Pitt | Swanson Engineering
Evaluation of the Anterolateral Capsule of the Knee

Anterior Cruciate Ligament related injuries

Injuries of the anterolateral capsule of the knee are often related to tears of the anterior cruciate ligament (ACL). These related injuries could easily be underdiagnosed due to focusing on the common ACL procedure. However, consequence of this may be decreased rotational stability of the joint. This can lead to a persistent giving-way phenomenon as well as early arthritic changes. It is of clinical interest whether anterolateral capsule-injuries in ACL-deficient knees should be assessed and repaired at the time of ACL surgery and whether a combined intra- and extra articular reconstruction can achieve good postoperative stability.

The following ongoing studies are related to this project:

1. Knee Stability Provided By Anterolateral Structures

The purpose of this study is to determine the in-situ forces in the anterolateral structures in response to an anterior tibial load and internal tibial torque in the intact and the anterior cruciate ligament (ACL)-deficient knee. Our hypotheses are (1) that the anterolateral capsule experiences significantly greater in situ force in the ACL-deficient knee compared to the intact knee and (2) that the separation of the structures will have a bigger effect on the in-situ forces of the capsule than cutting the capsule itself.

2. Reconstruction of Anterolateral Capsule can Contribute to Knee Stability with a Combined ACL and Capsular Injury

The purpose of this study is to determine the effects of ACL injury, anterolateral capsule injury, ACL reconstruction and extra-articular reconstruction on joint motion in response to an anterior tibial load and internal tibial torque.

3. Direction of strain in the anterolateral capsule of the knee during internal tibial rotation

The purpose of the study is to determine the strain pattern in the anterolateral capsule of the knee joint during internal rotation. Our hypothesis is that based on the anatomical description of an anterolateral ligament a ligament-like strain pattern during an internal rotational torque is present and that the vector of the strain is in line with the ligament.

4. Strain Pattern in the Anterolateral Capsule of the Knee Joint during different loading conditions

The purpose of the study is to determine the surface strain of the anterolateral capsule in response to multiple loading conditions in the intact and ACL-deficient knee during 30°, 60° and 90° of flexion to define the loading condition, which causes the highest strain in the anterolateral capsule.

5. The Effect of Anterolateral Capsule Injuries and Reconstructions on the Pivot Shift Test

The purpose of the study is to determine the influence of anterolateral capsule injuries of the knee on the pivot shift test in the ACL intact and ACL deficient knee.