RESUMO
Objective:To measure the morphological parameters of distal tibiofibular syndesmosis in healthy adults using multi-slice CT (MSCT) so as to provide a reference for the diagnosis of distal tibiofibular syndesmosis injury.Methods:The ankle MSCT imaging data in 110 normal adults were retrieved from the image report database of Cangzhou People′s Hospital from May 2019 to May 2021, including 56 males and 54 females; aged 18-60 years [(38.2±11.0)years]. There were 51 patients with imaging on the right ankle and 59 on the left ankle. Picture archiving and communication system (PACS) was used to measure parameters at 10 mm above the articular surface of the distal tibia on MSCT, including the anterior tibiofibular space (L1), posterior tibiofibular space (L2), middle tibiofibular space (L3), depth of fibula in notch (L4), distance of anterior tibiofibular edge (L5), distance of posterior tibiofibular edge (L6), anterior tibiofibular syndesmosis angle (A1), and fibular rotation angle (A2), and the measurements were compared by sex, age and side. The positive rate of "tibiofibular line" was observed. The morphological classification of distal tibiofibular syndesmosis was performed.Results:There was no significant difference in L1-L6, A1 and A2 among different age and side (all P>0.05). No significant difference was found in L4, L5, A1 and A2 between males and females ( P>0.05), but L1, L2, L3 and L6 were larger in males than in females ( P<0.05 or 0.01). The positive rate of "tibiofibular line" was 80.4% (45/56) in males compared to 74.1% (40/54) in females ( P>0.05), 77.2% (44/57) in the youth compared to 77.4% (41/53) in the middle-aged, and 78.0% (46/59) in the left ankle compared to 76.5% (39/51) in the right ankle (all P>0.05). Morphological classification of distal tibiofibular syndesmosis was crescent in 61 patients (55.5%), trapezoid in 14 (12.7%), I-shaped in 3 (2.7%), M-shaped in 17 (15.5%), V-shaped in 10 (9.1%), Г-shaped in 5 (4.5%). Conclusions:When L1, L2, L3 and L6 are used as references in the diagnosis of adult distal tibiofibular syndesmosis injury, gender factors rather than age or side factors should be considered. Males have wider distal tibiofibular space than females, with the fibula more forward. The "tibiofibular line" has a high positive rate and is not affected by gender, age or sides, providing a new idea for the diagnosis of distal tibiofibular syndesmosis injury and anatomical reduction. There are many variations in the morphology of distal tibiofibular syndesmosis, so it is easy to be misdiagnosed as the separation of distal tibiofibular syndesmosis on X-ray, which should be noted.