The bridging infix : a modified, minimally invasive subcutaneous anterior pelvic fixation technique

Abstract

Various methods for anterior pelvic ring fixation have been described in the literature, each with specific advantages and disadvantages. We describe a modified minimally invasive subcutaneous technique for anterior fixation: the Bridging Infix. It combines the benefits of internal plate fixation with external fixator principles. We merged and modified features of the existing INFIX and Pelvic Bridge techniques during the design. Similar to these techniques, we use plate-rods typically used during occipitocervical fusions. The design changes allow for less discomfort due to prominent hardware in thin patients and eliminate the need for an intact medial pubic rami for fixation. There is also no risk of bladder injury due to accidental screw perforation through the pubic rami. The Bridging Infix is ideal for patients who are physiologically too frail for extensive open reduction and plate osteosynthesis, such as elderly patients with pelvic fragility fractures who are failing to mobilise due to pain. It can also be used for patients in whom external fixators may be impractical or poorly tolerated, such as obese patients or those with increased nursing demands. This technique does not provide adequate posterior pelvic ring stability, thus it requires an intact posterior tension band or the addition of separate posterior fixation. Patients can commence in-bed mobilisation the same day as the procedure, with weight-bearing as tolerated allowed for most cases, and toe-touching reserved for highly unstable injury patterns only. The implants are not routinely removed unless requested by the patient, especially in the elderly to avoid additional anaesthetic exposure. Potential complaints include lateral thigh pain, due to lateral femoral nerve compression, and mechanical discomfort during exercise activities.