Hinged elbow fixator: an extracorporeal technique to position the hinge based on an original guidewire device

The application of a hinged elbow external fixator is technically demanding because the hinge axis must coincide exactly with the flexion-extension axis of the elbow. The standard technique involves inserting a 3-mm K-wire freehand into the distal humerus to materialize the flexion-extension axis. We designed a guidewire device for extracorporeal hinge positioning without K-wire insertion. In a cadaver study, we compared freehand K-wire insertion and our extracorporeal technique.

In 12 cadaveric elbows, we induced acute elbow instability by sectioning the medial collateral ligament complex and the anterior and posterior capsule. A hinged external fixator was applied to each elbow using both techniques. The outcome measures were procedure duration, number of image-intensifier shots (as a measure of radiation exposure), and passive motion range after fixator implantation.

Compared with the freehand K-wire technique, the extracorporeal technique provided greater range of motion and significantly lower values for procedure duration and number of image-intensifier shots. Data dispersion was less marked with the extracorporeal technique, indicating better reproducibility.

The extracorporeal technique based on a guidewire device enabled non-invasive positioning of a hinged elbow external fixator. This technique was faster, less irradiating, and more reproducible than the freehand K-wire technique.