Effect of Obesity on Short- and Long-Term Complications After Ankle Fracture Fixation

Objectives: This study evaluated the relationship between obesity and postoperative complications in patients undergoing ankle open reduction internal fixation (ORIF).

Design: Retrospective cohort study.

Setting: PearlDiver-Mariner All-Payor Database.

Patient selection criteria: Patients who underwent ankle ORIF from 2010 to 2021 and had a minimum of 2 years of follow-up were identified using Current Procedural Terminology, ICD-9, and ICD-10 codes.

Outcome measures and outcomes: Patients were stratified by body mass index into nonobese, obese, morbidly obese, and super-obese groups. Complication rates, including 90-day readmissions, infection, and post-traumatic osteoarthritis, were compared between obesity groups. Patients were additionally compared with a 1:1 matched analysis that controlled for demographics and comorbidities.

Results: A total of 160,415 patients undergoing ankle ORIF from 2010 to 2021 were identified. The cohort consisted mostly of females (64.8%) and the average age was 52.5 (SD 18.4) years. There were higher rates of 90-day readmissions, UTIs, DVT/PE, pneumonia, superficial infections, and acute kidney injuries in patients with increasing levels of obesity (P < 0.001). There were increased odds of nonunion and post-traumatic arthritis in the matched analysis at 2 years in the obesity group [OR: 2.36, 95% confidence interval (CI): 1.68-3.31, P < 0.001; OR: 2.18, 95% CI: 1.77-2.68, P < 0.001, respectively].

Conclusions: Postoperative medical complication rates in patients undergoing ankle ORIF, including infection, are higher in obese patients, even in the 1:1 matched analysis that controlled for demographic and comorbidity factors. Rates of nonunion and post-traumatic arthritis were higher in obese patients, as well. As such, it is important for surgeons to provide appropriate education regarding the risks after ankle ORIF in patients with obesity.

Level of evidence: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.