A Closer Look At Supplemental Fixation Techniques For High Risk Ankle Trauma

Ankle fractures are seemingly uncomplicated injuries. However, in the elderly and people with diabetes, this seemingly straightforward injury can have catastrophic outcomes.

   Systemic illnesses such as diabetes with end-organ damage clearly affect the overall outcome of ankle fractures and complications may occur due to a failure to recognize the unique treatments necessary for this high-risk patient population. Researchers have reported increased rates of complications with conservative and surgical management.
Following the open reduction and internal fixation (ORIF) of ankle fractures in this patient population, authors have cited high rates of complications including wound infection, nonunion, Charcot neuroarthropathy, loss of fixation, increased rates of revision surgery and amputation.1,2

   Accordingly, it is important to be fully aware of the treatment options available to optimize outcomes. With this in mind, let us take a closer look at advanced fixation techniques and constructs that are advantageous for the management of high-risk foot and ankle trauma.

   In patients with decreased bone mineral density, it is at times unrealistic to expect traditional fixation constructs to maintain compression and stability. Consequently, fixation failure and loss of correction may occur. Advances in fixation technology and techniques have aided the evolution and complexity of procedures for high-risk ankle trauma. Recent advances in fixation design (such as locking plate technology) as well as advances in techniques (such as supplemental fixation) have effectively enhanced outcomes in this high-risk population.

What About Post-ORIF Complications?

Diabetic neuropathy clearly affects the overall patient management and complications often occur after an ankle fracture. In a large population-based study using a California discharge database, SooHoo and colleagues identified 57,183 patients who underwent ORIF for an ankle fracture.1 The researchers found that patients with complicated diabetes (defined as those with end-organ damage) had the highest rates of short-term complications. The study authors examined short-term complications on the basis of readmission rates within 90 days of discharge and examined factors including wound infection and rates of revision surgery.

   Overall, the authors found a 1.4 percent wound infection rate and a 0.8 percent rate of revision surgery for the entire study patient population. In contrast, the wound infection rate in those with complicated diabetes was 7.7 percent and the revision rate was 4.4 percent.

   Wukich and colleagues reported on their outcomes of ankle fractures in patients with uncomplicated diabetes and compared the results to those with complicated diabetes.2 The authors found that patients with complicated diabetes had the highest rates of ankle complications, occurring 50 percent of the time. Nearly 25 percent of patients with complicated diabetes required revisional surgery. The authors noted that it is the complications of diabetes (neuropathy) that increase the risk of complications following ORIF of ankle fractures. Patients with complicated diabetes were 3.8 times more likely to experience a postoperative problem. Fracture care in this patient population requires an understanding of the pathophysiology of the disease process and its inherent challenges.

   The primary goal of ORIF of an ankle fracture is achieving anatomic alignment with restoration of the ankle mortise. One must employ adequate fixation constructs for fracture union. In a case series of ankle fractures in patients with diabetes and neuropathy, Schon and colleagues attributed poor outcome after ORIF to inadequate reduction, suboptimal fixation and an inadequate period of non-weightbearing.3

   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.

   The surgeon would place the screws from lateral to medial through the fibular plate and drive them into the tibia, purchasing all four cortices. I currently recommend the use of syndesmotic screw fixation for all unstable diabetic ankle fractures, especially those with poor bone stock. One may also employ syndesmotic screw fixation for lateral malleolar fractures with an associated deltoid ligament rupture to further stabilize the ankle mortise.7

   Surgeons may use multiple or stacked plates for severely comminuted distal tibia or pilon fractures. Multiple plates offer increased stability and help neutralize the deforming forces that may occur over the time it takes for the bone to heal. This added stability helps prevent late collapse and malunion. One should only consider multiple plates if the soft tissue permits.

   Intramedullary nail fixation with percutaneous reduction of the fracture has the advantage of limited soft tissue disruption and preserves the soft tissue envelope around the fracture site. With the introduction of a new fibular rod system, one may now consider this fixation method for unstable fibula fractures in the elderly or patients with diabetes, neuropathy and/or peripheral vascular disease.

   Static and dynamic external fixation constructs may further stabilize and enhance the overall fixation construct. One can supplement an internal fixation construct with a static external fixator.10 Transarticular fixation is another method to stabilize a severe diabetic foot and ankle fracture.11 The disadvantage of transarticular fixation is the iatrogenic injury created across the articular surface. Often, this is not a major concern, particularly among people with diabetes and neuropathy with loss of sensation.

In Conclusion

The surgeon must understand the advantages and disadvantages of the selected fixation construct and also recognize how the particular fixation will affect the biologic events necessary for healing. All fractures require mechanical stability along with sufficient vascularity to allow for an environment that is conducive to healing. The surgeon should note the fracture pattern, consider the soft tissue envelope and recognize the potential for the development of complications. The presence of infection and/or ischemia will affect fixation choice as well. In general, surgeons should tailor the choice of fixation on an individual basis. At times, certain situations may require creativity to achieve a successful outcome.

   Dr. Bevilacqua is an Associate of Foot and Ankle Surgery at North Jersey Orthopaedic Specialists in Teaneck and Englewood, N.J. He is board certified in both Foot and Reconstructive Rearfoot and Ankle Surgery by the American Board of Podiatric Surgery. He is a Fellow of the American College of Foot and Ankle Surgeons.

References
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7. Bevilacqua NJ, Stapleton JJ. Advanced foot and ankle fixation techniques in patients with diabetes. Clin Podiatr Med Surg. 2011; 28(4):661-671.
8. Wukich DK, Kline AJ. The management of ankle fractures in patients with diabetes. J Bone Joint Surg Am. 2008; 90(7):1570-1578.
9. Perry MD, Taranow WS, Manoli A, 2nd, Carr JB. Salvage of failed neuropathic ankle fractures: use of large-fragment fibular plating and multiple syndesmotic screws. J Surg Orthop Adv. 2005; 14(2):85-91.
10. Marin LE, Wukich DK, Zgonis T. The surgical management of high- and low-energy tibial plafond fractures: A combination of internal and external fixation devices. Clin Podiatr Med Surg. 2006; 23(2):423-444, vii.
11. Jani MM, Ricci WM, Borrelli J Jr., Barrett SE, Johnson JE. A protocol for treatment of unstable ankle fractures using transarticular fixation in patients with diabetes mellitus and loss of protective sensibility. Foot Ankle Int. 2003; 24(11):838-844.