Ultrasonographic Evaluation of Anterolateral Ligament Injuries: Correlation With Magnetic Resonance Imaging and Pivot-Shift Testing.
OBJECTIVE
(1) To compare the diagnostic ability of ultrasonography (US) and magnetic resonance imaging (MRI) to detect anterolateral ligament (ALL) injuries in anterior cruciate ligament (ACL)-deficient patients, and (2) to evaluate the correlation between ALL injury status (as determined by US and MRI) and the knee's rotational stability.


METHODS
Thirty patients with an isolated ACL injury were included prospectively over a 3-month period. The condition of the ALL was evaluated by 2 experienced radiologists using both US and MRI. Rotational stability was evaluated by 2 surgeons with the pivot-shift test with patients under general anesthesia. It was classified as either negative (grades 0 and I) or positive (grades II and III). The radiologists were blinded to the knee's rotational stability, and the surgeons were blinded to the ALL's status based on the US images. The correlation between the ALL's injury status (US and MRI) and the pivot shift was determined with the Pearson χ2test. To evaluate the reproducibility of the results, the agreement between observers was determined with the Cohen κ coefficient.


RESULTS
On US, the ALL was identified and visible over its entire length in 100% of patients (30 of 30, κ = 1). The ALL was injured in 63% of patients (19 of 30, κ = 0.93). On MRI, the ALL was identified in 96% of patients (29 of 30, κ = 0.91). The ALL appeared injured in 53% of cases (16 of 30, κ = 0.93). An ALL that appeared injured on US was more often associated with a positive pivot shift than was an uninjured ALL (75% vs 39%, χ2= 13.7, P < .05). The interobserver agreement was high for both US (κ = 0.91-1) and MRI (κ = 0.76-1).


CONCLUSIONS
US is a reproducible examination for the diagnosis of ALL injury. An ALL injury is most often associated with a high pivot-shift grade.


METHODS
Level II, prospective comparative study.
Department of Orthopedic Surgery and Trauma, Hôpital Pierre Paul Riquet, Toulouse, France. Electronic address: cavaignac.etienne@gmail.com.
Etienne
E
Cavaignac
Department of Radiology, Centre Hospitalier Universitaire Toulouse, Toulouse, France.
Marie
M
Faruch
Department of Orthopedic Surgery and Trauma, Hôpital Pierre Paul Riquet, Toulouse, France.
Karine
K
Wytrykowski
Department of Radiology, Centre Hospitalier Universitaire Toulouse, Toulouse, France.
Olivia
O
Constant
Department of Orthopedic Surgery and Trauma, Hôpital Pierre Paul Riquet, Toulouse, France.
Jérôme
J
Murgier
Department of Epidemiology, Health Economics and Public Health, Unité Mixte de Recherche (UMR) 1027 Institut National de la Santé Et de la Recherche Médical (INSERM)-University of Toulouse III, Toulouse University Hospital, Toulouse, France.
Emilie
E
Berard
Department of Orthopedic Surgery and Trauma, Hôpital Pierre Paul Riquet, Toulouse, France.
Philippe
P
Chiron
D000328:Adult; D000070598:Anterior Cruciate Ligament Injuries / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D010808:Physical Examination / Q000379:methods; D011446:Prospective Studies; D014463:Ultrasonography