Restoring Volar Tilt in AO Type C2 Fractures of the Distal Radius With Unilateral External Fixation.

PURPOSE: To determine whether unilateral external fixation using a staged multiplanar reduction technique restores anatomic volar tilt in a distal radius fracture model.

METHODS

We used radiographic images to obtain baseline measurements in 20 fresh-frozen cadaveric wrists. Through a standard dorsal approach to the radius, we performed osteotomies to simulate displaced AO/ASIF type C2 fractures. After placement of a unilateral external fixator, a stepwise technique of applying longitudinal traction followed by a volar translational maneuver was performed. Radiographic imaging was obtained after each step of the multiplanar reduction technique.

RESULTS

Standard longitudinal traction did not restore volar tilt angles to their baseline measurements. The addition of a volar translation maneuver had a significant effect on restoring baseline volar tilt. There was a statistically significant difference in volar tilt measurements between straight longitudinal traction and volar translation. Radial inclination, radial height, and ulnar variance did not differ significantly between longitudinal traction and the addition of volar translation.

CONCLUSIONS

A criticism of traditional external fixation is the inability of longitudinal ligamentotaxis to attain sagittal plane (volar tilt) reduction of the articular surface. This study demonstrates that a multiplanar reduction technique using unilateral external fixation devices on cadaveric distal radius fractures can achieve an acceptable reduction.

CLINICAL RELEVANCE: External fixation of distal radius fractures may be favorable in situations where soft tissue loss, wound contamination, and comorbid medical factors preclude the use of internal fixation techniques. A multiplanar reduction technique using a unilateral external fixation device may facilitate fracture reduction in acceptable alignment.