ObjectiveTo investigate the effectiveness of spring hook plate for posterior malleolus fracture by comparing with cannulated screw. MethodsBetween March 2012 and September 2013, 100 cases of posterior malleolus fracture were treated. Fracture was fixed with spring hook plate in 50 cases (research group) or with cannulated screw in 50 cases (control group). There was no significant difference in gender, age, cause of injury, associated injury, and injury to operation time between 2 groups P>0.05). The operation time, intraoperative blood loss, union time of fracture, ankle range of motion (ROM), and complications were recorded and compared. The ankle joint function was evaluated by the ankle hindfoot scale of American Orthopedic Foot and Ankle Society (AOFAS). ResultsThere was no significant difference in operation time and intraoperative blood loss between 2 groups P>0.05). The patients were followed up 6-12 months (mean, 9.8 months) in the control group and 6-12 months (mean, 9.2 months) in the research group. The X-ray films showed that fracture union was achieved in 2 groups; the union time of the research group[(9.5±1.4) weeks] was significantly shorter than that of the control group[(10.5±1.3) weeks] (t=2.029, P=0.017). The ROM was (25.1±3.2)° for dorsal extension and was (45.3±2.3)° for plantar flexion in the research group at 6 months after operation, which were significantly better than those of the control group[(22.2±2.3)° and (41.2±2.5)°] (t=-3.950, P=0.001; t=-5.212, P=0.000). The ankle hindfoot scale of AOFAS was 85.1±8.6 in the control group at 6 months; the results were excellent in 15 cases, good in 20 cases, and moderate in 15 cases with an excellent and good rate of 70%. The ankle hindfoot scale of AOFAS was 89.4±7.9 in the research group; the results were excellent in 20 cases, good in 22 cases, and moderate in 8 cases with an excellent and good rate of 84%; there was significant difference between 2 groups (t=-2.191, P=0.042; χ2=0.413, P=0.018). Incision infection occurred in 3 cases of the control group and in 2 cases of the research group, which was cured after dressing change; screw loosening and fracture displacement occurred in 3 and 4 cases of the control group, but did not in the research group. The complication rate of the control group and the research group was 20% and 4% respectively, showing significant difference between 2 groups (χ2=6.061, P=0.028). ConclusionSpring hook plate can shorten the time of union, increase the ROM of the ankle after operation, get good functional restoration, and decrease the rate of complication compared with cannulated screw fixation.