Biomechanical comparison of anterior oblique ligament versus dorsal radial ligament reconstruction of the trapeziometacarpal joint

Objective To compare the axial shortening resistance of anterior oblique ligament and dorsal radial ligament reconstruction of trapeziometacarpal joint after trapezium excision for the patients with osteoarthritis of trapeziometacarpal joint, and to determine which method was more stable. Methods Twenty cases of male adult fresh cadaver hand specimens were dissected. After the trapezium excision, ten cases of anterior oblique ligament and ten cases of dorsal radial ligament were reconstructed using half bundle of flexor carpi radialis tendon. Biomechanical testing was performed to obtain maximum load when the first metacarpal sinking 10 mm and to determine which ligament reconstruction method yielded larger axial shortening resistance. Results After the trapezium excision, the maximum load of the dorsal radial ligament reconstruction when the first metacarpal sinking 10 mm was (67.67±7.98) N and that of the anterior oblique ligament reconstruction was (77.11±8.25) N. The difference between two groups was significant (P<0.05). Conclusion After the trapezium excision, anterior oblique ligament reconstruction using flexor carpi radialis tendon can achieve more stable trapeziometacarpal joint. We should reconstruct the anterior oblique ligament firstly. Key words: Thumb; Carpometacarpal joints; Ligaments; Biomechanics