J Korean Radiol Soc.  1995 Sep;33(3):423-428.

Anterolateral Subluxation of the Tibia Associated with Combined Anterior Cruciate and IVledial Collateral Ligament Tears: IVIR Imaging of the Knee

• Kang HK
• Park JG
• Lee JK
• Phelps CT

Abstract

PURPOSE
To evaluate the passive subluxation of the tibia on MR' images in patient with both anterior cruciate ligament (ACL) and medial collateral ligament (MCL) tears and to demonstrate the usefulness of its measurement. MATERIALS & METHODS: The authors performed a retrospective study of 123 knees with tears of both ACL (complete, n=70, partial, n=53) and MCL (complete, n=10, partial, n=113). ACL tears were documented at arthroscopy and MCL tears were interpreted by abnormal MR findings. One hundred normal knees were also studied for comparison. Using new internal landmarks, anterior subluxation was measured on an intercondylar sagittal image and lateral subluxation was measured on a mid-coronal image.
RESULTS
Anterior subluxation of 3 mm or more was seen in 45/123(37%) abnormal knees, lateral subluxation of 3 mm or more in 20/123 (16%), and anterolateral subluxation in 15/123 (12%). Anterior subluxation of 5mm or more was seen in 25/70 (36%) complete ACL tears, and no knees with partial ACL tears showed anterior subluxation of 5 mm or more.
CONCLUSION
Static anterolateral subluxation of the tibia occurs in knees with combined ACL and MCL tears, as measured on routine MR imaging. These measurements may help confirm the presence of ligament injuries and differentiate complete from partial ACLtear.

MeSH Terms

Anterior Cruciate Ligament
Arthroscopy
Collateral Ligaments*
Humans
Knee*
Ligaments
Magnetic Resonance Imaging
Retrospective Studies
Tibia*