Keys To Treating Acute Ankle Fractures In Patients With Diabetes
Successful management of traumatic ankle fractures in the increasingly prevalent diabetic population is tenuous.1 The surgical demands one encounters with typical fracture repairs are compounded by the dynamic needs of this widely varied population of individuals with diabetes. The pathophysiology that has eroded the innate healing capacity of the limb is suddenly revealed and corrective attempts can fall short of the acute need. However, successful outcomes with functional return to activity are achievable.
Risk assessment is an appropriate first step. Initial stratification should be based on the severity of the patient’s systemic disease process. Patients with uncomplicated diabetes, those without end-stage organ disease and a HbA1c less than 6.5 mg/dl demonstrate improved outcomes regardless of whether they had surgical intervention for an ankle fracture in comparison to the remaining population of patients with diabetes.2,3
For patients with complicated diabetes, the risk of any complication is 3.8 times that of the group with uncomplicated diabetes.2 There are many reasons for this. Hardware failure and periprosthetic fractures may occur when renal derangement results in subsequent osteoporosis and poor bone healing. Infection can occur in part due to chronic immunosuppression and incisions can break down from macro- and microangiopathy. Peripheral neuropathy creates further risk. With 10 percent of those with diabetes already having some form of peripheral neuropathy and 40 percent being diagnosed within a decade of learning of their diabetes, there should be a low threshold for early Charcot recognition and joint collapse prevention.4
In the past, the threat of increased local complications in this complicated cohort understandably swayed surgeons toward conservative, non-operative management regardless of the fracture pattern. This approach remains appropriate in those with stable, well-reduced unimalleolar fractures. Emerging research, however, favors aggressive intervention and repair of those fractures that display gross instability.5
With this in mind, there should be a low threshold for advanced imaging. Kumar and colleagues found a 23.2 percent change in operative plan following CT evaluation of a fracture pattern.6 While CT evaluation of fracture patterns may not be routinely warranted in a healthy patient, for the patient with diabetes, more liberal use of such imaging may be justifiable.
The timing of intervention is also subject to debate. In 2001, Bibbo and colleagues suggested a standard 10- to 14-day waiting period and maintaining the diabetic ankle fracture with initial closed reduction and splinting before attempting an open approach for repair.7 Wukich, Kline and colleagues suggested following the staged protocol for pilon fracture management as an appropriate method for determining delay, but additionally noted higher complication rates with the use of temporizing external fixation in patients with diabetes.2,8
Assessing Fixation Options In A Difficult Patient Population
Despite the high complication rate, maintaining anatomic reduction with robust internal fixation in both primary and revision procedures is critical to achieving successful outcomes in patients with diabetic ankle fractures. One should accomplish this through standard AO principles with augmentation to improve construct stability and reduce soft tissue insult. Generally, increased screw and plate caliber, utility of solid over cannulated fixtion, and implementation of locking plate technology will improve fixation strength.
Surgeons have also employed situation-specific constructs. The following are examples of these options in the management of diabetic ankle fractures.
Repair of fractures of the lateral malleolus is specifically at risk for incision complications. This is especially true with a direct lateral approach that violates the center of the peroneal artery angiosome.9 Prominent hardware placing additional tension on the closure can induce further peri-incisional ischemia. Surgeons may avoid this insult by using a posterior approach with a no-touch technique to the anterior flap. One can apply a posterior anti-glide plate from this approach with ease and researchers have demonstrated this is a superior construct to standard lateral plating options.10
Synostosis of the distal tibiofibular articulation was first suggested in 1995 as a fixation reinforcement for osteoporotic fractures.11 It has since become a popular construct for repair of diabetic ankle fractures. The technique termed “fibula-pro-tibia” uses multiple tetracortical, transsyndesmotic screws that the surgeon passes medially through a lateral fibular plate. This rigid superconstruct is protective against hardware failure and may be prophylactic against progression to an acute Charcot event.12 Furthermore, this superconstruct maintains the tibiofibular relationship. Some have advocated for percutaneous placement of dual transarticular, tibiotalocalcaneal (TTC) Steinman pins through the heel to further reinforce a standard repair but this has shown mixed results.13
Could Less Invasive Approaches To Fixation Have An Impact?
There are times when traditional ORIF may not be appropriate at all and yet there is a need for surgical intervention. This is true in cases when the soft tissue envelope or the patient’s systemic health are poor, and leave the patient at high risk for complications. In these cases, one may consider options for minimally-invasive or semi-open procedures.
Retrograde, tibiotalocalcaneal intramedullary nailing, with or without joint preparation, is a feasible option and may be especially warranted in patients with severely comminuted intra-articular fractures. In a 2019 retrospective series of 27 limbs, Ebaugh and colleagues reported a 92.6 percent limb salvage rate when utilizing retrograde TTC intramedullary nailing without joint preparation.14 While the study authors only considered the procedure for the high-risk diabetic population with low functional demand, they demonstrated both reduced OR time and a more rapid return to weightbearing in comparison to traditional ORIF.
