Chronic distal radioulnar joint (DRUJ) instability impairs wrist kinematics, leading to a highly disabling condition and degenerative lesion. Numerous reconstructive techniques have been described either intra-articular, extra-articular or both. Recent literature has focused attention on the distal interosseous membrane (DIOM) and its contribution to DRUJ stability in all forearm position in addition to the TFCC.

Here, we describe a new ligament reconstruction of the DIOM to treat chronic DRUJ instability and report the results of a series of four cases.

We operated four patients who had chronic post-traumatic DRUJ instability. Preoperative clinical evaluation confirmed the instability, associated with painful pronosupination and a grip strength weakness (48 to 60% of the contralateral side). Arthrogram excluded arthritis in the DRUJ and TFCC lesion.

We use a free palmaris longus (or extensor carpi radialis brevis slip) graft to reconstruct the DIOM and the DOB. The ligamentoplasty is located 15% of the length of the ulna from the ulnar head, midway between the radial and ulnar insertions of the DOB. The graft is passed through two tunnels, a bicortical posteroanterior ulnar tunnel and a 15° oblique transverse blind radial tunnel.

All patients were reviewed one year after the surgery. DRUJ instability was systematically resolved. All patients were painless during pronosupination. Grip strength improved from 85 to 90% relative to the contralateral side. There was no difference in flexion-extension and pronation. Supination was reduced by 10 to 20°. All patients were able to resume working in the same occupation at a mean time of 4 months. Postoperative axial CT scans confirmed joint congruence restoration in pronation and supination.

Longitudinal axis of the reconstruction mechanically provide the best possible support against posterior-anterior instability. We believe that having an exact graft length avoids overtensioning the graft and allows easier control over the tension of the reconstructed ligament. Using interference screw reinforces the strength of the ligamentoplasty.

This surgical reconstruction of the DOB may offer an alternative technique, allowing it to be purely extra-articular, thus reducing stiffening of the radiocarpal and ulnocarpal joints. It appears to be technically simple and effective procedure to contend posterior-anterior ulnar head instability.