ObjectiveTo evaluate the effect of reconstruction of forearm interosseous membrane (IOM) using extensor carpi radialis longus combined with radial head replacement for restoring the forearm longitudinal stability. MethodsTen fresh-frozen adult cadaveric forearms were selected, including 8 males and 2 females with a mean age of 38.2 years (range, 29-74 years). Each forearm was treated as following steps: radial head excision (group A), radial head excision+the distal ulnar radial joints separation (group B), radial head excision+the distal ulnar radial joints separation+IOM central band excision (group C), reconstructed IOM with extensor carpi radialis longus tendon (group D), radial head prothesis replacement (group E), and reconstructed IOM with extensor carpi radialis longus tendon+radial head prothesis replacement (group F). The distance between ulna and radius and radioulnar joint displacement were observed under load and non load. The force loading on both ends of specimen was recorded when the radius shifted 5 mm proximally. ResultsRestoring the radial length could maintain normal distance between radius and ulna. The interosseous membrance reconstruction could restore the load transmission between radius and ulna. The force loading specimen was (74.507±4.967), (49.227±1.940), (17.827±1.496), (24.561±1.390), (140.247±8.029), and (158.423±9.142)N in groups A, B, C, D, E, and F respectively when the radius shifted 5 mm proximally, showing significant difference among groups (P < 0.01). ConclusionReconstruction of the IOM with the extensor carpi radialis longus tendon is insufficient to restore the forearm longitudinal stability. Reconstruction using extensor carpi radialis longus tendon combined with radial head replacement may be a new choice for treatment of forearm longitudinal instability.