Essential Pearls On Treating Diabetic Ankle Fractures

Author(s): 
Keith D. Cook, DPM, FACFAS, Carl Brandon Lindberg, DPM, and Joseph Genualdi, DPM

Ankle fractures are very common injuries that foot and ankle surgeons see. An estimated 585,000 ankle fractures occur in the United States each year and 25 percent receive surgical intervention.1 Ankle fractures are the most common intraarticular fracture of a weightbearing surface and account for 9 percent of all fractures.1

   Management of ankle fractures in the subpopulation of patients with diabetes mellitus can prove to be especially challenging due to the high rate of complications associated with diabetes. Complications of diabetic ankle fractures include delayed fracture healing, malalignment, wound complications, infection and the development of Charcot neuroarthropathy.2-4

   Operative management of ankle fractures in patients with diabetes has also been associated with significant increases in hospital length of stay, mortality and cost in comparison to fractures in those without diabetes.5 Unfortunately, diabetic ankle fractures also reportedly have a high complication rate with non-operative treatment.4

What The Research Says About Complications That Affect Fracture Healing

A number of clinical case reports have noted delayed fracture healing with diabetes in comparison to non-diabetic controls.6-8 Researchers have investigated the mechanism for delayed healing in experimental rat models. Lu and colleagues compared diabetic rats to a control group and found them to have decreased expression of osteocalcin, type I collagen and transcription factors that enable the differentiation of osteoblasts.9 Administering insulin resulted in a substantial reversal in these findings.

   In another study, Kayal and coworkers found diabetic rats to have similar cartilage formation during the initial stage of callus formation in comparison to non-diabetic rats. However, on day 16, diabetic rats had decreased fracture callus size, cartilaginous tissue and new bone area in comparison to the control group.10 Additionally, Bibbo and colleagues found the rate of healing in patients with diabetes to be nearly double that of patients without diabetes independent of treatment type.11

   Patients with diabetes and associated comorbidities also have an increased rate of complications. Diabetes-related comorbidities, which may have a negative effect on fracture healing, include peripheral arterial disease (PAD), peripheral neuropathy, Charcot neuroarthropathy and nephropathy.

   Jones and colleagues compared ankle fractures in patients with diabetes to patients without diabetes mellitus, analyzing the outcomes as well as diabetic comorbidities.12 The subgroup of patients with diabetes without comorbidities had similar outcomes in comparison with the control group. However, the authors found that the subgroup of patients with diabetic comorbidities had a higher rate of complications than patients without comorbidities. The study authors also concluded there was no significant difference between conservative and surgical treatment although a history of Charcot neuroarthropathy correlated with the highest rate of complications.

   A study by Costigan and coworkers reported significantly increased rates of complications in diabetic ankle fractures treated with open reduction and internal fixation (ORIF) when there was associated comorbid conditions of PAD and/or neuropathy.13 Additional risk factors that are associated with poor healing potential in patients with diabetes are a history of smoking, hypertension, advanced age and increased body mass index.11

   The rate of fracture healing in patients with diabetes also appears to be dependent on blood glucose levels. Recent studies by Liu and colleagues have shown that ankle fractures in patients with diabetes with HbA1c levels greater than 6.5% had poor radiologic outcomes and a lower American Orthopaedic Foot and Ankle Society score in comparison to patients with an HbA1c less than 6.5%.14 Elevated blood glucose levels have also been associated with wound healing complications.15 This is due to a number of combined systemic effects such as macro- and microvascular disease, accumulation of glycosylation byproducts in the tissue, and poor healing secondary to an increase in inflammatory cytokines.11 One must educate the patient on the importance of glycemic control during the initial encounter to decrease complications.

   Patients with diabetic neuropathy who suffer ankle fractures have a higher risk of developing Charcot neuroarthropathy secondary to the direct injury sustained. Charcot first described neuropathic osteoarthropathy in 1868 and Johnson published the neurotraumatic theory of developing Charcot foot in 1967.16 Reportedly 5 to 10 percent of all patients with diabetes who sustain an ankle fracture develop Charcot neuroarthropathy.11 There is an increased risk for developing Charcot in a neuropathic patient who is not immobilized or in whom a delay in immobilization takes place. Once clinical and radiographic healing have occurred with a neuropathic ankle fracture, we advise bracing with a Charcot Restraint Orthotic Walker (CROW). One should also direct attention to the non-injured limb as patients with Charcot have a greater risk of developing neuroarthropathy on the contralateral side due to the increased weightbearing requirements.

A Closer Look At Treatment Options

The question of when to perform surgery on diabetic ankle fractures should depend on the patient’s comorbidities and fracture type. When it comes to a stable, non-displaced ankle fracture, one can provide conservative treatment and educate the patient regarding blood glucose control, immobilization and strict adherence to the non-weightbearing protocol.3,14,15,17 In 1998, Schon and coworkers reported the outcomes of conservative treatment for 15 patients with non-displaced ankle fractures.3 The authors found casting and/or bracing of the non-displaced fractures for three to nine months resulted in favorable outcomes.

