Intraoperative Use of External Fixator Attachments for Reduction of Lower Extremity Fractures and Dislocations
The mainstay of complex open lower extremity fractures and dislocations is the temporizing external fixator. We propose the use of external fixator attachments that allow for the reduction of fractures and dislocations intraoperatively. By using external fixator carbon fiber rods, the surgeon is able to create a capital “T” (sweet T) shaped attachment and connect this to a Schanz pin. Simultaneously, the external fixator carbon fiber rods can be configured into the shape of a capital Greek letter pi (Cherry II) and applied to an external fixator pin. When both of these configurations are used, multi-directional forces can be applied across the fracture fragments with the added benefit of using extrinsic hand muscle power for force generation and manipulation of fracture fragments to facilitate reduction.
Results
The fully assembled apparatus provides a firm, well-fixed configuration for applying traction in multiple directions. Axial traction can be applied, as can anterior or posterior translation forces, which may be helpful in fracture reduction and joint dislocation. For difficult-to-reduce fractures or dislocations, the surgeon can apply multidirectional traction distally while the assistant applies countertraction proximally. Fracture reduction is confirmed with fluoroscopy, and the external fixator is locked in position to maintain reduction. After reduction is confirmed, Sweet T and Cherry II are easily removed. The end result is a reduced fracture or dislocation that has the typical appearance of the temporizing external fixator.
Discussion
The Sweet T–Cherry II configuration is assembled quickly and can aid the orthopedic surgeon and assistant in managing trauma cases involving difficult-to-reduce fractures. The principle is the same as in any other traction-countertraction model, though the materials required for assembly are already available to the surgeon, and additional equipment is not required. Furthermore, the large size of the attachments has the potential to offer more points of manipulation by the surgeon and assistant, when compared with Schanz and Denham pins alone. The configuration allows full extrinsic grip power as well (Figure 4), whereas only intrinsic hand power is allowed with traction applied through Schanz and Denham pins alone.
These attachments also have the potential to reduce surgeon and assistant radiation exposure. By positioning Sweet T and Cherry II proximally and distally, with the fluoroscopy machine over the zone of injury, the operators of the attachments increase their distance from the source of radiation. This strategic positioning decreases radiation exposure and reduces direct and scatter energy from the fluoroscopy machine and the patient.4 In addition, with the operators of the attachments farther from the zone of injury, the surgeon has a clear and direct view of the procedure, which may otherwise be obstructed with use of tensioning devices or conventional external fixator configurations. Sweet T and Cherry II attachments theoretically could be used for any configuration that uses proximal and distal fixation points. There is also the added benefit that these attachments are not restricted to applying traction axially but can also translate fracture fragments anteriorly, posteriorly, medially, or laterally, which has the potential to aid in reducing fractures and dislocations with varying degrees of translation, not only shortening. Although these attachments have mechanical counterparts, such as femoral distractors and other tensioning devices, the counterparts may take longer to assemble, apply, and activate. Sweet T and Cherry II attachments are included in the external fixator equipment and may generate more force and control while achieving reduction and stabilization similar to those achieved with other traction or tensioning devices. In addition, other tensioning devices may be cumbersome and unwieldy relative to Sweet T and Cherry II. For these attachments, research is needed on forces generated, time of assembly, and ease of use.
Conclusion
The Sweet T and Cherry II external fixator attachments have the potential to aid in managing difficult-to-reduce complex fractures and dislocations. These attachments are quickly assembled and may generate more force than does reduction with Schanz and Denham pins alone. The shape of these attachments may also provide a more comfortable and easier-to-manipulate base for application of traction in multiple directions. An added benefit is extrinsic grip power. Use of these attachments also has the potential to reduce operator radiation exposure and may provide an unobstructed view of the operative field, as the attachment operators are farther from the zone of injury. In addition, the materials used to assemble these attachments are included in almost all external fixation sets. More research comparing standard external fixator configurations with external fixator configurations using Sweet T and Cherry II attachments is needed.
