Feasibility study of simultaneous physical examination and dynamic MR imaging of medial collateral ligament knee injuries in a 1.5-T large-bore magnet.
OBJECTIVE
To determine the feasibility of evaluating medial knee joint laxity with dynamic magnetic resonance (MR) imaging and simultaneous physical joint examination in a large-bore 1.5-T system.


METHODS
The study included 10 patients (5 women, 5 men; mean age 35 years) with clinically diagnosed and categorized acute injuries of the medial collateral ligament (MCL). Intermittent valgus stress was applied separately to both the affected and the contralateral knee joint during dynamic MR imaging with a two-dimensional fast low-angle shot sequence. The width of the medial joint space and the opening angle between the femoral condyles and the tibial plateau were measured. Results obtained from dynamic MR imaging of the affected knee were compared with morphological MCL changes on static MRI, to kinematics of the contralateral side and to the clinical grading of MCL injuries.


RESULTS
On clinical examination, all patients had grade 2 MCL injuries except one, who had a grade 1 lesion. Using morphological MRI criteria, 9 grade II and 1 grade III injuries were seen. Mean medial joint space width and opening angles of all affected knees were 2.8 mm and 2.7° respectively, compared with 1.7 mm and 2.1° on the contralateral side. The Wilcoxon signed rank test indicated that the differences in width (P = 0.005) and opening angle (P = 0.037) between the affected and contralateral knees were significant.


CONCLUSIONS
Dynamic MR imaging and simultaneous physical joint examination is feasible. Our results suggest that this technique might enable the imaging documentation of medial ligamentous knee instability.
Department of Medical Imaging, Mount Sinai Hospital and University Health Network, University of Toronto, 600 University Avenue, Toronto, ON, M5G 1X5, Canada. studleru@uhbs.ch
Ueli
U
Studler
Lawrence M
LM
White
Melanie
M
Deslandes
Christopher
C
Geddes
Marshall S
MS
Sussman
John
J
Theodoropoulos
D000293:Adolescent; D000328:Adult; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D007718:Knee Injuries / Q000473:pathology*; D008279:Magnetic Resonance Imaging / Q000295:instrumentation* / Q000379:methods*; D008280:Magnetics / Q000295:instrumentation; D008297:Male; D017888:Medial Collateral Ligament, Knee / Q000293:injuries* / Q000473:pathology*; D008875:Middle Aged; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D055815:Young Adult