Prevalence of Asymptomatic Achilles Tendinosis

Background: Most patients who sustain Achilles tendon ruptures (ATRs) have no clinical symptoms prior to ATR. The objective of this study was to define the prevalence of ultrasound-detectable Achilles tendinopathy in asymptomatic patients in an at-risk group. Methods: This was a cross-sectional study that collected data from a group of volunteers. All participants were given IPAQ questionnaires to gauge daily activity level, in addition to a demographic form. Participants underwent a physical examination, Silfverskiold test, and an ultrasonographic examination to evaluate for presence of Achilles tendinopathy. Fifty-one volunteers (30 female, 21 male) and 102 Achilles tendons were assessed in this study. The mean age was 27.4±6.3, with an average BMI of 23.5±3.9. Ninety-two percent of participants were categorized as having moderate or high activity levels per the iPAQ questionnaire. Results: Sixteen tendons had at least 1 abnormality: 10 (9.8%) had hypoechoic foci, 9 (8.8%) had calcifications, 1 (0.9%) had increased vascularity, and 1 (0.9%) had a low-grade interstitial tear. Approximately 40% of patients were noted to have a gastroc equinus contracture on Silfverskiold testing. In addition, 14.7% of patients with a gastroc equinus had a hypoechoic focus compared to 8.6% of patients without gastroc equinus (P =.5003). Logistic regression analysis demonstrated that an increased BMI was a significant risk factor for having an Achilles tendon abnormality on ultrasonography (P <.01, odds ratio = 1.41). Conclusion: In this study, 16% of the Achilles tendons were abnormal and had at least 1 abnormality on ultrasonography. This group of patients was generally young, healthy, and active, thus a group at risk for ATRs. Only 40% of patients had gastrocnemius equinus, although a slightly higher non-significant percentage of those with hypoechoic foci had gastrocnemius equinus. It may be advantageous to prophylactically treat these patients with rehabilitation exercises to minimize the risk of ATR. Level of Evidence: Level II, comparative prognostic study.