Treatment outcomes of applying external fixator on distal radius fractures: a randomized clinical trial to compare between two directions of force exertion in parallel to radius shaft and perpendicular to the distal radius articular surface.

BACKGROUND: External fixation has been one of the conventional managements of unstable distal radius fracture. The main aim of this paper is to compare two methods of applying distractive force along the radius shaft versus perpendicular to the distal radius articular surface. DESIGN: Sixty patients with unstable distal radius fracture were included in present clinical trial and randomized in two groups, using block randomization method. In group A (first arm), distraction force was exerted parallel to the radius shaft. In group B (second arm), the external fixator was adjusted based on radial and palmar tilt of the mean population healthy wrist so that distraction was exerted perpendicular to the wrist articular surface. METHODS: Radiological and clinical parameters were evaluated in both groups of patients pre-operatively, immediately after surgery, and 6 weeks post-operatively. We also followed up patients clinically at 12 weeks after surgery. Patient-Rated Wrist Evaluation (PRWE), Mayo wrist score, and Quick Disabilities of the Arm, Shoulder and Hand (DASH) questionnaires were used in order to assess patients' clinical and functional states. RESULTS: The method used in group B resulted in better improvement of palmar tilt both immediately (P = 0.007) and at 6 weeks follow up (P = 0.013) post-operatively in comparison with patients in group A. Radius height and radial inclination were also better restored when using the proposed modified method (P = 0.001 and < 0.001, respectively). There was no difference in any of clinical results (range of motion, grip strength, PRWE, Mayo, and DASH scores) between two groups of study, 12 weeks after surgery. CONCLUSION: Applying distractive force perpendicular to the distal radius articular surface seems to improve some radiological outcomes, probably due to better reduction maintenance, when compared with the technique of applying distraction force along distal radius shaft axis. LEVEL OF EVIDENCE: Level I (clinical trial study). TRIAL REGISTRATION: This study is registered at Iranian Registry of Clinical Trials (IRCT) with approval code of IRCT20200313046759N1.