A Closer Look At Supplemental Fixation Techniques For High Risk Ankle Trauma
- Volume 25 - Issue 1 - January 2012
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Soft tissue preservation is an important management priority for ankle fractures. This becomes especially critical in the high-risk patient. It is important to consider the timing of surgery and the surgical approach. Ideally, one should delay operative management until edema is under control and skin lines have returned.4 The surgeon may reduce any marked deformities or dislocations, and then place patients in a splint with a compressive bandage with strict instructions for ice and elevation.
Advances in lower extremity plating designs have allowed surgeons the opportunity to use a biologically friendly approach for fracture reduction and fixation. Combining a percutaneous or a mini-open approach with newer generation locking plates may decrease complications associated with disruption of the soft tissue envelope and associated osseous complications.5
However, a completely percutaneous approach is often not possible. Accordingly, one can perform a limited open approach of the ankle joint and supplement this with longer plates extended through a proximal percutaneous approach. The goal of fracture management is to achieve adequate fracture reduction and osseous stability while minimizing iatrogenic vascular insult to the osseous segments.
What Are The Advantages Of Supplemental Fixation?
Poor bone quality is often present in patients with diabetes and neuropathy as well as in the elderly. Osteoporosis affects over 25 million Americans and there has been an increase in the prevalence and severity of ankle fractures in the elderly. In the United States, ankle fractures occur in 8.3 per 1,000 Medicare recipients.6 As a result, the associated changes in cortical bone will reduce the pullout strength of traditional fixation constructs. In this situation, locking plates and supplemental fixation may enhance osseous stability.
Locking plates offer a fixed angle construct with increased pullout strength. The locking mechanism between the plate and screw head prevents toggle and pullout, which may occur in osteoporotic bone. Newer pre-contoured locking plates offer multiple options for supraperiosteal screw placement. Bridge plating with locking plates overcomes several of the disadvantages of conventional plate fixation and provides a sufficiently stable construct to allow for osseous healing.7
Although locking plates are beneficial among this high-risk population, the surgeon must understand the absolute rigidity that occurs with the locking plate. If one does not apply locking plates correctly, they may impede bone healing and result in a nonunion. This may occur when one neglects compression across the fracture site and secures the plate with only locking screws. In general, the surgeon should only add locking screws after obtaining compression. Always remember to lag before you lock.
A technical pearl to consider for fracture care in the elderly or diabetic population is to increase the working length of the plate and bridge across the fracture zone. Longer plates with fewer screws offer optimal stability.
Supplemental fixation can be helpful in managing osteoporotic or neuropathic diabetic ankle fractures.8 When it comes to ankle fractures, there is a variety of supplemental fixation options including: plate and screw fixation supplemented with Kirschner wires; syndesmotic screws with tetra-cortical purchase; multiple or stacked plates; intramedullary fixation; static external fixation devices; or transarticular fixation.8-11
Plate and screw fixation supplemented with K-wires provide improved fixation for high-risk diabetic fibular fractures. Syndesmotic fixation may enhance fixation, especially for unstable ankle fractures in patients with diabetes and neuropathy.3,9 The use of multiple trans-syndesmotic screws increases the rigidity of the entire fixation construct.