Reconstructing the anterolateral ligament does not decrease rotational knee laxity in ACL-reconstructed knees.
OBJECTIVE
Little is known about the anterolateral ligament's (ALL) influence on knee laxity. The purpose of this study was to investigate rotational knee laxity against a pure axial rotational stress using radiostereometric analysis (RSA) after cutting and reconstructing both the anterior cruciate ligament (ACL) and the ALL.


METHODS
Eight human donor legs were positioned and stereoradiographically recorded at 0°, 30° and 60° of knee flexion using a motorised fixture, while an internally rotating force of 4 Nm was applied to the foot. Anterior-posterior and rotational laxity were investigated for knees with intact ligaments and compared with those observed after successive ACL and ALL resection and reconstruction.


RESULTS
After cutting the ALL in ACL-deficient knees, the internal rotation was increased in all three knee flexion angles, 0° (p = 0.04), 30° (p = 0.03) and 60° (p < 0.01) by 1.0°, 1.6° and 2.5°, respectively. However, no decrease in laxity was found after reconstructing the ALL in ACL-reconstructed knees.


CONCLUSIONS
The ALL was confirmed as a stabiliser of internal rotation in ACL-deficient knees. However, reconstructing the ALL using a gracilis autograft tendon did not decrease the internal rotation laxity in the ACL-reconstructed knee. Based on the results of this study, we do not recommend reconstructing the ALL in ACL-reconstructed knees to decrease internal knee laxity.
Orthopedic Research Unit, Aarhus University Hospital, Tage Hansens Gade 2, 8000, Aarhus C, Denmark. kasperstentz@gmail.com.
Kasper
http://orcid.org/0000-0001-9714-5609
K
Stentz-Olesen
Department of Health Science and Technology, Aalborg University, Fredrik Bajers Vej 7 D2, 9220, Aalborg East, Denmark.
Emil Toft
ET
Nielsen
Orthopedic Research Unit, Aarhus University Hospital, Tage Hansens Gade 2, 8000, Aarhus C, Denmark.|Nordisk Røntgen Teknik, Birkegaardsvej 16, 8361, Hasselager, Denmark.
Sepp
S
de Raedt
Orthopedic Research Unit, Aarhus University Hospital, Tage Hansens Gade 2, 8000, Aarhus C, Denmark.
Peter Bo
PB
Jørgensen
Orthopedic Research Unit, Aarhus University Hospital, Tage Hansens Gade 2, 8000, Aarhus C, Denmark.
Ole Gade
OG
Sørensen
Biomechanics and Imaging Group, Department of Orthopedic Surgery, Leiden University Medical Center, Albinusdreef 2, 2333, ZA Leiden, The Netherlands.
Bart
B
Kaptein
Orthopedic Research Unit, Aarhus University Hospital, Tage Hansens Gade 2, 8000, Aarhus C, Denmark.
Kjeld
K
Søballe
Orthopedic Research Unit, Aarhus University Hospital, Tage Hansens Gade 2, 8000, Aarhus C, Denmark.|Department of Clinical Medicine, University of Aarhus, Aarhus C, Denmark.
Maiken
M
Stilling
D000368:Aged; D000369:Aged, 80 and over; D016118:Anterior Cruciate Ligament / Q000601:surgery*; D002102:Cadaver; D005260:Female; D006801:Humans; D007593:Joint Instability / Q000503:physiopathology*; D007719:Knee Joint / Q000000981:diagnostic imaging / Q000503:physiopathology*; D008023:Ligaments, Articular / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D059869:Radiostereometric Analysis; D012399:Rotation
Anterior cruciate ligament; Anterolateral ligament; Knee laxity; RSA; Rotational instability