Biomechanical analysis of anterolateral rotatory instability in anterior cruciate ligament reconstruction with or without lateral extra-articular tenodesis.

Even the most recent anterior cruciate ligament (ACL) reconstruction techniques
remain unable to fully restore normal knee joint biomechanics to normal. The
key to restoring better knee kinematics in ACL surgery lies in understanding
the structures that are damaged in addition to the ACL. Previous studies have
shown that anterolateral extra-articular structures (ALES) may be injured
during initial ACL injury of the knee. Failure to recognize and manage these
concomitant injuries might result in persistent postoperative anterolateral
rotatory instability of the knee, increased forces through the ACL graft and
eventually lead to failure of the primary ACL reconstruction. Concomitant
lateral extra-articular tenodesis (LET) to the ACL reconstruction might be able
to restore the kinematics of the knee. However, no in vivo information on the
combined ACL with LET exists.

The specific aim of this research project is to measure the tibiofemoral
kinematics during in vivo weight bearing lunges of patients at two time points:
(1) prior to ACL reconstruction with or without LET, and (2) six months after
ACL reconstruction with or without LET using a combined dual fluoroscopic and
magnetic resonance (MR) imaging technique, with the healthy contralateral knee
as control.

This study is a randomized clinical trial, consisting of 52 patients with 6
months follow-up. The ACL injured patients will be evenly randomized into two
groups of 26 patients. One group will be reconstructed with the ACL
reconstruction with LET and the other group of patients will be reconstructed
with solely ACL reconstruction.

Patients will be tested two times through weight bearing lunges. *Test 1*,
prior to the ACL reconstruction: MR imaging of both knees i.e. the injured and
healthy contralateral knees, and dual fluoroscopic imaging of both the injured
and healthy contralateral knees. *Test 2*, six months after ACL surgery with or
without LET: dual fluoroscopic imaging of the operated knees, no additional MR
imaging will be made.

na

For the purpose of this study one extra MR-scan will be made of the healthy
contralateral knee (20min); two dual fluoroscopic imaging studies will be used
to evaluate the tibiofemoral kinematics (30min/study). However, the total
amount of radiation is within the acceptable health standards and is lower than
the natural background radiation and the annual allowed radiation exposure. All
patients whom have ACL surgery in our hospital are asked to fill out
standardized questionnaires (IKDC, KOOS, Tegner, anchor questions). These
questionnaires will be used to analyze the patient related outcome measures
(PROMs).