Imaging anatomy characters and surgery treatment of gradeIIsupination-adduction ankle joint fractures

Objective To define the imaging characters and effective surgery treatment of stageⅡsupination-adduction type ankle fractures. Methods From June 2014 to December 2017 in the First Affiliated Hospital of University of Science and Technology of China(Anhui Provincial Hospital), 36 patients (24 males and 12 females) with stageⅡsupination-adduction type ankle fractures (21 left ankles and 15 right ankles) ranged from 19 to 56 years old. All patients accepted the treatment of open reduction and internal fixation with buttres plate, and eight patients who also suffered bone defect were treated with bone transplantation. Before operation, all imaging data, including X-ray and computerized tomography(CT) examination, were analyzed the angle (α) between fracture surface and tibia longitudinal axis, the distance (d) from fracture zone to arched roof of tibia distal end joint surface, and area (S) and volume (V) of collapse joint surface, and the relationship between them with three dimension (3D) visualization operation and simulation software system (V1.0.0). The distance (L) between fracture line of fibula and arched roof of tibia distal end joint surface was also measured. The correlation analysis between d, V and α were performed. And then all data were used to analyzed the imaging characters of stageⅡsupination-adduction type ankle fractures. After operations, the results were evaluated with AOFAS and VAS. Results From the pre-operation results of CT imaging of 36 patients, α angle was 4.5°-15.5°(9.85°±4.05°) . And α angle of 20 other patients with collapse of tibia distal end joint surface was 9.85°±4.05°, which was significant smaller than that of the other 16 patients without collapse (12.83°±2.87°) (t=-9.847, P 0.05), the fracture line of fibula mainly lied in the top point of tibia dome, and the L was 1.27-12.22(5.50±5.54) mm. All patients achieved anatomic reduction and were followed up 10(6-15) months without infection or bone absorption or transposition. Healing time were 10.5 (9-16) weeks. AOFAS and VAS improved to(85±8)and(2.1±0.9). Conclusions The fracture line of stageⅡsupination-adduction type ankle fractures is close to vertical line. Open reduction and internal fixation with buttress plate for tibia fracture fragment is commendable option because of great shear force, larger defect should restore joint surface height by bone grafting, and plate is a good choice to treat fibular fractures. Key words: Ankle joint; Fractures, bone; Fracture fixation, internal; Supination-adduction type ankle fractures; Imaging Characters