Assessment of anterolateral rotatory instability in the anterior cruciate ligament-deficient knee using an open magnetic resonance imaging system.
BACKGROUND
In the clinical evaluation of the anterior cruciate ligament-deficient knee, anterolateral rotatory instability is assessed by manual tests such as the pivot-shift test, which is subjective and not quantitative.


OBJECTIVE
The anterolateral rotatory instability in an anterior cruciate ligament-deficient knee can be quantified by our newly developed method using open magnetic resonance imaging.


METHODS
Controlled laboratory study.


METHODS
Eighteen subjects with anterior cruciate ligament-deficient knees and 18 with normal knees were recruited. We administered the Slocum anterolateral rotatory instability test in the open magnetic resonance imaging scanner and scanned the sagittal view of the knee. The anterior displacements of the tibia at the medial and lateral compartments were measured. Furthermore, we examined 14 anterior cruciate ligament-deficient knees twice to assess intraobserver and interobserver reproducibility and evaluated the difference and interclass correlation coefficient of 2 measures.


RESULTS
In the anterior cruciate ligament-deficient knee, displacement was 14.4 +/- 5.5 mm at the lateral compartment and 1.6 +/- 2.3 mm at the medial compartment; in the normal knee, displacement was 0.7 +/- 1.9 mm and -1.1 +/- 1.2 mm, respectively. The difference and interclass correlation coefficient between 2 repeated measures at the lateral compartment were 1.0 +/- 0.7 mm and .98 for intraobserver reproducibility and 1.1 +/- 0.7 mm and .91 for interobserver reproducibility.


CONCLUSIONS
This method is useful to assess the anterolateral rotatory instability of the anterior cruciate ligament-deficient knee.


CONCLUSIONS
This method can be used in the clinical assessment of anterior cruciate ligament stability, such as comparing studies of graft positions or 2-bundle anatomic reconstruction and the conventional 1-bundle technique.
Okazaki
Ken
K
Department of Orthopaedic Surgery, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan. okazaki@med.kyushu-u.ac.jp
Miura
Hiromasa
H
Matsuda
Shuich
S
Yasunaga
Takefumi
T
Nakashima
Hideaki
H
Konishi
Kozo
K
Iwamoto
Yukihide
Y
Hashizume
Makoto
M
D000328:Adult; D016118:Anterior Cruciate Ligament / Q000000981:diagnostic imaging; D000070598:Anterior Cruciate Ligament Injuries; D001696:Biomechanical Phenomena; D005260:Female; D006801:Humans; D007593:Joint Instability / Q000175:diagnosis* / Q000000981:diagnostic imaging; D007718:Knee Injuries / Q000000981:diagnostic imaging*; D008279:Magnetic Resonance Imaging / Q000295:instrumentation*; D008297:Male; D011859:Radiography; D012399:Rotation