Temporary external fixation in correction of non articular mal-unions of the distal radius

Purpose of the study The authors reviewed 21 cases of extra articular malun ions of the distal radius treated by osteotomy, temporary external fixation , then osteosynthesis. Two groups were studied: Group A of 14 patients with dorsal tilt of the distal radius and Group B of 7 patients with palmar til t of the distal radius. Mean follow-up of this series was 69 months ranged from 12 to 109 months. Material and methods In Group A, after exposure of the distal radius throug h a dorsal approach, the site of osteotomy, proximal to the distal radio-ul nar joint, was determined by fluoroscopy. The angular correction was done b y progressive opening using a small external fixator. After checking on the correction, the bone graft was harvested 7 times on the radius as describe d by Watson et Castle, 7 times on the iliac crest. Bone fixation was done b y two K-wires and a cast for 8 to 10 weeks. Three Sauve-Kapandji procedures was done at the same time. In Group B, the approach was palmar, extended d istally to open the carpal tunnel, The distraction was done with a distal T -shaped external fixator. The bone graft was always harvested on the iliac crest. Bone fixation was done with a T-shaped palmar plate. Two Sauve-Kapan dji procedures was done at the same time. Results Group A: Flexion-extension are was improved of 15,5 p. 100, pronati on-supination of 83,7 p. 100 and grip strength of 80 per cent of the pre-op erative values. Radiological evaluation showed good correction except one c ase of undercorrection of the dorsal tilt (- 7 degrees) and one case of und ercorrection of the radial inclination (+ 6 degrees). The distal radio-ulna r index was measured at the mean of 0mm postoperatively compared to + 5 mm pre-operatively. One patient developed a postoperative radiocarpal arthriti s. Group B: Flexion-extension are was improved of 96,2 p. 100, pronation-su pination of 76,9 p. 100 and grip strength of 108,3 p. 100 of the preoperati ve values. Radiological evaluation showed good correction except one case o f overcorrection of the palmer tilt (- 10 degrees) and one case of undercor rection of the radial inclination (+ 7 degrees). The distal radio-ulnar ind ex was measured at the mean of 0mm postoperatively compared to + 7 mm pre-o peratively. Discussion The functional consequences of malunions of the distal radius ha ve been stressed by others for more than sixty years. Since, many authors h ave contributed to refine and improve their surgical correction, Several di splacements should be taked into account for the preoperative planning. The y are sagittal ti It, frontal horizontalisation, shortening, sagittal and f rontal translation, and axial rotation. Many types of osteotomies could be done; closing wedge, opening wedge or reorientation. In some cases, an oper ative procedure of the distal radio-ulnar joint should be done at the same time. We chose an opening-wedge osteotomy and the use of a temporary extern al fixator to ensure progressive distraction and good adjustment in the cor rection of angular deformities. In the dorsal tilt group we were satisfied in using on 7 patients a trapezoidal cortico-cancellous bone graft harveste d on the radius. Conclusion The authors would like to stress two points: - The technical int erest of using a temporary external fixator to adjust the angular correctio n of the distal radius, - The importance of an adequate treatment of distal radius fractures in emergency situation, considering the functional and co smetic alterations due to malunions and their need for surgical corrections in main instances.