SLR - September 2020 - Michael J. Bouchard

Effects of Diabetes Mellitus on Functional Outcomes and Complications After Torsional Ankle Fractures

Reference: Schmidt T, Simske NM, Audet MA, Benedick A, Kim CY, Vallier HA. Effects of Diabeets Mellitus on Functional Outcomes and Complications After Torsional Ankle Fractures. Journal of the American Academy of Orthopedic Surgeons. 2020 Jan 09

Scientific Literature Review

Reviewed By: Michael J. Bouchard, DPM
Residency Program: Hoboken University Medical Center – Hoboken, NJ

Podiatric Relevance: It is well known that the diabetic patient population are prone to higher complication rates and alternative functional outcomes following podiatric surgical procedures. Torsional ankle fractures carry their own specific rates of complication and functional outcomes, however it is less understood how the effects of diabetes can alter the functional outcomes following surgical repair of these ankle fractures. This study aims to investigate the effects of diabetes on surgical complications, secondary operations and functional outcomes following torsional ankle fractures. 

Methods: Nine hundred seventy-nine patients with surgically treated torsional ankle injuries were restrospectively analyzed. Specific information reviewed included demographic data, comorbidities, injury characteristics, complications, and secondary procedures. Treatment modality was based on injury and all complications were recorded, with strict definitions for infectious, wound-healing, malunion and non-union complications. The patient-reported outcome surveys utilized included the Foot Function Index and Short Musculoskeletal Function assessment, collected 12 months post-op. Multivariable analysis was used to assess for correlation among variables.

Results: One hundred thirty-one patients (13.4 percent) had diabetes. Patient mean age was 44.8 years, with the diabetic population being older (56.4 versus 43.0 years, P<0.001). Sixty-two percent of injuries were sustained following low-energy falls while 23.7 percent of injuries were sustained during high-energy motor vehicle collisions. One hundred fifty-two patients (15.5 percent) had open injuries and 388 patients had associated dislocation. There were 158 complications (16.1 percent) and 101 unplanned operations (10.3 percent). Diabetic patients had higher rates of unplanned operations (18.3 percent versus 9.1 percent, P = 0.001) and a significantly higher rate of post-operative complications (26.0 percent versus 14.6 percent, P = 0.001). Four hundred five patients completed the FFI survey and 393 patients completed the SMFA surveys at a median time of 65 months. There was more reported limitation in activity through the FFI survey in the diabetic patients (36.4 versus 23.9, P = 0.001), while no significant differences in activity limitations were found in the SMFA survey. African American race and obesity were determined to be independent predictors of worse functional outcomes in every subcategory of both surveys, while diabetes, neuropathy and tobacco use were found to be independent predictors of limitation of subcategories of the FFI survey, but not the SMFA. 

Conclusions: The authors conclude that while the diabetic population have a higher risk of complication and unplanned secondary operation rates of greater than twice that of non-diabetic patients, the long-term functional outcomes between the two cohorts were comparable. These findings are valuable for both clinicians and patients for adjusting post-operative expectations following similar injuries and operative management. Limitations of this study include the retrospective design, lack of standardization across surgical repair, inconsistencies across diabetic control, and less than half of the cohort responding to outcome surveys. 

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