Retrocalcaneal Enthesophytes and Radiographic Predictors of Failing Nonoperative Management in Insertional Achilles Tendinopathy: A Retrospective Cohort Study.

BackgroundThe purpose of this study was to investigate the relationship between radiographic characteristics of retrocalcaneal enthesophytes in insertional Achilles tendinopathy (IAT) and likelihood of failing nonoperative management.MethodsA retrospective cohort study of 200 patients diagnosed IAT with symptomatic enthesophytes were identified and separated into operative and nonoperative cohorts. 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.ResultsThe 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 with 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.ConclusionRadiographic measurements of retrocalcaneal enthesophytes are a simple and reliable method for predicting which patients have a higher likelihood of failing nonoperative management of IAT.Level of Evidence:III, retrospective cohort study.