Abstract:[Objective] To investigate the biomechanical properties of NICE knot fixation for mid-shaft clavicle fracture. [Methods] A total of 60 human clavicle specimens were randomly divided into 4 groups. The mid-shaft clavicle fracture models (OTA /AO type 15-A2) were made with an oscillating saw. After that, the fracture was fixed with lag screw, 2-0 suture NICE knot, 1-0 suture NICE knot and 1# su- ture NICE knot, respectively. Failure load, maximum displacement and yield stiffness of fracture models were measured by Instron biome- chanical machine. [Results] There were no significant differences between the lag screw group and 1 # suture NICE knot group in terms of failure load [(98.4±0.7)N vs (99.0±1.7)N, P＞0.05], the maximal displacement [(10.1±0.4)mm vs (10.0±0.4)mm, P＜0.05] and yield stiffness [(24.4±0.4)N/mm vs (24.5±0.5)N/mm, P＞0.05]. However, the lag screw proved significantly superior to 2-0 suture NICE group and 1-0 su- ture NICE group in terms of the failure load [(99.0±1.7)N vs (45.2±0.5)N and (64.8±0.7)N, P＜0.05], the maximal displacement [(10.0±0.4) mm vs (9.4±0.6)mm and (5.6±0.5)mm, P＜0.05] and yield stiffness [(24.5±0.5)N/mm vs (5.0±0.3)N/mm and (12.5±0.3)N/mm, P＜0.05]. In ad- dition, the 1-0 suture group was significantly superior to the 2-0 suture NICE group regarding failure load [(64.8±0.7)N vs (45.2±0.5)N, P＜ 0.05] and yield stiffness [(12.5±0.3)N/mm vs (5.0±0.3)N/mm, P＜0.05], despite that the former had significantly less maximum displacement than the latter [(5.6±0.5)mm vs (9.4±0.6)mm, P＜0.05]. [Conclusion] The biomechanical performance of NICE knot with 1# suture for fixa- tion of mid-shaft clavicle fractures is comparable to that of lag screw fixation.