gms | German Medical Science

Objectives/Interrogation: Corrective osteotomies of the distal radius for symptomatic malunion are time-tested procedures that rely on accurate corrections. The positioning of the radius osteotomy line and the creation of a suitable cortico-cancellous bone graft are the two delicate elements during the procedure. In order to facilitate and obtain more precision for these two steps, we propose an approach consisting of a computer-assisted planning and realization. On the preoperative, CT-scans of the pathological and the healthy wrists are made. On these two exams, radial inclination, ulnar variance and palmar tilt are calculated. On the pathological wrist, it is also specified the height and orientation of the old fracture line. Comparing the data and superpostion procedure will make it possible to obtain the better correction. Using specific software and a 3D printer, Newclip Technics lab will provide a specific osteotomy guide, a perfect graft template and an anatomic locking plate. The length of the screws will also be simulated.

Methods: The approach is anterior according to Henry. Elevation of the pronator quadratus muscle, visualization of the distal radius and the original fracture callus. The osteotomy guide is positioned and stabilized by pins. One of them comes to be placed in line with the future osteotomy. A first scopic control is performed to confirm, the correct position of the osteotomy. The radius osteotomy is then performed with the oscillating saw. Using the same guide, the holes of the epiphyseal screws are made. The guide is then removed. The second step is the realization of a cortico-cancellous iliac graft using the model printed in 3D. Then, we performed the distraction of the osteotomy site and the introduction of the bone graft. The third step is the osteosynthesis using the anatomic plate. The epiphyseal screws are first positioned at the level of pre-holes and the metaphyseal screws thereafter. The final scopic control confirms the good correction of the malunion with restitution of a physiological distal radius anatomy. It is also verified the correct positioning of the osteosynthesis material and the bone graft. Skin closure with drainage completed the procedure. An immobilization during the consolidation will be carried out.

Results and Conclusions: We reported results of the first ten cases operated at the same facility. we noted a significant improvement of the pain and mobilities, a restoration of prono-supination and a systematic consolidation with the stability of the reduction.