   For closed, displaced ankle fractures, the timing of surgical intervention can become more difficult. A literature search revealed no prospective controlled trials comparing treatment modalities for displaced diabetic ankle fractures. Compounding the problem is that not all displaced ankle fractures are equal and the degree of comorbidities may be different from patient to patient.

   In a study of patients with peripheral neuropathy, Schon and coworkers reported the outcomes of conservative treatment for four patients with displaced ankle fractures and surgical treatment for nine patients with displaced ankle fractures.3 All of the patients in the conservative treatment group had a non-union or malunion, requiring late open reduction and internal fixation (ORIF) in one case and ankle arthrodesis in the remaining three patients. In the surgical treatment group, seven out of the nine patients had favorable outcomes with ORIF and immobilization for three months.

   In a meta-analysis by Lillmars and Meister, the authors compared ankle fracture outcomes in 140 patients with diabetes with 223 non-diabetic controls.4 The authors reported an overall complication rate of 30 percent for patients with diabetes who had surgical treatment, 77 percent for patients with diabetes who received conservative care and 7 percent for non-diabetic controls.

   The risk of postoperative complications with diabetic ankle fractures is reportedly nearly three times that of non-diabetic groups.18 The aforementioned comorbidities associated with complicated diabetes can result in a high rate of postoperative complications when using traditional hardware and fixation techniques.19

   Patients with diabetes as a whole have decreased bone mineral density and research has proven that osteoporotic fracture healing can benefit from the use of locking plates.20 The technology of locking plates is designed to eliminate toggle, thereby increasing the force needed to produce failure of the hardware.20

   In patients with peripheral arterial disease and neuropathy, open reduction with internal fixation has significant risks for complications of wound healing, fracture malalignment and the development of Charcot neuroarthropathy.12-13 A comprehensive evaluation and ancillary testing as needed should occur prior to taking these patients to the operating room. Researchers have recently described supplemental fixation methods to aid in fracture healing and the prevention of complications. One such method includes standard ORIF with the temporary placement of Steinmann pins across the subtalar and ankle joints.19,21

   An alternative technique involves lateral plating of the fibula with the use of multiple transsyndesmotic screws.22-23 The study authors believe one should not remove these transsyndesmotic screws in the patient with diabetic comorbidities unless complications necessitate removal. The combined use of external and internal fixation may also augment stability and allow for preservation of soft tissue. Both static and dynamic fixation can allow for bone healing with adequate reduction and alignment of the fracture deformity. One may also use percutaneous fixation techniques to prevent soft tissue envelope complications.

In Conclusion

Diabetic ankle fractures can be difficult injuries to treat given the increased rate of complications. Evaluating patients for comorbidities at the time of diagnosis is paramount to selecting proper treatment options in order to minimize complications. Foot and ankle surgeons must be aware of predictors of poor outcomes such as peripheral neuropathy, peripheral arterial disease and a history of Charcot neuroarthropathy.

   For isolated, non-displaced ankle fractures, conservative treatment may be the best option. Following medical optimization of the patient, one can treat displaced ankle fractures with open reduction and internal fixation. The use of locking plates, additional augmented internal fixation and/or external fixation to increase fracture stability all play a role in preventing complications and allowing the fractures to heal properly. Patient education on blood glucose control and adherence with an extended period of non-weightbearing are necessary to promote successful outcomes.

   Dr. Cook is the Director of Podiatric Medical Education at University Hospital in Newark, N.J. He is a Fellow of the American College of Foot and Ankle Surgeons.

   Dr. Lindberg is a third-year resident in the Podiatric Medicine and Surgery Residency Program at University Hospital in Newark, N.J.

   Dr. Genualdi is a first-year resident in the Podiatric Medicine and Surgery Residency Program at University Hospital in Newark, N.J.

References

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2. Gandhi A, Liporace F, Azad V, et al. Diabetic fracture healing. Foot Ankle Clin. 2006;11(4):805-24
3. Schon LC, Easley ME, Weinfeld SB. Charcot neuroarthropathy of the foot and ankle. Clin Orthop Relat Res. 1998;349:116-31
4. Lillmars SA, Meister BR. Acute trauma to the diabetic foot and ankle. Curr Opin Orthop. 2001;12(2):100-105.
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16. Dellenbaugh SG, DiPreta JA, Uhl RL. Treatment of ankle fractures in patients with diabetes. Orthopedics. 2011 May;34(5):383-388
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18. Blotter RH, Connolly E, Wasan A, Chapman MW. Acute complications in the operative treatment of isolated ankle fractures in patients with diabetes mellitus. Foot Ankle Int. 1999;20(11):687-94.
19. Johnson JE. Operative treatment of neuropathic arthropathy of the foot andankle. J Bone Joint Surg Am. 1998;80(6):1700-9.
20. Miranda M. Locking plate technology and its role in osteoporotic fractures injury. Injury, 2007; 38(Suppl 3):S35–S39.
21. Jani MM, Ricci WM, Borrelli J Jr., et al. 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):838-44.
22. Perry MD, Taranow WS, Manoli A 2d, 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.
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   Editor’s note: For a related article, see “Current Insights On Treating Ankle Fractures In Patients With Diabetes” in the June 2013 issue of Podiatry Today or visit the archives at www.podiatrytoday.com .

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