[Classification and imaging diagnosis of Lisfranc joint injuries].

OBJECTIVE: To accelerate the detection rate and accuracy of diagnosis in damage imaging of Lisfranc joint through research on the information of X-ray, CT, and MR imaging of tarsometatarsus joint (also called Lisfranc joint) damage.

METHODS: A total of 153 cases of tarsometratisus damage or Lisfranc ligamentous injury patients were chosen during November 2012 to November 2015. Lisfranc injuries were classified according to the Myerson fracture displacements classification and Nunley-Vertullo low-grade injury classification. All the treatment data was performed using SPSS 17.0 software.

RESULTS: For Myerson fracture displacements, there were 16 cases in Myerson Ⅰ type (homolateral complete), 100 cases in Myerson Ⅱ type (homolateral incomplete), and 5 cases in Myerson Ⅲ type (divergent). For the low-grade injury, there were 7 cases, 24 cases, and 1 case in Nunley-Vertullo Ⅰ, Ⅱ, Ⅲ type respectively. The probability was 14.9% (18/121) for patients that the initial survey found negative by X-ray imaging diagnosis and was confirmed by subsequent CT or MRI. It was found that the distance between the base of first (M1) and second (M2) metatarsus which was larger than 2 mm was 69.4%(84/121)from the X-ray imaging; there were small chip fractures between the base of M1 and M2 was 47.1% (57/121), and 71.2% (37/52)of small chip fractures in the inside of base of M2 from CT. On MRI, ligament disruption showed the discontinue or normal signal disappearing, and there were 15 cases in the complete disruption condition.

CONCLUSION: It should be suggested to take a CT or MRI check for the patients who have highly suspicious Lisfranc injure and the X-ray imaging diagnosis was negative, since there is a certain rate of missed diagnosis for the Lisfranc injure using X-ray imaging. For children and teenagers, the sports injuries and joint strain are common style, such as the injuries caused by jump from higher platform, football/skateboarding injures, etc. If the distance between the base of M1 and M2 is larger than 2 mm or there are small chip fractures between the M1 and M2, the patients would be suspected bone fracture or Lisfranc ligament injure. Myerson Ⅱ type is the most common Lisfranc joint injury , and MRI is best for Lisfranc ligament injury.