Back to 2018 ePosters

Purpose: To describe a technique for two screw scaphoid fixation and report early clinical outcomes and radiographic analysis.

Background: The current standard of care for displaced or unstable scaphoid fractures is surgical fixation with a single headless compression screw¹. However, single screw fixation may have a higher non-union rate than previously thought and may not provide adequate stability for complex, multidirectional motion^2,3. Two-screw fixation may provide a stiffer construct and better torsional stability⁴.

Methods: A standard dorsal approach to the scaphoid is used for open reduction. With the wrist in full flexion, two guide wires are placed in the scaphoid under fluoroscopic guidance starting volar and dorsal to the central axis. The volar wire is placed first followed by the dorsal wire. In the coronal plane, both wires are in the central axis of the scaphoid. In the sagittal plane, the wires are spaced out as much as possible, usually a distance of 3-5mm (Figure 1). Placing both wires prior to screw insertion allows one wire to provide rotational stability during screw placement. Both screws are inserted simultaneously to avoid fracture gapping at the opposite end of the scaphoid. The patient is immobilized for 4 weeks post operatively and allowed to return to full activity at 3 months. The scaphoid width, screw length, distance between screws and fracture healing were obtained from post-operative radiographs. Post-operative function and range of motion was recorded for each patient in office note documentation.

Results: There are 8 patients included in our single surgeon series. The average measured scaphoid width is 10.7mm. The average distance between the two screws is 2.6mm. The average lengths of the volar and dorsal screws are 22.1mm and 19.6mm, respectively. All patients achieved clinical and radiographic union. All patients returned to pre-injury function and wrist range of motion. There were no complications. One proximal pole scaphoid fracture had propagation of fracture during second screw insertion, but healed uneventfully.

Conclusion: Open reduction internal fixation of scaphoid fractures using the described two screw technique is a successful procedure leading to good radiographic and clinical results in our small case series. There is sufficient scaphoid bone stock to tolerate the placement of two screws and allow for fracture healing. Fracture fragmentation of proximal pole scaphoid fractures is of concern for two screw fixation.

(a) (b)

Figure 1: Screw placement in the (a) coronal plane viewed on PA radiograph (b) sagittal plane viewed on lateral radiograph.