On a smaller scale, retrograde fibular nailing has also become popular and shown comparable outcomes to standard ORIF.15 To our knowledge, no study has evaluated the use of retrograde fibular nailing in fractures in patients with diabetes but a 2006 study investigated the use of this modality in elderly, high-risk patients.15 The reports were mixed as the study authors noted some limitations of the fixation with poor bone stock. One disadvantage is the limited number of trans-syndesmotic screws that surgeons can use. Current systems allow for a maximum of two screws with perpendicular placement of an additional derotational screw in the fibula. In a patient with complicated diabetes, this may prove to be focally under-fixated with a potential for hardware failure, especially when a more rigid construct such as a fibula-pro-tibia approach is desired. Revisions in current fibular nailing systems that allow for the ability to add more syndesmotic screws may facilitate expanded use in the patient population with diabetes.
For the medial malleolus, one can extend the length of the dual interfragmentary screws to achieve purchase of the lateral tibial cortex. In the case of compromised soft tissue, surgeons can achieve this percutaneously with cannulated fixation or in a semi-open fashion with solid screws. Arthroscopically-assisted reduction may also be beneficial for reducing surgical trauma. One can debride fractures of the medial malleolus arthroscopically, reduce them under direct visualization and subsequently perform percutaneous fixation. This decreases the risk of nonunion secondary to soft tissue apposition, a potential complication with percutaneous fracture reduction.
Addressing Revisional Surgery And Postoperative Care
In the event of failed primary repair, limb salvage becomes the defining outcome of success. In their recent retrospective series of revisional ankle fractures, Vaudreuil and coworkers noted 100 percent salvage when revision reconstruction included arthrodesis of the rearfoot or ankle in comparison to joint-sparing procedures.12 The authors performed this with retrograde intramedullary nailing for full TTC arthrodesis or, in the case of ankle-only arthrodesis, an anterior plate and screw construct with no difference in salvage rates between the groups.
As with any procedure, postoperative care is critical. The nuances of the pathophysiology of diabetes delays both osseous and soft tissue repair. Most authors recommend a period of extended non-weightbearing followed by a transition to protected weightbearing before full return to activity at roughly the three-month mark. Numerous variations of this protocol exist. Preference is surgeon-dependent with most placing an emphasis on frequent, serial evaluations during the postoperative recovery period.
Final Thoughts
Despite the increased risk, a functional extremity allowing for return to pain-free activity remains attainable in patients with diabetic ankle fractures. Risk mitigation and outcome improvement steps are emerging, but further study is clearly needed. A detailed algorithm to delineate standard treatment would be optimal to better understand the complexities of fixation and repair in patients with diabetic ankle fractures.
Dr. Kennedy is a current Limb Salvage Fellow at MedStar Georgetown University Hospital in Washington, D.C.
Dr. Rahnama is a fellowship-trained foot and ankle surgeon affiliated with MedStar Washington Hospital Center and MedStar Georgetown University Hospital in Washington, D.C. He is an Assistant Professor at the Georgetown University School of Medicine. Dr. Rahnama also discloses he has been a consultant for Arthrex in the past.
1. Centers for Disease Control and Prevention. National diabetes statistics report, 2017. Estimates of diabetes and its burden in the United States. Available at: https://www.cdc.gov/diabetes/pdfs/data/statistics/national-diabetes-statistics-report.pdf. Accessed October 28, 2019.
2. Wukich DK, Joseph A, Ryan M, Ramirez C, Irrgang JJ. Outcomes of ankle fractures in patients with uncomplicated versus complicated diabetes. Foot Ankle Int. 2011;32(2):120-130.
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4. Wukich DK, Kline AJ. The management of ankle fractures in patients with diabetes. J Bone Joint Surg Am. 2008;90(7):1570–1578.
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11. Panchbhavi VK, Mody MG, Mason WT. Combination of hook plate and tibial pro-fibular screw fixation of osteoporotic fractures: a clinical evaluation of operative strategy. Foot Ankle Int. 2005;26(7):510–515.
12. Vaudreuil NJ, Fourman MS, Wukich DK. Limb salvage after failed initial operative management of bimalleolar ankle fractures in diabetic neuropathy. Foot Ankle Int. 2017;38(3):248-254.
13. Jani MM, Ricci WM, Borrelli J, 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.
14. Ebaugh MP, Umbel B, Goss D, Taylor BC. Outcomes of primary tibiotalocalcaneal nailing for complicated diabetic ankle fractures. Foot Ankle Int. 2019. doi: 10.1177/1071100719869639. Accessed October 28, 2019.
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