Fulltext

Radiographic quantification of dynamic hip screw migration

Audigé, Laurent ; Cagienard, Flurin ; Sprecher, Christoph ; Suhm, Norbert ; Müller, Marc

In: International Orthopaedics, 2014, vol. 38, no. 4, p. 839-845

Add to personal list
    Title
    • Radiographic quantification of dynamic hip screw migration
    Author
    • Audigé, Laurent. AO Clinical Investigation and Documentation, AO Foundation, Duebendorf, Switzerland
    • Cagienard, Flurin. Department of Orthopaedic Surgery and Traumatology, University Hospital of Basel, Spitalstrasse 21, CH-4031, Basel, Switzerland
    • Sprecher, Christoph. AO Research Institute, AO Foundation, Davos, Switzerland
    • Suhm, Norbert. Department of Orthopaedic Surgery and Traumatology, University Hospital of Basel, Spitalstrasse 21, CH-4031, Basel, Switzerland
    • Müller, Marc. Department of Orthopaedic Surgery and Traumatology, University Hospital of Basel, Spitalstrasse 21, CH-4031, Basel, Switzerland
    Document Type
    • Postprint
    OAI-PMH Identifier
    • oai:doc.rero.ch:325933
    Summary
    Purpose: This study aimed to propose a technique to quantify dynamic hip screw (DHS®) migration on serial anteroposterior (AP) radiographs by accounting for femoral rotation and flexion. Methods: Femoral rotation and flexion were estimated using radiographic projections of the DHS® plate thickness and length, respectively. The method accuracy was evaluated using a synthetic femur fixed with a DHS® and positioned at pre-defined rotation and flexion settings. Standardised measurements of DHS® migration were trigonometrically adjusted for femoral rotation and flexion, and compared with unadjusted estimates in 34 patients. Results: The mean difference between the estimated and true femoral rotation and flexion values was 1.3° (95% CI 0.9-1.7°) and −3.0° (95% CI - 4.2° to −1.9°), respectively. Adjusted measurements of DHS® migration were significantly larger than unadjusted measurements (p = 0.045). Conclusion: The presented method allows quantification of DHS® migration with adequate bias correction due to femoral rotation and flexion.