Use of a spinal cage for creating stable constructs in ankle and subtalar fusion

In complicated foot surgery with reconstruction of the hindfoot, a gap will sometimes be present between the bones that must be filled and stabilized. Bone grafting with structural bone graft is 1 alternative; however, it can collapse and must be stabilized with screws or a nail. A locking intramedullary nail can be used but could lead to nonunion owing to distraction. Newer nails include a compression device but that can result in shortening. We developed a technique that includes distraction of the fusion area with a spinal cage and then compression of the construct by inserting a compression screw through the cage. We present our experience with this technique.We reviewed the data from 7 patients who had undergone surgery using this technique. The technique included distraction of the fusion area and insertion of a titanium cylindrical spinal cage filled with autologous cancellous bone graft. A cannulated compression screw was then inserted through the cage, creating compression of the fusion area against the cage and achieving stabilization of the fusion area. Postoperatively, a non-weightbearing cast was applied for 3 months, followed by a full weightbearing cast until radiographic fusion was apparent. Complete radiographic union was observed in all 7 patients within 6 to 12months postoperatively. At the latest follow-up visit, the mean American Orthopaedic Foot and Ankle Society scale score was 54±16 (range 30 to 71) points. The use of a cylindrical titanium cage with a local bone graft and stabilization by distraction and compression provided a stable construct, avoided shortening, and led to good fusion. In addition, donor site complications and unpredictable strength loss and lysis of bone allograft were avoided.