To evaluate the changes in stabil ity of the wrist after experimental traumatic triangular fibrocartilage complex (TFCC) lesions, and to provide basic theoretical criteria for cl inical treatment. Methods Fourteen adult cadaver upper extremities specimens were included. Two of 14 specimens were tested in pre-experiment. The specimens were tested in a INSTRON 8874 biomechanics measuring instrument. First a dorsal arthrotomy (ART) was performed, and second test was with 1 of 4 different experimental lesions according to Palmer’s classification of traumatic TFCC lesions (n=3). 1A: central perforation; 1B: ulnar avulsion with or without fracture of processus styloideus ulnae; 1C: distal avulsion with l igament injury; 1D: radial avulsion. Forced internal∕external rotation torque were recorded in the interval — 60° to 60° of flexion. Results The average torque of the dorsal ART was (0.713 ± 0.121) Nm, and the 1B-1 lesion (ulnar avulsion without ulnar styloid fracture) was (0.709 ± 0.134) Nm, the 1B-2 lesion (ulnar avulsion with ulnar styloid fracture) was (0.409 ± 0.113) Nm. The difference between the 1B-1 lesion and the dorsal ART was not significant but the difference between the 1B-2 lesion and the dorsal ART was significant (P lt; 0.05). The average torque of the 1C lesion in about 45° of wrist extention and flexion were (0.878 ± 0.184) Nm and (0.988 ± 0.197) Nm, and the dorsal ART were (1.510 ± 0.173) Nm and (1.540 ± 0.093) Nm. The difference between the two groups was significant (P lt; 0.05). The 1A lesion and 1D lesion did not alter significantly wrist stabil ity. Conclusion The 1B-2 lesion and 1C lesion alter significantly the stabil ity of the wrist.