A New Test for Achilles Tendinopathy Based on Kager’s Fat Pad Clinical Assessment Predictive Values

Abstract

Background This study aimed to check the diagnostic accuracy of a new test to identify Achilles tendinopathy. Study Design: Observational study. Methods: Seventy patients recruited from a private medical centre met the diagnostic criteria for unilateral Achilles tendinopathy (age, 45.1 ± 12.7 years; weight, 75.00 ± 10 kg; height, 1.75 ± 0.1 m) and were tested based on both Achilles tendons. Seventy patients with a unilateral Achilles tendinopathy ultrasound diagnosis were tested using David’s test. Results: Most (86%) subjects demonstrated Kager’s fat pad asymmetry in relation to the Achilles tendon in the complete passive dorsiflexion in the prone position (David’s sign). No healthy tendons had David’s sign. Conclusions: The presence of asymmetry in Kager’s fat pad in relation to the Achilles tendon during complete passive dorsiflexion is strongly indicative of ultrasound-diagnosed tendinopathy. David’s test demonstrated a sensitivity of 85.71% (95% CI, 77.51% to 93.91%) and a specificity of 100% (95% CI, 100% to 100%), while noting the lack of blinding of the assessors and the uncertainty of the diagnostic measures (95% CI). Asymmetry of the fat pad could potentially serve as a characteristic marker for patients with Achilles tendinopathy.