Nonunion in Foot and Ankle Arthrodesis Surgery: Review of Risk Factors, Identification of High-risk Patients, and a Guide to Perioperative Testing and Optimization.

Foot and ankle arthrodesis surgery is often associated with high rates of nonunion ranging from 8% to 40%. This complication can result in individual patient burden and system burden in the management of these complex patients. Biologic factors contribute greatly to the development of a nonunion, including patient-related modifiable risk factors, metabolic and endocrine factors, systemic disease, previous surgeries, medications, weight loss treatments, and posttraumatic and postsurgical factors. Despite the high nonunion rate, there is a lack of high-level evidence in the identification of high-risk patients, strategies to minimize nonunion, and the management of patients with nonunion. An accepted standard of practice has not been established. This review aims to provide foot and ankle surgeons with (1) a comprehensive review of risk factors for nonunion, (2) a tool to identify high-risk patients using a preoperative patient questionnaire, (3) a clinical practice guide to preoperative and intraoperative testing that aims to improve preoperative counselling and patient optimization, and (4) perioperative strategies to minimize nonunion risk. With the above framework, our goal is to minimize nonunion risk in patients undergoing foot and ankle arthrodesis surgery to improve patient care and outcomes.