Current Concepts In Surgery For Adult-Acquired Flatfoot
We fixate our lateral column lengthening procedures with one small diameter screw. We have been fixating these osteotomies over the last several years. However, the senior authors did not use fixation for this procedure in their first 25 years of practice. We place these bone grafts with a large amount of tension and displacement is unlikely. Nonetheless, fixation will secure the bone graft and diminish micromotion at the host-graft interface. Our goal with fixation is to expedite bone graft incorporation and lessen the risk of nonunion. Furthermore, surgeons must consider whether fixation of these osteotomies is the standard of care in their specific region of practice.
Dunn and Meyer evaluated displacement of the anterior process of the calcaneus after lateral column lengthening.24 They found that fixation captured a statistically significant amount of early sagittal plane displacement whereas the amount of displacement was insignificant when surgeons used no fixation. Therefore, the decision to use fixation is based on surgeon preference.
Researchers have described lateral column pain as a potential complication following lengthening and attribute this to inappropriate graft size.25-30 Graft sizing can be an intraoperative challenge and there are no guidelines for estimating the amount of lateral column lengthening necessary to reduce the deformity. We have found the magnitude of deformity and suppleness of soft tissues to be important factors that influence graft size. In the past, the senior authors would place as large a graft as possible. However, this often resulted in hindfoot stiffness and lateral column pain. These were cases in which we performed lateral column lengthening without a medial transpositional osteotomy of the posterior calcaneus. We tried to achieve complete realignment with one osteotomy.
However, with the addition of the medial transpositional osteotomy to lateral column lengthening, we can now control the amount of displacement and lengthening at both osteotomy sites. In other words, we can use a smaller size graft for the lateral column lengthening by increasing the displacement at the medial transpositional osteotomy site. The risk of lateral column pain diminishes with a smaller size bone graft. We also test the amount of remaining eversion following graft placement. We will move to a smaller graft size if eversion is severely limited.
We also use trial wedges when ascertaining graft size. One can take the tritarsal complex through a range of motion after the wedge is in place to evaluate remaining eversion. Additionally, we obtain intraoperative images to evaluate realignment with the wedge in place. Placement of the trial wedges, however, can weaken the osteotomy but this is not an issue when one is using fixation. In addition to evaluating the clinical position of the foot and range of motion, we often obtain intraoperative images with simulated weightbearing to confirm restoration of angular relationships.