J Korean Radiol Soc.
1997 Apr;36(4):687-695.
Anterior Cruciate Ligament Tear: Comparison of MR Features between Complete and Partial Tear
- Affiliations
-
- 1Department of Radiology, Kangnam General Hospital Public Corporation.
- 2Department of Orthopedic Surgery, Kangnam General Hospital Public Corporation.
- 3Department of Radiology, Hallym University College of Medicine.
- 4Department of Radiology, Samsung Medical Center.
Abstract
- PURPOSE
To determine the MRI features which distinguish complete and partial tear of the anterior cruciate ligament (ACL) and to thus improve MRI interpretation.
MATERIALS AND METHODS
In 80 patients, we analyzed MR findings of direct and indirect signs of ACL tear (complete tear, 61 cases, partial tear, 19 cases) confirmed by arthroscopy or surgery, and compared the relative incidence of each sign in cases of complete and partial tear.
RESULTS
Direct and indirect signs were found in 61 (100%) and 60 cases (98.4%), respectively, in complete tears, but in 16 (84.2%) and 15 cases (78.9%), respectively, in partial tears. Poor visualization, discontinuity and hyperintensity were seen in all complete tears but in only nine case (47.4%) of partial tear. A wavy or abnormal contour was seen in 53 cases (86.9%) of complete tear and 14 (73.7%) of partial tear. A wavy contour without other direct signs was seen in only five cases (26.3%) of partial tear. Three cases (15.8%) of partial tear showed normal MR finding. Indirect signs, i. e. abnormal ACL angle, abnormal ACL-Blumensaat line angle, abnormal posterior cruciate ligament (PCL) line, abnormal PCL angle, PCL buckling, anterior displacement of tibia, posterior displacement of lateral meniscus, bone bruise, Segond fracture, tear of collateral ligaments, PCL, and tear of meniscus were commoner in complete than in partial tears. Two cases of O'Donoghue's triad and two of popliteus injury were seen only in complete tears.
CONCLUSION
Direct and indirect signs of ACL tear were more commonly noted in complete than in partial tears. The latter showed MR features varying from normal to almost complete tear. We suggest that a wavy contour other direct signs is indicative of a partial tear, and that O'Donoghue's triad and popliteus muscle injury are indirect signs of a complete tear.