Use of Computed Tomography in Determining the Occurrence of Dorsal and Intra-articular Screw Penetration in Volar Locking Plate Osteosynthesis of Distal Radius Fracture.

BACKGROUND: The use of volar locking plate in distal radius fracture can lead to extensor tendon rupture due to dorsal screw penetration. The aim of our study was to investigate the occurrence of dorsal and intra-articular screw penetration using CT scan after volar distal radius osteosynthesis for distal radius fractures.

METHODS: Thirty patients who underwent distal volar locking plate for distal radius fracture were included in a retrospective study. In all 30 patients no dorsal and intra-articular screw penetration were detected on standard AP and lateral views of a plain radiograph. CT scan of the operated wrist was performed to determine the number of intra-articular and dorsal screw penetrations. Clinical examination was performed to determine the wrist functions in comparison to the normal wrist.

RESULTS: Nineteen wrists were noted to have screw penetration either dorsally or intraarticularly. The highest incidence is in the 2nd extensor compartment where 13 screws had penetrated with a mean of 2.46 mm. Six screws penetrated into the distal radial ulnar joint and five screws into the wrist joint with a mean of 2.83 mm and 2.6 mm, respectively. However, there was no incidence of tendon irritation or rupture.

CONCLUSIONS: This study demonstrated a high incidence of dorsal and intra-articular screw penetration detected by CT scan which was not apparent in plain radiograph. We recommend that surgeons adhere to the principle of only near cortex fixation and downsizing the locking screw length by 2 mm.