Biomechanical Analysis of Simulated Clinical Testing and Reconstruction of the Anterolateral Ligament of the Knee

Abstract

Background:Anatomic anterolateral ligament (ALL) reconstruction has been proposed to assist anterior cruciate ligament (ACL) reconstruction in controlling anterolateral rotational laxity of the knee. However, the biomechanical effects have not been reported.Purpose:(1) To investigate the effect of ALL transection on rotational knee kinematics and (2) to determine the effect on knee biomechanics of ALL reconstruction procedures compared with lateral extra-articular tenodesis (LET).Study Design:Controlled laboratory study.Methods:A total of 12 cadaveric knee specimens were tested in the following sequence: (1) ACLintact, (2) anteromedial bundle of ACL sectioned (ACLamb), (3) complete ACL sectioned (ACLfull), (4) ALL sectioned (ALLsec), (5) anatomic ALL reconstruction (ALLanat), and (6) LET. Biomechanical anterior drawer and Lachman tests were performed in which a 90-N load was applied to the posterior tibia, and anterior translation was measured. A combined load to simulate the early phase of the pivot-shift test was executed in which a 5-N·m internal rotation moment was applied to a fully extended knee; anterior translation and internal rotation were measured.Results:Anterior translation increased across conditions for the biomechanical tests. Internal rotation during the simulated early-phase pivot-shift test was significantly different between ACLfull and ALLsec. Anatomic ALL reconstruction did not significantly reduce internal rotation or anterior translation during the simulated early-phase pivot-shift test. After LET, a significant decrease in anterior translation was found. There was no evidence of over-constraint of the knee with either anatomic ALL reconstruction or LET.Conclusion:The ALL demonstrated a role in controlling anterolateral laxity. LET had a composite effect in governing both anterior and rotational laxity. Anatomic ALL reconstruction did not reduce anterolateral rotational laxity. Clinical Relevance: Profiling the biomechanical characteristics of anterolateral reconstruction is integral to understanding the implications and potential benefit of such an additional procedure to ACL reconstruction.

Revisión sistemática: ligamento anterolateral de la rodilla

“…En el estudio biomecánico de Ruiz et al (16) , se demostró que se produce un aumento de la rotación interna a 30° tras la sección del LCA y sobre todo de las estructuras anterolaterales, aumentando esta rotación si se producía la sección de ambos. Estos resultados estaban en consonancia con el estudio de Spencer et al (18) . El orden en que se realizaba la sección no influyó en la rotación resultante, por lo que se podía deducir que ambos ligamentos eran independientes y sinérgicos.…”

“…Parece ser que presenta mayor tensión en grados cercanos a la extensión (1,(8)(9)(10)13,16,17) , pero estudios recientes defienden su control a mayor flexión de rodilla (15,(18)(19)(20)(21) . Para el diagnóstico de esta lesión se ha puesto de manifiesto ser el causante del pivot shift en la exploración, aunque este concepto es controvertido (22)(23)(24)(25)(26) .…”

Anterolateral Ligament (ALL) — Myth or Reality?

“…36 From a biomechanical point of view, internal rotation of the knee is better controlled by a lateral extra-articular structure compared to the centrally located ACL because of a longer lever arm. 37,38 Cadaveric studies showed that starting with 30 degrees of flexion, the deep capsulo-osseous fibers of the iliotibial tract play an important role regarding the rotational stability of the knee, while the ALL is just of secondary importance. 12 Other studies showed that sectioning of the ALL in addition to the ACL, in cadaver specimens, enhanced the pivot shift significantly.…”

Minimally Invasive Anterolateral Ligament Reconstruction of the Knee

“…This is in contrast to a graft placed in the position originally described by Claes anterior and distal to the lateral epicondyle where the graft would be tight in flexion but loose in extension. [13][14][15] Plus, this chosen position avoids the lateral collateral femoral attachment as depicted with the cadaver dissection (Fig 4).…”