SLR - August 2010 - Jahangir Habib
Reference:
McMahon, PJ; Dheer, S; Raikin, SM; Elias, I; Morrison, WB; Kavanagh, EC; Zoga, A. (2008). MRI of Injuries to the First Interosseous Cuneometatarsal (Lisfranc) Ligament. Skeletal Radiology, 38, 255-260.
Scientific Literature Reviews
Reviewed by: Jahangir Habib, DPM, PGY-3
Residency Program: OCPM/UHHS Richmond Medical Center
Podiatric Relevance:
Lisfranc injuries are commonly seen in foot and ankle surgical practices. The Lisfranc ligament is one of the key stabilizers of the midfoot, and MRIs are routinely used to aid in the diagnosis and treatment of these injuries.
Methods:
Fifteen patients (16 feet) received an MRI without contrast of the Lisfranc ligament following injury between 2002 and 2006, and had operative exploration or examination under anesthesia. Several specific imaging components were evaluated: the dorsal and plantar bundles of the Lisfranc ligament, the plantar tarsal metatarsal ligaments, soft tissue edema and fluid, bone marrow edema, and fractures. Ligamentous injuries were classified as grade 1 (fluid surrounding the ligament only), grade 2 (abnormal signal within the ligament, but no evidence of complete ligament rupture), or grade 3 (complete tears) injuries.
Results:
Seven of 10 cases of grade 3 Lisfranc ligament injuries at surgery were correctly graded on MRI. No cases of surgically proven complete Lisfranc ligament tears (grade 3) were interpreted as normal on MRI. All Lisfranc ligament sprains (grade 2 or grade 3) at surgery were detected on MRI. Two of six cases reported as grade 1 injuries on MRI were normal at surgery. No cases of surgically proven normal or sprained Lisfranc ligaments were interpreted as grade 3 tears on MRI.
Conclusions:
Based on these results, the authors conclude that MRI is reasonably accurate at detecting injuries to the Lisfranc ligament. Long axis (axial) MRI sequences are an accurate method for detecting grade 3 injuries and sprains. However, in clinically suspected cases of traumatic Lisfranc ligament injury, the appearance of a normal Lisfranc ligament may be confused with a sprain. Differentiating grade 1 and grade 2 sprains by MRI may inconsistent.