ANGLE STABLE PLATE OR ANGLE STABLE LOCKED NAIL FIXATION IN DISTAL RADIUS FRACTURES. AN EXPERIMENTAL EXAMINATION AND PHASE I CLINICAL STUDY

Abstract

Distal radius fractures are typical and frequent fracture of elderly woman with reduced bone density. Thus implant fixation is more difficult. Dorsal and radial comminution are frequent in these patients and so reduction and angle stable osteosynthesis needed. The angle stable plate, often also multidirectional is today the most common stabilisation device. Because of the introduction of bulky and bended implants as the Micronail or Targon DR wich require difficult opening of the bone with awles we decided to test the XS radius nail witch is a 4,5mm or 3,5mm straight nail and witch is introduced after guide wire placement and over drilling with a canulated drill of the same diameter. It is locked parallel to the joint in 3 different directions with angular stability with threaded wires.

Methods 16 radius sawbones were osteotomised corresponding to a A3 Fracture and stabilised with a angle stable plate (8) and XS nail (8). 1000 alternating load cycles from 20–200N were performed and the deformation was registered. Also a FE analysis with the MSC Patran/Marc softwere were performed.

Also the calculated deformation in the FE study was 20% lower. Also deformation amplitude was lower with 0.31mm compared to 0.42mm in the plate group. The differences however were not significant.

Both devices show good biomechanical results. The XS nail has the advantage of mainly intraosseus position, simple operation technique with introduction over a guide wire from the proc. Styloideus radii and over drilling with a canulated drill of the same size. The exposure of the N rad. superf. must be performed. First clinical evaluation is presented.

Due to the results we developed a anatomically adapted XS radius nail. The results of the first 100 patients are presented.