Prevalence of Abnormal Ultrasound Findings in Asymptomatic Posterior Tibial Tendons

Background: Posterior tibial tendon dysfunction (PTTD) is a pathological condition that can cause failure of the posterior tibial tendon (PTT). Initially, patients with PTTD are often asymptomatic, making early identification and treatment challenging. Certain ultrasound (US) characteristics have been implicated in the presence of tendinopathy, but their frequency has yet to be assessed in the PTT. The purpose of this study was to identify and report on the frequency of incidental, or potentially early subclinical, tendinopathic US characteristics in asymptomatic PTTs. Methods: Following institutional review board approval, 150 participants underwent a bilateral-comprehensive US assessment. The resulting images were reviewed and assessed to identify the presence of abnormalities demonstrated to represent tendinopathy. Results: Overall, 266 tendons were assessed and 128 (48.1%) were determined to have at least one tendinopathic trait. Specifically, 51 (19.2%) had circumferential fluid, 69 (25.9%) had noncircumferential fluid, 22 (8.3%) had thickening, 31 (11.7%) had heterogenicity, 19 (7.1%) had hyperemia, and 2 (0.8%) had calcification. Additionally, Caucasian participants were found to be nearly 3 times more likely to have tendinopathic findings when compared with African American participants. Conclusion: Sixty-seven percent of participants and 48.1% of PTTs evaluated had at least one tendinopathic feature identified on US. The prevalence rates of these findings, observed in participants, were as follows: noncircumferential fluid, circumferential fluid, heterogenicity, and thickening. Knowing the frequency of these traits may help clinicians to identify subclinical tendinopathy in the PTT before it progresses to PTTD. Level of Evidence: Level IV, case series.