[Non-articular malunions of the distal radius: evaluation and techniques of correction]

Malunion remains the most common complication following fracture of the distal radius. Deformities can be observed in all three planes with displacement in dorsal or palmar tilt, translation, shortening and axial rotation. Preoperative evaluation requires a comparative analysis with clinical, radiological and scanographic assessment. The functional consequences affect the radiocarpal and distal radio-ulnar joints and the carpus. Biomechanical aspects include changes in pressure forces on the distal radius and ulna, and displacement of the centers of rotation. If present, associated lesions should be evaluated. The degree of clinical acceptance depends on each patient, but generally functional outcome is closely correlated with the anatomic result. Limits of radiological acceptance should be defined at 20 degrees dorsal tilt, 5 degrees radial inclination, and a - 4 mm distal radio-ulnar index. Corrective osteotomy is performed on the radius, with or without a complementary ulnar procedure. Closing wedge and re-orientation osteotomies are no longer used. Opening wedge osteotomy with or without lengthening is preferred, generally with an access on the same side as the sagittal tilt. The osteotomy should be performed just above the distal radio-ulnar joint. A temporary external fixator provides the best way to check peroperative corrections. Bone grafts may be harvested from the radius or the iliac crest. Pins and cast are sufficient to immobilize the dorsal tilt corrections. In case of volar tilt, an internal plate fixation is best. Depending on the status of the distal radio-ulnar joint, a conservative (shortening osteotomy, wafer procedure) or non-conservative (Darrach-Moore, Kapandji-Sauvé.) procedure should be performed on the ulna. If needed, associated lesions of the carpus must be treated. Surgical correction is mainly indicated in case of a functionally unacceptable deformation, but should be discussed if the radiographical limits have been overrun. The goal of such corrective procedures is to recover anatomical restitution.