Radiographic Predictors of Surgical Management of Symptomatic Calcaneal Spurs: A Retrospective Cohort Study

Category: Hindfoot; Other Introduction/Purpose: Insertional Achilles tendinopathy (IAT) is one of the most common causes of posterior heel pain and affects thousands of patients every year. Enthesophytes can form at the Achilles tendon insertion in response to excessive loads and lead to pain and discomfort. There is limited evidence regarding patient factors associated with likelihood of failing non-operative management, specifically the size of the enthesophyte and its proximity to the posterior heel skin. The purpose of this study was to investigate the relationship between radiographic characteristics of retrocalcaneal enthesophytes in IAT and likelihood of failing non-operative management. Methods: A retrospective cohort study of 295 patients diagnosed IAT with symptomatic enthesophytes were identified and separated into operative and nonoperative cohorts. A power analysis was conducted and determined that a minimum of 100 patients within each cohort was required. All patients had lateral weight bearing radiographs which were used to measure the Calcaneal Spur-to-Skin Distance (CSK), Calcaneal Spur Width (CSW), Calcaneal Spur Height (CSH), and the Fowler-Philip Angle (FPA). Demographic and radiographic parameters were compared between both groups. Multivariate regression analysis was performed to identify independent risk factors associated with failing nonoperative management. Results: The operative group had significantly smaller CSK (6.0 mm vs. 6.6 mm; p = .02), larger CSW (7.9 mm vs 6.2 mm; p < .001), and larger CSH (14.1 mm vs. 11.1 mm; p < .001) compared to the nonoperative group. There was no significant between-group difference in FPA (61.9° nonoperative vs 63.3° operative; p = .052). Multivariate logistic regression analysis demonstrated CSK, CSW, and CSH as independent risk factors for failing nonoperative management. Conclusion: Radiographic measurements of retrocalcaneal enthesophytes are a simple and reliable method for predicting which patients have a higher likelihood of failing nonoperative management of IAT.