Epidemiology of Insertional Achilles Tendinosis in Patients Requiring Surgical Intervention

Category: Hindfoot Introduction/Purpose: While many patients benefit from non-operative treatment of insertional Achilles tendinosis (IAT), some require surgical debridement and reconstruction. While numerous studies have looked for factors that may contribute to the development of IAT, there is a lack of studies that identify factors that contribute to the need for surgical management. Identification of these factors could better inform physicians on the progression of IAT and could help guide doctor and patient decision-making. The purpose of this study is to determine the relationship of patient demographic characteristics, comorbidity profiles, and radiological markers with the need for future surgical or non-surgical management of IAT. Methods: A retrospective chart review was performed to identify patients who received either surgical or non-surgical treatment of IAT at an academic institution from September 2015 - June 2019. Patients were identified using ICD-10 diagnosis codes for Achilles tendinosis, and all cases of non-insertional tendinosis were excluded (N=226). This sample was further separated into patients who received surgical treatment (n=48) and those who were managed conservatively without surgery (178). Demographic and comorbidity data was collected and compared between groups. Additionally, the presence and magnitude of radiological markers including Haglund's deformity, calcaneal enthesophytes, relevant calcaneal angles, and maximum cross- sectional tendon disease involvement on MRI were collected and compared between groups (Figure 1). A multivariate, binomial logistic regression model was then constructed in order to identify independent predictors of the need for surgical management. Results: There were no significant differences between groups in regard to age, sex, race, BMI, tobacco or alcohol use, hypertension, diabetes, arthritis, previous arthroplasty, or previous platelet-rich plasma injection. The surgery group was significantly more likely to have evidence of Haglund's deformity on clinical exam (83% vs. 69%; p=.005) and to have depression (27% vs. 12%; p=.012). Patients who received an ankle MRI were more likely undergo surgery (63% vs. 27%; p=.006), and patients treated surgically had a higher percentage of maximum cross-sectional tendon disease involvement on MRI (41% vs. 26%; p<.001). Multivariate logistic regression analysis showed that increased cross-sectional disease involvement was an independent predictor of the need for surgery, with involvement of at least 18% being significantly predictive of this need. Conclusion: Patients who received surgery for IAT were significantly more likely to have evidence of Haglund's deformity on clinical exam, have a previous diagnosis of depression, have received an MRI, and have a higher percentage of cross-sectional tendon disease involvement. Patients with at least 18% cross-sectional tendon involvement on axial MRI are more likely to go on to surgery and should therefore be counseled as such. Foot and ankle surgeons should use this information to facilitate shared decision-making regarding conservative versus surgical treatment of IAT.