BACKGROUND:TDI elastosonography allows, in contrast to conventional methods, a quantitative-numerical evaluation of the quality of a tendon on the basis of so-called strain scores. Previous studies on elastosonography were mainly based on qualitative methods, which only allow for a graduated colour and optical-visual representation. The aim of this study was to assess the strain scores of non-symptomatic compared to symptomatic patellar tendons in order to estimate reference values. Furthermore, the correlation between the neovascularisation apparent in power Doppler sonography and the magnitude of the strain scores was investigated. METHODS:In total n = 75 athletes aged 33.2 ± 12.7 years were included in the study, with the ligamentum patellae diagnosed in n = 37 as being clinical non-symptomatic and in n = 38 as being symptomatic. After a detailed anamnesis and a clinical examination, all subjects underwent a conventional B-mode, a Dynaflow power Doppler and a TDI elastosonography of the ligamentum patellae using the Aplio MX (Toshiba Medical Systems, Corp.) in the longitudinal and cross-section planes, respectively. RESULTS:The strain scores of the non-symptomatic ligamentum patellae in the longitudinal section were on average 0.070 (± 0.039) depending on the measuring field. The symptomatic tendons showed significantly higher values in the longitudinal section with an average of 0.137 (± 0.052). Similar values were evident in the cross-section. In 58 % of the symptomatic tendons neovascularisation was detected. A correlation between the duration of the medical history and the presence of neovascularisation was thereby verified. CONCLUSIONS:The presented results show that TDI elastosonography in the hands of an experienced examiner is an appropriate method for quantifying the quality of the patellar tendon and gives additional information beyond that of B-mode, power Doppler sonography and MRI. To what extent the strain scores of the TDI elastosonography in addition to conventional sonography can influence the choice of the therapeutic procedure must be evaluated by conducting further studies.