tibia, and measurements were obtained using a goniometer. The obtained data were compared against the intact ACL, then to progressive sections of the ACL, iliotibial tract, and anterolateral ligament.

Isolated release of the ACL induced an increase (+55.6%,
p
 < 0.001) in internal rotation at 90 degrees of flexion, when compared to the the intact knee. After ACL release, associated release of the iliotibial tract (ITT) induced an increase (+31.6%,
p
 < 0.001) in the internal rotation of the knee at 90 degrees of flexion, and a marked increase (+104%,
p
 < 0.001) when compared to the ACL-intact knee. After ACL and ITT release, ALL release induced a significant increase (+27.8%,
p
 < 0.001) in the internal rotation of the knee at 90 degrees of flexion, and in comparison with the intact ACL knee (+162%,
p
 < 0.001).

There is an increase in internal rotation of the knee in the ACL injury. The association with ALL injury leads to a pronounced increase of internal rotation when compared to the uninjured knee. Therefore, the presence of pronounced internal knee rotation is a clinical sign of associated injury to these structures.